| Commit message (Collapse) | Author | Files | Lines |
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Many new generic allocation functions like the kvmalloc family have been
added recently to the kernel.
The allocation functions test now includes:
o kvmalloc and variants
o kstrdup_const
o kmemdup_nul
o dma_alloc_coherent
o alloc_skb and variants
Add a separate $allocFunctions variable to help make the allocation
functions test a bit more readable.
Miscellanea:
o Use $allocFunctions in the unnecessary OOM message test and
add exclude uses with __GFP_NOWARN
o Use $allocFunctions in the unnecessary cast test
o Add the kvmalloc family to the preferred sizeof alloc style
foo = kvmalloc(sizeof(*foo), ...)
Link: http://lkml.kernel.org/r/a5e60a2b93e10baf84af063f6c8e56402273105d.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Using SPDX commenting style // or /* is specified for various file types
in Documentation/process/license-rules.rst so add an appropriate test for
.[chsS] files because many proposed file additions and patches do not use
the correct style.
Link: http://lkml.kernel.org/r/8b02899853247a2c67669561761f354dd3bd110e.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The test_fw_config->reqs allocation succeeded so these addresses can't
be NULL.
Also on the second error path, we forgot to set "rc = -ENOMEM;".
Link: http://lkml.kernel.org/r/20190221183700.GA1737@kadam
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
This patch fixes the following warning:
lib/assoc_array.c: In function `assoc_array_delete':
lib/assoc_array.c:1110:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
for (slot = 0; slot < ASSOC_ARRAY_FAN_OUT; slot++) {
^~~
lib/assoc_array.c:1118:2: note: here
case assoc_array_walk_tree_empty:
^~~~
Warning level 3 was used: -Wimplicit-fallthrough=3
This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.
Link: http://lkml.kernel.org/r/20190212212206.GA16378@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Since we now build with -Wvla, any use of VLA throws a warning.
Including this test, so... maybe we should just remove the test?
lib/test_ubsan.c: In function 'test_ubsan_vla_bound_not_positive':
lib/test_ubsan.c:48:2: warning: ISO C90 forbids variable length array 'buf' [-Wvla]
For the out-of-bounds test, switch to non-VLA setup.
lib/test_ubsan.c: In function 'test_ubsan_out_of_bounds':
lib/test_ubsan.c:64:2: warning: ISO C90 forbids variable length array 'arr' [-Wvla]
Link: http://lkml.kernel.org/r/20190113183210.56154-1-olof@lixom.net
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Jinbum Park <jinb.park7@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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fls counts bits starting from 1 to 32 (returns 0 for zero argument). If
we add 1 we shift right one bit more and loose precision from divisor,
what cause function incorect results with some numbers.
Corrected code was tested in user-space, see bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=202391
Link: http://lkml.kernel.org/r/1548686944-11891-1-git-send-email-sgruszka@redhat.com
Fixes: 658716d19f8f ("div64_u64(): improve precision on 32bit platforms")
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Reported-by: Siarhei Volkau <lis8215@gmail.com>
Tested-by: Siarhei Volkau <lis8215@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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| > Also, set_mask_bits is used in fs quite a bit and we can possibly come up
| > with a generic llsc based implementation (w/o the cmpxchg loop)
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| May I also suggest changing the return value of set_mask_bits() to old.
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| You can compute the new value given old, but you cannot compute the old
| value given new, therefore old is the better return value. Also, no
| current user seems to use the return value, so changing it is without
| risk.
Link: http://lkml.kernel.org/g/20150807110955.GH16853@twins.programming.kicks-ass.net
Link: http://lkml.kernel.org/r/1548275584-18096-4-git-send-email-vgupta@synopsys.com
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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With coming changes on x86-64, all dynamic debug descriptors in a
translation unit must have distinct names. The macro _dynamic_func_call
takes care of that. No functional change.
Link: http://lkml.kernel.org/r/20190212214150.4807-15-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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If CONFIG_DYNAMIC_DEBUG is not set, acpi_handle_debug directly invokes
acpi_handle_printk (if DEBUG) or does a no-printk (if !DEBUG). So this
macro is never used.
Link: http://lkml.kernel.org/r/20190212214150.4807-14-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jason Baron <jbaron@akamai.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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dynamic debug may be implemented via static keys, but ACPI is missing
out on that runtime benefit since it open-codes one possible definition
of DYNAMIC_DEBUG_BRANCH.
Link: http://lkml.kernel.org/r/20190212214150.4807-13-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jason Baron <jbaron@akamai.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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First, the btrfs_debug macros open-code (one possible definition of)
DYNAMIC_DEBUG_BRANCH, so they don't benefit from the CONFIG_JUMP_LABEL
optimization.
Second, a planned change of struct _ddebug (to reduce its size on 64 bit
machines) requires that all descriptors in a translation unit use
distinct identifiers.
Using the new _dynamic_func_call_no_desc helper macro from
dynamic_debug.h takes care of both of these. No functional change.
Link: http://lkml.kernel.org/r/20190212214150.4807-12-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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For the upcoming 'define the _ddebug descriptor in assembly', we need
all the descriptors in a translation unit to have distinct names
(because asm does not understand C scope). The easiest way to achieve
that is as usual with an extra level of macros, passing the identifier
to use to the innermost macro, generating it via __UNIQUE_ID or
something.
However, instead of repeating that exercise for dynamic_pr_debug,
dynamic_dev_dbg, dynamic_netdev_dbg and dynamic_hex_dump separately, we
can use the similarity between their bodies to implement them via a
common macro, _dynamic_func_call - though the hex_dump case requires a
slight variant, since print_hex_dump does not take the _ddebug
descriptor. We'll also get to use that variant elsewhere (btrfs).
Link: http://lkml.kernel.org/r/20190212214150.4807-11-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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For symmetry with ddebug_remove_module, and to avoid a bit of ifdeffery
in module.c, move the declaration of ddebug_add_module inside #if
defined(CONFIG_DYNAMIC_DEBUG) and add a corresponding no-op stub in the
#else branch.
Link: http://lkml.kernel.org/r/20190212214150.4807-10-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This serves two purposes: First, we get a diagnostic if (though
extremely unlikely), any of the calls of ddebug_add_module for built-in
code fails, effectively disabling dynamic_debug. Second, I want to make
struct _ddebug opaque, and avoid accessing any of its members outside
dynamic_debug.[ch].
Link: http://lkml.kernel.org/r/20190212214150.4807-9-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The only caller of ddebug_{add,remove}_module outside dynamic_debug.c is
kernel/module.c, which is obviously not itself modular (though it would
be an interesting exercise to make that happen...). I also fail to see
how these interfaces can be used by modules, in-tree or not.
Link: http://lkml.kernel.org/r/20190212214150.4807-8-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Now that we store the passed-in string directly in ddebug_add_module, we
can use pointer equality instead of strcmp. This is a little more
efficient, but more importantly, this also makes the code somewhat more
correct:
Currently, if one loads and then unloads a module whose name happens to
match the KBUILD_MODNAME of some built-in functionality (which need not
even be modular at all), all of their dynamic debug entries vanish along
with those of the actual module. For example, loading and unloading a
core.ko hides all pr_debugs from drivers/base/core.c and other built-in
files called core.c (incidentally, there is an in-tree module whose name
is core, but I just tested this with an out-of-tree trivial one).
Link: http://lkml.kernel.org/r/20190212214150.4807-7-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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For built-in modules, we're already reusing the passed-in string via
kstrdup_const(). But for actual modules (i.e. when we're called from
dynamic_debug_setup in module.c), the passed-in string (which points at
the name[] array inside struct module) is also guaranteed to live at
least as long as the struct ddebug_table, since free_module() calls
ddebug_remove_module().
Link: http://lkml.kernel.org/r/20190212214150.4807-6-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Instead of defining DEFINE_DYNAMIC_DEBUG_METADATA in terms of a helper
DEFINE_DYNAMIC_DEBUG_METADATA_KEY, that needs another helper dd_key_init
to be properly defined, just make the various #ifdef branches define a
_DPRINTK_KEY_INIT that can be used directly, similar to
_DPRINTK_FLAGS_DEFAULT.
Link: http://lkml.kernel.org/r/20190212214150.4807-5-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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pr_debug_ratelimited tests the dynamic debug descriptor the
old-fashioned way, and doesn't utilize the static key/jump label
implementation when CONFIG_JUMP_LABEL is set. Use the
DYNAMIC_DEBUG_BRANCH which is defined appropriately.
Link: http://lkml.kernel.org/r/20190212214150.4807-4-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Petr Mladek <pmladek@suse.com>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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net_dbg_ratelimited tests the dynamic debug descriptor the old-fashioned
way, and doesn't utilize the static key/jump label implementation when
CONFIG_JUMP_LABEL is set. Use the DYNAMIC_DEBUG_BRANCH which is defined
appropriately.
Link: http://lkml.kernel.org/r/20190212214150.4807-3-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Patch series "various dynamic_debug patches", v4.
This started as an experiment to see how hard it would be to change the
four pointers in struct _ddebug into relative offsets, a la
CONFIG_GENERIC_BUG_RELATIVE_POINTERS, thus saving 16 bytes per pr_debug
site (and thus exactly making up for the extra space used by the
introduction of jump labels in 9049fc74). I stumbled on a few things
that are probably worth fixing regardless of whether that goal is deemed
worthwhile.
Back at v3 (in November), I redid the implementation on top of the fancy
new asm-macros stuff. Luckily enough, v3 didn't get picked up, since
the asm-macros were backed out again. I still want to do the
relative-pointers thing eventually, but we're close to the merge window
opening, so here's just most of the "incidental" patches, some of which
also serve as preparation for the relative pointers.
This patch (of 4):
dev_dbg_ratelimited tests the dynamic debug descriptor the old-fashioned
way, and doesn't utilize the static key/jump label implementation when
CONFIG_JUMP_LABEL is set. Use the DYNAMIC_DEBUG_BRANCH which is defined
appropriately.
Link: http://lkml.kernel.org/r/20190212214150.4807-2-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Commit 95846ecf9dac ("pid: replace pid bitmap implementation with IDR
API") removed next_pidmap() but left its declaration.
Remove it. No functional change.
Link: http://lkml.kernel.org/r/20190213113736.21922-1-namit@vmware.com
Signed-off-by: Nadav Amit <namit@vmware.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gargi Sharma <gs051095@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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<linux/kernel.h> tends to be cluttered because we often put various sort
of unrelated stuff in it. So, we have split out a sensible chunk of
code into a separate header from time to time.
This commit splits out the *_MAX and *_MIN defines.
The standard header <limits.h> contains various MAX, MIN constants
including numerial limits. [1]
I think it makes sense to move in-kernel MAX, MIN constants into
include/linux/limits.h.
We already have include/uapi/linux/limits.h to contain some user-space
constants. I changed its include guard to _UAPI_LINUX_LIMITS_H. This
change has no impact to the user-space because
scripts/headers_install.sh rips off the '_UAPI' prefix from the include
guards of exported headers.
[1] http://pubs.opengroup.org/onlinepubs/009604499/basedefs/limits.h.html
Link: http://lkml.kernel.org/r/1549156242-20806-2-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Alex Elder <elder@linaro.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The commit log of 44f564a4bf6a ("ipc: add definitions of USHORT_MAX and
others") did not explain why it used (s16) and (u16) instead of (short)
and (unsigned short).
Let's use (short) and (unsigned short), which is more sensible, and more
consistent with the other MAX/MIN defines.
As you see in include/uapi/asm-generic/int-ll64.h, s16/u16 are
typedef'ed as signed/unsigned short. So, this commit does not have a
functional change.
Remove the unneeded parentheses around ~0U while we are here.
Link: http://lkml.kernel.org/r/1549156242-20806-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Zhang Yanmin <yanmin.zhang@intel.com>
Cc: Alex Elder <elder@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Instead of doing this compile-time check in some slightly arbitrary user
of struct filename, put it next to the definition.
Link: http://lkml.kernel.org/r/20190208203015.29702-3-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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At the time of commit d048419311ff ("lib/vsprintf.c: expand field_width
to 24 bits"), there was no compiletime_assert/BUILD_BUG/.... variant
that could be used outside function scope. Now we have static_assert(),
so move the assertion next to the definition instead of hiding it in
some arbitrary function.
Also add the appropriate #include to avoid relying on build_bug.h being
pulled in via some arbitrary chain of includes.
Link: http://lkml.kernel.org/r/20190208203015.29702-2-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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BUILD_BUG_ON() is a little annoying, since it cannot be used outside
function scope. So one cannot put assertions about the sizeof() a
struct next to the struct definition, but has to hide that in some more
or less arbitrary function.
Since gcc 4.6 (which is now also the required minimum), there is support
for the C11 _Static_assert in all C modes, including gnu89. So add a
simple wrapper for that.
_Static_assert() requires a message argument, which is usually quite
redundant (and I believe that bug got fixed at least in newer C++
standards), but we can easily work around that with a little macro
magic, making it optional.
For example, adding
static_assert(sizeof(struct printf_spec) == 8);
in vsprintf.c and modifying that struct to violate it, one gets
./include/linux/build_bug.h:78:41: error: static assertion failed: "sizeof(struct printf_spec) == 8"
#define __static_assert(expr, msg, ...) _Static_assert(expr, "" msg "")
godbolt.org suggests that _Static_assert() has been support by clang
since at least 3.0.0.
Link: http://lkml.kernel.org/r/20190208203015.29702-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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Here are some of the more common spelling mistakes and typos that I've
found while fixing up spelling mistakes in the kernel over the past 4
months.
Link: http://lkml.kernel.org/r/20190114110215.1986-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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There is a plan to build the kernel with -Wimplicit-fallthrough and this
place in the code produced a warning (W=1).
This commit remove the following warning:
kernel/sys.c:1748:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
Link: http://lkml.kernel.org/r/20190114203347.17530-1-malat@debian.org
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Since commit a2e514453861 ("kernel/hung_task.c: allow to set checking
interval separately from timeout") added hung_task_check_interval_secs,
setting a value different from hung_task_timeout_secs
echo 0 > /proc/sys/kernel/hung_task_panic
echo 120 > /proc/sys/kernel/hung_task_timeout_secs
echo 5 > /proc/sys/kernel/hung_task_check_interval_secs
causes confusing output as if the task was blocked for
hung_task_timeout_secs seconds from the previous report.
[ 399.395930] INFO: task kswapd0:75 blocked for more than 120 seconds.
[ 405.027637] INFO: task kswapd0:75 blocked for more than 120 seconds.
[ 410.659725] INFO: task kswapd0:75 blocked for more than 120 seconds.
[ 416.292860] INFO: task kswapd0:75 blocked for more than 120 seconds.
[ 421.932305] INFO: task kswapd0:75 blocked for more than 120 seconds.
Although we could update t->last_switch_time after sched_show_task(t) if
we want to report only every 120 seconds, reporting every 5 seconds
might not be very bad for monitoring after a problematic situation has
started. Thus, let's use continuously blocked time instead of updating
previously reported time.
[ 677.985011] INFO: task kswapd0:80 blocked for more than 122 seconds.
[ 693.856126] INFO: task kswapd0:80 blocked for more than 138 seconds.
[ 709.728075] INFO: task kswapd0:80 blocked for more than 154 seconds.
[ 725.600018] INFO: task kswapd0:80 blocked for more than 170 seconds.
[ 741.473133] INFO: task kswapd0:80 blocked for more than 186 seconds.
Link: http://lkml.kernel.org/r/1551175083-10669-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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sparse complains:
CHECK kernel/hung_task.c
kernel/hung_task.c:28:19: warning: symbol 'sysctl_hung_task_check_count' was not declared. Should it be static?
kernel/hung_task.c:42:29: warning: symbol 'sysctl_hung_task_timeout_secs' was not declared. Should it be static?
kernel/hung_task.c:47:29: warning: symbol 'sysctl_hung_task_check_interval_secs' was not declared. Should it be static?
kernel/hung_task.c:49:19: warning: symbol 'sysctl_hung_task_warnings' was not declared. Should it be static?
kernel/hung_task.c:61:28: warning: symbol 'sysctl_hung_task_panic' was not declared. Should it be static?
kernel/hung_task.c:219:5: warning: symbol 'proc_dohung_task_timeout_secs' was not declared. Should it be static?
Add the appropriate header file to provide declarations.
Link: http://lkml.kernel.org/r/467.1548649525@turing-police.cc.vt.edu
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Use "unsigned int" instead of "unsigned", to make code more clear.
Link: http://lkml.kernel.org/r/1551354739-6648-1-git-send-email-wdjjwb@163.com
Signed-off-by: WangBo <wang.bo116@zte.com.cn>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The single quotation marks around "const" were causing a documentation
markup warning with reST. Instead of fixing that warning, just delete
that comment line and the gcc-3.3 hack of using "const" in the roundup()
macro since gcc-3.3 is no longer supported for kernel builds.
I did around 20 different $arch builds with no problems, but we'll just
have to see if this causes problems for anyone else out there.
Link: http://lkml.kernel.org/r/ec5dcf72-7c3e-3513-af0c-4003ed598854@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE for
debugfs files.
Semantic patch information:
Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file()
imposes some significant overhead as compared to
DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe().
Generated by: scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci
The _unsafe() part suggests that some of them "safeness
responsibilities" are now panic.c responsibilities. The patch is OK
since panic's clear_warn_once_fops struct file_operations is safe
against removal, so we don't have to use otherwise necessary
debugfs_file_get()/debugfs_file_put().
[sergey.senozhatsky.work@gmail.com: changelog addition]
Link: http://lkml.kernel.org/r/1545990861-158097-1-git-send-email-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Include asm/div64.h for do_div() usage in DIV_ROUND_DOWN_ULL() and
DIV_ROUND_CLOSEST_ULL(). Remove the old CONFIG_LBDAF=y conditional
include.
Link: http://lkml.kernel.org/r/20181228153430.23763-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The pm8xxx_get_channel() implementation is unclear, and causes gcc to
suddenly generate odd warnings. The trigger for the warning (at least
for me) was the entirely unrelated commit 79a4e91d1bb2 ("device.h: Add
__cold to dev_<level> logging functions"), which apparently changes gcc
code generation in the caller function enough to cause this:
drivers/iio/adc/qcom-pm8xxx-xoadc.c: In function ‘pm8xxx_xoadc_probe’:
drivers/iio/adc/qcom-pm8xxx-xoadc.c:633:8: warning: ‘ch’ may be used uninitialized in this function [-Wmaybe-uninitialized]
ret = pm8xxx_read_channel_rsv(adc, ch, AMUX_RSV4,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
&read_nomux_rsv4, true);
~~~~~~~~~~~~~~~~~~~~~~~
drivers/iio/adc/qcom-pm8xxx-xoadc.c:426:27: note: ‘ch’ was declared here
struct pm8xxx_chan_info *ch;
^~
because gcc for some reason then isn't able to see that the termination
condition for the "for( )" loop in that function is also the condition
for returning NULL.
So it's not _actually_ uninitialized, but the function is admittedly
just unnecessarily oddly written.
Simplify and clarify the function, making gcc also see that it always
returns a valid initialized value.
Cc: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: David Brown <david.brown@linaro.org>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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As John Stultz noticed, my y2038 syscall series caused a link
failure when CONFIG_SYSVIPC is disabled but CONFIG_COMPAT is
enabled:
arch/arm64/kernel/sys32.o:(.rodata+0x960): undefined reference to `__arm64_compat_sys_old_semctl'
arch/arm64/kernel/sys32.o:(.rodata+0x980): undefined reference to `__arm64_compat_sys_old_msgctl'
arch/arm64/kernel/sys32.o:(.rodata+0x9a0): undefined reference to `__arm64_compat_sys_old_shmctl'
Add the missing entries in kernel/sys_ni.c for the new system
calls.
Cc: Laura Abbott <labbott@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Remove duplicate header which is included twice.
Link: http://lkml.kernel.org/r/20190304182719.GA6606@jordon-HP-15-Notebook-PC
Signed-off-by: Sabyasachi Gupta <sabyasachi.linux@gmail.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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/proc may not be mounted and test will exit successfully.
Ensure proc is mounted at /proc.
Link: http://lkml.kernel.org/r/20190209105613.GA10384@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Start testing VM related fiels found in per-process files.
Do it by jiting small executable which brings its address space to
precisely known state, then comparing /proc/*/maps, smaps, smaps_rollup,
and statm files to expected values.
Currently only x86_64 is supported.
[adobriyan@gmail.com: exit correctly in /proc/*/maps test]
Link: http://lkml.kernel.org/r/20190206073659.GB15311@avx2
Link: http://lkml.kernel.org/r/20190203165806.GA14568@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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seq_printf() without format specifiers == faster seq_puts()
Link: http://lkml.kernel.org/r/20190114200545.GC9680@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Help gcc generate better code:
$ ./scripts/bloat-o-meter ../vmlinux-000 ../vmlinux-001
add/remove: 2/2 grow/shrink: 0/1 up/down: 92/-142 (-50)
Function old new delta
get_iowait_time.isra - 46 +46
get_idle_time.isra - 46 +46
show_stat 1489 1477 -12
get_iowait_time 65 - -65
get_idle_time 65 - -65
Link: http://lkml.kernel.org/r/20190114195907.GA9680@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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[adobriyan@gmail.com: delete "extern" from prototype]
Link: http://lkml.kernel.org/r/20190114195635.GA9372@avx2
Signed-off-by: Zhikang Zhang <zhangzhikang1@huawei.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Remove unnecessary ERR_PTR()/PTR_ERR() cast in proc_setup_thread_self().
Link: http://lkml.kernel.org/r/20190124030150.8472-2-cgxu519@gmx.com
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Remove unnecessary ERR_PTR()/PTR_ERR() cast in proc_setup_self().
Link: http://lkml.kernel.org/r/20190124030150.8472-1-cgxu519@gmx.com
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Test harness uses 4 for SKIP, not 2.
Link: http://lkml.kernel.org/r/20190108193108.GA12259@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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When using mremap() syscall in addition to MREMAP_FIXED flag, mremap()
calls mremap_to() which does the following:
1) unmaps the destination region where we are going to move the map
2) If the new region is going to be smaller, we unmap the last part
of the old region
Then, we will eventually call move_vma() to do the actual move.
move_vma() checks whether we are at least 4 maps below max_map_count
before going further, otherwise it bails out with -ENOMEM. The problem
is that we might have already unmapped the vma's in steps 1) and 2), so
it is not possible for userspace to figure out the state of the vmas
after it gets -ENOMEM, and it gets tricky for userspace to clean up
properly on error path.
While it is true that we can return -ENOMEM for more reasons (e.g: see
may_expand_vm() or move_page_tables()), I think that we can avoid this
scenario if we check early in mremap_to() if the operation has high
chances to succeed map-wise.
Should that not be the case, we can bail out before we even try to unmap
anything, so we make sure the vma's are left untouched in case we are
likely to be short of maps.
The thumb-rule now is to rely on the worst-scenario case we can have.
That is when both vma's (old region and new region) are going to be
split in 3, so we get two more maps to the ones we already hold (one per
each). If current map count + 2 maps still leads us to 4 maps below the
threshold, we are going to pass the check in move_vma().
Of course, this is not free, as it might generate false positives when
it is true that we are tight map-wise, but the unmap operation can
release several vma's leading us to a good state.
Another approach was also investigated [1], but it may be too much
hassle for what it brings.
[1] https://lore.kernel.org/lkml/20190219155320.tkfkwvqk53tfdojt@d104.suse.de/
Link: http://lkml.kernel.org/r/20190226091314.18446-1-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Cyril Hrubis <chrubis@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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next_present_section_nr() could only return an unsigned number -1, so
just check it specifically where compilers will convert -1 to unsigned
if needed.
mm/sparse.c: In function 'sparse_init_nid':
mm/sparse.c:200:20: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
((section_nr >= 0) && \
^~
mm/sparse.c:478:2: note: in expansion of macro
'for_each_present_section_nr'
for_each_present_section_nr(pnum_begin, pnum) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/sparse.c:200:20: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
((section_nr >= 0) && \
^~
mm/sparse.c:497:2: note: in expansion of macro
'for_each_present_section_nr'
for_each_present_section_nr(pnum_begin, pnum) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/sparse.c: In function 'sparse_init':
mm/sparse.c:200:20: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
((section_nr >= 0) && \
^~
mm/sparse.c:520:2: note: in expansion of macro
'for_each_present_section_nr'
for_each_present_section_nr(pnum_begin + 1, pnum_end) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~
Link: http://lkml.kernel.org/r/20190228181839.86504-1-cai@lca.pw
Fixes: c4e1be9ec113 ("mm, sparsemem: break out of loops early")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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LTP testcase mtest06 [1] can trigger a crash on s390x running 5.0.0-rc8.
This is a stress test, where one thread mmaps/writes/munmaps memory area
and other thread is trying to read from it:
CPU: 0 PID: 2611 Comm: mmap1 Not tainted 5.0.0-rc8+ #51
Hardware name: IBM 2964 N63 400 (z/VM 6.4.0)
Krnl PSW : 0404e00180000000 00000000001ac8d8 (__lock_acquire+0x7/0x7a8)
Call Trace:
([<0000000000000000>] (null))
[<00000000001adae4>] lock_acquire+0xec/0x258
[<000000000080d1ac>] _raw_spin_lock_bh+0x5c/0x98
[<000000000012a780>] page_table_free+0x48/0x1a8
[<00000000002f6e54>] do_fault+0xdc/0x670
[<00000000002fadae>] __handle_mm_fault+0x416/0x5f0
[<00000000002fb138>] handle_mm_fault+0x1b0/0x320
[<00000000001248cc>] do_dat_exception+0x19c/0x2c8
[<000000000080e5ee>] pgm_check_handler+0x19e/0x200
page_table_free() is called with NULL mm parameter, but because "0" is a
valid address on s390 (see S390_lowcore), it keeps going until it
eventually crashes in lockdep's lock_acquire. This crash is
reproducible at least since 4.14.
Problem is that "vmf->vma" used in do_fault() can become stale. Because
mmap_sem may be released, other threads can come in, call munmap() and
cause "vma" be returned to kmem cache, and get zeroed/re-initialized and
re-used:
handle_mm_fault |
__handle_mm_fault |
do_fault |
vma = vmf->vma |
do_read_fault |
__do_fault |
vma->vm_ops->fault(vmf); |
mmap_sem is released |
|
| do_munmap()
| remove_vma_list()
| remove_vma()
| vm_area_free()
| # vma is released
| ...
| # same vma is allocated
| # from kmem cache
| do_mmap()
| vm_area_alloc()
| memset(vma, 0, ...)
|
pte_free(vma->vm_mm, ...); |
page_table_free |
spin_lock_bh(&mm->context.lock);|
<crash> |
Cache mm_struct to avoid using potentially stale "vma".
[1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/mem/mtest06/mmap1.c
Link: http://lkml.kernel.org/r/5b3fdf19e2a5be460a384b936f5b56e13733f1b8.1551595137.git.jstancek@redhat.com
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Rafael Aquini <aquini@redhat.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Commit 682aa8e1a6a1 ("writeback: implement unlocked_inode_to_wb
transaction and use it for stat updates") refers to
inode_switch_wb_work_fn() which never got merged.
Switch the comments to inode_switch_wbs_work_fn().
Link: http://lkml.kernel.org/r/20190305004617.142590-1-gthelen@google.com
Fixes: 682aa8e1a6a1 ("writeback: implement unlocked_inode_to_wb transaction and use it for stat updates")
Signed-off-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|