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authorLinus Torvalds <torvalds@linux-foundation.org>2023-04-28 01:36:55 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2023-04-28 01:36:55 +0200
commitb6a7828502dc769e1a5329027bc5048222fa210a (patch)
tree60418229584831505036bd2d368320b7387e7b3a /kernel
parentcdx: fix build failure due to sysfs 'bus_type' argument needing to be const (diff)
parentmodule: add debugging auto-load duplicate module support (diff)
downloadlinux-b6a7828502dc769e1a5329027bc5048222fa210a.tar.xz
linux-b6a7828502dc769e1a5329027bc5048222fa210a.zip
Merge tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull module updates from Luis Chamberlain: "The summary of the changes for this pull requests is: - Song Liu's new struct module_memory replacement - Nick Alcock's MODULE_LICENSE() removal for non-modules - My cleanups and enhancements to reduce the areas where we vmalloc module memory for duplicates, and the respective debug code which proves the remaining vmalloc pressure comes from userspace. Most of the changes have been in linux-next for quite some time except the minor fixes I made to check if a module was already loaded prior to allocating the final module memory with vmalloc and the respective debug code it introduces to help clarify the issue. Although the functional change is small it is rather safe as it can only *help* reduce vmalloc space for duplicates and is confirmed to fix a bootup issue with over 400 CPUs with KASAN enabled. I don't expect stable kernels to pick up that fix as the cleanups would have also had to have been picked up. Folks on larger CPU systems with modules will want to just upgrade if vmalloc space has been an issue on bootup. Given the size of this request, here's some more elaborate details: The functional change change in this pull request is the very first patch from Song Liu which replaces the 'struct module_layout' with a new 'struct module_memory'. The old data structure tried to put together all types of supported module memory types in one data structure, the new one abstracts the differences in memory types in a module to allow each one to provide their own set of details. This paves the way in the future so we can deal with them in a cleaner way. If you look at changes they also provide a nice cleanup of how we handle these different memory areas in a module. This change has been in linux-next since before the merge window opened for v6.3 so to provide more than a full kernel cycle of testing. It's a good thing as quite a bit of fixes have been found for it. Jason Baron then made dynamic debug a first class citizen module user by using module notifier callbacks to allocate / remove module specific dynamic debug information. Nick Alcock has done quite a bit of work cross-tree to remove module license tags from things which cannot possibly be module at my request so to: a) help him with his longer term tooling goals which require a deterministic evaluation if a piece a symbol code could ever be part of a module or not. But quite recently it is has been made clear that tooling is not the only one that would benefit. Disambiguating symbols also helps efforts such as live patching, kprobes and BPF, but for other reasons and R&D on this area is active with no clear solution in sight. b) help us inch closer to the now generally accepted long term goal of automating all the MODULE_LICENSE() tags from SPDX license tags In so far as a) is concerned, although module license tags are a no-op for non-modules, tools which would want create a mapping of possible modules can only rely on the module license tag after the commit 8b41fc4454e ("kbuild: create modules.builtin without Makefile.modbuiltin or tristate.conf"). Nick has been working on this *for years* and AFAICT I was the only one to suggest two alternatives to this approach for tooling. The complexity in one of my suggested approaches lies in that we'd need a possible-obj-m and a could-be-module which would check if the object being built is part of any kconfig build which could ever lead to it being part of a module, and if so define a new define -DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've suggested would be to have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as well but that means getting kconfig symbol names mapping to modules always, and I don't think that's the case today. I am not aware of Nick or anyone exploring either of these options. Quite recently Josh Poimboeuf has pointed out that live patching, kprobes and BPF would benefit from resolving some part of the disambiguation as well but for other reasons. The function granularity KASLR (fgkaslr) patches were mentioned but Joe Lawrence has clarified this effort has been dropped with no clear solution in sight [1]. In the meantime removing module license tags from code which could never be modules is welcomed for both objectives mentioned above. Some developers have also welcomed these changes as it has helped clarify when a module was never possible and they forgot to clean this up, and so you'll see quite a bit of Nick's patches in other pull requests for this merge window. I just picked up the stragglers after rc3. LWN has good coverage on the motivation behind this work [2] and the typical cross-tree issues he ran into along the way. The only concrete blocker issue he ran into was that we should not remove the MODULE_LICENSE() tags from files which have no SPDX tags yet, even if they can never be modules. Nick ended up giving up on his efforts due to having to do this vetting and backlash he ran into from folks who really did *not understand* the core of the issue nor were providing any alternative / guidance. I've gone through his changes and dropped the patches which dropped the module license tags where an SPDX license tag was missing, it only consisted of 11 drivers. To see if a pull request deals with a file which lacks SPDX tags you can just use: ./scripts/spdxcheck.py -f \ $(git diff --name-only commid-id | xargs echo) You'll see a core module file in this pull request for the above, but that's not related to his changes. WE just need to add the SPDX license tag for the kernel/module/kmod.c file in the future but it demonstrates the effectiveness of the script. Most of Nick's changes were spread out through different trees, and I just picked up the slack after rc3 for the last kernel was out. Those changes have been in linux-next for over two weeks. The cleanups, debug code I added and final fix I added for modules were motivated by David Hildenbrand's report of boot failing on a systems with over 400 CPUs when KASAN was enabled due to running out of virtual memory space. Although the functional change only consists of 3 lines in the patch "module: avoid allocation if module is already present and ready", proving that this was the best we can do on the modules side took quite a bit of effort and new debug code. The initial cleanups I did on the modules side of things has been in linux-next since around rc3 of the last kernel, the actual final fix for and debug code however have only been in linux-next for about a week or so but I think it is worth getting that code in for this merge window as it does help fix / prove / evaluate the issues reported with larger number of CPUs. Userspace is not yet fixed as it is taking a bit of time for folks to understand the crux of the issue and find a proper resolution. Worst come to worst, I have a kludge-of-concept [3] of how to make kernel_read*() calls for modules unique / converge them, but I'm currently inclined to just see if userspace can fix this instead" Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0] Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1] Link: https://lwn.net/Articles/927569/ [2] Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3] * tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits) module: add debugging auto-load duplicate module support module: stats: fix invalid_mod_bytes typo module: remove use of uninitialized variable len module: fix building stats for 32-bit targets module: stats: include uapi/linux/module.h module: avoid allocation if module is already present and ready module: add debug stats to help identify memory pressure module: extract patient module check into helper modules/kmod: replace implementation with a semaphore Change DEFINE_SEMAPHORE() to take a number argument module: fix kmemleak annotations for non init ELF sections module: Ignore L0 and rename is_arm_mapping_symbol() module: Move is_arm_mapping_symbol() to module_symbol.h module: Sync code of is_arm_mapping_symbol() scripts/gdb: use mem instead of core_layout to get the module address interconnect: remove module-related code interconnect: remove MODULE_LICENSE in non-modules zswap: remove MODULE_LICENSE in non-modules zpool: remove MODULE_LICENSE in non-modules x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/dma/map_benchmark.c1
-rw-r--r--kernel/events/hw_breakpoint_test.c1
-rw-r--r--kernel/kallsyms.c5
-rw-r--r--kernel/kallsyms_selftest.c6
-rw-r--r--kernel/livepatch/core.c3
-rw-r--r--kernel/module/Kconfig100
-rw-r--r--kernel/module/Makefile6
-rw-r--r--kernel/module/decompress.c6
-rw-r--r--kernel/module/dups.c246
-rw-r--r--kernel/module/internal.h140
-rw-r--r--kernel/module/kallsyms.c78
-rw-r--r--kernel/module/kdb.c17
-rw-r--r--kernel/module/kmod.c (renamed from kernel/kmod.c)49
-rw-r--r--kernel/module/main.c1091
-rw-r--r--kernel/module/procfs.c16
-rw-r--r--kernel/module/stats.c430
-rw-r--r--kernel/module/strict_rwx.c99
-rw-r--r--kernel/module/tracking.c7
-rw-r--r--kernel/module/tree_lookup.c39
-rw-r--r--kernel/params.c2
-rw-r--r--kernel/printk/printk.c2
-rw-r--r--kernel/trace/ftrace.c3
-rw-r--r--kernel/trace/rv/reactor_panic.c1
-rw-r--r--kernel/trace/rv/reactor_printk.c1
-rw-r--r--kernel/watch_queue.c1
26 files changed, 1641 insertions, 710 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 6fc72b3afbde..b69c95315480 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -13,7 +13,6 @@ obj-y = fork.o exec_domain.o panic.o \
async.o range.o smpboot.o ucount.o regset.o
obj-$(CONFIG_USERMODE_DRIVER) += usermode_driver.o
-obj-$(CONFIG_MODULES) += kmod.o
obj-$(CONFIG_MULTIUSER) += groups.o
obj-$(CONFIG_VHOST_TASK) += vhost_task.o
diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c
index 0520a8f4fb1d..02205ab53b7e 100644
--- a/kernel/dma/map_benchmark.c
+++ b/kernel/dma/map_benchmark.c
@@ -356,4 +356,3 @@ module_exit(map_benchmark_cleanup);
MODULE_AUTHOR("Barry Song <song.bao.hua@hisilicon.com>");
MODULE_DESCRIPTION("dma_map benchmark driver");
-MODULE_LICENSE("GPL");
diff --git a/kernel/events/hw_breakpoint_test.c b/kernel/events/hw_breakpoint_test.c
index c57610f52bb4..2cfeeecf8de9 100644
--- a/kernel/events/hw_breakpoint_test.c
+++ b/kernel/events/hw_breakpoint_test.c
@@ -329,5 +329,4 @@ static struct kunit_suite hw_breakpoint_test_suite = {
kunit_test_suites(&hw_breakpoint_test_suite);
-MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marco Elver <elver@google.com>");
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 83f499182c9a..77747391f49b 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -288,8 +288,7 @@ unsigned long kallsyms_lookup_name(const char *name)
* Iterate over all symbols in vmlinux. For symbols from modules use
* module_kallsyms_on_each_symbol instead.
*/
-int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
- unsigned long),
+int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long),
void *data)
{
char namebuf[KSYM_NAME_LEN];
@@ -299,7 +298,7 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
- ret = fn(data, namebuf, NULL, kallsyms_sym_address(i));
+ ret = fn(data, namebuf, kallsyms_sym_address(i));
if (ret != 0)
return ret;
cond_resched();
diff --git a/kernel/kallsyms_selftest.c b/kernel/kallsyms_selftest.c
index bfbc12da3326..a2e3745d15c4 100644
--- a/kernel/kallsyms_selftest.c
+++ b/kernel/kallsyms_selftest.c
@@ -95,7 +95,7 @@ static struct test_item test_items[] = {
static char stub_name[KSYM_NAME_LEN];
-static int stat_symbol_len(void *data, const char *name, struct module *mod, unsigned long addr)
+static int stat_symbol_len(void *data, const char *name, unsigned long addr)
{
*(u32 *)data += strlen(name);
@@ -154,7 +154,7 @@ static void test_kallsyms_compression_ratio(void)
pr_info(" ---------------------------------------------------------\n");
}
-static int lookup_name(void *data, const char *name, struct module *mod, unsigned long addr)
+static int lookup_name(void *data, const char *name, unsigned long addr)
{
u64 t0, t1, t;
struct test_stat *stat = (struct test_stat *)data;
@@ -207,7 +207,7 @@ static bool match_cleanup_name(const char *s, const char *name)
return !strncmp(s, name, len);
}
-static int find_symbol(void *data, const char *name, struct module *mod, unsigned long addr)
+static int find_symbol(void *data, const char *name, unsigned long addr)
{
struct test_stat *stat = (struct test_stat *)data;
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index feaf90c5e537..fc851455740c 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -142,8 +142,7 @@ static int klp_match_callback(void *data, unsigned long addr)
return 0;
}
-static int klp_find_callback(void *data, const char *name,
- struct module *mod, unsigned long addr)
+static int klp_find_callback(void *data, const char *name, unsigned long addr)
{
struct klp_find_arg *args = data;
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index 424b3bc58f3f..33a2e991f608 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -22,6 +22,104 @@ menuconfig MODULES
if MODULES
+config MODULE_DEBUGFS
+ bool
+
+config MODULE_DEBUG
+ bool "Module debugging"
+ depends on DEBUG_FS
+ help
+ Allows you to enable / disable features which can help you debug
+ modules. You don't need these options on production systems.
+
+if MODULE_DEBUG
+
+config MODULE_STATS
+ bool "Module statistics"
+ depends on DEBUG_FS
+ select MODULE_DEBUGFS
+ help
+ This option allows you to maintain a record of module statistics.
+ For example, size of all modules, average size, text size, a list
+ of failed modules and the size for each of those. For failed
+ modules we keep track of modules which failed due to either the
+ existing module taking too long to load or that module was already
+ loaded.
+
+ You should enable this if you are debugging production loads
+ and want to see if userspace or the kernel is doing stupid things
+ with loading modules when it shouldn't or if you want to help
+ optimize userspace / kernel space module autoloading schemes.
+ You might want to do this because failed modules tend to use
+ up significant amount of memory, and so you'd be doing everyone a
+ favor in avoiding these failures proactively.
+
+ This functionality is also useful for those experimenting with
+ module .text ELF section optimization.
+
+ If unsure, say N.
+
+config MODULE_DEBUG_AUTOLOAD_DUPS
+ bool "Debug duplicate modules with auto-loading"
+ help
+ Module autoloading allows in-kernel code to request modules through
+ the *request_module*() API calls. This in turn just calls userspace
+ modprobe. Although modprobe checks to see if a module is already
+ loaded before trying to load a module there is a small time window in
+ which multiple duplicate requests can end up in userspace and multiple
+ modprobe calls race calling finit_module() around the same time for
+ duplicate modules. The finit_module() system call can consume in the
+ worst case more than twice the respective module size in virtual
+ memory for each duplicate module requests. Although duplicate module
+ requests are non-fatal virtual memory is a limited resource and each
+ duplicate module request ends up just unnecessarily straining virtual
+ memory.
+
+ This debugging facility will create pr_warn() splats for duplicate
+ module requests to help identify if module auto-loading may be the
+ culprit to your early boot virtual memory pressure. Since virtual
+ memory abuse caused by duplicate module requests could render a
+ system unusable this functionality will also converge races in
+ requests for the same module to a single request. You can boot with
+ the module.enable_dups_trace=1 kernel parameter to use WARN_ON()
+ instead of the pr_warn().
+
+ If the first module request used request_module_nowait() we cannot
+ use that as the anchor to wait for duplicate module requests, since
+ users of request_module() do want a proper return value. If a call
+ for the same module happened earlier with request_module() though,
+ then a duplicate request_module_nowait() would be detected. The
+ non-wait request_module() call is synchronous and waits until modprobe
+ completes. Subsequent auto-loading requests for the same module do
+ not trigger a new finit_module() calls and do not strain virtual
+ memory, and so as soon as modprobe successfully completes we remove
+ tracking for duplicates for that module.
+
+ Enable this functionality to try to debug virtual memory abuse during
+ boot on systems which are failing to boot or if you suspect you may be
+ straining virtual memory during boot, and you want to identify if the
+ abuse was due to module auto-loading. These issues are currently only
+ known to occur on systems with many CPUs (over 400) and is likely the
+ result of udev issuing duplicate module requests for each CPU, and so
+ module auto-loading is not the culprit. There may very well still be
+ many duplicate module auto-loading requests which could be optimized
+ for and this debugging facility can be used to help identify them.
+
+ Only enable this for debugging system functionality, never have it
+ enabled on real systems.
+
+config MODULE_DEBUG_AUTOLOAD_DUPS_TRACE
+ bool "Force full stack trace when duplicates are found"
+ depends on MODULE_DEBUG_AUTOLOAD_DUPS
+ help
+ Enabling this will force a full stack trace for duplicate module
+ auto-loading requests using WARN_ON() instead of pr_warn(). You
+ should keep this disabled at all times unless you are a developer
+ and are doing a manual inspection and want to debug exactly why
+ these duplicates occur.
+
+endif # MODULE_DEBUG
+
config MODULE_FORCE_LOAD
bool "Forced module loading"
default n
@@ -51,7 +149,7 @@ config MODULE_FORCE_UNLOAD
config MODULE_UNLOAD_TAINT_TRACKING
bool "Tainted module unload tracking"
depends on MODULE_UNLOAD
- default n
+ select MODULE_DEBUGFS
help
This option allows you to maintain a record of each unloaded
module that tainted the kernel. In addition to displaying a
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 948efea81e85..a10b2b9a6fdf 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -7,7 +7,10 @@
# and produce insane amounts of uninteresting coverage.
KCOV_INSTRUMENT_module.o := n
-obj-y += main.o strict_rwx.o
+obj-y += main.o
+obj-y += strict_rwx.o
+obj-y += kmod.o
+obj-$(CONFIG_MODULE_DEBUG_AUTOLOAD_DUPS) += dups.o
obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o
obj-$(CONFIG_MODULE_SIG) += signing.o
obj-$(CONFIG_LIVEPATCH) += livepatch.o
@@ -19,3 +22,4 @@ obj-$(CONFIG_SYSFS) += sysfs.o
obj-$(CONFIG_KGDB_KDB) += kdb.o
obj-$(CONFIG_MODVERSIONS) += version.o
obj-$(CONFIG_MODULE_UNLOAD_TAINT_TRACKING) += tracking.o
+obj-$(CONFIG_MODULE_STATS) += stats.o
diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c
index bb79ac1a6d8f..e97232b125eb 100644
--- a/kernel/module/decompress.c
+++ b/kernel/module/decompress.c
@@ -267,7 +267,7 @@ static ssize_t module_zstd_decompress(struct load_info *info,
zstd_dec.size = PAGE_SIZE;
ret = zstd_decompress_stream(dstream, &zstd_dec, &zstd_buf);
- kunmap(page);
+ kunmap_local(zstd_dec.dst);
retval = zstd_get_error_code(ret);
if (retval)
break;
@@ -297,6 +297,10 @@ int module_decompress(struct load_info *info, const void *buf, size_t size)
ssize_t data_size;
int error;
+#if defined(CONFIG_MODULE_STATS)
+ info->compressed_len = size;
+#endif
+
/*
* Start with number of pages twice as big as needed for
* compressed data.
diff --git a/kernel/module/dups.c b/kernel/module/dups.c
new file mode 100644
index 000000000000..aa8e1361fdb5
--- /dev/null
+++ b/kernel/module/dups.c
@@ -0,0 +1,246 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * kmod dups - the kernel module autoloader duplicate suppressor
+ *
+ * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
+ */
+
+#define pr_fmt(fmt) "module: " fmt
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sched/task.h>
+#include <linux/binfmts.h>
+#include <linux/syscalls.h>
+#include <linux/unistd.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/completion.h>
+#include <linux/cred.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/workqueue.h>
+#include <linux/security.h>
+#include <linux/mount.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/resource.h>
+#include <linux/notifier.h>
+#include <linux/suspend.h>
+#include <linux/rwsem.h>
+#include <linux/ptrace.h>
+#include <linux/async.h>
+#include <linux/uaccess.h>
+
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "module."
+static bool enable_dups_trace = IS_ENABLED(CONFIG_MODULE_DEBUG_AUTOLOAD_DUPS_TRACE);
+module_param(enable_dups_trace, bool_enable_only, 0644);
+
+/*
+ * Protects dup_kmod_reqs list, adds / removals with RCU.
+ */
+static DEFINE_MUTEX(kmod_dup_mutex);
+static LIST_HEAD(dup_kmod_reqs);
+
+struct kmod_dup_req {
+ struct list_head list;
+ char name[MODULE_NAME_LEN];
+ struct completion first_req_done;
+ struct work_struct complete_work;
+ struct delayed_work delete_work;
+ int dup_ret;
+};
+
+static struct kmod_dup_req *kmod_dup_request_lookup(char *module_name)
+{
+ struct kmod_dup_req *kmod_req;
+
+ list_for_each_entry_rcu(kmod_req, &dup_kmod_reqs, list,
+ lockdep_is_held(&kmod_dup_mutex)) {
+ if (strlen(kmod_req->name) == strlen(module_name) &&
+ !memcmp(kmod_req->name, module_name, strlen(module_name))) {
+ return kmod_req;
+ }
+ }
+
+ return NULL;
+}
+
+static void kmod_dup_request_delete(struct work_struct *work)
+{
+ struct kmod_dup_req *kmod_req;
+ kmod_req = container_of(to_delayed_work(work), struct kmod_dup_req, delete_work);
+
+ /*
+ * The typical situation is a module successully loaded. In that
+ * situation the module will be present already in userspace. If
+ * new requests come in after that, userspace will already know the
+ * module is loaded so will just return 0 right away. There is still
+ * a small chance right after we delete this entry new request_module()
+ * calls may happen after that, they can happen. These heuristics
+ * are to protect finit_module() abuse for auto-loading, if modules
+ * are still tryign to auto-load even if a module is already loaded,
+ * that's on them, and those inneficiencies should not be fixed by
+ * kmod. The inneficies there are a call to modprobe and modprobe
+ * just returning 0.
+ */
+ mutex_lock(&kmod_dup_mutex);
+ list_del_rcu(&kmod_req->list);
+ synchronize_rcu();
+ mutex_unlock(&kmod_dup_mutex);
+ kfree(kmod_req);
+}
+
+static void kmod_dup_request_complete(struct work_struct *work)
+{
+ struct kmod_dup_req *kmod_req;
+
+ kmod_req = container_of(work, struct kmod_dup_req, complete_work);
+
+ /*
+ * This will ensure that the kernel will let all the waiters get
+ * informed its time to check the return value. It's time to
+ * go home.
+ */
+ complete_all(&kmod_req->first_req_done);
+
+ /*
+ * Now that we have allowed prior request_module() calls to go on
+ * with life, let's schedule deleting this entry. We don't have
+ * to do it right away, but we *eventually* want to do it so to not
+ * let this linger forever as this is just a boot optimization for
+ * possible abuses of vmalloc() incurred by finit_module() thrashing.
+ */
+ queue_delayed_work(system_wq, &kmod_req->delete_work, 60 * HZ);
+}
+
+bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret)
+{
+ struct kmod_dup_req *kmod_req, *new_kmod_req;
+ int ret;
+
+ /*
+ * Pre-allocate the entry in case we have to use it later
+ * to avoid contention with the mutex.
+ */
+ new_kmod_req = kzalloc(sizeof(*new_kmod_req), GFP_KERNEL);
+ if (!new_kmod_req)
+ return false;
+
+ memcpy(new_kmod_req->name, module_name, strlen(module_name));
+ INIT_WORK(&new_kmod_req->complete_work, kmod_dup_request_complete);
+ INIT_DELAYED_WORK(&new_kmod_req->delete_work, kmod_dup_request_delete);
+ init_completion(&new_kmod_req->first_req_done);
+
+ mutex_lock(&kmod_dup_mutex);
+
+ kmod_req = kmod_dup_request_lookup(module_name);
+ if (!kmod_req) {
+ /*
+ * If the first request that came through for a module
+ * was with request_module_nowait() we cannot wait for it
+ * and share its return value with other users which may
+ * have used request_module() and need a proper return value
+ * so just skip using them as an anchor.
+ *
+ * If a prior request to this one came through with
+ * request_module() though, then a request_module_nowait()
+ * would benefit from duplicate detection.
+ */
+ if (!wait) {
+ kfree(new_kmod_req);
+ pr_debug("New request_module_nowait() for %s -- cannot track duplicates for this request\n", module_name);
+ mutex_unlock(&kmod_dup_mutex);
+ return false;
+ }
+
+ /*
+ * There was no duplicate, just add the request so we can
+ * keep tab on duplicates later.
+ */
+ pr_debug("New request_module() for %s\n", module_name);
+ list_add_rcu(&new_kmod_req->list, &dup_kmod_reqs);
+ mutex_unlock(&kmod_dup_mutex);
+ return false;
+ }
+ mutex_unlock(&kmod_dup_mutex);
+
+ /* We are dealing with a duplicate request now */
+ kfree(new_kmod_req);
+
+ /*
+ * To fix these try to use try_then_request_module() instead as that
+ * will check if the component you are looking for is present or not.
+ * You could also just queue a single request to load the module once,
+ * instead of having each and everything you need try to request for
+ * the module.
+ *
+ * Duplicate request_module() calls can cause quite a bit of wasted
+ * vmalloc() space when racing with userspace.
+ */
+ if (enable_dups_trace)
+ WARN(1, "module-autoload: duplicate request for module %s\n", module_name);
+ else
+ pr_warn("module-autoload: duplicate request for module %s\n", module_name);
+
+ if (!wait) {
+ /*
+ * If request_module_nowait() was used then the user just
+ * wanted to issue the request and if another module request
+ * was already its way with the same name we don't care for
+ * the return value either. Let duplicate request_module_nowait()
+ * calls bail out right away.
+ */
+ *dup_ret = 0;
+ return true;
+ }
+
+ /*
+ * If a duplicate request_module() was used they *may* care for
+ * the return value, so we have no other option but to wait for
+ * the first caller to complete. If the first caller used
+ * the request_module_nowait() call, subsquent callers will
+ * deal with the comprmise of getting a successful call with this
+ * optimization enabled ...
+ */
+ ret = wait_for_completion_state(&kmod_req->first_req_done,
+ TASK_UNINTERRUPTIBLE | TASK_KILLABLE);
+ if (ret) {
+ *dup_ret = ret;
+ return true;
+ }
+
+ /* Now the duplicate request has the same exact return value as the first request */
+ *dup_ret = kmod_req->dup_ret;
+
+ return true;
+}
+
+void kmod_dup_request_announce(char *module_name, int ret)
+{
+ struct kmod_dup_req *kmod_req;
+
+ mutex_lock(&kmod_dup_mutex);
+
+ kmod_req = kmod_dup_request_lookup(module_name);
+ if (!kmod_req)
+ goto out;
+
+ kmod_req->dup_ret = ret;
+
+ /*
+ * If we complete() here we may allow duplicate threads
+ * to continue before the first one that submitted the
+ * request. We're in no rush also, given that each and
+ * every bounce back to userspace is slow we avoid that
+ * with a slight delay here. So queueue up the completion
+ * and let duplicates suffer, just wait a tad bit longer.
+ * There is no rush. But we also don't want to hold the
+ * caller up forever or introduce any boot delays.
+ */
+ queue_work(system_wq, &kmod_req->complete_work);
+
+out:
+ mutex_unlock(&kmod_dup_mutex);
+}
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 1c877561a7d2..dc7b0160c480 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -3,6 +3,7 @@
*
* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
+ * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
*/
#include <linux/elf.h>
@@ -17,27 +18,19 @@
#define ARCH_SHF_SMALL 0
#endif
-/* If this is set, the section belongs in the init part of the module */
-#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG - 1))
-/* Maximum number of characters written by module_flags() */
-#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
-
-#ifndef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
-#define data_layout core_layout
-#endif
-
/*
- * Modules' sections will be aligned on page boundaries
- * to ensure complete separation of code and data, but
- * only when CONFIG_STRICT_MODULE_RWX=y
+ * Use highest 4 bits of sh_entsize to store the mod_mem_type of this
+ * section. This leaves 28 bits for offset on 32-bit systems, which is
+ * about 256 MiB (WARN_ON_ONCE if we exceed that).
*/
-static inline unsigned int strict_align(unsigned int size)
-{
- if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
- return PAGE_ALIGN(size);
- else
- return size;
-}
+
+#define SH_ENTSIZE_TYPE_BITS 4
+#define SH_ENTSIZE_TYPE_SHIFT (BITS_PER_LONG - SH_ENTSIZE_TYPE_BITS)
+#define SH_ENTSIZE_TYPE_MASK ((1UL << SH_ENTSIZE_TYPE_BITS) - 1)
+#define SH_ENTSIZE_OFFSET_MASK ((1UL << (BITS_PER_LONG - SH_ENTSIZE_TYPE_BITS)) - 1)
+
+/* Maximum number of characters written by module_flags() */
+#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
extern struct mutex module_mutex;
extern struct list_head modules;
@@ -53,7 +46,6 @@ extern const struct kernel_symbol __stop___ksymtab_gpl[];
extern const s32 __start___kcrctab[];
extern const s32 __start___kcrctab_gpl[];
-#include <linux/dynamic_debug.h>
struct load_info {
const char *name;
/* pointer to module in temporary copy, freed at end of load_module() */
@@ -63,12 +55,14 @@ struct load_info {
Elf_Shdr *sechdrs;
char *secstrings, *strtab;
unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs;
- struct _ddebug_info dyndbg;
bool sig_ok;
#ifdef CONFIG_KALLSYMS
unsigned long mod_kallsyms_init_off;
#endif
#ifdef CONFIG_MODULE_DECOMPRESS
+#ifdef CONFIG_MODULE_STATS
+ unsigned long compressed_len;
+#endif
struct page **pages;
unsigned int max_pages;
unsigned int used_pages;
@@ -101,11 +95,16 @@ int try_to_force_load(struct module *mod, const char *reason);
bool find_symbol(struct find_symbol_arg *fsa);
struct module *find_module_all(const char *name, size_t len, bool even_unformed);
int cmp_name(const void *name, const void *sym);
-long module_get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr,
- unsigned int section);
+long module_get_offset_and_type(struct module *mod, enum mod_mem_type type,
+ Elf_Shdr *sechdr, unsigned int section);
char *module_flags(struct module *mod, char *buf, bool show_state);
size_t module_flags_taint(unsigned long taints, char *buf);
+char *module_next_tag_pair(char *string, unsigned long *secsize);
+
+#define for_each_modinfo_entry(entry, info, name) \
+ for (entry = get_modinfo(info, name); entry; entry = get_next_modinfo(info, name, entry))
+
static inline void module_assert_mutex_or_preempt(void)
{
#ifdef CONFIG_LOCKDEP
@@ -148,6 +147,95 @@ static inline bool set_livepatch_module(struct module *mod)
#endif
}
+/**
+ * enum fail_dup_mod_reason - state at which a duplicate module was detected
+ *
+ * @FAIL_DUP_MOD_BECOMING: the module is read properly, passes all checks but
+ * we've determined that another module with the same name is already loaded
+ * or being processed on our &modules list. This happens on early_mod_check()
+ * right before layout_and_allocate(). The kernel would have already
+ * vmalloc()'d space for the entire module through finit_module(). If
+ * decompression was used two vmap() spaces were used. These failures can
+ * happen when userspace has not seen the module present on the kernel and
+ * tries to load the module multiple times at same time.
+ * @FAIL_DUP_MOD_LOAD: the module has been read properly, passes all validation
+ * checks and the kernel determines that the module was unique and because
+ * of this allocated yet another private kernel copy of the module space in
+ * layout_and_allocate() but after this determined in add_unformed_module()
+ * that another module with the same name is already loaded or being processed.
+ * These failures should be mitigated as much as possible and are indicative
+ * of really fast races in loading modules. Without module decompression
+ * they waste twice as much vmap space. With module decompression three
+ * times the module's size vmap space is wasted.
+ */
+enum fail_dup_mod_reason {
+ FAIL_DUP_MOD_BECOMING = 0,
+ FAIL_DUP_MOD_LOAD,
+};
+
+#ifdef CONFIG_MODULE_DEBUGFS
+extern struct dentry *mod_debugfs_root;
+#endif
+
+#ifdef CONFIG_MODULE_STATS
+
+#define mod_stat_add_long(count, var) atomic_long_add(count, var)
+#define mod_stat_inc(name) atomic_inc(name)
+
+extern atomic_long_t total_mod_size;
+extern atomic_long_t total_text_size;
+extern atomic_long_t invalid_kread_bytes;
+extern atomic_long_t invalid_decompress_bytes;
+
+extern atomic_t modcount;
+extern atomic_t failed_kreads;
+extern atomic_t failed_decompress;
+struct mod_fail_load {
+ struct list_head list;
+ char name[MODULE_NAME_LEN];
+ atomic_long_t count;
+ unsigned long dup_fail_mask;
+};
+
+int try_add_failed_module(const char *name, enum fail_dup_mod_reason reason);
+void mod_stat_bump_invalid(struct load_info *info, int flags);
+void mod_stat_bump_becoming(struct load_info *info, int flags);
+
+#else
+
+#define mod_stat_add_long(name, var)
+#define mod_stat_inc(name)
+
+static inline int try_add_failed_module(const char *name,
+ enum fail_dup_mod_reason reason)
+{
+ return 0;
+}
+
+static inline void mod_stat_bump_invalid(struct load_info *info, int flags)
+{
+}
+
+static inline void mod_stat_bump_becoming(struct load_info *info, int flags)
+{
+}
+
+#endif /* CONFIG_MODULE_STATS */
+
+#ifdef CONFIG_MODULE_DEBUG_AUTOLOAD_DUPS
+bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret);
+void kmod_dup_request_announce(char *module_name, int ret);
+#else
+static inline bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret)
+{
+ return false;
+}
+
+static inline void kmod_dup_request_announce(char *module_name, int ret)
+{
+}
+#endif
+
#ifdef CONFIG_MODULE_UNLOAD_TAINT_TRACKING
struct mod_unload_taint {
struct list_head list;
@@ -190,10 +278,13 @@ struct mod_tree_root {
#endif
unsigned long addr_min;
unsigned long addr_max;
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ unsigned long data_addr_min;
+ unsigned long data_addr_max;
+#endif
};
extern struct mod_tree_root mod_tree;
-extern struct mod_tree_root mod_data_tree;
#ifdef CONFIG_MODULES_TREE_LOOKUP
void mod_tree_insert(struct module *mod);
@@ -224,7 +315,6 @@ void module_enable_nx(const struct module *mod);
void module_enable_x(const struct module *mod);
int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
char *secstrings, struct module *mod);
-bool module_check_misalignment(const struct module *mod);
#ifdef CONFIG_MODULE_SIG
int module_sig_check(struct load_info *info, int flags);
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
index bdc911dbcde5..c550d7d45f2f 100644
--- a/kernel/module/kallsyms.c
+++ b/kernel/module/kallsyms.c
@@ -6,6 +6,7 @@
*/
#include <linux/module.h>
+#include <linux/module_symbol.h>
#include <linux/kallsyms.h>
#include <linux/buildid.h>
#include <linux/bsearch.h>
@@ -78,6 +79,7 @@ static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
unsigned int shnum, unsigned int pcpundx)
{
const Elf_Shdr *sec;
+ enum mod_mem_type type;
if (src->st_shndx == SHN_UNDEF ||
src->st_shndx >= shnum ||
@@ -90,11 +92,12 @@ static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
#endif
sec = sechdrs + src->st_shndx;
+ type = sec->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT;
if (!(sec->sh_flags & SHF_ALLOC)
#ifndef CONFIG_KALLSYMS_ALL
|| !(sec->sh_flags & SHF_EXECINSTR)
#endif
- || (sec->sh_entsize & INIT_OFFSET_MASK))
+ || mod_mem_type_is_init(type))
return false;
return true;
@@ -113,11 +116,13 @@ void layout_symtab(struct module *mod, struct load_info *info)
Elf_Shdr *strsect = info->sechdrs + info->index.str;
const Elf_Sym *src;
unsigned int i, nsrc, ndst, strtab_size = 0;
+ struct module_memory *mod_mem_data = &mod->mem[MOD_DATA];
+ struct module_memory *mod_mem_init_data = &mod->mem[MOD_INIT_DATA];
/* Put symbol section at end of init part of module. */
symsect->sh_flags |= SHF_ALLOC;
- symsect->sh_entsize = module_get_offset(mod, &mod->init_layout.size, symsect,
- info->index.sym) | INIT_OFFSET_MASK;
+ symsect->sh_entsize = module_get_offset_and_type(mod, MOD_INIT_DATA,
+ symsect, info->index.sym);
pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
src = (void *)info->hdr + symsect->sh_offset;
@@ -134,28 +139,27 @@ void layout_symtab(struct module *mod, struct load_info *info)
}
/* Append room for core symbols at end of core part. */
- info->symoffs = ALIGN(mod->data_layout.size, symsect->sh_addralign ?: 1);
- info->stroffs = mod->data_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
- mod->data_layout.size += strtab_size;
+ info->symoffs = ALIGN(mod_mem_data->size, symsect->sh_addralign ?: 1);
+ info->stroffs = mod_mem_data->size = info->symoffs + ndst * sizeof(Elf_Sym);
+ mod_mem_data->size += strtab_size;
/* Note add_kallsyms() computes strtab_size as core_typeoffs - stroffs */
- info->core_typeoffs = mod->data_layout.size;
- mod->data_layout.size += ndst * sizeof(char);
- mod->data_layout.size = strict_align(mod->data_layout.size);
+ info->core_typeoffs = mod_mem_data->size;
+ mod_mem_data->size += ndst * sizeof(char);
/* Put string table section at end of init part of module. */
strsect->sh_flags |= SHF_ALLOC;
- strsect->sh_entsize = module_get_offset(mod, &mod->init_layout.size, strsect,
- info->index.str) | INIT_OFFSET_MASK;
+ strsect->sh_entsize = module_get_offset_and_type(mod, MOD_INIT_DATA,
+ strsect, info->index.str);
pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
/* We'll tack temporary mod_kallsyms on the end. */
- mod->init_layout.size = ALIGN(mod->init_layout.size,
- __alignof__(struct mod_kallsyms));
- info->mod_kallsyms_init_off = mod->init_layout.size;
- mod->init_layout.size += sizeof(struct mod_kallsyms);
- info->init_typeoffs = mod->init_layout.size;
- mod->init_layout.size += nsrc * sizeof(char);
- mod->init_layout.size = strict_align(mod->init_layout.size);
+ mod_mem_init_data->size = ALIGN(mod_mem_init_data->size,
+ __alignof__(struct mod_kallsyms));
+ info->mod_kallsyms_init_off = mod_mem_init_data->size;
+
+ mod_mem_init_data->size += sizeof(struct mod_kallsyms);
+ info->init_typeoffs = mod_mem_init_data->size;
+ mod_mem_init_data->size += nsrc * sizeof(char);
}
/*
@@ -171,9 +175,11 @@ void add_kallsyms(struct module *mod, const struct load_info *info)
char *s;
Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
unsigned long strtab_size;
+ void *data_base = mod->mem[MOD_DATA].base;
+ void *init_data_base = mod->mem[MOD_INIT_DATA].base;
/* Set up to point into init section. */
- mod->kallsyms = (void __rcu *)mod->init_layout.base +
+ mod->kallsyms = (void __rcu *)init_data_base +
info->mod_kallsyms_init_off;
rcu_read_lock();
@@ -183,15 +189,15 @@ void add_kallsyms(struct module *mod, const struct load_info *info)
/* Make sure we get permanent strtab: don't use info->strtab. */
rcu_dereference(mod->kallsyms)->strtab =
(void *)info->sechdrs[info->index.str].sh_addr;
- rcu_dereference(mod->kallsyms)->typetab = mod->init_layout.base + info->init_typeoffs;
+ rcu_dereference(mod->kallsyms)->typetab = init_data_base + info->init_typeoffs;
/*
* Now populate the cut down core kallsyms for after init
* and set types up while we still have access to sections.
*/
- mod->core_kallsyms.symtab = dst = mod->data_layout.base + info->symoffs;
- mod->core_kallsyms.strtab = s = mod->data_layout.base + info->stroffs;
- mod->core_kallsyms.typetab = mod->data_layout.base + info->core_typeoffs;
+ mod->core_kallsyms.symtab = dst = data_base + info->symoffs;
+ mod->core_kallsyms.strtab = s = data_base + info->stroffs;
+ mod->core_kallsyms.typetab = data_base + info->core_typeoffs;
strtab_size = info->core_typeoffs - info->stroffs;
src = rcu_dereference(mod->kallsyms)->symtab;
for (ndst = i = 0; i < rcu_dereference(mod->kallsyms)->num_symtab; i++) {
@@ -238,18 +244,6 @@ void init_build_id(struct module *mod, const struct load_info *info)
}
#endif
-/*
- * This ignores the intensely annoying "mapping symbols" found
- * in ARM ELF files: $a, $t and $d.
- */
-static inline int is_arm_mapping_symbol(const char *str)
-{
- if (str[0] == '.' && str[1] == 'L')
- return true;
- return str[0] == '$' && strchr("axtd", str[1]) &&
- (str[2] == '\0' || str[2] == '.');
-}
-
static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
{
return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
@@ -267,12 +261,15 @@ static const char *find_kallsyms_symbol(struct module *mod,
unsigned int i, best = 0;
unsigned long nextval, bestval;
struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
+ struct module_memory *mod_mem;
/* At worse, next value is at end of module */
if (within_module_init(addr, mod))
- nextval = (unsigned long)mod->init_layout.base + mod->init_layout.text_size;
+ mod_mem = &mod->mem[MOD_INIT_TEXT];
else
- nextval = (unsigned long)mod->core_layout.base + mod->core_layout.text_size;
+ mod_mem = &mod->mem[MOD_TEXT];
+
+ nextval = (unsigned long)mod_mem->base + mod_mem->size;
bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
@@ -292,7 +289,7 @@ static const char *find_kallsyms_symbol(struct module *mod,
* and inserted at a whim.
*/
if (*kallsyms_symbol_name(kallsyms, i) == '\0' ||
- is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
+ is_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
continue;
if (thisval <= addr && thisval > bestval) {
@@ -505,8 +502,7 @@ unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
}
int module_kallsyms_on_each_symbol(const char *modname,
- int (*fn)(void *, const char *,
- struct module *, unsigned long),
+ int (*fn)(void *, const char *, unsigned long),
void *data)
{
struct module *mod;
@@ -535,7 +531,7 @@ int module_kallsyms_on_each_symbol(const char *modname,
continue;
ret = fn(data, kallsyms_symbol_name(kallsyms, i),
- mod, kallsyms_symbol_value(sym));
+ kallsyms_symbol_value(sym));
if (ret != 0)
goto out;
}
diff --git a/kernel/module/kdb.c b/kernel/module/kdb.c
index f4317f92e189..995c32d3698f 100644
--- a/kernel/module/kdb.c
+++ b/kernel/module/kdb.c
@@ -26,10 +26,11 @@ int kdb_lsmod(int argc, const char **argv)
if (mod->state == MODULE_STATE_UNFORMED)
continue;
- kdb_printf("%-20s%8u", mod->name, mod->core_layout.size);
-#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
- kdb_printf("/%8u", mod->data_layout.size);
-#endif
+ kdb_printf("%-20s%8u", mod->name, mod->mem[MOD_TEXT].size);
+ kdb_printf("/%8u", mod->mem[MOD_RODATA].size);
+ kdb_printf("/%8u", mod->mem[MOD_RO_AFTER_INIT].size);
+ kdb_printf("/%8u", mod->mem[MOD_DATA].size);
+
kdb_printf(" 0x%px ", (void *)mod);
#ifdef CONFIG_MODULE_UNLOAD
kdb_printf("%4d ", module_refcount(mod));
@@ -40,10 +41,10 @@ int kdb_lsmod(int argc, const char **argv)
kdb_printf(" (Loading)");
else
kdb_printf(" (Live)");
- kdb_printf(" 0x%px", mod->core_layout.base);
-#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
- kdb_printf("/0x%px", mod->data_layout.base);
-#endif
+ kdb_printf(" 0x%px", mod->mem[MOD_TEXT].base);
+ kdb_printf("/0x%px", mod->mem[MOD_RODATA].base);
+ kdb_printf("/0x%px", mod->mem[MOD_RO_AFTER_INIT].base);
+ kdb_printf("/0x%px", mod->mem[MOD_DATA].base);
#ifdef CONFIG_MODULE_UNLOAD
{
diff --git a/kernel/kmod.c b/kernel/module/kmod.c
index b717134ebe17..0800d9891692 100644
--- a/kernel/kmod.c
+++ b/kernel/module/kmod.c
@@ -1,6 +1,9 @@
/*
* kmod - the kernel module loader
+ *
+ * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
*/
+
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/sched/task.h>
@@ -27,6 +30,7 @@
#include <linux/uaccess.h>
#include <trace/events/module.h>
+#include "internal.h"
/*
* Assuming:
@@ -40,8 +44,7 @@
* effect. Systems like these are very unlikely if modules are enabled.
*/
#define MAX_KMOD_CONCURRENT 50
-static atomic_t kmod_concurrent_max = ATOMIC_INIT(MAX_KMOD_CONCURRENT);
-static DECLARE_WAIT_QUEUE_HEAD(kmod_wq);
+static DEFINE_SEMAPHORE(kmod_concurrent_max, MAX_KMOD_CONCURRENT);
/*
* This is a restriction on having *all* MAX_KMOD_CONCURRENT threads
@@ -66,7 +69,7 @@ static void free_modprobe_argv(struct subprocess_info *info)
kfree(info->argv);
}
-static int call_modprobe(char *module_name, int wait)
+static int call_modprobe(char *orig_module_name, int wait)
{
struct subprocess_info *info;
static char *envp[] = {
@@ -75,12 +78,14 @@ static int call_modprobe(char *module_name, int wait)
"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
NULL
};
+ char *module_name;
+ int ret;
char **argv = kmalloc(sizeof(char *[5]), GFP_KERNEL);
if (!argv)
goto out;
- module_name = kstrdup(module_name, GFP_KERNEL);
+ module_name = kstrdup(orig_module_name, GFP_KERNEL);
if (!module_name)
goto free_argv;
@@ -95,13 +100,16 @@ static int call_modprobe(char *module_name, int wait)
if (!info)
goto free_module_name;
- return call_usermodehelper_exec(info, wait | UMH_KILLABLE);
+ ret = call_usermodehelper_exec(info, wait | UMH_KILLABLE);
+ kmod_dup_request_announce(orig_module_name, ret);
+ return ret;
free_module_name:
kfree(module_name);
free_argv:
kfree(argv);
out:
+ kmod_dup_request_announce(orig_module_name, -ENOMEM);
return -ENOMEM;
}
@@ -125,7 +133,7 @@ int __request_module(bool wait, const char *fmt, ...)
{
va_list args;
char module_name[MODULE_NAME_LEN];
- int ret;
+ int ret, dup_ret;
/*
* We don't allow synchronous module loading from async. Module
@@ -148,29 +156,24 @@ int __request_module(bool wait, const char *fmt, ...)
if (ret)
return ret;
- if (atomic_dec_if_positive(&kmod_concurrent_max) < 0) {
- pr_warn_ratelimited("request_module: kmod_concurrent_max (%u) close to 0 (max_modprobes: %u), for module %s, throttling...",
- atomic_read(&kmod_concurrent_max),
- MAX_KMOD_CONCURRENT, module_name);
- ret = wait_event_killable_timeout(kmod_wq,
- atomic_dec_if_positive(&kmod_concurrent_max) >= 0,
- MAX_KMOD_ALL_BUSY_TIMEOUT * HZ);
- if (!ret) {
- pr_warn_ratelimited("request_module: modprobe %s cannot be processed, kmod busy with %d threads for more than %d seconds now",
- module_name, MAX_KMOD_CONCURRENT, MAX_KMOD_ALL_BUSY_TIMEOUT);
- return -ETIME;
- } else if (ret == -ERESTARTSYS) {
- pr_warn_ratelimited("request_module: sigkill sent for modprobe %s, giving up", module_name);
- return ret;
- }
+ ret = down_timeout(&kmod_concurrent_max, MAX_KMOD_ALL_BUSY_TIMEOUT * HZ);
+ if (ret) {
+ pr_warn_ratelimited("request_module: modprobe %s cannot be processed, kmod busy with %d threads for more than %d seconds now",
+ module_name, MAX_KMOD_CONCURRENT, MAX_KMOD_ALL_BUSY_TIMEOUT);
+ return ret;
}
trace_module_request(module_name, wait, _RET_IP_);
+ if (kmod_dup_request_exists_wait(module_name, wait, &dup_ret)) {
+ ret = dup_ret;
+ goto out;
+ }
+
ret = call_modprobe(module_name, wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC);
- atomic_inc(&kmod_concurrent_max);
- wake_up(&kmod_wq);
+out:
+ up(&kmod_concurrent_max);
return ret;
}
diff --git a/kernel/module/main.c b/kernel/module/main.c
index d3be89de706d..044aa2c9e3cb 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2,6 +2,7 @@
/*
* Copyright (C) 2002 Richard Henderson
* Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
+ * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
*/
#define INCLUDE_VERMAGIC
@@ -55,6 +56,7 @@
#include <linux/dynamic_debug.h>
#include <linux/audit.h>
#include <linux/cfi.h>
+#include <linux/debugfs.h>
#include <uapi/linux/module.h>
#include "internal.h"
@@ -80,12 +82,6 @@ struct mod_tree_root mod_tree __cacheline_aligned = {
.addr_min = -1UL,
};
-#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
-struct mod_tree_root mod_data_tree __cacheline_aligned = {
- .addr_min = -1UL,
-};
-#endif
-
struct symsearch {
const struct kernel_symbol *start, *stop;
const s32 *crcs;
@@ -93,14 +89,24 @@ struct symsearch {
};
/*
- * Bounds of module text, for speeding up __module_address.
+ * Bounds of module memory, for speeding up __module_address.
* Protected by module_mutex.
*/
-static void __mod_update_bounds(void *base, unsigned int size, struct mod_tree_root *tree)
+static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base,
+ unsigned int size, struct mod_tree_root *tree)
{
unsigned long min = (unsigned long)base;
unsigned long max = min + size;
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ if (mod_mem_type_is_core_data(type)) {
+ if (min < tree->data_addr_min)
+ tree->data_addr_min = min;
+ if (max > tree->data_addr_max)
+ tree->data_addr_max = max;
+ return;
+ }
+#endif
if (min < tree->addr_min)
tree->addr_min = min;
if (max > tree->addr_max)
@@ -109,12 +115,12 @@ static void __mod_update_bounds(void *base, unsigned int size, struct mod_tree_r
static void mod_update_bounds(struct module *mod)
{
- __mod_update_bounds(mod->core_layout.base, mod->core_layout.size, &mod_tree);
- if (mod->init_layout.size)
- __mod_update_bounds(mod->init_layout.base, mod->init_layout.size, &mod_tree);
-#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
- __mod_update_bounds(mod->data_layout.base, mod->data_layout.size, &mod_data_tree);
-#endif
+ for_each_mod_mem_type(type) {
+ struct module_memory *mod_mem = &mod->mem[type];
+
+ if (mod_mem->size)
+ __mod_update_bounds(type, mod_mem->base, mod_mem->size, &mod_tree);
+ }
}
/* Block module loading/unloading? */
@@ -559,10 +565,8 @@ static int already_uses(struct module *a, struct module *b)
struct module_use *use;
list_for_each_entry(use, &b->source_list, source_list) {
- if (use->source == a) {
- pr_debug("%s uses %s!\n", a->name, b->name);
+ if (use->source == a)
return 1;
- }
}
pr_debug("%s does not use %s!\n", a->name, b->name);
return 0;
@@ -926,7 +930,13 @@ struct module_attribute module_uevent =
static ssize_t show_coresize(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
- return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
+ unsigned int size = mk->mod->mem[MOD_TEXT].size;
+
+ if (!IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC)) {
+ for_class_mod_mem_type(type, core_data)
+ size += mk->mod->mem[type].size;
+ }
+ return sprintf(buffer, "%u\n", size);
}
static struct module_attribute modinfo_coresize =
@@ -936,7 +946,11 @@ static struct module_attribute modinfo_coresize =
static ssize_t show_datasize(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
- return sprintf(buffer, "%u\n", mk->mod->data_layout.size);
+ unsigned int size = 0;
+
+ for_class_mod_mem_type(type, core_data)
+ size += mk->mod->mem[type].size;
+ return sprintf(buffer, "%u\n", size);
}
static struct module_attribute modinfo_datasize =
@@ -946,7 +960,11 @@ static struct module_attribute modinfo_datasize =
static ssize_t show_initsize(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
- return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
+ unsigned int size = 0;
+
+ for_class_mod_mem_type(type, init)
+ size += mk->mod->mem[type].size;
+ return sprintf(buffer, "%u\n", size);
}
static struct module_attribute modinfo_initsize =
@@ -998,9 +1016,55 @@ int try_to_force_load(struct module *mod, const char *reason)
#endif
}
-static char *get_modinfo(const struct load_info *info, const char *tag);
+/* Parse tag=value strings from .modinfo section */
+char *module_next_tag_pair(char *string, unsigned long *secsize)
+{
+ /* Skip non-zero chars */
+ while (string[0]) {
+ string++;
+ if ((*secsize)-- <= 1)
+ return NULL;
+ }
+
+ /* Skip any zero padding. */
+ while (!string[0]) {
+ string++;
+ if ((*secsize)-- <= 1)
+ return NULL;
+ }
+ return string;
+}
+
static char *get_next_modinfo(const struct load_info *info, const char *tag,
- char *prev);
+ char *prev)
+{
+ char *p;
+ unsigned int taglen = strlen(tag);
+ Elf_Shdr *infosec = &info->sechdrs[info->index.info];
+ unsigned long size = infosec->sh_size;
+
+ /*
+ * get_modinfo() calls made before rewrite_section_headers()
+ * must use sh_offset, as sh_addr isn't set!
+ */
+ char *modinfo = (char *)info->hdr + infosec->sh_offset;
+
+ if (prev) {
+ size -= prev - modinfo;
+ modinfo = module_next_tag_pair(prev, &size);
+ }
+
+ for (p = modinfo; p; p = module_next_tag_pair(p, &size)) {
+ if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
+ return p + taglen + 1;
+ }
+ return NULL;
+}
+
+static char *get_modinfo(const struct load_info *info, const char *tag)
+{
+ return get_next_modinfo(info, tag, NULL);
+}
static int verify_namespace_is_imported(const struct load_info *info,
const struct kernel_symbol *sym,
@@ -1011,12 +1075,9 @@ static int verify_namespace_is_imported(const struct load_info *info,
namespace = kernel_symbol_namespace(sym);
if (namespace && namespace[0]) {
- imported_namespace = get_modinfo(info, "import_ns");
- while (imported_namespace) {
+ for_each_modinfo_entry(imported_namespace, info, "import_ns") {
if (strcmp(namespace, imported_namespace) == 0)
return 0;
- imported_namespace = get_next_modinfo(
- info, "import_ns", imported_namespace);
}
#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
pr_warn(
@@ -1143,6 +1204,46 @@ void __weak module_arch_freeing_init(struct module *mod)
{
}
+static bool mod_mem_use_vmalloc(enum mod_mem_type type)
+{
+ return IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC) &&
+ mod_mem_type_is_core_data(type);
+}
+
+static void *module_memory_alloc(unsigned int size, enum mod_mem_type type)
+{
+ if (mod_mem_use_vmalloc(type))
+ return vzalloc(size);
+ return module_alloc(size);
+}
+
+static void module_memory_free(void *ptr, enum mod_mem_type type)
+{
+ if (mod_mem_use_vmalloc(type))
+ vfree(ptr);
+ else
+ module_memfree(ptr);
+}
+
+static void free_mod_mem(struct module *mod)
+{
+ for_each_mod_mem_type(type) {
+ struct module_memory *mod_mem = &mod->mem[type];
+
+ if (type == MOD_DATA)
+ continue;
+
+ /* Free lock-classes; relies on the preceding sync_rcu(). */
+ lockdep_free_key_range(mod_mem->base, mod_mem->size);
+ if (mod_mem->size)
+ module_memory_free(mod_mem->base, type);
+ }
+
+ /* MOD_DATA hosts mod, so free it at last */
+ lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size);
+ module_memory_free(mod->mem[MOD_DATA].base, MOD_DATA);
+}
+
/* Free a module, remove from lists, etc. */
static void free_module(struct module *mod)
{
@@ -1158,9 +1259,6 @@ static void free_module(struct module *mod)
mod->state = MODULE_STATE_UNFORMED;
mutex_unlock(&module_mutex);
- /* Remove dynamic debug info */
- ddebug_remove_module(mod->name);
-
/* Arch-specific cleanup. */
module_arch_cleanup(mod);
@@ -1189,18 +1287,10 @@ static void free_module(struct module *mod)
/* This may be empty, but that's OK */
module_arch_freeing_init(mod);
- module_memfree(mod->init_layout.base);
kfree(mod->args);
percpu_modfree(mod);
- /* Free lock-classes; relies on the preceding sync_rcu(). */
- lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size);
-
- /* Finally, free the core (containing the module structure) */
- module_memfree(mod->core_layout.base);
-#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
- vfree(mod->data_layout.base);
-#endif
+ free_mod_mem(mod);
}
void *__symbol_get(const char *symbol)
@@ -1303,8 +1393,8 @@ static int simplify_symbols(struct module *mod, const struct load_info *info)
case SHN_ABS:
/* Don't need to do anything */
- pr_debug("Absolute symbol: 0x%08lx\n",
- (long)sym[i].st_value);
+ pr_debug("Absolute symbol: 0x%08lx %s\n",
+ (long)sym[i].st_value, name);
break;
case SHN_LIVEPATCH:
@@ -1387,16 +1477,18 @@ unsigned int __weak arch_mod_section_prepend(struct module *mod,
return 0;
}
-/* Update size with this section: return offset. */
-long module_get_offset(struct module *mod, unsigned int *size,
- Elf_Shdr *sechdr, unsigned int section)
+long module_get_offset_and_type(struct module *mod, enum mod_mem_type type,
+ Elf_Shdr *sechdr, unsigned int section)
{
- long ret;
+ long offset;
+ long mask = ((unsigned long)(type) & SH_ENTSIZE_TYPE_MASK) << SH_ENTSIZE_TYPE_SHIFT;
- *size += arch_mod_section_prepend(mod, section);
- ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
- *size = ret + sechdr->sh_size;
- return ret;
+ mod->mem[type].size += arch_mod_section_prepend(mod, section);
+ offset = ALIGN(mod->mem[type].size, sechdr->sh_addralign ?: 1);
+ mod->mem[type].size = offset + sechdr->sh_size;
+
+ WARN_ON_ONCE(offset & mask);
+ return offset | mask;
}
static bool module_init_layout_section(const char *sname)
@@ -1408,15 +1500,11 @@ static bool module_init_layout_section(const char *sname)
return module_init_section(sname);
}
-/*
- * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
- * might -- code, read-only data, read-write data, small data. Tally
- * sizes, and place the offsets into sh_entsize fields: high bit means it
- * belongs in init.
- */
-static void layout_sections(struct module *mod, struct load_info *info)
+static void __layout_sections(struct module *mod, struct load_info *info, bool is_init)
{
- static unsigned long const masks[][2] = {
+ unsigned int m, i;
+
+ static const unsigned long masks[][2] = {
/*
* NOTE: all executable code must be the first section
* in this array; otherwise modify the text_size
@@ -1428,85 +1516,64 @@ static void layout_sections(struct module *mod, struct load_info *info)
{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
};
- unsigned int m, i;
-
- for (i = 0; i < info->hdr->e_shnum; i++)
- info->sechdrs[i].sh_entsize = ~0UL;
+ static const int core_m_to_mem_type[] = {
+ MOD_TEXT,
+ MOD_RODATA,
+ MOD_RO_AFTER_INIT,
+ MOD_DATA,
+ MOD_INVALID, /* This is needed to match the masks array */
+ };
+ static const int init_m_to_mem_type[] = {
+ MOD_INIT_TEXT,
+ MOD_INIT_RODATA,
+ MOD_INVALID,
+ MOD_INIT_DATA,
+ MOD_INVALID, /* This is needed to match the masks array */
+ };
- pr_debug("Core section allocation order:\n");
for (m = 0; m < ARRAY_SIZE(masks); ++m) {
+ enum mod_mem_type type = is_init ? init_m_to_mem_type[m] : core_m_to_mem_type[m];
+
for (i = 0; i < info->hdr->e_shnum; ++i) {
Elf_Shdr *s = &info->sechdrs[i];
const char *sname = info->secstrings + s->sh_name;
- unsigned int *sizep;
if ((s->sh_flags & masks[m][0]) != masks[m][0]
|| (s->sh_flags & masks[m][1])
|| s->sh_entsize != ~0UL
- || module_init_layout_section(sname))
+ || is_init != module_init_layout_section(sname))
continue;
- sizep = m ? &mod->data_layout.size : &mod->core_layout.size;
- s->sh_entsize = module_get_offset(mod, sizep, s, i);
- pr_debug("\t%s\n", sname);
- }
- switch (m) {
- case 0: /* executable */
- mod->core_layout.size = strict_align(mod->core_layout.size);
- mod->core_layout.text_size = mod->core_layout.size;
- break;
- case 1: /* RO: text and ro-data */
- mod->data_layout.size = strict_align(mod->data_layout.size);
- mod->data_layout.ro_size = mod->data_layout.size;
- break;
- case 2: /* RO after init */
- mod->data_layout.size = strict_align(mod->data_layout.size);
- mod->data_layout.ro_after_init_size = mod->data_layout.size;
- break;
- case 4: /* whole core */
- mod->data_layout.size = strict_align(mod->data_layout.size);
- break;
- }
- }
-
- pr_debug("Init section allocation order:\n");
- for (m = 0; m < ARRAY_SIZE(masks); ++m) {
- for (i = 0; i < info->hdr->e_shnum; ++i) {
- Elf_Shdr *s = &info->sechdrs[i];
- const char *sname = info->secstrings + s->sh_name;
- if ((s->sh_flags & masks[m][0]) != masks[m][0]
- || (s->sh_flags & masks[m][1])
- || s->sh_entsize != ~0UL
- || !module_init_layout_section(sname))
+ if (WARN_ON_ONCE(type == MOD_INVALID))
continue;
- s->sh_entsize = (module_get_offset(mod, &mod->init_layout.size, s, i)
- | INIT_OFFSET_MASK);
+
+ s->sh_entsize = module_get_offset_and_type(mod, type, s, i);
pr_debug("\t%s\n", sname);
}
- switch (m) {
- case 0: /* executable */
- mod->init_layout.size = strict_align(mod->init_layout.size);
- mod->init_layout.text_size = mod->init_layout.size;
- break;
- case 1: /* RO: text and ro-data */
- mod->init_layout.size = strict_align(mod->init_layout.size);
- mod->init_layout.ro_size = mod->init_layout.size;
- break;
- case 2:
- /*
- * RO after init doesn't apply to init_layout (only
- * core_layout), so it just takes the value of ro_size.
- */
- mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
- break;
- case 4: /* whole init */
- mod->init_layout.size = strict_align(mod->init_layout.size);
- break;
- }
}
}
-static void set_license(struct module *mod, const char *license)
+/*
+ * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
+ * might -- code, read-only data, read-write data, small data. Tally
+ * sizes, and place the offsets into sh_entsize fields: high bit means it
+ * belongs in init.
+ */
+static void layout_sections(struct module *mod, struct load_info *info)
+{
+ unsigned int i;
+
+ for (i = 0; i < info->hdr->e_shnum; i++)
+ info->sechdrs[i].sh_entsize = ~0UL;
+
+ pr_debug("Core section allocation order for %s:\n", mod->name);
+ __layout_sections(mod, info, false);
+
+ pr_debug("Init section allocation order for %s:\n", mod->name);
+ __layout_sections(mod, info, true);
+}
+
+static void module_license_taint_check(struct module *mod, const char *license)
{
if (!license)
license = "unspecified";
@@ -1520,56 +1587,6 @@ static void set_license(struct module *mod, const char *license)
}
}
-/* Parse tag=value strings from .modinfo section */
-static char *next_string(char *string, unsigned long *secsize)
-{
- /* Skip non-zero chars */
- while (string[0]) {
- string++;
- if ((*secsize)-- <= 1)
- return NULL;
- }
-
- /* Skip any zero padding. */
- while (!string[0]) {
- string++;
- if ((*secsize)-- <= 1)
- return NULL;
- }
- return string;
-}
-
-static char *get_next_modinfo(const struct load_info *info, const char *tag,
- char *prev)
-{
- char *p;
- unsigned int taglen = strlen(tag);
- Elf_Shdr *infosec = &info->sechdrs[info->index.info];
- unsigned long size = infosec->sh_size;
-
- /*
- * get_modinfo() calls made before rewrite_section_headers()
- * must use sh_offset, as sh_addr isn't set!
- */
- char *modinfo = (char *)info->hdr + infosec->sh_offset;
-
- if (prev) {
- size -= prev - modinfo;
- modinfo = next_string(prev, &size);
- }
-
- for (p = modinfo; p; p = next_string(p, &size)) {
- if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
- return p + taglen + 1;
- }
- return NULL;
-}
-
-static char *get_modinfo(const struct load_info *info, const char *tag)
-{
- return get_next_modinfo(info, tag, NULL);
-}
-
static void setup_modinfo(struct module *mod, struct load_info *info)
{
struct module_attribute *attr;
@@ -1592,19 +1609,6 @@ static void free_modinfo(struct module *mod)
}
}
-static void dynamic_debug_setup(struct module *mod, struct _ddebug_info *dyndbg)
-{
- if (!dyndbg->num_descs)
- return;
- ddebug_add_module(dyndbg, mod->name);
-}
-
-static void dynamic_debug_remove(struct module *mod, struct _ddebug_info *dyndbg)
-{
- if (dyndbg->num_descs)
- ddebug_remove_module(mod->name);
-}
-
void * __weak module_alloc(unsigned long size)
{
return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
@@ -1642,16 +1646,33 @@ static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
}
/*
- * Sanity checks against invalid binaries, wrong arch, weird elf version.
+ * Check userspace passed ELF module against our expectations, and cache
+ * useful variables for further processing as we go.
*
- * Also do basic validity checks against section offsets and sizes, the
+ * This does basic validity checks against section offsets and sizes, the
* section name string table, and the indices used for it (sh_name).
+ *
+ * As a last step, since we're already checking the ELF sections we cache
+ * useful variables which will be used later for our convenience:
+ *
+ * o pointers to section headers
+ * o cache the modinfo symbol section
+ * o cache the string symbol section
+ * o cache the module section
+ *
+ * As a last step we set info->mod to the temporary copy of the module in
+ * info->hdr. The final one will be allocated in move_module(). Any
+ * modifications we make to our copy of the module will be carried over
+ * to the final minted module.
*/
-static int elf_validity_check(struct load_info *info)
+static int elf_validity_cache_copy(struct load_info *info, int flags)
{
unsigned int i;
Elf_Shdr *shdr, *strhdr;
int err;
+ unsigned int num_mod_secs = 0, mod_idx;
+ unsigned int num_info_secs = 0, info_idx;
+ unsigned int num_sym_secs = 0, sym_idx;
if (info->len < sizeof(*(info->hdr))) {
pr_err("Invalid ELF header len %lu\n", info->len);
@@ -1755,6 +1776,8 @@ static int elf_validity_check(struct load_info *info)
info->hdr->e_shnum);
goto no_exec;
}
+ num_sym_secs++;
+ sym_idx = i;
fallthrough;
default:
err = validate_section_offset(info, shdr);
@@ -1763,6 +1786,15 @@ static int elf_validity_check(struct load_info *info)
i, shdr->sh_type);
return err;
}
+ if (strcmp(info->secstrings + shdr->sh_name,
+ ".gnu.linkonce.this_module") == 0) {
+ num_mod_secs++;
+ mod_idx = i;
+ } else if (strcmp(info->secstrings + shdr->sh_name,
+ ".modinfo") == 0) {
+ num_info_secs++;
+ info_idx = i;
+ }
if (shdr->sh_flags & SHF_ALLOC) {
if (shdr->sh_name >= strhdr->sh_size) {
@@ -1775,6 +1807,91 @@ static int elf_validity_check(struct load_info *info)
}
}
+ if (num_info_secs > 1) {
+ pr_err("Only one .modinfo section must exist.\n");
+ goto no_exec;
+ } else if (num_info_secs == 1) {
+ /* Try to find a name early so we can log errors with a module name */
+ info->index.info = info_idx;
+ info->name = get_modinfo(info, "name");
+ }
+
+ if (num_sym_secs != 1) {
+ pr_warn("%s: module has no symbols (stripped?)\n",
+ info->name ?: "(missing .modinfo section or name field)");
+ goto no_exec;
+ }
+
+ /* Sets internal symbols and strings. */
+ info->index.sym = sym_idx;
+ shdr = &info->sechdrs[sym_idx];
+ info->index.str = shdr->sh_link;
+ info->strtab = (char *)info->hdr + info->sechdrs[info->index.str].sh_offset;
+
+ /*
+ * The ".gnu.linkonce.this_module" ELF section is special. It is
+ * what modpost uses to refer to __this_module and let's use rely
+ * on THIS_MODULE to point to &__this_module properly. The kernel's
+ * modpost declares it on each modules's *.mod.c file. If the struct
+ * module of the kernel changes a full kernel rebuild is required.
+ *
+ * We have a few expectaions for this special section, the following
+ * code validates all this for us:
+ *
+ * o Only one section must exist
+ * o We expect the kernel to always have to allocate it: SHF_ALLOC
+ * o The section size must match the kernel's run time's struct module
+ * size
+ */
+ if (num_mod_secs != 1) {
+ pr_err("module %s: Only one .gnu.linkonce.this_module section must exist.\n",
+ info->name ?: "(missing .modinfo section or name field)");
+ goto no_exec;
+ }
+
+ shdr = &info->sechdrs[mod_idx];
+
+ /*
+ * This is already implied on the switch above, however let's be
+ * pedantic about it.
+ */
+ if (shdr->sh_type == SHT_NOBITS) {
+ pr_err("module %s: .gnu.linkonce.this_module section must have a size set\n",
+ info->name ?: "(missing .modinfo section or name field)");
+ goto no_exec;
+ }
+
+ if (!(shdr->sh_flags & SHF_ALLOC)) {
+ pr_err("module %s: .gnu.linkonce.this_module must occupy memory during process execution\n",
+ info->name ?: "(missing .modinfo section or name field)");
+ goto no_exec;
+ }
+
+ if (shdr->sh_size != sizeof(struct module)) {
+ pr_err("module %s: .gnu.linkonce.this_module section size must match the kernel's built struct module size at run time\n",
+ info->name ?: "(missing .modinfo section or name field)");
+ goto no_exec;
+ }
+
+ info->index.mod = mod_idx;
+
+ /* This is temporary: point mod into copy of data. */
+ info->mod = (void *)info->hdr + shdr->sh_offset;
+
+ /*
+ * If we didn't load the .modinfo 'name' field earlier, fall back to
+ * on-disk struct mod 'name' field.
+ */
+ if (!info->name)
+ info->name = info->mod->name;
+
+ if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
+ info->index.vers = 0; /* Pretend no __versions section! */
+ else
+ info->index.vers = find_sec(info, "__versions");
+
+ info->index.pcpu = find_pcpusec(info);
+
return 0;
no_exec:
@@ -1804,12 +1921,8 @@ static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
/* Nothing more to do */
return 0;
- if (set_livepatch_module(mod)) {
- add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
- pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
- mod->name);
+ if (set_livepatch_module(mod))
return 0;
- }
pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
mod->name);
@@ -1892,63 +2005,71 @@ static int rewrite_section_headers(struct load_info *info, int flags)
}
/*
- * Set up our basic convenience variables (pointers to section headers,
- * search for module section index etc), and do some basic section
- * verification.
- *
- * Set info->mod to the temporary copy of the module in info->hdr. The final one
- * will be allocated in move_module().
- */
-static int setup_load_info(struct load_info *info, int flags)
+ * These calls taint the kernel depending certain module circumstances */
+static void module_augment_kernel_taints(struct module *mod, struct load_info *info)
{
- unsigned int i;
+ int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
- /* Try to find a name early so we can log errors with a module name */
- info->index.info = find_sec(info, ".modinfo");
- if (info->index.info)
- info->name = get_modinfo(info, "name");
+ if (!get_modinfo(info, "intree")) {
+ if (!test_taint(TAINT_OOT_MODULE))
+ pr_warn("%s: loading out-of-tree module taints kernel.\n",
+ mod->name);
+ add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
+ }
- /* Find internal symbols and strings. */
- for (i = 1; i < info->hdr->e_shnum; i++) {
- if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
- info->index.sym = i;
- info->index.str = info->sechdrs[i].sh_link;
- info->strtab = (char *)info->hdr
- + info->sechdrs[info->index.str].sh_offset;
- break;
- }
+ check_modinfo_retpoline(mod, info);
+
+ if (get_modinfo(info, "staging")) {
+ add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
+ pr_warn("%s: module is from the staging directory, the quality "
+ "is unknown, you have been warned.\n", mod->name);
}
- if (info->index.sym == 0) {
- pr_warn("%s: module has no symbols (stripped?)\n",
- info->name ?: "(missing .modinfo section or name field)");
- return -ENOEXEC;
+ if (is_livepatch_module(mod)) {
+ add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
+ pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
+ mod->name);
}
- info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
- if (!info->index.mod) {
- pr_warn("%s: No module found in object\n",
- info->name ?: "(missing .modinfo section or name field)");
- return -ENOEXEC;
+ module_license_taint_check(mod, get_modinfo(info, "license"));
+
+ if (get_modinfo(info, "test")) {
+ if (!test_taint(TAINT_TEST))
+ pr_warn("%s: loading test module taints kernel.\n",
+ mod->name);
+ add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
}
- /* This is temporary: point mod into copy of data. */
- info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
+#ifdef CONFIG_MODULE_SIG
+ mod->sig_ok = info->sig_ok;
+ if (!mod->sig_ok) {
+ pr_notice_once("%s: module verification failed: signature "
+ "and/or required key missing - tainting "
+ "kernel\n", mod->name);
+ add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
+ }
+#endif
/*
- * If we didn't load the .modinfo 'name' field earlier, fall back to
- * on-disk struct mod 'name' field.
+ * ndiswrapper is under GPL by itself, but loads proprietary modules.
+ * Don't use add_taint_module(), as it would prevent ndiswrapper from
+ * using GPL-only symbols it needs.
*/
- if (!info->name)
- info->name = info->mod->name;
+ if (strcmp(mod->name, "ndiswrapper") == 0)
+ add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
- if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
- info->index.vers = 0; /* Pretend no __versions section! */
- else
- info->index.vers = find_sec(info, "__versions");
+ /* driverloader was caught wrongly pretending to be under GPL */
+ if (strcmp(mod->name, "driverloader") == 0)
+ add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+ LOCKDEP_NOW_UNRELIABLE);
- info->index.pcpu = find_pcpusec(info);
+ /* lve claims to be GPL but upstream won't provide source */
+ if (strcmp(mod->name, "lve") == 0)
+ add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+ LOCKDEP_NOW_UNRELIABLE);
+
+ if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
+ pr_warn("%s: module license taints kernel.\n", mod->name);
- return 0;
}
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
@@ -1970,35 +2091,10 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
return -ENOEXEC;
}
- if (!get_modinfo(info, "intree")) {
- if (!test_taint(TAINT_OOT_MODULE))
- pr_warn("%s: loading out-of-tree module taints kernel.\n",
- mod->name);
- add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
- }
-
- check_modinfo_retpoline(mod, info);
-
- if (get_modinfo(info, "staging")) {
- add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
- pr_warn("%s: module is from the staging directory, the quality "
- "is unknown, you have been warned.\n", mod->name);
- }
-
err = check_modinfo_livepatch(mod, info);
if (err)
return err;
- /* Set up license info based on the info section */
- set_license(mod, get_modinfo(info, "license"));
-
- if (get_modinfo(info, "test")) {
- if (!test_taint(TAINT_TEST))
- pr_warn("%s: loading test module taints kernel.\n",
- mod->name);
- add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
- }
-
return 0;
}
@@ -2110,10 +2206,14 @@ static int find_module_sections(struct module *mod, struct load_info *info)
if (section_addr(info, "__obsparm"))
pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
- info->dyndbg.descs = section_objs(info, "__dyndbg",
- sizeof(*info->dyndbg.descs), &info->dyndbg.num_descs);
- info->dyndbg.classes = section_objs(info, "__dyndbg_classes",
- sizeof(*info->dyndbg.classes), &info->dyndbg.num_classes);
+#ifdef CONFIG_DYNAMIC_DEBUG_CORE
+ mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
+ sizeof(*mod->dyndbg_info.descs),
+ &mod->dyndbg_info.num_descs);
+ mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
+ sizeof(*mod->dyndbg_info.classes),
+ &mod->dyndbg_info.num_classes);
+#endif
return 0;
}
@@ -2122,109 +2222,82 @@ static int move_module(struct module *mod, struct load_info *info)
{
int i;
void *ptr;
+ enum mod_mem_type t = 0;
+ int ret = -ENOMEM;
- /* Do the allocs. */
- ptr = module_alloc(mod->core_layout.size);
- /*
- * The pointer to this block is stored in the module structure
- * which is inside the block. Just mark it as not being a
- * leak.
- */
- kmemleak_not_leak(ptr);
- if (!ptr)
- return -ENOMEM;
-
- memset(ptr, 0, mod->core_layout.size);
- mod->core_layout.base = ptr;
-
- if (mod->init_layout.size) {
- ptr = module_alloc(mod->init_layout.size);
+ for_each_mod_mem_type(type) {
+ if (!mod->mem[type].size) {
+ mod->mem[type].base = NULL;
+ continue;
+ }
+ mod->mem[type].size = PAGE_ALIGN(mod->mem[type].size);
+ ptr = module_memory_alloc(mod->mem[type].size, type);
/*
- * The pointer to this block is stored in the module structure
- * which is inside the block. This block doesn't need to be
- * scanned as it contains data and code that will be freed
- * after the module is initialized.
+ * The pointer to these blocks of memory are stored on the module
+ * structure and we keep that around so long as the module is
+ * around. We only free that memory when we unload the module.
+ * Just mark them as not being a leak then. The .init* ELF
+ * sections *do* get freed after boot so we *could* treat them
+ * slightly differently with kmemleak_ignore() and only grey
+ * them out as they work as typical memory allocations which
+ * *do* eventually get freed, but let's just keep things simple
+ * and avoid *any* false positives.
*/
- kmemleak_ignore(ptr);
+ kmemleak_not_leak(ptr);
if (!ptr) {
- module_memfree(mod->core_layout.base);
- return -ENOMEM;
+ t = type;
+ goto out_enomem;
}
- memset(ptr, 0, mod->init_layout.size);
- mod->init_layout.base = ptr;
- } else
- mod->init_layout.base = NULL;
-
-#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
- /* Do the allocs. */
- ptr = vzalloc(mod->data_layout.size);
- /*
- * The pointer to this block is stored in the module structure
- * which is inside the block. Just mark it as not being a
- * leak.
- */
- kmemleak_not_leak(ptr);
- if (!ptr) {
- module_memfree(mod->core_layout.base);
- module_memfree(mod->init_layout.base);
- return -ENOMEM;
+ memset(ptr, 0, mod->mem[type].size);
+ mod->mem[type].base = ptr;
}
- mod->data_layout.base = ptr;
-#endif
/* Transfer each section which specifies SHF_ALLOC */
- pr_debug("final section addresses:\n");
+ pr_debug("Final section addresses for %s:\n", mod->name);
for (i = 0; i < info->hdr->e_shnum; i++) {
void *dest;
Elf_Shdr *shdr = &info->sechdrs[i];
+ enum mod_mem_type type = shdr->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT;
if (!(shdr->sh_flags & SHF_ALLOC))
continue;
- if (shdr->sh_entsize & INIT_OFFSET_MASK)
- dest = mod->init_layout.base
- + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
- else if (!(shdr->sh_flags & SHF_EXECINSTR))
- dest = mod->data_layout.base + shdr->sh_entsize;
- else
- dest = mod->core_layout.base + shdr->sh_entsize;
+ dest = mod->mem[type].base + (shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK);
- if (shdr->sh_type != SHT_NOBITS)
+ if (shdr->sh_type != SHT_NOBITS) {
+ /*
+ * Our ELF checker already validated this, but let's
+ * be pedantic and make the goal clearer. We actually
+ * end up copying over all modifications made to the
+ * userspace copy of the entire struct module.
+ */
+ if (i == info->index.mod &&
+ (WARN_ON_ONCE(shdr->sh_size != sizeof(struct module)))) {
+ ret = -ENOEXEC;
+ goto out_enomem;
+ }
memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
- /* Update sh_addr to point to copy in image. */
+ }
+ /*
+ * Update the userspace copy's ELF section address to point to
+ * our newly allocated memory as a pure convenience so that
+ * users of info can keep taking advantage and using the newly
+ * minted official memory area.
+ */
shdr->sh_addr = (unsigned long)dest;
- pr_debug("\t0x%lx %s\n",
- (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
+ pr_debug("\t0x%lx 0x%.8lx %s\n", (long)shdr->sh_addr,
+ (long)shdr->sh_size, info->secstrings + shdr->sh_name);
}
return 0;
+out_enomem:
+ for (t--; t >= 0; t--)
+ module_memory_free(mod->mem[t].base, t);
+ return ret;
}
-static int check_module_license_and_versions(struct module *mod)
+static int check_export_symbol_versions(struct module *mod)
{
- int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
-
- /*
- * ndiswrapper is under GPL by itself, but loads proprietary modules.
- * Don't use add_taint_module(), as it would prevent ndiswrapper from
- * using GPL-only symbols it needs.
- */
- if (strcmp(mod->name, "ndiswrapper") == 0)
- add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
-
- /* driverloader was caught wrongly pretending to be under GPL */
- if (strcmp(mod->name, "driverloader") == 0)
- add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
- LOCKDEP_NOW_UNRELIABLE);
-
- /* lve claims to be GPL but upstream won't provide source */
- if (strcmp(mod->name, "lve") == 0)
- add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
- LOCKDEP_NOW_UNRELIABLE);
-
- if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
- pr_warn("%s: module license taints kernel.\n", mod->name);
-
#ifdef CONFIG_MODVERSIONS
if ((mod->num_syms && !mod->crcs) ||
(mod->num_gpl_syms && !mod->gpl_crcs)) {
@@ -2242,12 +2315,14 @@ static void flush_module_icache(const struct module *mod)
* Do it before processing of module parameters, so the module
* can provide parameter accessor functions of its own.
*/
- if (mod->init_layout.base)
- flush_icache_range((unsigned long)mod->init_layout.base,
- (unsigned long)mod->init_layout.base
- + mod->init_layout.size);
- flush_icache_range((unsigned long)mod->core_layout.base,
- (unsigned long)mod->core_layout.base + mod->core_layout.size);
+ for_each_mod_mem_type(type) {
+ const struct module_memory *mod_mem = &mod->mem[type];
+
+ if (mod_mem->size) {
+ flush_icache_range((unsigned long)mod_mem->base,
+ (unsigned long)mod_mem->base + mod_mem->size);
+ }
+ }
}
bool __weak module_elf_check_arch(Elf_Ehdr *hdr)
@@ -2290,10 +2365,6 @@ static struct module *layout_and_allocate(struct load_info *info, int flags)
unsigned int ndx;
int err;
- err = check_modinfo(info->mod, info, flags);
- if (err)
- return ERR_PTR(err);
-
/* Allow arches to frob section contents and sizes. */
err = module_frob_arch_sections(info->hdr, info->sechdrs,
info->secstrings, info->mod);
@@ -2350,11 +2421,8 @@ static void module_deallocate(struct module *mod, struct load_info *info)
{
percpu_modfree(mod);
module_arch_freeing_init(mod);
- module_memfree(mod->init_layout.base);
- module_memfree(mod->core_layout.base);
-#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
- vfree(mod->data_layout.base);
-#endif
+
+ free_mod_mem(mod);
}
int __weak module_finalize(const Elf_Ehdr *hdr,
@@ -2380,27 +2448,6 @@ static int post_relocation(struct module *mod, const struct load_info *info)
return module_finalize(info->hdr, info->sechdrs, mod);
}
-/* Is this module of this name done loading? No locks held. */
-static bool finished_loading(const char *name)
-{
- struct module *mod;
- bool ret;
-
- /*
- * The module_mutex should not be a heavily contended lock;
- * if we get the occasional sleep here, we'll go an extra iteration
- * in the wait_event_interruptible(), which is harmless.
- */
- sched_annotate_sleep();
- mutex_lock(&module_mutex);
- mod = find_module_all(name, strlen(name), true);
- ret = !mod || mod->state == MODULE_STATE_LIVE
- || mod->state == MODULE_STATE_GOING;
- mutex_unlock(&module_mutex);
-
- return ret;
-}
-
/* Call module constructors. */
static void do_mod_ctors(struct module *mod)
{
@@ -2415,7 +2462,9 @@ static void do_mod_ctors(struct module *mod)
/* For freeing module_init on success, in case kallsyms traversing */
struct mod_initfree {
struct llist_node node;
- void *module_init;
+ void *init_text;
+ void *init_data;
+ void *init_rodata;
};
static void do_free_init(struct work_struct *w)
@@ -2429,7 +2478,9 @@ static void do_free_init(struct work_struct *w)
llist_for_each_safe(pos, n, list) {
initfree = container_of(pos, struct mod_initfree, node);
- module_memfree(initfree->module_init);
+ module_memfree(initfree->init_text);
+ module_memfree(initfree->init_data);
+ module_memfree(initfree->init_rodata);
kfree(initfree);
}
}
@@ -2450,13 +2501,27 @@ static noinline int do_init_module(struct module *mod)
{
int ret = 0;
struct mod_initfree *freeinit;
+#if defined(CONFIG_MODULE_STATS)
+ unsigned int text_size = 0, total_size = 0;
+
+ for_each_mod_mem_type(type) {
+ const struct module_memory *mod_mem = &mod->mem[type];
+ if (mod_mem->size) {
+ total_size += mod_mem->size;
+ if (type == MOD_TEXT || type == MOD_INIT_TEXT)
+ text_size += mod_mem->size;
+ }
+ }
+#endif
freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
if (!freeinit) {
ret = -ENOMEM;
goto fail;
}
- freeinit->module_init = mod->init_layout.base;
+ freeinit->init_text = mod->mem[MOD_INIT_TEXT].base;
+ freeinit->init_data = mod->mem[MOD_INIT_DATA].base;
+ freeinit->init_rodata = mod->mem[MOD_INIT_RODATA].base;
do_mod_ctors(mod);
/* Start the module */
@@ -2492,8 +2557,8 @@ static noinline int do_init_module(struct module *mod)
if (!mod->async_probe_requested)
async_synchronize_full();
- ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
- mod->init_layout.size);
+ ftrace_free_mem(mod, mod->mem[MOD_INIT_TEXT].base,
+ mod->mem[MOD_INIT_TEXT].base + mod->mem[MOD_INIT_TEXT].size);
mutex_lock(&module_mutex);
/* Drop initial reference. */
module_put(mod);
@@ -2505,11 +2570,11 @@ static noinline int do_init_module(struct module *mod)
module_enable_ro(mod, true);
mod_tree_remove_init(mod);
module_arch_freeing_init(mod);
- mod->init_layout.base = NULL;
- mod->init_layout.size = 0;
- mod->init_layout.ro_size = 0;
- mod->init_layout.ro_after_init_size = 0;
- mod->init_layout.text_size = 0;
+ for_class_mod_mem_type(type, init) {
+ mod->mem[type].base = NULL;
+ mod->mem[type].size = 0;
+ }
+
#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
/* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
mod->btf_data = NULL;
@@ -2533,6 +2598,11 @@ static noinline int do_init_module(struct module *mod)
mutex_unlock(&module_mutex);
wake_up_all(&module_wq);
+ mod_stat_add_long(text_size, &total_text_size);
+ mod_stat_add_long(total_size, &total_mod_size);
+
+ mod_stat_inc(&modcount);
+
return 0;
fail_free_freeinit:
@@ -2548,6 +2618,7 @@ fail:
ftrace_release_mod(mod);
free_module(mod);
wake_up_all(&module_wq);
+
return ret;
}
@@ -2559,6 +2630,67 @@ static int may_init_module(void)
return 0;
}
+/* Is this module of this name done loading? No locks held. */
+static bool finished_loading(const char *name)
+{
+ struct module *mod;
+ bool ret;
+
+ /*
+ * The module_mutex should not be a heavily contended lock;
+ * if we get the occasional sleep here, we'll go an extra iteration
+ * in the wait_event_interruptible(), which is harmless.
+ */
+ sched_annotate_sleep();
+ mutex_lock(&module_mutex);
+ mod = find_module_all(name, strlen(name), true);
+ ret = !mod || mod->state == MODULE_STATE_LIVE
+ || mod->state == MODULE_STATE_GOING;
+ mutex_unlock(&module_mutex);
+
+ return ret;
+}
+
+/* Must be called with module_mutex held */
+static int module_patient_check_exists(const char *name,
+ enum fail_dup_mod_reason reason)
+{
+ struct module *old;
+ int err = 0;
+
+ old = find_module_all(name, strlen(name), true);
+ if (old == NULL)
+ return 0;
+
+ if (old->state == MODULE_STATE_COMING ||
+ old->state == MODULE_STATE_UNFORMED) {
+ /* Wait in case it fails to load. */
+ mutex_unlock(&module_mutex);
+ err = wait_event_interruptible(module_wq,
+ finished_loading(name));
+ mutex_lock(&module_mutex);
+ if (err)
+ return err;
+
+ /* The module might have gone in the meantime. */
+ old = find_module_all(name, strlen(name), true);
+ }
+
+ if (try_add_failed_module(name, reason))
+ pr_warn("Could not add fail-tracking for module: %s\n", name);
+
+ /*
+ * We are here only when the same module was being loaded. Do
+ * not try to load it again right now. It prevents long delays
+ * caused by serialized module load failures. It might happen
+ * when more devices of the same type trigger load of
+ * a particular module.
+ */
+ if (old && old->state == MODULE_STATE_LIVE)
+ return -EEXIST;
+ return -EBUSY;
+}
+
/*
* We try to place it in the list now to make sure it's unique before
* we dedicate too many resources. In particular, temporary percpu
@@ -2567,41 +2699,14 @@ static int may_init_module(void)
static int add_unformed_module(struct module *mod)
{
int err;
- struct module *old;
mod->state = MODULE_STATE_UNFORMED;
mutex_lock(&module_mutex);
- old = find_module_all(mod->name, strlen(mod->name), true);
- if (old != NULL) {
- if (old->state == MODULE_STATE_COMING
- || old->state == MODULE_STATE_UNFORMED) {
- /* Wait in case it fails to load. */
- mutex_unlock(&module_mutex);
- err = wait_event_interruptible(module_wq,
- finished_loading(mod->name));
- if (err)
- goto out_unlocked;
-
- /* The module might have gone in the meantime. */
- mutex_lock(&module_mutex);
- old = find_module_all(mod->name, strlen(mod->name),
- true);
- }
-
- /*
- * We are here only when the same module was being loaded. Do
- * not try to load it again right now. It prevents long delays
- * caused by serialized module load failures. It might happen
- * when more devices of the same type trigger load of
- * a particular module.
- */
- if (old && old->state == MODULE_STATE_LIVE)
- err = -EEXIST;
- else
- err = -EBUSY;
+ err = module_patient_check_exists(mod->name, FAIL_DUP_MOD_LOAD);
+ if (err)
goto out;
- }
+
mod_update_bounds(mod);
list_add_rcu(&mod->list, &modules);
mod_tree_insert(mod);
@@ -2609,7 +2714,6 @@ static int add_unformed_module(struct module *mod)
out:
mutex_unlock(&module_mutex);
-out_unlocked:
return err;
}
@@ -2628,9 +2732,6 @@ static int complete_formation(struct module *mod, struct load_info *info)
module_bug_finalize(info->hdr, info->sechdrs, mod);
module_cfi_finalize(info->hdr, info->sechdrs, mod);
- if (module_check_misalignment(mod))
- goto out_misaligned;
-
module_enable_ro(mod, false);
module_enable_nx(mod);
module_enable_x(mod);
@@ -2644,8 +2745,6 @@ static int complete_formation(struct module *mod, struct load_info *info)
return 0;
-out_misaligned:
- err = -EINVAL;
out:
mutex_unlock(&module_mutex);
return err;
@@ -2688,6 +2787,39 @@ static int unknown_module_param_cb(char *param, char *val, const char *modname,
return 0;
}
+/* Module within temporary copy, this doesn't do any allocation */
+static int early_mod_check(struct load_info *info, int flags)
+{
+ int err;
+
+ /*
+ * Now that we know we have the correct module name, check
+ * if it's blacklisted.
+ */
+ if (blacklisted(info->name)) {
+ pr_err("Module %s is blacklisted\n", info->name);
+ return -EPERM;
+ }
+
+ err = rewrite_section_headers(info, flags);
+ if (err)
+ return err;
+
+ /* Check module struct version now, before we try to use module. */
+ if (!check_modstruct_version(info, info->mod))
+ return -ENOEXEC;
+
+ err = check_modinfo(info->mod, info, flags);
+ if (err)
+ return err;
+
+ mutex_lock(&module_mutex);
+ err = module_patient_check_exists(info->mod->name, FAIL_DUP_MOD_BECOMING);
+ mutex_unlock(&module_mutex);
+
+ return err;
+}
+
/*
* Allocate and load the module: note that size of section 0 is always
* zero, and we rely on this for optional sections.
@@ -2696,6 +2828,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
int flags)
{
struct module *mod;
+ bool module_allocated = false;
long err = 0;
char *after_dashes;
@@ -2717,40 +2850,17 @@ static int load_module(struct load_info *info, const char __user *uargs,
/*
* Do basic sanity checks against the ELF header and
- * sections.
+ * sections. Cache useful sections and set the
+ * info->mod to the userspace passed struct module.
*/
- err = elf_validity_check(info);
+ err = elf_validity_cache_copy(info, flags);
if (err)
goto free_copy;
- /*
- * Everything checks out, so set up the section info
- * in the info structure.
- */
- err = setup_load_info(info, flags);
+ err = early_mod_check(info, flags);
if (err)
goto free_copy;
- /*
- * Now that we know we have the correct module name, check
- * if it's blacklisted.
- */
- if (blacklisted(info->name)) {
- err = -EPERM;
- pr_err("Module %s is blacklisted\n", info->name);
- goto free_copy;
- }
-
- err = rewrite_section_headers(info, flags);
- if (err)
- goto free_copy;
-
- /* Check module struct version now, before we try to use module. */
- if (!check_modstruct_version(info, info->mod)) {
- err = -ENOEXEC;
- goto free_copy;
- }
-
/* Figure out module layout, and allocate all the memory. */
mod = layout_and_allocate(info, flags);
if (IS_ERR(mod)) {
@@ -2758,6 +2868,8 @@ static int load_module(struct load_info *info, const char __user *uargs,
goto free_copy;
}
+ module_allocated = true;
+
audit_log_kern_module(mod->name);
/* Reserve our place in the list. */
@@ -2765,15 +2877,11 @@ static int load_module(struct load_info *info, const char __user *uargs,
if (err)
goto free_module;
-#ifdef CONFIG_MODULE_SIG
- mod->sig_ok = info->sig_ok;
- if (!mod->sig_ok) {
- pr_notice_once("%s: module verification failed: signature "
- "and/or required key missing - tainting "
- "kernel\n", mod->name);
- add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
- }
-#endif
+ /*
+ * We are tainting your kernel if your module gets into
+ * the modules linked list somehow.
+ */
+ module_augment_kernel_taints(mod, info);
/* To avoid stressing percpu allocator, do this once we're unique. */
err = percpu_modalloc(mod, info);
@@ -2795,7 +2903,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
if (err)
goto free_unload;
- err = check_module_license_and_versions(mod);
+ err = check_export_symbol_versions(mod);
if (err)
goto free_unload;
@@ -2825,7 +2933,6 @@ static int load_module(struct load_info *info, const char __user *uargs,
}
init_build_id(mod, info);
- dynamic_debug_setup(mod, &info->dyndbg);
/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
ftrace_module_init(mod);
@@ -2889,7 +2996,6 @@ static int load_module(struct load_info *info, const char __user *uargs,
ddebug_cleanup:
ftrace_release_mod(mod);
- dynamic_debug_remove(mod, &info->dyndbg);
synchronize_rcu();
kfree(mod->args);
free_arch_cleanup:
@@ -2908,11 +3014,22 @@ static int load_module(struct load_info *info, const char __user *uargs,
synchronize_rcu();
mutex_unlock(&module_mutex);
free_module:
+ mod_stat_bump_invalid(info, flags);
/* Free lock-classes; relies on the preceding sync_rcu() */
- lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size);
+ for_class_mod_mem_type(type, core_data) {
+ lockdep_free_key_range(mod->mem[type].base,
+ mod->mem[type].size);
+ }
module_deallocate(mod, info);
free_copy:
+ /*
+ * The info->len is always set. We distinguish between
+ * failures once the proper module was allocated and
+ * before that.
+ */
+ if (!module_allocated)
+ mod_stat_bump_becoming(info, flags);
free_copy(info, flags);
return err;
}
@@ -2931,8 +3048,11 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
umod, len, uargs);
err = copy_module_from_user(umod, len, &info);
- if (err)
+ if (err) {
+ mod_stat_inc(&failed_kreads);
+ mod_stat_add_long(len, &invalid_kread_bytes);
return err;
+ }
return load_module(&info, uargs, 0);
}
@@ -2957,14 +3077,20 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
len = kernel_read_file_from_fd(fd, 0, &buf, INT_MAX, NULL,
READING_MODULE);
- if (len < 0)
+ if (len < 0) {
+ mod_stat_inc(&failed_kreads);
+ mod_stat_add_long(len, &invalid_kread_bytes);
return len;
+ }
if (flags & MODULE_INIT_COMPRESSED_FILE) {
err = module_decompress(&info, buf, len);
vfree(buf); /* compressed data is no longer needed */
- if (err)
+ if (err) {
+ mod_stat_inc(&failed_decompress);
+ mod_stat_add_long(len, &invalid_decompress_bytes);
return err;
+ }
} else {
info.hdr = buf;
info.len = len;
@@ -2973,11 +3099,6 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
return load_module(&info, uargs, flags);
}
-static inline int within(unsigned long addr, void *start, unsigned long size)
-{
- return ((void *)addr >= start && (void *)addr < start + size);
-}
-
/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
char *module_flags(struct module *mod, char *buf, bool show_state)
{
@@ -3060,20 +3181,21 @@ bool is_module_address(unsigned long addr)
struct module *__module_address(unsigned long addr)
{
struct module *mod;
- struct mod_tree_root *tree;
if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max)
- tree = &mod_tree;
+ goto lookup;
+
#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
- else if (addr >= mod_data_tree.addr_min && addr <= mod_data_tree.addr_max)
- tree = &mod_data_tree;
+ if (addr >= mod_tree.data_addr_min && addr <= mod_tree.data_addr_max)
+ goto lookup;
#endif
- else
- return NULL;
+ return NULL;
+
+lookup:
module_assert_mutex_or_preempt();
- mod = mod_find(addr, tree);
+ mod = mod_find(addr, &mod_tree);
if (mod) {
BUG_ON(!within_module(addr, mod));
if (mod->state == MODULE_STATE_UNFORMED)
@@ -3113,8 +3235,8 @@ struct module *__module_text_address(unsigned long addr)
struct module *mod = __module_address(addr);
if (mod) {
/* Make sure it's within the text section. */
- if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
- && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
+ if (!within_module_mem_type(addr, mod, MOD_TEXT) &&
+ !within_module_mem_type(addr, mod, MOD_INIT_TEXT))
mod = NULL;
}
return mod;
@@ -3142,3 +3264,14 @@ void print_modules(void)
last_unloaded_module.taints);
pr_cont("\n");
}
+
+#ifdef CONFIG_MODULE_DEBUGFS
+struct dentry *mod_debugfs_root;
+
+static int module_debugfs_init(void)
+{
+ mod_debugfs_root = debugfs_create_dir("modules", NULL);
+ return 0;
+}
+module_init(module_debugfs_init);
+#endif
diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c
index cf5b9f1e6ec4..0a4841e88adb 100644
--- a/kernel/module/procfs.c
+++ b/kernel/module/procfs.c
@@ -62,6 +62,15 @@ static void m_stop(struct seq_file *m, void *p)
mutex_unlock(&module_mutex);
}
+static unsigned int module_total_size(struct module *mod)
+{
+ int size = 0;
+
+ for_each_mod_mem_type(type)
+ size += mod->mem[type].size;
+ return size;
+}
+
static int m_show(struct seq_file *m, void *p)
{
struct module *mod = list_entry(p, struct module, list);
@@ -73,10 +82,7 @@ static int m_show(struct seq_file *m, void *p)
if (mod->state == MODULE_STATE_UNFORMED)
return 0;
- size = mod->init_layout.size + mod->core_layout.size;
-#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
- size += mod->data_layout.size;
-#endif
+ size = module_total_size(mod);
seq_printf(m, "%s %u", mod->name, size);
print_unload_info(m, mod);
@@ -86,7 +92,7 @@ static int m_show(struct seq_file *m, void *p)
mod->state == MODULE_STATE_COMING ? "Loading" :
"Live");
/* Used by oprofile and other similar tools. */
- value = m->private ? NULL : mod->core_layout.base;
+ value = m->private ? NULL : mod->mem[MOD_TEXT].base;
seq_printf(m, " 0x%px", value);
/* Taints info */
diff --git a/kernel/module/stats.c b/kernel/module/stats.c
new file mode 100644
index 000000000000..ad7b6ada29f2
--- /dev/null
+++ b/kernel/module/stats.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Debugging module statistics.
+ *
+ * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
+ */
+
+#include <linux/module.h>
+#include <uapi/linux/module.h>
+#include <linux/string.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/debugfs.h>
+#include <linux/rculist.h>
+#include <linux/math.h>
+
+#include "internal.h"
+
+/**
+ * DOC: module debugging statistics overview
+ *
+ * Enabling CONFIG_MODULE_STATS enables module debugging statistics which
+ * are useful to monitor and root cause memory pressure issues with module
+ * loading. These statistics are useful to allow us to improve production
+ * workloads.
+ *
+ * The current module debugging statistics supported help keep track of module
+ * loading failures to enable improvements either for kernel module auto-loading
+ * usage (request_module()) or interactions with userspace. Statistics are
+ * provided to track all possible failures in the finit_module() path and memory
+ * wasted in this process space. Each of the failure counters are associated
+ * to a type of module loading failure which is known to incur a certain amount
+ * of memory allocation loss. In the worst case loading a module will fail after
+ * a 3 step memory allocation process:
+ *
+ * a) memory allocated with kernel_read_file_from_fd()
+ * b) module decompression processes the file read from
+ * kernel_read_file_from_fd(), and vmap() is used to map
+ * the decompressed module to a new local buffer which represents
+ * a copy of the decompressed module passed from userspace. The buffer
+ * from kernel_read_file_from_fd() is freed right away.
+ * c) layout_and_allocate() allocates space for the final resting
+ * place where we would keep the module if it were to be processed
+ * successfully.
+ *
+ * If a failure occurs after these three different allocations only one
+ * counter will be incremented with the summation of the allocated bytes freed
+ * incurred during this failure. Likewise, if module loading failed only after
+ * step b) a separate counter is used and incremented for the bytes freed and
+ * not used during both of those allocations.
+ *
+ * Virtual memory space can be limited, for example on x86 virtual memory size
+ * defaults to 128 MiB. We should strive to limit and avoid wasting virtual
+ * memory allocations when possible. These module debugging statistics help
+ * to evaluate how much memory is being wasted on bootup due to module loading
+ * failures.
+ *
+ * All counters are designed to be incremental. Atomic counters are used so to
+ * remain simple and avoid delays and deadlocks.
+ */
+
+/**
+ * DOC: dup_failed_modules - tracks duplicate failed modules
+ *
+ * Linked list of modules which failed to be loaded because an already existing
+ * module with the same name was already being processed or already loaded.
+ * The finit_module() system call incurs heavy virtual memory allocations. In
+ * the worst case an finit_module() system call can end up allocating virtual
+ * memory 3 times:
+ *
+ * 1) kernel_read_file_from_fd() call uses vmalloc()
+ * 2) optional module decompression uses vmap()
+ * 3) layout_and allocate() can use vzalloc() or an arch specific variation of
+ * vmalloc to deal with ELF sections requiring special permissions
+ *
+ * In practice on a typical boot today most finit_module() calls fail due to
+ * the module with the same name already being loaded or about to be processed.
+ * All virtual memory allocated to these failed modules will be freed with
+ * no functional use.
+ *
+ * To help with this the dup_failed_modules allows us to track modules which
+ * failed to load due to the fact that a module was already loaded or being
+ * processed. There are only two points at which we can fail such calls,
+ * we list them below along with the number of virtual memory allocation
+ * calls:
+ *
+ * a) FAIL_DUP_MOD_BECOMING: at the end of early_mod_check() before
+ * layout_and_allocate().
+ * - with module decompression: 2 virtual memory allocation calls
+ * - without module decompression: 1 virtual memory allocation calls
+ * b) FAIL_DUP_MOD_LOAD: after layout_and_allocate() on add_unformed_module()
+ * - with module decompression 3 virtual memory allocation calls
+ * - without module decompression 2 virtual memory allocation calls
+ *
+ * We should strive to get this list to be as small as possible. If this list
+ * is not empty it is a reflection of possible work or optimizations possible
+ * either in-kernel or in userspace.
+ */
+static LIST_HEAD(dup_failed_modules);
+
+/**
+ * DOC: module statistics debugfs counters
+ *
+ * The total amount of wasted virtual memory allocation space during module
+ * loading can be computed by adding the total from the summation:
+ *
+ * * @invalid_kread_bytes +
+ * @invalid_decompress_bytes +
+ * @invalid_becoming_bytes +
+ * @invalid_mod_bytes
+ *
+ * The following debugfs counters are available to inspect module loading
+ * failures:
+ *
+ * * total_mod_size: total bytes ever used by all modules we've dealt with on
+ * this system
+ * * total_text_size: total bytes of the .text and .init.text ELF section
+ * sizes we've dealt with on this system
+ * * invalid_kread_bytes: bytes allocated and then freed on failures which
+ * happen due to the initial kernel_read_file_from_fd(). kernel_read_file_from_fd()
+ * uses vmalloc(). These should typically not happen unless your system is
+ * under memory pressure.
+ * * invalid_decompress_bytes: number of bytes allocated and freed due to
+ * memory allocations in the module decompression path that use vmap().
+ * These typically should not happen unless your system is under memory
+ * pressure.
+ * * invalid_becoming_bytes: total number of bytes allocated and freed used
+ * used to read the kernel module userspace wants us to read before we
+ * promote it to be processed to be added to our @modules linked list. These
+ * failures can happen if we had a check in between a successful kernel_read_file_from_fd()
+ * call and right before we allocate the our private memory for the module
+ * which would be kept if the module is successfully loaded. The most common
+ * reason for this failure is when userspace is racing to load a module
+ * which it does not yet see loaded. The first module to succeed in
+ * add_unformed_module() will add a module to our &modules list and
+ * subsequent loads of modules with the same name will error out at the
+ * end of early_mod_check(). The check for module_patient_check_exists()
+ * at the end of early_mod_check() prevents duplicate allocations
+ * on layout_and_allocate() for modules already being processed. These
+ * duplicate failed modules are non-fatal, however they typically are
+ * indicative of userspace not seeing a module in userspace loaded yet and
+ * unnecessarily trying to load a module before the kernel even has a chance
+ * to begin to process prior requests. Although duplicate failures can be
+ * non-fatal, we should try to reduce vmalloc() pressure proactively, so
+ * ideally after boot this will be close to as 0 as possible. If module
+ * decompression was used we also add to this counter the cost of the
+ * initial kernel_read_file_from_fd() of the compressed module. If module
+ * decompression was not used the value represents the total allocated and
+ * freed bytes in kernel_read_file_from_fd() calls for these type of
+ * failures. These failures can occur because:
+ *
+ * * module_sig_check() - module signature checks
+ * * elf_validity_cache_copy() - some ELF validation issue
+ * * early_mod_check():
+ *
+ * * blacklisting
+ * * failed to rewrite section headers
+ * * version magic
+ * * live patch requirements didn't check out
+ * * the module was detected as being already present
+ *
+ * * invalid_mod_bytes: these are the total number of bytes allocated and
+ * freed due to failures after we did all the sanity checks of the module
+ * which userspace passed to us and after our first check that the module
+ * is unique. A module can still fail to load if we detect the module is
+ * loaded after we allocate space for it with layout_and_allocate(), we do
+ * this check right before processing the module as live and run its
+ * initialization routines. Note that you have a failure of this type it
+ * also means the respective kernel_read_file_from_fd() memory space was
+ * also freed and not used, and so we increment this counter with twice
+ * the size of the module. Additionally if you used module decompression
+ * the size of the compressed module is also added to this counter.
+ *
+ * * modcount: how many modules we've loaded in our kernel life time
+ * * failed_kreads: how many modules failed due to failed kernel_read_file_from_fd()
+ * * failed_decompress: how many failed module decompression attempts we've had.
+ * These really should not happen unless your compression / decompression
+ * might be broken.
+ * * failed_becoming: how many modules failed after we kernel_read_file_from_fd()
+ * it and before we allocate memory for it with layout_and_allocate(). This
+ * counter is never incremented if you manage to validate the module and
+ * call layout_and_allocate() for it.
+ * * failed_load_modules: how many modules failed once we've allocated our
+ * private space for our module using layout_and_allocate(). These failures
+ * should hopefully mostly be dealt with already. Races in theory could
+ * still exist here, but it would just mean the kernel had started processing
+ * two threads concurrently up to early_mod_check() and one thread won.
+ * These failures are good signs the kernel or userspace is doing something
+ * seriously stupid or that could be improved. We should strive to fix these,
+ * but it is perhaps not easy to fix them. A recent example are the modules
+ * requests incurred for frequency modules, a separate module request was
+ * being issued for each CPU on a system.
+ */
+
+atomic_long_t total_mod_size;
+atomic_long_t total_text_size;
+atomic_long_t invalid_kread_bytes;
+atomic_long_t invalid_decompress_bytes;
+static atomic_long_t invalid_becoming_bytes;
+static atomic_long_t invalid_mod_bytes;
+atomic_t modcount;
+atomic_t failed_kreads;
+atomic_t failed_decompress;
+static atomic_t failed_becoming;
+static atomic_t failed_load_modules;
+
+static const char *mod_fail_to_str(struct mod_fail_load *mod_fail)
+{
+ if (test_bit(FAIL_DUP_MOD_BECOMING, &mod_fail->dup_fail_mask) &&
+ test_bit(FAIL_DUP_MOD_LOAD, &mod_fail->dup_fail_mask))
+ return "Becoming & Load";
+ if (test_bit(FAIL_DUP_MOD_BECOMING, &mod_fail->dup_fail_mask))
+ return "Becoming";
+ if (test_bit(FAIL_DUP_MOD_LOAD, &mod_fail->dup_fail_mask))
+ return "Load";
+ return "Bug-on-stats";
+}
+
+void mod_stat_bump_invalid(struct load_info *info, int flags)
+{
+ atomic_long_add(info->len * 2, &invalid_mod_bytes);
+ atomic_inc(&failed_load_modules);
+#if defined(CONFIG_MODULE_DECOMPRESS)
+ if (flags & MODULE_INIT_COMPRESSED_FILE)
+ atomic_long_add(info->compressed_len, &invalid_mod_bytes);
+#endif
+}
+
+void mod_stat_bump_becoming(struct load_info *info, int flags)
+{
+ atomic_inc(&failed_becoming);
+ atomic_long_add(info->len, &invalid_becoming_bytes);
+#if defined(CONFIG_MODULE_DECOMPRESS)
+ if (flags & MODULE_INIT_COMPRESSED_FILE)
+ atomic_long_add(info->compressed_len, &invalid_becoming_bytes);
+#endif
+}
+
+int try_add_failed_module(const char *name, enum fail_dup_mod_reason reason)
+{
+ struct mod_fail_load *mod_fail;
+
+ list_for_each_entry_rcu(mod_fail, &dup_failed_modules, list,
+ lockdep_is_held(&module_mutex)) {
+ if (!strcmp(mod_fail->name, name)) {
+ atomic_long_inc(&mod_fail->count);
+ __set_bit(reason, &mod_fail->dup_fail_mask);
+ goto out;
+ }
+ }
+
+ mod_fail = kzalloc(sizeof(*mod_fail), GFP_KERNEL);
+ if (!mod_fail)
+ return -ENOMEM;
+ memcpy(mod_fail->name, name, strlen(name));
+ __set_bit(reason, &mod_fail->dup_fail_mask);
+ atomic_long_inc(&mod_fail->count);
+ list_add_rcu(&mod_fail->list, &dup_failed_modules);
+out:
+ return 0;
+}
+
+/*
+ * At 64 bytes per module and assuming a 1024 bytes preamble we can fit the
+ * 112 module prints within 8k.
+ *
+ * 1024 + (64*112) = 8k
+ */
+#define MAX_PREAMBLE 1024
+#define MAX_FAILED_MOD_PRINT 112
+#define MAX_BYTES_PER_MOD 64
+static ssize_t read_file_mod_stats(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct mod_fail_load *mod_fail;
+ unsigned int len, size, count_failed = 0;
+ char *buf;
+ u32 live_mod_count, fkreads, fdecompress, fbecoming, floads;
+ unsigned long total_size, text_size, ikread_bytes, ibecoming_bytes,
+ idecompress_bytes, imod_bytes, total_virtual_lost;
+
+ live_mod_count = atomic_read(&modcount);
+ fkreads = atomic_read(&failed_kreads);
+ fdecompress = atomic_read(&failed_decompress);
+ fbecoming = atomic_read(&failed_becoming);
+ floads = atomic_read(&failed_load_modules);
+
+ total_size = atomic_long_read(&total_mod_size);
+ text_size = atomic_long_read(&total_text_size);
+ ikread_bytes = atomic_long_read(&invalid_kread_bytes);
+ idecompress_bytes = atomic_long_read(&invalid_decompress_bytes);
+ ibecoming_bytes = atomic_long_read(&invalid_becoming_bytes);
+ imod_bytes = atomic_long_read(&invalid_mod_bytes);
+
+ total_virtual_lost = ikread_bytes + idecompress_bytes + ibecoming_bytes + imod_bytes;
+
+ size = MAX_PREAMBLE + min((unsigned int)(floads + fbecoming),
+ (unsigned int)MAX_FAILED_MOD_PRINT) * MAX_BYTES_PER_MOD;
+ buf = kzalloc(size, GFP_KERNEL);
+ if (buf == NULL)
+ return -ENOMEM;
+
+ /* The beginning of our debug preamble */
+ len = scnprintf(buf, size, "%25s\t%u\n", "Mods ever loaded", live_mod_count);
+
+ len += scnprintf(buf + len, size - len, "%25s\t%u\n", "Mods failed on kread", fkreads);
+
+ len += scnprintf(buf + len, size - len, "%25s\t%u\n", "Mods failed on decompress",
+ fdecompress);
+ len += scnprintf(buf + len, size - len, "%25s\t%u\n", "Mods failed on becoming", fbecoming);
+
+ len += scnprintf(buf + len, size - len, "%25s\t%u\n", "Mods failed on load", floads);
+
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Total module size", total_size);
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Total mod text size", text_size);
+
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Failed kread bytes", ikread_bytes);
+
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Failed decompress bytes",
+ idecompress_bytes);
+
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Failed becoming bytes", ibecoming_bytes);
+
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Failed kmod bytes", imod_bytes);
+
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Virtual mem wasted bytes", total_virtual_lost);
+
+ if (live_mod_count && total_size) {
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Average mod size",
+ DIV_ROUND_UP(total_size, live_mod_count));
+ }
+
+ if (live_mod_count && text_size) {
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Average mod text size",
+ DIV_ROUND_UP(text_size, live_mod_count));
+ }
+
+ /*
+ * We use WARN_ON_ONCE() for the counters to ensure we always have parity
+ * for keeping tabs on a type of failure with one type of byte counter.
+ * The counters for imod_bytes does not increase for fkreads failures
+ * for example, and so on.
+ */
+
+ WARN_ON_ONCE(ikread_bytes && !fkreads);
+ if (fkreads && ikread_bytes) {
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Avg fail kread bytes",
+ DIV_ROUND_UP(ikread_bytes, fkreads));
+ }
+
+ WARN_ON_ONCE(ibecoming_bytes && !fbecoming);
+ if (fbecoming && ibecoming_bytes) {
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Avg fail becoming bytes",
+ DIV_ROUND_UP(ibecoming_bytes, fbecoming));
+ }
+
+ WARN_ON_ONCE(idecompress_bytes && !fdecompress);
+ if (fdecompress && idecompress_bytes) {
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Avg fail decomp bytes",
+ DIV_ROUND_UP(idecompress_bytes, fdecompress));
+ }
+
+ WARN_ON_ONCE(imod_bytes && !floads);
+ if (floads && imod_bytes) {
+ len += scnprintf(buf + len, size - len, "%25s\t%lu\n", "Average fail load bytes",
+ DIV_ROUND_UP(imod_bytes, floads));
+ }
+
+ /* End of our debug preamble header. */
+
+ /* Catch when we've gone beyond our expected preamble */
+ WARN_ON_ONCE(len >= MAX_PREAMBLE);
+
+ if (list_empty(&dup_failed_modules))
+ goto out;
+
+ len += scnprintf(buf + len, size - len, "Duplicate failed modules:\n");
+ len += scnprintf(buf + len, size - len, "%25s\t%15s\t%25s\n",
+ "Module-name", "How-many-times", "Reason");
+ mutex_lock(&module_mutex);
+
+
+ list_for_each_entry_rcu(mod_fail, &dup_failed_modules, list) {
+ if (WARN_ON_ONCE(++count_failed >= MAX_FAILED_MOD_PRINT))
+ goto out_unlock;
+ len += scnprintf(buf + len, size - len, "%25s\t%15lu\t%25s\n", mod_fail->name,
+ atomic_long_read(&mod_fail->count), mod_fail_to_str(mod_fail));
+ }
+out_unlock:
+ mutex_unlock(&module_mutex);
+out:
+ kfree(buf);
+ return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+#undef MAX_PREAMBLE
+#undef MAX_FAILED_MOD_PRINT
+#undef MAX_BYTES_PER_MOD
+
+static const struct file_operations fops_mod_stats = {
+ .read = read_file_mod_stats,
+ .open = simple_open,
+ .owner = THIS_MODULE,
+ .llseek = default_llseek,
+};
+
+#define mod_debug_add_ulong(name) debugfs_create_ulong(#name, 0400, mod_debugfs_root, (unsigned long *) &name.counter)
+#define mod_debug_add_atomic(name) debugfs_create_atomic_t(#name, 0400, mod_debugfs_root, &name)
+static int __init module_stats_init(void)
+{
+ mod_debug_add_ulong(total_mod_size);
+ mod_debug_add_ulong(total_text_size);
+ mod_debug_add_ulong(invalid_kread_bytes);
+ mod_debug_add_ulong(invalid_decompress_bytes);
+ mod_debug_add_ulong(invalid_becoming_bytes);
+ mod_debug_add_ulong(invalid_mod_bytes);
+
+ mod_debug_add_atomic(modcount);
+ mod_debug_add_atomic(failed_kreads);
+ mod_debug_add_atomic(failed_decompress);
+ mod_debug_add_atomic(failed_becoming);
+ mod_debug_add_atomic(failed_load_modules);
+
+ debugfs_create_file("stats", 0400, mod_debugfs_root, mod_debugfs_root, &fops_mod_stats);
+
+ return 0;
+}
+#undef mod_debug_add_ulong
+#undef mod_debug_add_atomic
+module_init(module_stats_init);
diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c
index 14fbea66f12f..a2b656b4e3d2 100644
--- a/kernel/module/strict_rwx.c
+++ b/kernel/module/strict_rwx.c
@@ -11,82 +11,25 @@
#include <linux/set_memory.h>
#include "internal.h"
-/*
- * LKM RO/NX protection: protect module's text/ro-data
- * from modification and any data from execution.
- *
- * General layout of module is:
- * [text] [read-only-data] [ro-after-init] [writable data]
- * text_size -----^ ^ ^ ^
- * ro_size ------------------------| | |
- * ro_after_init_size -----------------------------| |
- * size -----------------------------------------------------------|
- *
- * These values are always page-aligned (as is base) when
- * CONFIG_STRICT_MODULE_RWX is set.
- */
+static void module_set_memory(const struct module *mod, enum mod_mem_type type,
+ int (*set_memory)(unsigned long start, int num_pages))
+{
+ const struct module_memory *mod_mem = &mod->mem[type];
+
+ set_vm_flush_reset_perms(mod_mem->base);
+ set_memory((unsigned long)mod_mem->base, mod_mem->size >> PAGE_SHIFT);
+}
/*
* Since some arches are moving towards PAGE_KERNEL module allocations instead
- * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() independent of
+ * of PAGE_KERNEL_EXEC, keep module_enable_x() independent of
* CONFIG_STRICT_MODULE_RWX because they are needed regardless of whether we
* are strict.
*/
-static void frob_text(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- set_memory((unsigned long)layout->base,
- PAGE_ALIGN(layout->text_size) >> PAGE_SHIFT);
-}
-
-static void frob_rodata(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- set_memory((unsigned long)layout->base + layout->text_size,
- (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
-}
-
-static void frob_ro_after_init(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- set_memory((unsigned long)layout->base + layout->ro_size,
- (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
-}
-
-static void frob_writable_data(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- set_memory((unsigned long)layout->base + layout->ro_after_init_size,
- (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
-}
-
-static bool layout_check_misalignment(const struct module_layout *layout)
-{
- return WARN_ON(!PAGE_ALIGNED(layout->base)) ||
- WARN_ON(!PAGE_ALIGNED(layout->text_size)) ||
- WARN_ON(!PAGE_ALIGNED(layout->ro_size)) ||
- WARN_ON(!PAGE_ALIGNED(layout->ro_after_init_size)) ||
- WARN_ON(!PAGE_ALIGNED(layout->size));
-}
-
-bool module_check_misalignment(const struct module *mod)
-{
- if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
- return false;
-
- return layout_check_misalignment(&mod->core_layout) ||
- layout_check_misalignment(&mod->data_layout) ||
- layout_check_misalignment(&mod->init_layout);
-}
-
void module_enable_x(const struct module *mod)
{
- if (!PAGE_ALIGNED(mod->core_layout.base) ||
- !PAGE_ALIGNED(mod->init_layout.base))
- return;
-
- frob_text(&mod->core_layout, set_memory_x);
- frob_text(&mod->init_layout, set_memory_x);
+ for_class_mod_mem_type(type, text)
+ module_set_memory(mod, type, set_memory_x);
}
void module_enable_ro(const struct module *mod, bool after_init)
@@ -98,16 +41,13 @@ void module_enable_ro(const struct module *mod, bool after_init)
return;
#endif
- set_vm_flush_reset_perms(mod->core_layout.base);
- set_vm_flush_reset_perms(mod->init_layout.base);
- frob_text(&mod->core_layout, set_memory_ro);
-
- frob_rodata(&mod->data_layout, set_memory_ro);
- frob_text(&mod->init_layout, set_memory_ro);
- frob_rodata(&mod->init_layout, set_memory_ro);
+ module_set_memory(mod, MOD_TEXT, set_memory_ro);
+ module_set_memory(mod, MOD_INIT_TEXT, set_memory_ro);
+ module_set_memory(mod, MOD_RODATA, set_memory_ro);
+ module_set_memory(mod, MOD_INIT_RODATA, set_memory_ro);
if (after_init)
- frob_ro_after_init(&mod->data_layout, set_memory_ro);
+ module_set_memory(mod, MOD_RO_AFTER_INIT, set_memory_ro);
}
void module_enable_nx(const struct module *mod)
@@ -115,11 +55,8 @@ void module_enable_nx(const struct module *mod)
if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
return;
- frob_rodata(&mod->data_layout, set_memory_nx);
- frob_ro_after_init(&mod->data_layout, set_memory_nx);
- frob_writable_data(&mod->data_layout, set_memory_nx);
- frob_rodata(&mod->init_layout, set_memory_nx);
- frob_writable_data(&mod->init_layout, set_memory_nx);
+ for_class_mod_mem_type(type, data)
+ module_set_memory(mod, type, set_memory_nx);
}
int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
diff --git a/kernel/module/tracking.c b/kernel/module/tracking.c
index 26d812e07615..16742d1c630c 100644
--- a/kernel/module/tracking.c
+++ b/kernel/module/tracking.c
@@ -15,6 +15,7 @@
#include "internal.h"
static LIST_HEAD(unloaded_tainted_modules);
+extern struct dentry *mod_debugfs_root;
int try_add_tainted_module(struct module *mod)
{
@@ -120,12 +121,8 @@ static const struct file_operations unloaded_tainted_modules_fops = {
static int __init unloaded_tainted_modules_init(void)
{
- struct dentry *dir;
-
- dir = debugfs_create_dir("modules", NULL);
- debugfs_create_file("unloaded_tainted", 0444, dir, NULL,
+ debugfs_create_file("unloaded_tainted", 0444, mod_debugfs_root, NULL,
&unloaded_tainted_modules_fops);
-
return 0;
}
module_init(unloaded_tainted_modules_init);
diff --git a/kernel/module/tree_lookup.c b/kernel/module/tree_lookup.c
index 8ec5cfd60496..277197977d43 100644
--- a/kernel/module/tree_lookup.c
+++ b/kernel/module/tree_lookup.c
@@ -21,16 +21,16 @@
static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
{
- struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
+ struct module_memory *mod_mem = container_of(n, struct module_memory, mtn.node);
- return (unsigned long)layout->base;
+ return (unsigned long)mod_mem->base;
}
static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
{
- struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
+ struct module_memory *mod_mem = container_of(n, struct module_memory, mtn.node);
- return (unsigned long)layout->size;
+ return (unsigned long)mod_mem->size;
}
static __always_inline bool
@@ -77,32 +77,27 @@ static void __mod_tree_remove(struct mod_tree_node *node, struct mod_tree_root *
*/
void mod_tree_insert(struct module *mod)
{
- mod->core_layout.mtn.mod = mod;
- mod->init_layout.mtn.mod = mod;
-
- __mod_tree_insert(&mod->core_layout.mtn, &mod_tree);
- if (mod->init_layout.size)
- __mod_tree_insert(&mod->init_layout.mtn, &mod_tree);
-
-#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
- mod->data_layout.mtn.mod = mod;
- __mod_tree_insert(&mod->data_layout.mtn, &mod_data_tree);
-#endif
+ for_each_mod_mem_type(type) {
+ mod->mem[type].mtn.mod = mod;
+ if (mod->mem[type].size)
+ __mod_tree_insert(&mod->mem[type].mtn, &mod_tree);
+ }
}
void mod_tree_remove_init(struct module *mod)
{
- if (mod->init_layout.size)
- __mod_tree_remove(&mod->init_layout.mtn, &mod_tree);
+ for_class_mod_mem_type(type, init) {
+ if (mod->mem[type].size)
+ __mod_tree_remove(&mod->mem[type].mtn, &mod_tree);
+ }
}
void mod_tree_remove(struct module *mod)
{
- __mod_tree_remove(&mod->core_layout.mtn, &mod_tree);
- mod_tree_remove_init(mod);
-#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
- __mod_tree_remove(&mod->data_layout.mtn, &mod_data_tree);
-#endif
+ for_each_mod_mem_type(type) {
+ if (mod->mem[type].size)
+ __mod_tree_remove(&mod->mem[type].mtn, &mod_tree);
+ }
}
struct module *mod_find(unsigned long addr, struct mod_tree_root *tree)
diff --git a/kernel/params.c b/kernel/params.c
index 6e34ca89ebae..6a7548979aa9 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -948,7 +948,7 @@ static void module_kobj_release(struct kobject *kobj)
complete(mk->kobj_completion);
}
-struct kobj_type module_ktype = {
+const struct kobj_type module_ktype = {
.release = module_kobj_release,
.sysfs_ops = &module_sysfs_ops,
};
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 9644f6e5bf15..5bcb11ad50bf 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -89,7 +89,7 @@ static DEFINE_MUTEX(console_mutex);
* console_sem protects updates to console->seq and console_suspended,
* and also provides serialization for console printing.
*/
-static DEFINE_SEMAPHORE(console_sem);
+static DEFINE_SEMAPHORE(console_sem, 1);
HLIST_HEAD(console_list);
EXPORT_SYMBOL_GPL(console_list);
DEFINE_STATIC_SRCU(console_srcu);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 3b46dba3f69b..08155f652554 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -8006,8 +8006,7 @@ struct kallsyms_data {
* and returns 1 in case we resolved all the requested symbols,
* 0 otherwise.
*/
-static int kallsyms_callback(void *data, const char *name,
- struct module *mod, unsigned long addr)
+static int kallsyms_callback(void *data, const char *name, unsigned long addr)
{
struct kallsyms_data *args = data;
const char **sym;
diff --git a/kernel/trace/rv/reactor_panic.c b/kernel/trace/rv/reactor_panic.c
index d65f6c25a87c..0186ff4cbd0b 100644
--- a/kernel/trace/rv/reactor_panic.c
+++ b/kernel/trace/rv/reactor_panic.c
@@ -38,6 +38,5 @@ static void __exit unregister_react_panic(void)
module_init(register_react_panic);
module_exit(unregister_react_panic);
-MODULE_LICENSE("GPL");
MODULE_AUTHOR("Daniel Bristot de Oliveira");
MODULE_DESCRIPTION("panic rv reactor: panic if an exception is found.");
diff --git a/kernel/trace/rv/reactor_printk.c b/kernel/trace/rv/reactor_printk.c
index 4b6b7106a477..178759dbf89f 100644
--- a/kernel/trace/rv/reactor_printk.c
+++ b/kernel/trace/rv/reactor_printk.c
@@ -37,6 +37,5 @@ static void __exit unregister_react_printk(void)
module_init(register_react_printk);
module_exit(unregister_react_printk);
-MODULE_LICENSE("GPL");
MODULE_AUTHOR("Daniel Bristot de Oliveira");
MODULE_DESCRIPTION("printk rv reactor: printk if an exception is hit.");
diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c
index f10f403104e7..e91cb4c2833f 100644
--- a/kernel/watch_queue.c
+++ b/kernel/watch_queue.c
@@ -29,7 +29,6 @@
MODULE_DESCRIPTION("Watch queue");
MODULE_AUTHOR("Red Hat, Inc.");
-MODULE_LICENSE("GPL");
#define WATCH_QUEUE_NOTE_SIZE 128
#define WATCH_QUEUE_NOTES_PER_PAGE (PAGE_SIZE / WATCH_QUEUE_NOTE_SIZE)