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* Merge tag 'dma-mapping-5.7-1' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds2020-04-112-4/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | Pull dma-mapping fixes from Christoph Hellwig: - fix an integer truncation in dma_direct_get_required_mask (Kishon Vijay Abraham) - fix the display of dma mapping types (Grygorii Strashko) * tag 'dma-mapping-5.7-1' of git://git.infradead.org/users/hch/dma-mapping: dma-debug: fix displaying of dma allocation type dma-direct: fix data truncation in dma_direct_get_required_mask()
| * dma-debug: fix displaying of dma allocation typeGrygorii Strashko2020-04-081-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 2e05ea5cdc1a ("dma-mapping: implement dma_map_single_attrs using dma_map_page_attrs") removed "dma_debug_page" enum, but missed to update type2name string table. This causes incorrect displaying of dma allocation type. Fix it by removing "page" string from type2name string table and switch to use named initializers. Before (dma_alloc_coherent()): k3-ringacc 4b800000.ringacc: scather-gather idx 2208 P=d1140000 N=d114 D=d1140000 L=40 DMA_BIDIRECTIONAL dma map error check not applicable k3-ringacc 4b800000.ringacc: scather-gather idx 2216 P=d1150000 N=d115 D=d1150000 L=40 DMA_BIDIRECTIONAL dma map error check not applicable After: k3-ringacc 4b800000.ringacc: coherent idx 2208 P=d1140000 N=d114 D=d1140000 L=40 DMA_BIDIRECTIONAL dma map error check not applicable k3-ringacc 4b800000.ringacc: coherent idx 2216 P=d1150000 N=d115 D=d1150000 L=40 DMA_BIDIRECTIONAL dma map error check not applicable Fixes: 2e05ea5cdc1a ("dma-mapping: implement dma_map_single_attrs using dma_map_page_attrs") Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
| * dma-direct: fix data truncation in dma_direct_get_required_mask()Kishon Vijay Abraham I2020-04-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The upper 32-bit physical address gets truncated inadvertently when dma_direct_get_required_mask() invokes phys_to_dma_direct(). This results in dma_addressing_limited() return incorrect value when used in platforms with LPAE enabled. Fix it here by explicitly type casting 'max_pfn' to phys_addr_t in order to prevent overflow of intermediate value while evaluating '(max_pfn - 1) << PAGE_SHIFT'. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2020-04-112-3/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge yet more updates from Andrew Morton: - Almost all of the rest of MM (memcg, slab-generic, slab, pagealloc, gup, hugetlb, pagemap, memremap) - Various other things (hfs, ocfs2, kmod, misc, seqfile) * akpm: (34 commits) ipc/util.c: sysvipc_find_ipc() should increase position index kernel/gcov/fs.c: gcov_seq_next() should increase position index fs/seq_file.c: seq_read(): add info message about buggy .next functions drivers/dma/tegra20-apb-dma.c: fix platform_get_irq.cocci warnings change email address for Pali Rohár selftests: kmod: test disabling module autoloading selftests: kmod: fix handling test numbers above 9 docs: admin-guide: document the kernel.modprobe sysctl fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once() kmod: make request_module() return an error when autoloading is disabled mm/memremap: set caching mode for PCI P2PDMA memory to WC mm/memory_hotplug: add pgprot_t to mhp_params powerpc/mm: thread pgprot_t through create_section_mapping() x86/mm: introduce __set_memory_prot() x86/mm: thread pgprot_t through init_memory_mapping() mm/memory_hotplug: rename mhp_restrictions to mhp_params mm/memory_hotplug: drop the flags field from struct mhp_restrictions mm/special: create generic fallbacks for pte_special() and pte_mkspecial() mm/vma: introduce VM_ACCESS_FLAGS mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS ...
| * | kernel/gcov/fs.c: gcov_seq_next() should increase position indexVasily Averin2020-04-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If seq_file .next function does not change position index, read after some lseek can generate unexpected output. https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: NeilBrown <neilb@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Waiman Long <longman@redhat.com> Link: http://lkml.kernel.org/r/f65c6ee7-bd00-f910-2f8a-37cc67e4ff88@virtuozzo.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | kmod: make request_module() return an error when autoloading is disabledEric Biggers2020-04-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "module autoloading fixes and cleanups", v5. This series fixes a bug where request_module() was reporting success to kernel code when module autoloading had been completely disabled via 'echo > /proc/sys/kernel/modprobe'. It also addresses the issues raised on the original thread (https://lkml.kernel.org/lkml/20200310223731.126894-1-ebiggers@kernel.org/T/#u) bydocumenting the modprobe sysctl, adding a self-test for the empty path case, and downgrading a user-reachable WARN_ONCE(). This patch (of 4): It's long been possible to disable kernel module autoloading completely (while still allowing manual module insertion) by setting /proc/sys/kernel/modprobe to the empty string. This can be preferable to setting it to a nonexistent file since it avoids the overhead of an attempted execve(), avoids potential deadlocks, and avoids the call to security_kernel_module_request() and thus on SELinux-based systems eliminates the need to write SELinux rules to dontaudit module_request. However, when module autoloading is disabled in this way, request_module() returns 0. This is broken because callers expect 0 to mean that the module was successfully loaded. Apparently this was never noticed because this method of disabling module autoloading isn't used much, and also most callers don't use the return value of request_module() since it's always necessary to check whether the module registered its functionality or not anyway. But improperly returning 0 can indeed confuse a few callers, for example get_fs_type() in fs/filesystems.c where it causes a WARNING to be hit: if (!fs && (request_module("fs-%.*s", len, name) == 0)) { fs = __get_fs_type(name, len); WARN_ONCE(!fs, "request_module fs-%.*s succeeded, but still no fs?\n", len, name); } This is easily reproduced with: echo > /proc/sys/kernel/modprobe mount -t NONEXISTENT none / It causes: request_module fs-NONEXISTENT succeeded, but still no fs? WARNING: CPU: 1 PID: 1106 at fs/filesystems.c:275 get_fs_type+0xd6/0xf0 [...] This should actually use pr_warn_once() rather than WARN_ONCE(), since it's also user-reachable if userspace immediately unloads the module. Regardless, request_module() should correctly return an error when it fails. So let's make it return -ENOENT, which matches the error when the modprobe binary doesn't exist. I've also sent patches to document and test this case. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Jessica Yu <jeyu@kernel.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Ben Hutchings <benh@debian.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200310223731.126894-1-ebiggers@kernel.org Link: http://lkml.kernel.org/r/20200312202552.241885-1-ebiggers@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | printk: queue wake_up_klogd irq_work only if per-CPU areas are readySergey Senozhatsky2020-04-103-10/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | printk_deferred(), similarly to printk_safe/printk_nmi, does not immediately attempt to print a new message on the consoles, avoiding calls into non-reentrant kernel paths, e.g. scheduler or timekeeping, which potentially can deadlock the system. Those printk() flavors, instead, rely on per-CPU flush irq_work to print messages from safer contexts. For same reasons (recursive scheduler or timekeeping calls) printk() uses per-CPU irq_work in order to wake up user space syslog/kmsg readers. However, only printk_safe/printk_nmi do make sure that per-CPU areas have been initialised and that it's safe to modify per-CPU irq_work. This means that, for instance, should printk_deferred() be invoked "too early", that is before per-CPU areas are initialised, printk_deferred() will perform illegal per-CPU access. Lech Perczak [0] reports that after commit 1b710b1b10ef ("char/random: silence a lockdep splat with printk()") user-space syslog/kmsg readers are not able to read new kernel messages. The reason is printk_deferred() being called too early (as was pointed out by Petr and John). Fix printk_deferred() and do not queue per-CPU irq_work before per-CPU areas are initialized. Link: https://lore.kernel.org/lkml/aa0732c6-5c4e-8a8b-a1c1-75ebe3dca05b@camlintechnologies.com/ Reported-by: Lech Perczak <l.perczak@camlintechnologies.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Tested-by: Jann Horn <jannh@google.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: John Ogness <john.ogness@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2020-04-101-0/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull proc fix from Eric Biederman: "A brown paper bag slipped through my proc changes, and syzcaller caught it when the code ended up in your tree. I have opted to fix it the simplest cleanest way I know how, so there is no reasonable chance for the bug to repeat" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Use a dedicated lock in struct pid
| * | | proc: Use a dedicated lock in struct pidEric W. Biederman2020-04-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot wrote: > ======================================================== > WARNING: possible irq lock inversion dependency detected > 5.6.0-syzkaller #0 Not tainted > -------------------------------------------------------- > swapper/1/0 just changed the state of lock: > ffffffff898090d8 (tasklist_lock){.+.?}-{2:2}, at: send_sigurg+0x9f/0x320 fs/fcntl.c:840 > but this lock took another, SOFTIRQ-unsafe lock in the past: > (&pid->wait_pidfd){+.+.}-{2:2} > > > and interrupts could create inverse lock ordering between them. > > > other info that might help us debug this: > Possible interrupt unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&pid->wait_pidfd); > local_irq_disable(); > lock(tasklist_lock); > lock(&pid->wait_pidfd); > <Interrupt> > lock(tasklist_lock); > > *** DEADLOCK *** > > 4 locks held by swapper/1/0: The problem is that because wait_pidfd.lock is taken under the tasklist lock. It must always be taken with irqs disabled as tasklist_lock can be taken from interrupt context and if wait_pidfd.lock was already taken this would create a lock order inversion. Oleg suggested just disabling irqs where I have added extra calls to wait_pidfd.lock. That should be safe and I think the code will eventually do that. It was rightly pointed out by Christian that sharing the wait_pidfd.lock was a premature optimization. It is also true that my pre-merge window testing was insufficient. So remove the premature optimization and give struct pid a dedicated lock of it's own for struct pid things. I have verified that lockdep sees all 3 paths where we take the new pid->lock and lockdep does not complain. It is my current day dream that one day pid->lock can be used to guard the task lists as well and then the tasklist_lock won't need to be held to deliver signals. That will require taking pid->lock with irqs disabled. Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/lkml/00000000000011d66805a25cd73f@google.com/ Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Reported-by: syzbot+343f75cdeea091340956@syzkaller.appspotmail.com Reported-by: syzbot+832aabf700bc3ec920b9@syzkaller.appspotmail.com Reported-by: syzbot+f675f964019f884dbd0f@syzkaller.appspotmail.com Reported-by: syzbot+a9fb1457d720a55d6dc5@syzkaller.appspotmail.com Fixes: 7bc3e6e55acf ("proc: Use a list of inodes to flush from proc") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | | | Merge tag 'pm-5.7-rc1-3' of ↵Linus Torvalds2020-04-101-55/+46
|\ \ \ \ | |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "Rework compat ioctl handling in the user space hibernation interface (Christoph Hellwig) and fix a typo in a function name in the cpuidle haltpoll driver (Yihao Wu)" * tag 'pm-5.7-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpuidle-haltpoll: Fix small typo PM / sleep: handle the compat case in snapshot_set_swap_area() PM / sleep: move SNAPSHOT_SET_SWAP_AREA handling into a helper
| * | | PM / sleep: handle the compat case in snapshot_set_swap_area()Christoph Hellwig2020-04-061-32/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Use in_compat_syscall to copy directly from the 32-bit ABI structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | | PM / sleep: move SNAPSHOT_SET_SWAP_AREA handling into a helperChristoph Hellwig2020-04-061-28/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the handling of the SNAPSHOT_SET_SWAP_AREA ioctl from the main ioctl helper into a helper function. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | | | Merge tag 'modules-for-v5.7' of ↵Linus Torvalds2020-04-091-2/+2
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull module updates from Jessica Yu: "Only a small cleanup this time around: a trivial conversion of zero-length arrays to flexible arrays" * tag 'modules-for-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: kernel: module: Replace zero-length array with flexible-array member
| * | | kernel: module: Replace zero-length array with flexible-array memberGustavo A. R. Silva2020-02-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
* | | | kernel/gcov/fs.c: replace zero-length array with flexible-array memberGustavo A. R. Silva2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Link: http://lkml.kernel.org/r/20200302224851.GA26467@embeddedor Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | gcov: gcc_3_4: replace zero-length array with flexible-array memberGustavo A. R. Silva2020-04-071-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Link: http://lkml.kernel.org/r/20200302224501.GA14175@embeddedor Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | gcov: gcc_4_7: replace zero-length array with flexible-array memberGustavo A. R. Silva2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com> Link: http://lkml.kernel.org/r/20200213152241.GA877@embeddedor Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | kernel/kmod.c: fix a typo "assuems" -> "assumes"Qiujun Huang2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a typo in comment. Fix it. s/assuems/assumes/ Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Link: http://lkml.kernel.org/r/1585891029-6450-1-git-send-email-hqjagain@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()Will Deacon2020-04-071-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kallsyms_lookup_name() and kallsyms_on_each_symbol() are exported to modules despite having no in-tree users and being wide open to abuse by out-of-tree modules that can use them as a method to invoke arbitrary non-exported kernel functions. Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol(). Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Quentin Perret <qperret@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: http://lkml.kernel.org/r/20200221114404.14641-4-will@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | compiler: remove CONFIG_OPTIMIZE_INLINING entirelyMasahiro Yamada2020-04-071-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit ac7c3e4ff401 ("compiler: enable CONFIG_OPTIMIZE_INLINING forcibly") made this always-on option. We released v5.4 and v5.5 including that commit. Remove the CONFIG option and clean up the code now. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: David Miller <davem@davemloft.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200220110807.32534-2-masahiroy@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | kernel/extable.c: use address-of operator on section symbolsNathan Chancellor2020-04-071-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clang warns: ../kernel/extable.c:37:52: warning: array comparison always evaluates to a constant [-Wtautological-compare] if (main_extable_sort_needed && __stop___ex_table > __start___ex_table) { ^ 1 warning generated. These are not true arrays, they are linker defined symbols, which are just addresses. Using the address of operator silences the warning and does not change the resulting assembly with either clang/ld.lld or gcc/ld (tested with diff + objdump -Dr). Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: https://github.com/ClangBuiltLinux/linux/issues/892 Link: http://lkml.kernel.org/r/20200219202036.45702-1-natechancellor@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | proc: faster open/read/close with "permanent" filesAlexey Dobriyan2020-04-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that "struct proc_ops" exist we can start putting there stuff which could not fly with VFS "struct file_operations"... Most of fs/proc/inode.c file is dedicated to make open/read/.../close reliable in the event of disappearing /proc entries which usually happens if module is getting removed. Files like /proc/cpuinfo which never disappear simply do not need such protection. Save 2 atomic ops, 1 allocation, 1 free per open/read/close sequence for such "permanent" files. Enable "permanent" flag for /proc/cpuinfo /proc/kmsg /proc/modules /proc/slabinfo /proc/stat /proc/sysvipc/* /proc/swaps More will come once I figure out foolproof way to prevent out module authors from marking their stuff "permanent" for performance reasons when it is not. This should help with scalability: benchmark is "read /proc/cpuinfo R times by N threads scattered over the system". N R t, s (before) t, s (after) ----------------------------------------------------- 64 4096 1.582458 1.530502 -3.2% 256 4096 6.371926 6.125168 -3.9% 1024 4096 25.64888 24.47528 -4.6% Benchmark source: #include <chrono> #include <iostream> #include <thread> #include <vector> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> const int NR_CPUS = sysconf(_SC_NPROCESSORS_ONLN); int N; const char *filename; int R; int xxx = 0; int glue(int n) { cpu_set_t m; CPU_ZERO(&m); CPU_SET(n, &m); return sched_setaffinity(0, sizeof(cpu_set_t), &m); } void f(int n) { glue(n % NR_CPUS); while (*(volatile int *)&xxx == 0) { } for (int i = 0; i < R; i++) { int fd = open(filename, O_RDONLY); char buf[4096]; ssize_t rv = read(fd, buf, sizeof(buf)); asm volatile ("" :: "g" (rv)); close(fd); } } int main(int argc, char *argv[]) { if (argc < 4) { std::cerr << "usage: " << argv[0] << ' ' << "N /proc/filename R "; return 1; } N = atoi(argv[1]); filename = argv[2]; R = atoi(argv[3]); for (int i = 0; i < NR_CPUS; i++) { if (glue(i) == 0) break; } std::vector<std::thread> T; T.reserve(N); for (int i = 0; i < N; i++) { T.emplace_back(f, i); } auto t0 = std::chrono::system_clock::now(); { *(volatile int *)&xxx = 1; for (auto& t: T) { t.join(); } } auto t1 = std::chrono::system_clock::now(); std::chrono::duration<double> dt = t1 - t0; std::cout << dt.count() << ' '; return 0; } P.S.: Explicit randomization marker is added because adding non-function pointer will silently disable structure layout randomization. [akpm@linux-foundation.org: coding style fixes] Reported-by: kbuild test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Joe Perches <joe@perches.com> Link: http://lkml.kernel.org/r/20200222201539.GA22576@avx2 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | mm/vma: replace all remaining open encodings with is_vm_hugetlb_page()Anshuman Khandual2020-04-071-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This replaces all remaining open encodings with is_vm_hugetlb_page(). Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Will Deacon <will@kernel.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Nick Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Paul Burton <paulburton@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/1582520593-30704-4-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | mm/vma: make vma_is_accessible() available for general useAnshuman Khandual2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lets move vma_is_accessible() helper to include/linux/mm.h which makes it available for general use. While here, this replaces all remaining open encodings for VMA access check with vma_is_accessible(). Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Guo Ren <guoren@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Guo Ren <guoren@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paulburton@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Nick Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/1582520593-30704-3-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | mm: set vm_next and vm_prev to NULL in vm_area_dup()Li Xinhai2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set ->vm_next and ->vm_prev to NULL to prevent potential misuse from the new duplicated vma. Currently, only in fork path there are misuse for handling anon_vma. No other bugs been revealed with this patch applied. Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Link: http://lkml.kernel.org/r/1581150928-3214-4-git-send-email-lixinhai.lxh@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | mm: don't prepare anon_vma if vma has VM_WIPEONFORKLi Xinhai2020-04-071-3/+5
| |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm: Fix misuse of parent anon_vma in dup_mmap path". This patchset fixes the misuse of parenet anon_vma, which mainly caused by child vma's vm_next and vm_prev are left same as its parent after duplicate vma. Finally, code reached parent vma's neighbor by referring pointer of child vma and executed wrong logic. The first two patches fix relevant issues, and the third patch sets vm_next and vm_prev to NULL when duplicate vma to prevent potential misuse in future. Effects of the first bug is that causes rmap code to check both parent and child's page table, although a page couldn't be mapped by both parent and child, because child vma has WIPEONFORK so all pages mapped by child are 'new' and not relevant to parent. Effects of the second bug is that the relationship of anon_vma of parent and child are totallyconvoluted. It would cause 'son', 'grandson', ..., etc, to share 'parent' anon_vma, which disobey the design rule of reusing anon_vma (the rule to be followed is that reusing should among vma of same process, and vma should not gone through fork). So, both issues should cause unnecessary rmap walking and have unexpected complexity. These two issues would not be directly visible, I used debugging code to check the anon_vma pointers of parent and child when inspecting the suspicious implementation of issue #2, then find the problem. This patch (of 3): In dup_mmap(), anon_vma_prepare() is called for vma has VM_WIPEONFORK, and parameter 'tmp' (i.e., the new vma of child) has same ->vm_next and ->vm_prev as its parent vma. That allows anon_vma used by parent been mistakenly shared by child (find_mergeable_anon_vma() will do this reuse work). Besides this issue, call anon_vma_prepare() should be avoided because we don't copy page for this vma. Preparing anon_vma will be handled during fault. Fixes: d2cd9ede6e19 ("mm,fork: introduce MADV_WIPEONFORK") Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Link: http://lkml.kernel.org/r/1581150928-3214-2-git-send-email-lixinhai.lxh@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'pm-5.7-rc1-2' of ↵Linus Torvalds2020-04-062-1/+8
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "Additional power management updates. These fix a corner-case suspend-to-idle wakeup issue on systems where the ACPI SCI is shared with another wakeup source, add a kernel command line option to set pm_debug_messages via the kernel command line, add a document desctibing system-wide suspend and resume code flows, modify cpufreq Kconfig to choose schedutil as the preferred governor by default in a couple of cases and do some assorted cleanups. Specifics: - Fix corner-case suspend-to-idle wakeup issue on systems where the ACPI SCI is shared with another wakeup source (Hans de Goede). - Add document describing system-wide suspend and resume code flows to the admin guide (Rafael Wysocki). - Add kernel command line option to set pm_debug_messages (Chen Yu). - Choose schedutil as the preferred scaling governor by default on ARM big.LITTLE systems and on x86 systems using the intel_pstate driver in the passive mode (Linus Walleij, Rafael Wysocki). - Drop racy and redundant checks from the PM core's device_prepare() routine (Rafael Wysocki). - Make resume from hibernation take the hibernation_restore() return value into account (Dexuan Cui)" * tag 'pm-5.7-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: platform/x86: intel_int0002_vgpio: Use acpi_register_wakeup_handler() ACPI: PM: Add acpi_[un]register_wakeup_handler() Documentation: PM: sleep: Document system-wide suspend code flows cpufreq: Select schedutil when using big.LITTLE PM: sleep: Add pm_debug_messages kernel command line option PM: sleep: core: Drop racy and redundant checks from device_prepare() PM: hibernate: Propagate the return value of hibernation_restore() cpufreq: intel_pstate: Select schedutil as the default governor
| * | | PM: sleep: Add pm_debug_messages kernel command line optionChen Yu2020-04-021-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Debug messages from the system suspend/hibernation infrastructure are disabled by default, and can only be enabled after the system has boot up via /sys/power/pm_debug_messages. This makes the hibernation resume hard to track as it involves system boot up across hibernation. There's no chance for software_resume() to track the resume process, for example. Add a kernel command line option to set pm_debug_messages during boot up. Signed-off-by: Chen Yu <yu.c.chen@intel.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | | PM: hibernate: Propagate the return value of hibernation_restore()Dexuan Cui2020-04-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If hibernation_restore() fails, the 'error' should not be zero. Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | | | Merge tag 'fsnotify_for_v5.7-rc1' of ↵Linus Torvalds2020-04-062-25/+4
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify updates from Jan Kara: "This implements the fanotify FAN_DIR_MODIFY event. This event reports the name in a directory under which a change happened and together with the directory filehandle and fstatat() allows reliable and efficient implementation of directory synchronization" * tag 'fsnotify_for_v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fanotify: Fix the checks in fanotify_fsid_equal fanotify: report name info for FAN_DIR_MODIFY event fanotify: record name info for FAN_DIR_MODIFY event fanotify: Drop fanotify_event_has_fid() fanotify: prepare to report both parent and child fid's fanotify: send FAN_DIR_MODIFY event flavor with dir inode and name fanotify: divorce fanotify_path_event and fanotify_fid_event fanotify: Store fanotify handles differently fanotify: Simplify create_fd() fanotify: fix merging marks masks with FAN_ONDIR fanotify: merge duplicate events on parent and child fsnotify: replace inode pointer with an object id fsnotify: simplify arguments passing to fsnotify_parent() fsnotify: use helpers to access data by data_type fsnotify: funnel all dirent events through fsnotify_name() fsnotify: factor helpers fsnotify_dentry() and fsnotify_file() fsnotify: tidy up FS_ and FAN_ constants
| * | | | fsnotify: use helpers to access data by data_typeAmir Goldstein2020-03-232-25/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create helpers to access path and inode from different data types. Link: https://lore.kernel.org/r/20200319151022.31456-5-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
* | | | | Merge tag 'perf-urgent-2020-04-05' of ↵Linus Torvalds2020-04-051-0/+133
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more perf updates from Thomas Gleixner: "Perf updates all over the place: core: - Support for cgroup tracking in samples to allow cgroup based analysis tools: - Support for cgroup analysis - Commandline option and hotkey for perf top to change the sort order - A set of fixes all over the place - Various build system related improvements - Updates of the X86 pmu event JSON data - Documentation updates" * tag 'perf-urgent-2020-04-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits) perf python: Fix clang detection to strip out options passed in $CC perf tools: Support Python 3.8+ in Makefile perf script: Fix invalid read of directory entry after closedir() perf script report: Fix SEGFAULT when using DWARF mode perf script: add -S/--symbols documentation perf pmu-events x86: Use CPU_CLK_UNHALTED.THREAD in Kernel_Utilization metric perf events parser: Add missing Intel CPU events to parser perf script: Allow --symbol to accept hexadecimal addresses perf report/top TUI: Fix title line formatting perf top: Support hotkey to change sort order perf top: Support --group-sort-idx to change the sort order perf symbols: Fix arm64 gap between kernel start and module end perf build-test: Honour JOBS to override detection of number of cores perf script: Add --show-cgroup-events option perf top: Add --all-cgroups option perf record: Add --all-cgroups option perf record: Support synthesizing cgroup events perf report: Add 'cgroup' sort key perf cgroup: Maintain cgroup hierarchy perf tools: Basic support for CGROUP event ...
| * \ \ \ \ Merge tag 'perf-urgent-for-mingo-5.7-20200403' of ↵Ingo Molnar2020-04-041-0/+133
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes and improvements from Arnaldo Carvalho de Melo: perf python: Arnaldo Carvalho de Melo: - Fix clang detection to strip out options passed in $CC. build: He Zhe: - Normalize gcc parameter when generating arch errno table, fixing the build by removing options from $(CC). Sam Lunt: - Support Python 3.8+ in Makefile. perf report/top: Arnaldo Carvalho de Melo: - Fix title line formatting. perf script: Andreas Gerstmayr: - Fix SEGFAULT when using DWARF mode. - Fix invalid read of directory entry after closedir(), found with valgrind. Hagen Paul Pfeifer: - Introduce --deltatime option. Stephane Eranian: - Allow --symbol to accept hexadecimal addresses. Ian Rogers: - Add -S/--symbols documentation Namhyung Kim: - Add --show-cgroup-events option. perf python: Arnaldo Carvalho de Melo: - Include rwsem.c in the python binding, needed by the cgroups improvements. build-test: Arnaldo Carvalho de Melo: - Honour JOBS to override detection of number of cores perf top: Jin Yao: - Support --group-sort-idx to change the sort order - perf top: Support hotkey to change sort order perf pmu-events x86: Jin Yao: - Use CPU_CLK_UNHALTED.THREAD in Kernel_Utilization metric perf symbols arm64: Kemeng Shi: - Fix arm64 gap between kernel start and module end kernel perf subsystem: Namhyung Kim: - Add PERF_RECORD_CGROUP event and Add PERF_SAMPLE_CGROUP feature, to allow cgroup tracking, saving a link between cgroup path and its id number. perf cgroup: Namhyung Kim: - Maintain cgroup hierarchy. perf report: Namhyung Kim: - Add 'cgroup' sort key. perf record: Namhyung Kim: - Support synthesizing cgroup events for pre-existing cgroups. - Add --all-cgroups option Documentation: Tony Jones: - Update docs regarding kernel/user space unwinding. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | | perf/core: Add PERF_SAMPLE_CGROUP featureNamhyung Kim2020-03-271-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PERF_SAMPLE_CGROUP bit is to save (perf_event) cgroup information in the sample. It will add a 64-bit id to identify current cgroup and it's the file handle in the cgroup file system. Userspace should use this information with PERF_RECORD_CGROUP event to match which cgroup it belongs. I put it before PERF_SAMPLE_AUX for simplicity since it just needs a 64-bit word. But if we want bigger samples, I can work on that direction too. Committer testing: $ pahole perf_sample_data | grep -w cgroup -B5 -A5 /* --- cacheline 4 boundary (256 bytes) was 56 bytes ago --- */ struct perf_regs regs_intr; /* 312 16 */ /* --- cacheline 5 boundary (320 bytes) was 8 bytes ago --- */ u64 stack_user_size; /* 328 8 */ u64 phys_addr; /* 336 8 */ u64 cgroup; /* 344 8 */ /* size: 384, cachelines: 6, members: 22 */ /* padding: 32 */ }; $ Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lore.kernel.org/lkml/20200325124536.2800725-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | | perf/core: Add PERF_RECORD_CGROUP eventNamhyung Kim2020-03-271-0/+111
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To support cgroup tracking, add CGROUP event to save a link between cgroup path and id number. This is needed since cgroups can go away when userspace tries to read the cgroup info (from the id) later. The attr.cgroup bit was also added to enable cgroup tracking from userspace. This event will be generated when a new cgroup becomes active. Userspace might need to synthesize those events for existing cgroups. Committer testing: From the resulting kernel, using /sys/kernel/btf/vmlinux: $ pahole perf_event_attr | grep -w cgroup -B5 -A1 __u64 write_backward:1; /* 40:27 8 */ __u64 namespaces:1; /* 40:28 8 */ __u64 ksymbol:1; /* 40:29 8 */ __u64 bpf_event:1; /* 40:30 8 */ __u64 aux_output:1; /* 40:31 8 */ __u64 cgroup:1; /* 40:32 8 */ __u64 __reserved_1:31; /* 40:33 8 */ $ Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> [staticize perf_event_cgroup function] Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lore.kernel.org/lkml/20200325124536.2800725-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | | | | | | Merge tag 'timers-urgent-2020-04-05' of ↵Linus Torvalds2020-04-051-2/+3
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "Two timer subsystem fixes: - Prevent a use after free in the new lockdep state tracking for hrtimers - Add missing parenthesis in the VF pit timer driver" * tag 'timers-urgent-2020-04-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource/drivers/timer-vf-pit: Add missing parenthesis hrtimer: Don't dereference the hrtimer pointer after the callback
| * | | | | | | hrtimer: Don't dereference the hrtimer pointer after the callbackSebastian Andrzej Siewior2020-04-011-2/+3
| |/ / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A hrtimer can be released in its callback, but lockdep_hrtimer_exit() dereferences the pointer after the callback returns, i.e. a potential use after free. Retrieve the context in which the hrtimer expires before the callback is invoked and use it in lockdep_hrtimer_exit(). Fixes: 40db173965c0 ("lockdep: Add hrtimer context tracing bits") Reported-by: syzbot+62c155c276e580cfb606@syzkaller.appspotmail.com Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200331201849.fkp2siy3vcdqvqlz@linutronix.de
* | | | | | | Merge tag 'trace-v5.7' of ↵Linus Torvalds2020-04-0510-205/+714
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "New tracing features: - The ring buffer is no longer disabled when reading the trace file. The trace_pipe file was made to be used for live tracing and reading as it acted like the normal producer/consumer. As the trace file would not consume the data, the easy way of handling it was to just disable writes to the ring buffer. This came to a surprise to the BPF folks who complained about lost events due to reading. This is no longer an issue. If someone wants to keep the old disabling there's a new option "pause-on-trace" that can be set. - New set_ftrace_notrace_pid file. PIDs in this file will not be traced by the function tracer. Similar to set_ftrace_pid, which makes the function tracer only trace those tasks with PIDs in the file, the set_ftrace_notrace_pid does the reverse. - New set_event_notrace_pid file. PIDs in this file will cause events not to be traced if triggered by a task with a matching PID. Similar to the set_event_pid file but will not be traced. Note, sched_waking and sched_switch events may still be traced if one of the tasks referenced by those events contains a PID that is allowed to be traced. Tracing related features: - New bootconfig option, that is attached to the initrd file. If bootconfig is on the command line, then the initrd file is searched looking for a bootconfig appended at the end. - New GPU tracepoint infrastructure to help the gfx drivers to get off debugfs (acked by Greg Kroah-Hartman) And other minor updates and fixes" * tag 'trace-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits) tracing: Do not allocate buffer in trace_find_next_entry() in atomic tracing: Add documentation on set_ftrace_notrace_pid and set_event_notrace_pid selftests/ftrace: Add test to test new set_event_notrace_pid file selftests/ftrace: Add test to test new set_ftrace_notrace_pid file tracing: Create set_event_notrace_pid to not trace tasks ftrace: Create set_ftrace_notrace_pid to not trace tasks ftrace: Make function trace pid filtering a bit more exact ftrace/kprobe: Show the maxactive number on kprobe_events tracing: Have the document reflect that the trace file keeps tracing enabled ring-buffer/tracing: Have iterator acknowledge dropped events tracing: Do not disable tracing when reading the trace file ring-buffer: Do not disable recording when there is an iterator ring-buffer: Make resize disable per cpu buffer instead of total buffer ring-buffer: Optimize rb_iter_head_event() ring-buffer: Do not die if rb_iter_peek() fails more than thrice ring-buffer: Have rb_iter_head_event() handle concurrent writer ring-buffer: Add page_stamp to iterator for synchronization ring-buffer: Rename ring_buffer_read() to read_buffer_iter_advance() ring-buffer: Have ring_buffer_empty() not depend on tracing stopped tracing: Save off entry when peeking at next entry ...
| * | | | | | | tracing: Do not allocate buffer in trace_find_next_entry() in atomicSteven Rostedt (VMware)2020-04-031-1/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When dumping out the trace data in latency format, a check is made to peek at the next event to compare its timestamp to the current one, and if the delta is of a greater size, it will add a marker showing so. But to do this, it needs to save the current event otherwise peeking at the next event will remove the current event. To save the event, a temp buffer is used, and if the event is bigger than the temp buffer, the temp buffer is freed and a bigger buffer is allocated. This allocation is a problem when called in atomic context. The only way this gets called via atomic context is via ftrace_dump(). Thus, use a static buffer of 128 bytes (which covers most events), and if the event is bigger than that, simply return NULL. The callers of trace_find_next_entry() need to handle a NULL case, as that's what would happen if the allocation failed. Link: https://lore.kernel.org/r/20200326091256.GR11705@shao2-debian Fixes: ff895103a84ab ("tracing: Save off entry when peeking at next entry") Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | tracing: Create set_event_notrace_pid to not trace tasksSteven Rostedt (VMware)2020-03-273-72/+244
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's currently a way to select a task that should only have its events traced, but there's no way to select a task not to have itsevents traced. Add a set_event_notrace_pid file that acts the same as set_event_pid (and is also affected by event-fork), but the task pids in this file will not be traced even if they are listed in the set_event_pid file. This makes it easy for tools like trace-cmd to "hide" itself from beint traced by events when it is recording other tasks. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | ftrace: Create set_ftrace_notrace_pid to not trace tasksSteven Rostedt (VMware)2020-03-274-35/+180
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's currently a way to select a task that should only be traced by functions, but there's no way to select a task not to be traced by the function tracer. Add a set_ftrace_notrace_pid file that acts the same as set_ftrace_pid (and is also affected by function-fork), but the task pids in this file will not be traced even if they are listed in the set_ftrace_pid file. This makes it easy for tools like trace-cmd to "hide" itself from the function tracer when it is recording other tasks. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | ftrace: Make function trace pid filtering a bit more exactSteven Rostedt (VMware)2020-03-272-9/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The set_ftrace_pid file is used to filter function tracing to only trace tasks that are listed in that file. Instead of testing the pids listed in that file (it's a bitmask) at each function trace event, the logic is done via a sched_switch hook. A flag is set when the next task to run is in the list of pids in the set_ftrace_pid file. But the sched_switch hook is not at the exact location of when the task switches, and the flag gets set before the task to be traced actually runs. This leaves a residue of traced functions that do not belong to the pid that should be filtered on. By changing the logic slightly, where instead of having a boolean flag to test, record the pid that should be traced, with special values for not to trace and always trace. Then at each function call, a check will be made to see if the function should be ignored, or if the current pid matches the function that should be traced, and only trace if it matches (or if it has the special value to always trace). Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | ftrace/kprobe: Show the maxactive number on kprobe_eventsMasami Hiramatsu2020-03-271-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Show maxactive parameter on kprobe_events. This allows user to save the current configuration and restore it without losing maxactive parameter. Link: http://lkml.kernel.org/r/4762764a-6df7-bc93-ed60-e336146dce1f@gmail.com Link: http://lkml.kernel.org/r/158503528846.22706.5549974121212526020.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: 696ced4fb1d76 ("tracing/kprobes: expose maxactive for kretprobe in kprobe_events") Reported-by: Taeung Song <treeze.taeung@gmail.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | ring-buffer/tracing: Have iterator acknowledge dropped eventsSteven Rostedt (VMware)2020-03-272-4/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Have the ring_buffer_iterator set a flag if events were dropped as it were to go and peek at the next event. Have the trace file display this fact if it happened with a "LOST EVENTS" message. Link: http://lkml.kernel.org/r/20200317213417.045858900@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | tracing: Do not disable tracing when reading the trace fileSteven Rostedt (VMware)2020-03-272-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When opening the "trace" file, it is no longer necessary to disable tracing. Note, a new option is created called "pause-on-trace", when set, will cause the trace file to emulate its original behavior. Link: http://lkml.kernel.org/r/20200317213416.903351225@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Do not disable recording when there is an iteratorSteven Rostedt (VMware)2020-03-271-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the iterator can handle a concurrent writer, do not disable writing to the ring buffer when there is an iterator present. Link: http://lkml.kernel.org/r/20200317213416.759770696@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Make resize disable per cpu buffer instead of total bufferSteven Rostedt (VMware)2020-03-271-13/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the ring buffer becomes writable for even when the trace file is read, it must still not be resized. But since tracers can be activated while the trace file is being read, the irqsoff tracer can modify the per CPU buffers, and this can cause the reader of the trace file to update the wrong buffer's resize disable bit, as the irqsoff tracer swaps out cpu buffers. By making the resize disable per cpu_buffer, it makes the update follow the per cpu_buffer even if it's swapped out with the snapshot buffer and keeps the release of the trace file modifying the same data as the open did. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Optimize rb_iter_head_event()Steven Rostedt (VMware)2020-03-201-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As it is fine to perform several "peeks" of event data in the ring buffer via the iterator before moving it forward, do not re-read the event, just return what was read before. Otherwise, it can cause inconsistent results, especially when testing multiple CPU buffers to interleave them. Link: http://lkml.kernel.org/r/20200317213416.592032170@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Do not die if rb_iter_peek() fails more than thriceSteven Rostedt (VMware)2020-03-201-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As the iterator will be reading a live buffer, and if the event being read is on a page that a writer crosses, it will fail and try again, the condition in rb_iter_peek() that only allows a retry to happen three times is no longer valid. Allow rb_iter_peek() to retry more than three times without killing the ring buffer, but only if rb_iter_head_event() had failed at least once. Link: http://lkml.kernel.org/r/20200317213416.452888193@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Have rb_iter_head_event() handle concurrent writerSteven Rostedt (VMware)2020-03-201-31/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Have the ring_buffer_iter structure have a place to store an event, such that it can not be overwritten by a writer, and load it in such a way via rb_iter_head_event() that it will return NULL and reset the iter to the start of the current page if a writer updated the page. Link: http://lkml.kernel.org/r/20200317213416.306959216@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>