linux-stable.git/kernel/gcov, branch v4.9.321 Linux kernel stable tree gcov: add support for GCC 10.1 2020-09-23T06:46:14+00:00 Peter Oberparleiter oberpar@linux.ibm.com 2020-09-10T12:52:01+00:00 1ed38f207a11e3dd20d1367938acdb52e3da4775 [ Upstream commit 40249c6962075c040fd071339acae524f18bfac9 ] Using gcov to collect coverage data for kernels compiled with GCC 10.1 causes random malfunctions and kernel crashes. This is the result of a changed GCOV_COUNTERS value in GCC 10.1 that causes a mismatch between the layout of the gcov_info structure created by GCC profiling code and the related structure used by the kernel. Fix this by updating the in-kernel GCOV_COUNTERS value. Also re-enable config GCOV_KERNEL for use with GCC 10. Reported-by: Colin Ian King <colin.king@canonical.com> Reported-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Tested-by: Leon Romanovsky <leonro@nvidia.com> Tested-and-Acked-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 40249c6962075c040fd071339acae524f18bfac9 ]

Using gcov to collect coverage data for kernels compiled with GCC 10.1
causes random malfunctions and kernel crashes.  This is the result of a
changed GCOV_COUNTERS value in GCC 10.1 that causes a mismatch between
the layout of the gcov_info structure created by GCC profiling code and
the related structure used by the kernel.

Fix this by updating the in-kernel GCOV_COUNTERS value.  Also re-enable
config GCOV_KERNEL for use with GCC 10.

Reported-by: Colin Ian King <colin.king@canonical.com>
Reported-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Tested-by: Leon Romanovsky <leonro@nvidia.com>
Tested-and-Acked-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gcov: Disable gcov build with GCC 10 2020-09-23T06:46:10+00:00 Leon Romanovsky leonro@nvidia.com 2020-09-04T15:58:08+00:00 250f4087fc60a64c0f7954020da35cafa0a5af24 [ Upstream commit cfc905f158eaa099d6258031614d11869e7ef71c ] GCOV built with GCC 10 doesn't initialize n_function variable. This produces different kernel panics as was seen by Colin in Ubuntu and me in FC 32. As a workaround, let's disable GCOV build for broken GCC 10 version. Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1891288 Link: https://lore.kernel.org/lkml/20200827133932.3338519-1-leon@kernel.org Link: https://lore.kernel.org/lkml/CAHk-=whbijeSdSvx-Xcr0DPMj0BiwhJ+uiNnDSVZcr_h_kg7UA@mail.gmail.com/ Cc: Colin Ian King <colin.king@canonical.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit cfc905f158eaa099d6258031614d11869e7ef71c ]

GCOV built with GCC 10 doesn't initialize n_function variable.  This
produces different kernel panics as was seen by Colin in Ubuntu and me
in FC 32.

As a workaround, let's disable GCOV build for broken GCC 10 version.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1891288
Link: https://lore.kernel.org/lkml/20200827133932.3338519-1-leon@kernel.org
Link: https://lore.kernel.org/lkml/CAHk-=whbijeSdSvx-Xcr0DPMj0BiwhJ+uiNnDSVZcr_h_kg7UA@mail.gmail.com/
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
kernel/gcov/fs.c: gcov_seq_next() should increase position index 2020-05-02T15:23:05+00:00 Vasily Averin vvs@virtuozzo.com 2020-04-10T21:34:10+00:00 7526678b954d71f6349d0120e70721778fb72487 [ Upstream commit f4d74ef6220c1eda0875da30457bef5c7111ab06 ] If seq_file .next function does not change position index, read after some lseek can generate unexpected output. https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: NeilBrown <neilb@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Waiman Long <longman@redhat.com> Link: http://lkml.kernel.org/r/f65c6ee7-bd00-f910-2f8a-37cc67e4ff88@virtuozzo.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f4d74ef6220c1eda0875da30457bef5c7111ab06 ]

If seq_file .next function does not change position index, read after
some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: NeilBrown <neilb@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Waiman Long <longman@redhat.com>
Link: http://lkml.kernel.org/r/f65c6ee7-bd00-f910-2f8a-37cc67e4ff88@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gcov: support GCC 7.1 2017-09-02T05:07:53+00:00 Martin Liska mliska@suse.cz 2017-05-12T22:46:35+00:00 b8a1532b16fd49596304e1cfd285cf4509b6fba7 commit 05384213436ab690c46d9dfec706b80ef8d671ab upstream. Starting from GCC 7.1, __gcov_exit is a new symbol expected to be implemented in a profiling runtime. [akpm@linux-foundation.org: coding-style fixes] [mliska@suse.cz: v2] Link: http://lkml.kernel.org/r/e63a3c59-0149-c97e-4084-20ca8f146b26@suse.cz Link: http://lkml.kernel.org/r/8c4084fa-3885-29fe-5fc4-0d4ca199c785@suse.cz Signed-off-by: Martin Liska <mliska@suse.cz> Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 05384213436ab690c46d9dfec706b80ef8d671ab upstream.

Starting from GCC 7.1, __gcov_exit is a new symbol expected to be
implemented in a profiling runtime.

[akpm@linux-foundation.org: coding-style fixes]
[mliska@suse.cz: v2]
  Link: http://lkml.kernel.org/r/e63a3c59-0149-c97e-4084-20ca8f146b26@suse.cz
Link: http://lkml.kernel.org/r/8c4084fa-3885-29fe-5fc4-0d4ca199c785@suse.cz
Signed-off-by: Martin Liska <mliska@suse.cz>
Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gcov: add support for gcc version >= 6 2016-07-15T05:54:27+00:00 Florian Meier Florian.Meier@informatik.uni-erlangen.de 2016-07-14T19:07:26+00:00 d02038f972538b93011d78c068f44514fbde0a8c Link: http://lkml.kernel.org/r/20160701130914.GA23225@styxhp Signed-off-by: Florian Meier <Florian.Meier@informatik.uni-erlangen.de> Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Link: http://lkml.kernel.org/r/20160701130914.GA23225@styxhp
Signed-off-by: Florian Meier <Florian.Meier@informatik.uni-erlangen.de>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
gcov: disable for COMPILE_TEST 2016-05-10T15:12:49+00:00 Arnd Bergmann arnd@arndb.de 2016-04-25T15:35:29+00:00 cc622420798c4bcf093785d872525087a7798db9 Enabling gcov is counterproductive to compile testing: it significantly increases the kernel image size, compile time, and it produces lots of false positive "may be used uninitialized" warnings as the result of missed optimizations. This is in line with how UBSAN_SANITIZE_ALL and PROFILE_ALL_BRANCHES work, both of which have similar problems. With an ARM allmodconfig kernel, I see the build time drop from 283 minutes CPU time to 225 minutes, and the vmlinux size drops from 43MB to 26MB. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Michal Marek <mmarek@suse.com> 
Enabling gcov is counterproductive to compile testing: it significantly
increases the kernel image size, compile time, and it produces lots
of false positive "may be used uninitialized" warnings as the result
of missed optimizations.

This is in line with how UBSAN_SANITIZE_ALL and PROFILE_ALL_BRANCHES
work, both of which have similar problems.

With an ARM allmodconfig kernel, I see the build time drop from
283 minutes CPU time to 225 minutes, and the vmlinux size drops
from 43MB to 26MB.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
gcov: use within_module() helper. 2015-12-04T21:46:25+00:00 Rusty Russell rusty@rustcorp.com.au 2015-11-25T23:13:08+00:00 c65abf358f211c3f88c8ed714dff25775ab49fc1 An exact mapping would be within_module_core(), but at this stage (MODULE_STATE_GOING) the init section is empty, and this is clearer. Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz> 
An exact mapping would be within_module_core(), but at this stage
(MODULE_STATE_GOING) the init section is empty, and this is clearer.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
gcov: add support for GCC 5.1 2015-07-01T02:44:57+00:00 Lorenzo Stoakes lstoakes@gmail.com 2015-06-30T21:57:49+00:00 3e44c471a2dab210f7e9b1e5f7d4d54d52df59eb Fix kernel gcov support for GCC 5.1. Similar to commit a992bf836f9 ("gcov: add support for GCC 4.9"), this patch takes into account the existence of a new gcov counter (see gcc's gcc/gcov-counter.def.) Firstly, it increments GCOV_COUNTERS (to 10), which makes the data structure struct gcov_info compatible with GCC 5.1. Secondly, a corresponding counter function __gcov_merge_icall_topn (Top N value tracking for indirect calls) is included in base.c with the other gcov counters unused for kernel profiling. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Yuan Pengfei <coolypf@qq.com> Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Fix kernel gcov support for GCC 5.1.  Similar to commit a992bf836f9
("gcov: add support for GCC 4.9"), this patch takes into account the
existence of a new gcov counter (see gcc's gcc/gcov-counter.def.)

Firstly, it increments GCOV_COUNTERS (to 10), which makes the data
structure struct gcov_info compatible with GCC 5.1.

Secondly, a corresponding counter function __gcov_merge_icall_topn (Top N
value tracking for indirect calls) is included in base.c with the other
gcov counters unused for kernel profiling.

Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Yuan Pengfei <coolypf@qq.com>
Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
gcov: fix softlockups 2015-04-17T13:04:08+00:00 Andrey Ryabinin a.ryabinin@samsung.com 2015-04-16T19:48:10+00:00 9d796e66230205cd3366f5660387bd9ecca9d336 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): [<ffffffff86e8d10d>] mutex_lock_nested+0x7d9/0x930 hardirqs last disabled at (22823276): [<ffffffff86e9521d>] apic_timer_interrupt+0x6d/0x80 softirqs last enabled at (22823172): [<ffffffff811ed969>] __do_softirq+0x4db/0x729 softirqs last disabled at (22823167): [<ffffffff811edfcf>] 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 <a.ryabinin@samsung.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
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): [<ffffffff86e8d10d>] mutex_lock_nested+0x7d9/0x930
  hardirqs last disabled at (22823276): [<ffffffff86e9521d>] apic_timer_interrupt+0x6d/0x80
  softirqs last  enabled at (22823172): [<ffffffff811ed969>] __do_softirq+0x4db/0x729
  softirqs last disabled at (22823167): [<ffffffff811edfcf>] 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 <a.ryabinin@samsung.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kbuild,gcov: simplify kernel/gcov/Makefile more 2015-01-09T16:25:44+00:00 Masahiro Yamada yamada.m@jp.panasonic.com 2014-12-25T05:31:28+00:00 a75f8b8dab0f73459fa47a1daa10c84c4e8400a8 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 <yamada.m@jp.panasonic.com> Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Michal Marek <mmarek@suse.cz> 
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 <yamada.m@jp.panasonic.com>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>