litmus-rt.git/kernel/gcov, branch master

gcov: fix softlockups

2015-04-17T13:04:08+00:00

gcov profiling if enabled with other heavy compile-time instrumentation
like KASan could trigger following softlockups:

  NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1]
  Modules linked in:
  irq event stamp: 22823276
  hardirqs last  enabled at (22823275): [] mutex_lock_nested+0x7d9/0x930
  hardirqs last disabled at (22823276): [] apic_timer_interrupt+0x6d/0x80
  softirqs last  enabled at (22823172): [] __do_softirq+0x4db/0x729
  softirqs last disabled at (22823167): [] irq_exit+0x7d/0x15b
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W       3.19.0-05245-gbb33326-dirty #3
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
  task: ffff88006cba8000 ti: ffff88006cbb0000 task.ti: ffff88006cbb0000
  RIP: kasan_mem_to_shadow+0x1e/0x1f
  Call Trace:
    strcmp+0x28/0x70
    get_node_by_name+0x66/0x99
    gcov_event+0x4f/0x69e
    gcov_enable_events+0x54/0x7b
    gcov_fs_init+0xf8/0x134
    do_one_initcall+0x1b2/0x288
    kernel_init_freeable+0x467/0x580
    kernel_init+0x15/0x18b
    ret_from_fork+0x7c/0xb0
  Kernel panic - not syncing: softlockup: hung tasks

Fix this by sticking cond_resched() in gcov_enable_events().

Signed-off-by: Andrey Ryabinin 
Reported-by: Fengguang Wu 
Cc: Peter Oberparleiter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kbuild,gcov: simplify kernel/gcov/Makefile more

2015-01-09T16:25:44+00:00

CONFIG_GCOV_FORMAT_3_4 / _4_7 / _AUTODETECT are exclusive.
Compare the CC version only when _AUTODETECT is enabled.

This change should have no impact.

Signed-off-by: Masahiro Yamada 
Cc: Peter Oberparleiter 
Signed-off-by: Michal Marek

kbuild,gcov: simplify kernel/gcov/Makefile

2015-01-09T16:25:44+00:00

Kbuild descends into kernel/gcov/ directory only when
CONFIG_GCOV_KERNEL is enabled. (See kernel/Makefile)

CONFIG_GCOV_KERNEL check can be omitted in kernel/gcov/Makefile.

Signed-off-by: Masahiro Yamada 
Cc: Peter Oberparleiter 
Signed-off-by: Michal Marek

kbuild,gcov: remove unnecessary workaround

2015-01-09T16:25:44+00:00

Since commit 371fdc77af44 (kbuild: collect shorthands into
scripts/Kbuild.include), scripts/Makefile.clean includes
scripts/Kbuild.include.

The workaround and the comment block in kernel/gcov/Makefile
are no longer necessary.

Signed-off-by: Masahiro Yamada 
Cc: Peter Oberparleiter 
Signed-off-by: Michal Marek

kbuild: do not add $(call ...) to invoke cc-version or cc-fullversion

2015-01-09T16:25:44+00:00

The macros cc-version, cc-fullversion and ld-version take no argument.
It is not necessary to add $(call ...) to invoke them.

Signed-off-by: Masahiro Yamada 
Acked-by: Helge Deller  [parisc]
Signed-off-by: Michal Marek

gcov: enable GCOV_PROFILE_ALL from ARCH Kconfigs

2014-12-13T20:42:51+00:00

Following the suggestions from Andrew Morton and Stephen Rothwell,
Dont expand the ARCH list in kernel/gcov/Kconfig. Instead,
define a ARCH_HAS_GCOV_PROFILE_ALL bool which architectures
can enable.

set ARCH_HAS_GCOV_PROFILE_ALL on Architectures where it was
previously allowed + ARM64 which I tested.

Signed-off-by: Riku Voipio 
Cc: Peter Oberparleiter 
Cc: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gcov: add ARM64 to GCOV_PROFILE_ALL

2014-10-29T23:33:14+00:00

Following up the arm testing of gcov, turns out gcov on ARM64 works fine
as well.  Only change needed is adding ARM64 to Kconfig depends.

Tested with qemu and mach-virt

Signed-off-by: Riku Voipio 
Acked-by: Peter Oberparleiter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ARM: 8153/1: Enable gcov support on the ARM architecture

2014-09-26T13:39:57+00:00

Enable gcov support for ARM based on original patches by David
Singleton and George G. Davis

Riku - updated to patch to current mainline kernel. The patch
has been submitted in 2010, 2012 - for symmetry, now in 2014 too.

https://lwn.net/Articles/390419/
http://marc.info/?l=linux-arm-kernel&m=133823081813044

v2: remove arch/arm/kernel from gcov disabled files

Cc: Andrey Ryabinin 
Cc: Naresh Kamboju 
Acked-by: Arnd Bergmann 
Signed-off-by: Riku Voipio 
Signed-off-by: Vincent Sanders 
Signed-off-by: Russell King

kernel/gcov/fs.c: remove unnecessary null test before debugfs_remove

2014-08-08T22:57:24+00:00

This fixes checkpatch warning:

  WARNING: debugfs_remove(NULL) is safe this check is probably not required

Signed-off-by: Fabian Frederick 
Cc: Peter Oberparleiter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gcov: add support for GCC 4.9

2014-06-10T22:34:46+00:00

This patch handles the gcov-related changes in GCC 4.9:

  A new counter (time profile) is added. The total number is 9 now.

  A new profile merge function __gcov_merge_time_profile is added.

See gcc/gcov-io.h and libgcc/libgcov-merge.c

For the first change, the layout of struct gcov_info is affected.

For the second one, a dummy function is added to kernel/gcov/base.c
similarly.

Signed-off-by: Yuan Pengfei 
Acked-by: Peter Oberparleiter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds