Commit Graph

616086 Commits

Author SHA1 Message Date
Kees Cook
0036d1f7eb binfmt_elf: fix calculations for bss padding
A double-bug exists in the bss calculation code, where an overflow can
happen in the "last_bss - elf_bss" calculation, but vm_brk internally
aligns the argument, underflowing it, wrapping back around safe.  We
shouldn't depend on these bugs staying in sync, so this cleans up the
bss padding handling to avoid the overflow.

This moves the bss padzero() before the last_bss > elf_bss case, since
the zero-filling of the ELF_PAGE should have nothing to do with the
relationship of last_bss and elf_bss: any trailing portion should be
zeroed, and a zero size is already handled by padzero().

Then it handles the math on elf_bss vs last_bss correctly.  These need
to both be ELF_PAGE aligned to get the comparison correct, since that's
the expected granularity of the mappings.  Since elf_bss already had
alignment-based padding happen in padzero(), the "start" of the new
vm_brk() should be moved forward as done in the original code.  However,
since the "end" of the vm_brk() area will already become PAGE_ALIGNed in
vm_brk() then last_bss should get aligned here to avoid hiding it as a
side-effect.

Additionally makes a cosmetic change to the initial last_bss calculation
so it's easier to read in comparison to the load_addr calculation above
it (i.e.  the only difference is p_filesz vs p_memsz).

Link: http://lkml.kernel.org/r/1468014494-25291-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Ismael Ripoll Ripoll <iripoll@upv.es>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:14 -04:00
Allen Hubbe
45107ff6d5 checkpatch: if no filenames then read stdin
If no filenames are given, then read the patch from stdin.

Link: http://lkml.kernel.org/r/a8784f291ccb5067361992bf5d41ff6cfb0ce5cb.1469830917.git.allenbh@gmail.com
Signed-off-by: Allen Hubbe <allenbh@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:13 -04:00
Allen Hubbe
ed43c4e58a checkpatch: check signoff when reading stdin
Signoff was not checked if the filename is '-', indicating reading the
patch from stdin.  Commands such as the below would not warn about a
missing signoff, because the patch filename is '-'.  This change allows
checkpatch to warn about a missing signoff, even if the input filename
is '-', but only if the patch has a commit message.

  git show --pretty=email | scripts/checkpatch.pl -

A more common use of checkpatch with stdin is for piping git diff
through checkpatch.  The diff output would not contain a commit message,
and therefore it would not contain a signoff line.  For this common use
case, a warning should not be printed about the missing signoff.  With
this change we will only warn about a missing signoff if the input
contains a commit message.

  git diff | scripts/checkpatch.pl -

Before this patch, a workaround for the first command was to refer to
stdin by a name other than '-'.  The workaround is not an elegant
solution, because elsewhere checkpatch uses the fact that filename
equals '-', such as in setting '$vname' to 'Your patch' for stdin.  The
command below would report "/dev/stdin has style problems" instead of
"Your patch has style problems."

  git show --pretty=email | scripts/checkpatch.pl /dev/stdin

Link: http://lkml.kernel.org/r/48be31e414bddc65bccfa6b1322359be9ba032eb.1469670589.git.allenbh@gmail.com
Signed-off-by: Allen Hubbe <allenbh@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:13 -04:00
Joe Perches
c844711575 checkpatch: improve 'bare use of' signed/unsigned types warning
Fix false positive warning of identifiers ending in signed with an =
assignment of WARNING: Prefer 'signed int' to bare use of 'signed'.

Link: http://lkml.kernel.org/r/6a0e24c3e9102337528ecfcbbe91a0eb5b4820ed.1469529497.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Alan Douglas <alanjhd@gmail.com>
Acked-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:12 -04:00
Tomas Winkler
cec3aaa566 checkpatch: don't complain about BIT macro in uapi
BIT macro cannot be exported to UAPI, don't complain about it.

Link: http://lkml.kernel.org/r/1468707033-16173-1-git-send-email-tomas.winkler@intel.com
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:12 -04:00
Joe Perches
aab38f516a checkpatch: yet another commit id improvement
Using \b isn't good enough to isolate what appears to be a commit id in
a commit message.

Make sure there is a space or a quote like character after a continuous
run of hexadecimal characters that could be a commit id.

Link: http://lkml.kernel.org/r/fdd22b47463a21c21132edbb8aa35e372950a1e6.1468869915.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: "Zhuo, Qiuxu" <qiuxu.zhuo@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:11 -04:00
Joe Perches
dadf680de3 checkpatch: allow c99 style // comments
Sanitise the lines that contain c99 comments so that the error doesn't
get emitted.

Link: http://lkml.kernel.org/r/d4d22c34ad7bcc1bceb52f0742f76b7a6d585235.1468368420.git.joe@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>
2016-08-02 19:35:11 -04:00
Joe Perches
d560a5f8a4 checkpatch: skip long lines that use an EFI_GUID macro
These are also possible single line uses that exceed the generic maximum
line length (typically 80 columns)

Link: http://lkml.kernel.org/r/32a6a85fbd6161f1bb55ce176a464e44591afc5b.1468368420.git.joe@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>
2016-08-02 19:35:10 -04:00
Stephen Boyd
a098ecd2fa firmware: support loading into a pre-allocated buffer
Some systems are memory constrained but they need to load very large
firmwares.  The firmware subsystem allows drivers to request this
firmware be loaded from the filesystem, but this requires that the
entire firmware be loaded into kernel memory first before it's provided
to the driver.  This can lead to a situation where we map the firmware
twice, once to load the firmware into kernel memory and once to copy the
firmware into the final resting place.

This creates needless memory pressure and delays loading because we have
to copy from kernel memory to somewhere else.  Let's add a
request_firmware_into_buf() API that allows drivers to request firmware
be loaded directly into a pre-allocated buffer.  This skips the
intermediate step of allocating a buffer in kernel memory to hold the
firmware image while it's read from the filesystem.  It also requires
that drivers know how much memory they'll require before requesting the
firmware and negates any benefits of firmware caching because the
firmware layer doesn't manage the buffer lifetime.

For a 16MB buffer, about half the time is spent performing a memcpy from
the buffer to the final resting place.  I see loading times go from
0.081171 seconds to 0.047696 seconds after applying this patch.  Plus
the vmalloc pressure is reduced.

This is based on a patch from Vikram Mulukutla on codeaurora.org:
  https://www.codeaurora.org/cgit/quic/la/kernel/msm-3.18/commit/drivers/base/firmware_class.c?h=rel/msm-3.18&id=0a328c5f6cd999f5c591f172216835636f39bcb5

Link: http://lkml.kernel.org/r/20160607164741.31849-4-stephen.boyd@linaro.org
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Vikram Mulukutla <markivx@codeaurora.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Ming Lei <ming.lei@canonical.com>
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>
2016-08-02 19:35:10 -04:00
Vikram Mulukutla
0e742e9275 firmware: provide infrastructure to make fw caching optional
Some low memory systems with complex peripherals cannot afford to have
the relatively large firmware images taking up valuable memory during
suspend and resume.  Change the internal implementation of
firmware_class to disallow caching based on a configurable option.  In
the near future, variants of request_firmware will take advantage of
this feature.

Link: http://lkml.kernel.org/r/20160607164741.31849-3-stephen.boyd@linaro.org
[stephen.boyd@linaro.org: Drop firmware_desc design and use flags]
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Ming Lei <ming.lei@canonical.com>
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>
2016-08-02 19:35:09 -04:00
Stephen Boyd
9ccf981198 firmware: consolidate kmap/read/write logic
Some systems are memory constrained but they need to load very large
firmwares.  The firmware subsystem allows drivers to request this
firmware be loaded from the filesystem, but this requires that the
entire firmware be loaded into kernel memory first before it's provided
to the driver.  This can lead to a situation where we map the firmware
twice, once to load the firmware into kernel memory and once to copy the
firmware into the final resting place.

This design creates needless memory pressure and delays loading because
we have to copy from kernel memory to somewhere else.  This patch sets
adds support to the request firmware API to load the firmware directly
into a pre-allocated buffer, skipping the intermediate copying step and
alleviating memory pressure during firmware loading.  The drawback is
that we can't use the firmware caching feature because the memory for
the firmware cache is not managed by the firmware layer.

This patch (of 3):

We use similar structured code to read and write the kmapped firmware
pages.  The only difference is read copies from the kmap region and
write copies to it.  Consolidate this into one function to reduce
duplication.

Link: http://lkml.kernel.org/r/20160607164741.31849-2-stephen.boyd@linaro.org
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Vikram Mulukutla <markivx@codeaurora.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Ming Lei <ming.lei@canonical.com>
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>
2016-08-02 19:35:09 -04:00
Ross Zwisler
a23216a2f1 radix-tree: fix comment about "exceptional" bits
The bottom two bits of radix tree entries are reserved for special use
by the radix tree code itself.  A comment detailing their usage was
added by commit 3bcadd6fa6 ("radix-tree: free up the bottom bit of
exceptional entries for reuse")

This comment states that if the bottom two bits are '11', this means
that this is a locked exceptional entry.

It turns out that this bit combination was never actually used.  Radix
tree locking for DAX was indeed implemented, but it actually used the
third LSB:

  /* We use lowest available exceptional entry bit for locking */
  #define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT)

This locking code was also made specific to the DAX code instead of
being generally implemented in radix-tree.h.

So, fix the comment.

Link: http://lkml.kernel.org/r/1468997731-2155-1-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:08 -04:00
Arnd Bergmann
a9bfd33217 crc32: use ktime_get_ns() for measurement
The crc32 test function measures the elapsed time in nanoseconds, but
uses 'struct timespec' for that.  We want to remove timespec from the
kernel for y2038 compatibility, and ktime_get_ns() also helps make the
code simpler here.

It is also slightly better to use monontonic time, as we are only
interested in the time difference.

Link: http://lkml.kernel.org/r/20160617143932.3289626-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: "David S . Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:08 -04:00
Sebastian Ott
f003a1f182 lib/iommu-helper: skip to next segment
When a large enough area in the iommu bitmap is found but would span a
boundary we continue the search starting from the next bit position.
For large allocations this can lead to several useless invocations of
bitmap_find_next_zero_area() and iommu_is_span_boundary().

Continue the search from the start of the next segment (which is the
next bit position such that we'll not cross the same segment boundary
again).

Link: http://lkml.kernel.org/r/alpine.LFD.2.20.1606081910070.3211@schleppi
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:07 -04:00
Joe Perches
4cad35a7ca get_maintainer.pl: reduce need for command-line option -f
If a vcs is used, look to see if the vcs tracks the file specified and
so the -f option becomes optional.

Link: http://lkml.kernel.org/r/7c86a8df0d48770c45778a43b6b3e4627b2a90ee.1469746395.git.joe@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>
2016-08-02 19:35:07 -04:00
Borislav Petkov
750afe7bab printk: add kernel parameter to control writes to /dev/kmsg
Add a "printk.devkmsg" kernel command line parameter which controls how
userspace writes into /dev/kmsg.  It has three options:

 * ratelimit - ratelimit logging from userspace.
 * on  - unlimited logging from userspace
 * off - logging from userspace gets ignored

The default setting is to ratelimit the messages written to it.

This changes the kernel default setting of "on" to "ratelimit" and we do
that because we want to keep userspace spamming /dev/kmsg to sane
levels.  This is especially moot when a small kernel log buffer wraps
around and messages get lost.  So the ratelimiting setting should be a
sane setting where kernel messages should have a bit higher chance of
survival from all the spamming.

It additionally does not limit logging to /dev/kmsg while the system is
booting if we haven't disabled it on the command line.

Furthermore, we can control the logging from a lower priority sysctl
interface - kernel.printk_devkmsg.

That interface will succeed only if printk.devkmsg *hasn't* been
supplied on the command line.  If it has, then printk.devkmsg is a
one-time setting which remains for the duration of the system lifetime.
This "locking" of the setting is to prevent userspace from changing the
logging on us through sysctl(2).

This patch is based on previous patches from Linus and Steven.

[bp@suse.de: fixes]
  Link: http://lkml.kernel.org/r/20160719072344.GC25563@nazgul.tnic
Link: http://lkml.kernel.org/r/20160716061745.15795-3-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Dave Young <dyoung@redhat.com>
Cc: Franck Bui <fbui@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:06 -04:00
Borislav Petkov
6b1d174b0c ratelimit: extend to print suppressed messages on release
Extend the ratelimiting facility to print the amount of suppressed lines
when it is being released.

This use case is aimed at short-termed, burst-like users for which we
want to output the suppressed lines stats only once, after it has been
disposed of.  For an example, see /dev/kmsg usage in a follow-on patch.

Also, change the printk() line we issue on release to not use
"callbacks" as it is misleading: we're not suppressing callbacks but
printk() calls.

This has been separated from a previous patch by Linus.

Link: http://lkml.kernel.org/r/20160716061745.15795-2-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Dave Young <dyoung@redhat.com>
Cc: Franck Bui <fbui@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:06 -04:00
Borislav Petkov
b5644a153d fbdev/bfin_adv7393fb: move DRIVER_NAME before its first use
Move the DRIVER_NAME macro definition before the first usage site and
fix build error.

Link: http://lkml.kernel.org/r/20160801163937.GA28119@nazgul.tnic
Signed-off-by: Borislav Petkov <bp@suse.de>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:05 -04:00
Christoph Hellwig
40a7d9f5f9 printk: include <asm/sections.h> instead of <asm-generic/sections.h>
asm-generic headers are generic implementations for architecture
specific code and should not be included by common code.  Thus use the
asm/ version of sections.h to get at the linker sections.

Link: http://lkml.kernel.org/r/1468285008-7331-1-git-send-email-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:05 -04:00
Sergey Senozhatsky
cf7754441c printk: introduce suppress_message_printing()
Messages' levels and console log level are inspected when the actual
printing occurs, which may provoke console_unlock() and
console_cont_flush() to waste CPU cycles on every message that has
loglevel above the current console_loglevel.

Schematically, console_unlock() does the following:

console_unlock()
{
        ...
        for (;;) {
                ...
                raw_spin_lock_irqsave(&logbuf_lock, flags);
skip:
                msg = log_from_idx(console_idx);

                if (msg->flags & LOG_NOCONS) {
                        ...
                        goto skip;
                }

                level = msg->level;
                len += msg_print_text();                        >> sprintfs
                                                                   memcpy,
                                                                   etc.

                if (nr_ext_console_drivers) {
                        ext_len = msg_print_ext_header();       >> scnprintf
                        ext_len += msg_print_ext_body();        >> scnprintfs
                                                                   etc.
                }
                ...
                raw_spin_unlock(&logbuf_lock);

                call_console_drivers(level, ext_text, ext_len, text, len)
                {
                        if (level >= console_loglevel &&        >> drop the message
                                        !ignore_loglevel)
                                return;

                        console->write(...);
                }

                local_irq_restore(flags);
        }
        ...
}

The thing here is this deferred `level >= console_loglevel' check.  We
are wasting CPU cycles on sprintfs/memcpy/etc.  preparing the messages
that we will eventually drop.

This can be huge when we register a new CON_PRINTBUFFER console, for
instance.  For every such a console register_console() resets the

        console_seq, console_idx, console_prev

and sets a `exclusive console' pointer to replay the log buffer to that
just-registered console.  And there can be a lot of messages to replay,
in the worst case most of which can be dropped after console_loglevel
test.

We know messages' levels long before we call msg_print_text() and
friends, so we can just move console_loglevel check out of
call_console_drivers() and format a new message only if we are sure that
it won't be dropped.

The patch factors out loglevel check into suppress_message_printing()
function and tests message->level and console_loglevel before formatting
functions in console_unlock() and console_cont_flush() are getting
executed.  This improves things not only for exclusive CON_PRINTBUFFER
consoles, but for every console_unlock() that attempts to print a
message of level above the console_loglevel.

Link: http://lkml.kernel.org/r/20160627135012.8229-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Calvin Owens <calvinowens@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:04 -04:00
Joe Perches
874f9c7da9 printk: create pr_<level> functions
Using functions instead of macros can reduce overall code size by
eliminating unnecessary "KERN_SOH<digit>" prefixes from format strings.

  defconfig x86-64:

  $ size vmlinux*
     text    data     bss      dec     hex  filename
  10193570 4331464 1105920 15630954  ee826a vmlinux.new
  10192623 4335560 1105920 15634103  ee8eb7 vmlinux.old

As the return value are unimportant and unused in the kernel tree, these
new functions return void.

Miscellanea:

 - change pr_<level> macros to call new __pr_<level> functions
 - change vprintk_nmi and vprintk_default to add LOGLEVEL_<level> argument

[akpm@linux-foundation.org: fix LOGLEVEL_INFO, per Joe]
Link: http://lkml.kernel.org/r/e16cc34479dfefcae37c98b481e6646f0f69efc3.1466718827.git.joe@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>
2016-08-02 19:35:04 -04:00
Sergey Senozhatsky
bebca05281 printk: do not include interrupt.h
A trivial cosmetic change: interrupt.h header is redundant since commit
6b898c07cb ("console: use might_sleep in console_lock").

Link: http://lkml.kernel.org/r/20160620132847.21930-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:03 -04:00
Luis de Bethencourt
9d5059c959 dynamic_debug: only add header when used
kernel.h header doesn't directly use dynamic debug, instead we can
include it in module.c (which used it via kernel.h).  printk.h only uses
it if CONFIG_DYNAMIC_DEBUG is on, changing the inclusion to only happen
in that case.

Link: http://lkml.kernel.org/r/1468429793-16917-1-git-send-email-luisbg@osg.samsung.com
[luisbg@osg.samsung.com: include dynamic_debug.h in drb_int.h]
  Link: http://lkml.kernel.org/r/1468447828-18558-2-git-send-email-luisbg@osg.samsung.com
Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:03 -04:00
Oleg Nesterov
61e96496d3 task_work: use READ_ONCE/lockless_dereference, avoid pi_lock if !task_works
Change task_work_cancel() to use lockless_dereference(), this is what
the code really wants but we didn't have this helper when it was
written.

Also add the fast-path task->task_works == NULL check, in the likely
case this task has no pending works and we can avoid
spin_lock(task->pi_lock).

While at it, change other users of ACCESS_ONCE() to use READ_ONCE().

Link: http://lkml.kernel.org/r/20160610150042.GA13868@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:02 -04:00
Chen Gang
949bed2f57 include: mman: use bool instead of int for the return value of arch_validate_prot
For pure bool function's return value, bool is a little better more or
less than int.

Link: http://lkml.kernel.org/r/1469331815-2026-1-git-send-email-chengang@emindsoft.com.cn
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:02 -04:00
Linus Lüssing
bd804ba125 mailmap: add Linus Lüssing
For one thing, summarizes all non-umlaut versions into the umlaut one
(Linus Luessing -> Linus Lüssing).

For another, maps obsolete email addresses to the current @c0d3.blue
one.

Link: http://lkml.kernel.org/r/1467805371-2773-1-git-send-email-linus.luessing@c0d3.blue
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:34:14 -04:00
Borislav Petkov
79ad70de53 cpufreq: Do not default-yes CPU_FREQ_STAT
CPU frequency transition statistics are not absolutely required for
proper cpufreq operation on the system AFAICT so remove the default-yes
setting in Kconfig.

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-03 01:34:11 +02:00
Linus Torvalds
c7fac29967 Merge tag 'drm-psr-fixes-for-v4.8' of git://people.freedesktop.org/~airlied/linux
Pull i915 drm fixes from Dave Airlie:
 "These are the two fixes from Ville for the bug you are seeing on your
  HSW laptop.

  They pretty much disable PSR in some cases where the panel reports a
  setup time that would cause issues, like you seem to have"

* tag 'drm-psr-fixes-for-v4.8' of git://people.freedesktop.org/~airlied/linux:
  drm/i915: Check PSR setup time vs. vblank length
  drm/dp: Add drm_dp_psr_setup_time()
2016-08-02 19:29:03 -04:00
Benjamin Tissoires
e370cc8640 ACPI / button: remove pointer to old lid_sysfs on unbind
When we removed the procfs dir on error or if the driver is
unbound, the two variables acpi_lid_dir and acpi_button_dir
were not reset. On the next rebind, those static variables
were not null and we couldn't re-register the device again.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-03 01:27:20 +02:00
Dave Airlie
586efded6b Merge branch 'generic-zpos-v8' of http://git.linaro.org/people/benjamin.gaignard/kernel into drm-next
Merge generic ZPOS property support, this was backed up behind some other
changes I didn't have a stable branch point for. Now they are merged to Linus
tree this pull is just drm patches.

* 'generic-zpos-v8' of http://git.linaro.org/people/benjamin.gaignard/kernel:
  drm: rcar: use generic code for managing zpos plane property
  drm/exynos: use generic code for managing zpos plane property
  drm: sti: use generic zpos for plane
  drm: add generic zpos property
2016-08-03 08:40:24 +10:00
Alexey Dobriyan
db3f600124 uapi: move forward declarations of internal structures
Don't user forward declarations of internal kernel structures in headers
exported to userspace.

Move "struct completion;".
Move "struct task_struct;".

Link: http://lkml.kernel.org/r/20160713215808.GA22486@p183.telecom.by
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>
2016-08-02 17:31:41 -04:00
Fabian Frederick
bd721ea73e treewide: replace obsolete _refok by __ref
There was only one use of __initdata_refok and __exit_refok

__init_refok was used 46 times against 82 for __ref.

Those definitions are obsolete since commit 312b1485fb ("Introduce new
section reference annotations tags: __ref, __refdata, __refconst")

This patch removes the following compatibility definitions and replaces
them treewide.

/* compatibility defines */
#define __init_refok     __ref
#define __initdata_refok __refdata
#define __exit_refok     __ref

I can also provide separate patches if necessary.
(One patch per tree and check in 1 month or 2 to remove old definitions)

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1466796271-3043-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
NeilBrown
ca945e7152 memstick: don't allocate unused major for ms_block
When alloc_disk(0) is used the ->major number is completely ignored.
All devices are allocated with a major of BLOCK_EXT_MAJOR.

So remove registration and deregistration of 'major'.

Link: http://lkml.kernel.org/r/20160602064318.4403.49955.stgit@noble
Signed-off-by: NeilBrown <neilb@suse.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
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>
2016-08-02 17:31:41 -04:00
Richard Weinberger
bc083a64b6 init/Kconfig: make COMPILE_TEST depend on !UML
UML is a bit special since it does not have iomem nor dma.  That means a
lot of drivers will not build if they miss a dependency on HAS_IOMEM.
s390 used to have the same issues but since it gained PCI support UML is
the only stranger.

We are tired of patching dozens of new drivers after every merge window
just to un-break allmod/yesconfig UML builds.  One could argue that a
decent driver has to know on what it depends and therefore a missing
HAS_IOMEM dependency is a clear driver bug.  But the dependency not
obvious and not everyone does UML builds with COMPILE_TEST enabled when
developing a device driver.

A possible solution to make these builds succeed on UML would be
providing stub functions for ioremap() and friends which fail upon
runtime.  Another one is simply disabling COMPILE_TEST for UML.  Since
it is the least hassle and does not force use to fake iomem support
let's do the latter.

Link: http://lkml.kernel.org/r/1466152995-28367-1-git-send-email-richard@nod.at
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Valdis Kletnieks
ca52953f5f fs/proc/task_mmu.c: suppress compilation warnings with W=1
Suppress a bunch of warnings of the form:

  fs/proc/task_mmu.c: In function 'show_smap_vma_flags':
  fs/proc/task_mmu.c:635:22: warning: initialized field overwritten [-Wt override-init]
     [ilog2(VM_READ)] = "rd",
                        ^~~~
  fs/proc/task_mmu.c:635:22: note: (near initialization for 'mnemonics[0]')

They happen because of the way we intentionally build the table, so
silence the warning when building with 'make W=1'.

Link: http://lkml.kernel.org/r/8727.1470022083@turing-police.cc.vt.edu
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Arnd Bergmann
519ded5a89 procfs: avoid 32-bit time_t in /proc/*/stat
/proc/stat shows (among lots of other things) the current boottime (i.e.
number of seconds since boot).  While a 32-bit number is sufficient for
this particular case, we want to get rid of the 'struct timespec'
suffers from a 32-bit overflow in 2038.

This changes the code to use a struct timespec64, which is known to be
safe in all cases.

Link: http://lkml.kernel.org/r/20160617201247.2292101-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Oleg Nesterov
ef419398b6 proc_oom_score: remove tasklist_lock and pid_alive()
This was needed before to ensure that ->signal != 0 and do_each_thread()
is safe, see commit b95c35e76b ("oom: fix the unsafe usage of
badness() in proc_oom_score()") for details.

Today tsk->signal can't go away and for_each_thread(tsk) is always safe.

Link: http://lkml.kernel.org/r/20160608211921.GA15508@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Luis de Bethencourt
db4ad0360c MAINTAINERS: befs: add new maintainers
Salah Triki and Luis de Bethencourt are taking over maintainership of
befs.

Link: http://lkml.kernel.org/r/1469651079-32455-1-git-send-email-luisbg@osg.samsung.com
Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
seokhoon.yoon
9991a9c8db cgroup: update cgroup's document path
cgroup's document path is changed to "cgroup-v1".  update it.

Link: http://lkml.kernel.org/r/1470148443-6509-1-git-send-email-iamyooon@gmail.com
Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Nicolas Iooss
901d805c33 UBSAN: fix typo in format string
handle_object_size_mismatch() used %pk to format a kernel pointer with
pr_err().  This seemed to be a misspelling for %pK, but using this to
format a kernel pointer does not make much sence here.

Therefore use %p instead, like in handle_missaligned_access().

Link: http://lkml.kernel.org/r/20160730083010.11569-1-nicolas.iooss_linux@m4x.org
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Fabian Frederick
9b24fef9f0 sysv, ipc: fix security-layer leaking
Commit 53dad6d3a8 ("ipc: fix race with LSMs") updated ipc_rcu_putref()
to receive rcu freeing function but used generic ipc_rcu_free() instead
of msg_rcu_free() which does security cleaning.

Running LTP msgsnd06 with kmemleak gives the following:

  cat /sys/kernel/debug/kmemleak

  unreferenced object 0xffff88003c0a11f8 (size 8):
    comm "msgsnd06", pid 1645, jiffies 4294672526 (age 6.549s)
    hex dump (first 8 bytes):
      1b 00 00 00 01 00 00 00                          ........
    backtrace:
      kmemleak_alloc+0x23/0x40
      kmem_cache_alloc_trace+0xe1/0x180
      selinux_msg_queue_alloc_security+0x3f/0xd0
      security_msg_queue_alloc+0x2e/0x40
      newque+0x4e/0x150
      ipcget+0x159/0x1b0
      SyS_msgget+0x39/0x40
      entry_SYSCALL_64_fastpath+0x13/0x8f

Manfred Spraul suggested to fix sem.c as well and Davidlohr Bueso to
only use ipc_rcu_free in case of security allocation failure in newary()

Fixes: 53dad6d3a8 ("ipc: fix race with LSMs")
Link: http://lkml.kernel.org/r/1470083552-22966-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org>	[3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Vladimir Davydov
b5afba2974 mm: vmscan: fix memcg-aware shrinkers not called on global reclaim
We must call shrink_slab() for each memory cgroup on both global and
memcg reclaim in shrink_node_memcg().  Commit d71df22b55099 accidentally
changed that so that now shrink_slab() is only called with memcg != NULL
on memcg reclaim.  As a result, memcg-aware shrinkers (including
dentry/inode) are never invoked on global reclaim.  Fix that.

Fixes: b2e18757f2 ("mm, vmscan: begin reclaiming pages on a per-node basis")
Link: http://lkml.kernel.org/r/1470056590-7177-1-git-send-email-vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Vladimir Davydov
05eb6e7263 radix-tree: account nodes to memcg only if explicitly requested
Radix trees may be used not only for storing page cache pages, so
unconditionally accounting radix tree nodes to the current memory cgroup
is bad: if a radix tree node is used for storing data shared among
different cgroups we risk pinning dead memory cgroups forever.

So let's only account radix tree nodes if it was explicitly requested by
passing __GFP_ACCOUNT to INIT_RADIX_TREE.  Currently, we only want to
account page cache entries, so mark mapping->page_tree so.

Fixes: 58e698af4c ("radix-tree: account radix_tree_node to memory cgroup")
Link: http://lkml.kernel.org/r/1470057188-7864-1-git-send-email-vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>	[4.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Alexander Potapenko
c3cee37228 kasan: avoid overflowing quarantine size on low memory systems
If the total amount of memory assigned to quarantine is less than the
amount of memory assigned to per-cpu quarantines, |new_quarantine_size|
may overflow.  Instead, set it to zero.

[akpm@linux-foundation.org: cleanup: use WARN_ONCE return value]
Link: http://lkml.kernel.org/r/1470063563-96266-1-git-send-email-glider@google.com
Fixes: 55834c5909 ("mm: kasan: initial memory quarantine implementation")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
7e08897893 kasan: improve double-free reports
Currently we just dump stack in case of double free bug.
Let's dump all info about the object that we have.

[aryabinin@virtuozzo.com: change double free message per Alexander]
  Link: http://lkml.kernel.org/r/1470153654-30160-1-git-send-email-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/1470062715-14077-6-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
b3cbd9bf77 mm/kasan: get rid of ->state in struct kasan_alloc_meta
The state of object currently tracked in two places - shadow memory, and
the ->state field in struct kasan_alloc_meta.  We can get rid of the
latter.  The will save us a little bit of memory.  Also, this allow us
to move free stack into struct kasan_alloc_meta, without increasing
memory consumption.  So now we should always know when the last time the
object was freed.  This may be useful for long delayed use-after-free
bugs.

As a side effect this fixes following UBSAN warning:
	UBSAN: Undefined behaviour in mm/kasan/quarantine.c:102:13
	member access within misaligned address ffff88000d1efebc for type 'struct qlist_node'
	which requires 8 byte alignment

Link: http://lkml.kernel.org/r/1470062715-14077-5-git-send-email-aryabinin@virtuozzo.com
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
47b5c2a0f0 mm/kasan: get rid of ->alloc_size in struct kasan_alloc_meta
Size of slab object already stored in cache->object_size.

Note, that kmalloc() internally rounds up size of allocation, so
object_size may be not equal to alloc_size, but, usually we don't need
to know the exact size of allocated object.  In case if we need that
information, we still can figure it out from the report.  The dump of
shadow memory allows to identify the end of allocated memory, and
thereby the exact allocation size.

Link: http://lkml.kernel.org/r/1470062715-14077-4-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
f7376aed6c mm/kasan, slub: don't disable interrupts when object leaves quarantine
SLUB doesn't require disabled interrupts to call ___cache_free().

Link: http://lkml.kernel.org/r/1470062715-14077-3-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
4b3ec5a3f4 mm/kasan: don't reduce quarantine in atomic contexts
Currently we call quarantine_reduce() for ___GFP_KSWAPD_RECLAIM (implied
by __GFP_RECLAIM) allocation.  So, basically we call it on almost every
allocation.  quarantine_reduce() sometimes is heavy operation, and
calling it with disabled interrupts may trigger hard LOCKUP:

 NMI watchdog: Watchdog detected hard LOCKUP on cpu 2irq event stamp: 1411258
 Call Trace:
  <NMI>   dump_stack+0x68/0x96
   watchdog_overflow_callback+0x15b/0x190
   __perf_event_overflow+0x1b1/0x540
   perf_event_overflow+0x14/0x20
   intel_pmu_handle_irq+0x36a/0xad0
   perf_event_nmi_handler+0x2c/0x50
   nmi_handle+0x128/0x480
   default_do_nmi+0xb2/0x210
   do_nmi+0x1aa/0x220
   end_repeat_nmi+0x1a/0x1e
  <<EOE>>   __kernel_text_address+0x86/0xb0
   print_context_stack+0x7b/0x100
   dump_trace+0x12b/0x350
   save_stack_trace+0x2b/0x50
   set_track+0x83/0x140
   free_debug_processing+0x1aa/0x420
   __slab_free+0x1d6/0x2e0
   ___cache_free+0xb6/0xd0
   qlist_free_all+0x83/0x100
   quarantine_reduce+0x177/0x1b0
   kasan_kmalloc+0xf3/0x100

Reduce the quarantine_reduce iff direct reclaim is allowed.

Fixes: 55834c59098d("mm: kasan: initial memory quarantine implementation")
Link: http://lkml.kernel.org/r/1470062715-14077-2-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
4a3d308d66 mm/kasan: fix corruptions and false positive reports
Once an object is put into quarantine, we no longer own it, i.e.  object
could leave the quarantine and be reallocated.  So having set_track()
call after the quarantine_put() may corrupt slab objects.

 BUG kmalloc-4096 (Not tainted): Poison overwritten
 -----------------------------------------------------------------------------
 Disabling lock debugging due to kernel taint
 INFO: 0xffff8804540de850-0xffff8804540de857. First byte 0xb5 instead of 0x6b
...
 INFO: Freed in qlist_free_all+0x42/0x100 age=75 cpu=3 pid=24492
  __slab_free+0x1d6/0x2e0
  ___cache_free+0xb6/0xd0
  qlist_free_all+0x83/0x100
  quarantine_reduce+0x177/0x1b0
  kasan_kmalloc+0xf3/0x100
  kasan_slab_alloc+0x12/0x20
  kmem_cache_alloc+0x109/0x3e0
  mmap_region+0x53e/0xe40
  do_mmap+0x70f/0xa50
  vm_mmap_pgoff+0x147/0x1b0
  SyS_mmap_pgoff+0x2c7/0x5b0
  SyS_mmap+0x1b/0x30
  do_syscall_64+0x1a0/0x4e0
  return_from_SYSCALL_64+0x0/0x7a
 INFO: Slab 0xffffea0011503600 objects=7 used=7 fp=0x          (null) flags=0x8000000000004080
 INFO: Object 0xffff8804540de848 @offset=26696 fp=0xffff8804540dc588
 Redzone ffff8804540de840: bb bb bb bb bb bb bb bb                          ........
 Object ffff8804540de848: 6b 6b 6b 6b 6b 6b 6b 6b b5 52 00 00 f2 01 60 cc  kkkkkkkk.R....`.

Similarly, poisoning after the quarantine_put() leads to false positive
use-after-free reports:

 BUG: KASAN: use-after-free in anon_vma_interval_tree_insert+0x304/0x430 at addr ffff880405c540a0
 Read of size 8 by task trinity-c0/3036
 CPU: 0 PID: 3036 Comm: trinity-c0 Not tainted 4.7.0-think+ #9
 Call Trace:
   dump_stack+0x68/0x96
   kasan_report_error+0x222/0x600
   __asan_report_load8_noabort+0x61/0x70
   anon_vma_interval_tree_insert+0x304/0x430
   anon_vma_chain_link+0x91/0xd0
   anon_vma_clone+0x136/0x3f0
   anon_vma_fork+0x81/0x4c0
   copy_process.part.47+0x2c43/0x5b20
   _do_fork+0x16d/0xbd0
   SyS_clone+0x19/0x20
   do_syscall_64+0x1a0/0x4e0
   entry_SYSCALL64_slow_path+0x25/0x25

Fix this by putting an object in the quarantine after all other
operations.

Fixes: 80a9201a59 ("mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB")
Link: http://lkml.kernel.org/r/1470062715-14077-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Reported-by: Sasha Levin <alexander.levin@verizon.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00