* [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootable kernel.
@ 2013-09-07 16:00 Tetsuo Handa
2013-09-08 4:32 ` Tetsuo Handa
0 siblings, 1 reply; 15+ messages in thread
From: Tetsuo Handa @ 2013-09-07 16:00 UTC (permalink / raw)
To: maarten.lankhorst
Cc: linux-kernel, daniel.vetter, robdclark, a.p.zijlstra, mingo
Hello.
I noticed that 3.11 and current linux.git do not boot (they hang before
printing the "Linux version 3.10.0-rc7-00026-g040a0a3" line) when built with
CONFIG_DEBUG_MUTEXES=y using gcc (GCC) 3.3.5 (Debian 1:3.3.5-13). They boot OK
when built with the same config using gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3.
Bisection reached commit 040a0a37 "mutex: Add support for wound/wait style
locks". This commit might contain gcc version dependent trick, but how can I
find it?
Kernel config (only for testing whether the kernel version line is printed) is
at http://I-love.SAKURA.ne.jp/tmp/config-3.11-mutex and the command line I used
for testing is
$ qemu-system-i386 -m 512 -nographic -kernel arch/x86/boot/bzImage --append "console=ttyS0,115200n8"
.
Regards.
---------- bisection log start ----------
# bad: [ad81f0545ef01ea651886dddac4bef6cec930092] Linux 3.11-rc1
# good: [8bb495e3f02401ee6f76d1b1d77f3ac9f079e376] Linux 3.10
# good: [c1be5a5b1b355d40e6cf79cc979eb66dafa24ad1] Linux 3.9
# good: [19f949f52599ba7c3f67a5897ac6be14bfcb1200] Linux 3.8
# good: [29594404d7fe73cd80eaa4ee8c43dcc53970c60e] Linux 3.7
# good: [a0d271cbfed1dd50278c6b06bead3d00ba0a88f9] Linux 3.6
# good: [28a33cbc24e4256c143dce96c7d93bf423229f92] Linux 3.5
# good: [76e10d158efb6d4516018846f60c2ab5501900bc] Linux 3.4
# good: [c16fa4f2ad19908a47c63d8fa436a1178438c7e7] Linux 3.3
# good: [805a6af8dba5dfdd35ec35dc52ec0122400b2610] Linux 3.2
# good: [c3b92c8787367a8bb53d57d9789b558f1295cc96] Linux 3.1
# good: [02f8c6aee8df3cdc935e9bdd4f2d020306035dbe] Linux 3.0
git bisect start 'v3.11-rc1' 'v3.10' 'v3.9' 'v3.8' 'v3.7' 'v3.6' 'v3.5' 'v3.4' 'v3.3' 'v3.2' 'v3.1' 'v3.0'
# bad: [1286da8bc009cb2aee7f285e94623fc974c0c983] Merge tag 'sound-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
git bisect bad 1286da8bc009cb2aee7f285e94623fc974c0c983
# good: [ee1a8d402e7e204d57fb108aa40003b6d1633036] Merge tag 'dt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
git bisect good ee1a8d402e7e204d57fb108aa40003b6d1633036
# bad: [3e34131a65127e73fbae68c82748f32c8af7e4a4] Merge tag 'stable/for-linus-3.11-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
git bisect bad 3e34131a65127e73fbae68c82748f32c8af7e4a4
# bad: [790eac5640abf7a57fa3a644386df330e18c11b0] Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
git bisect bad 790eac5640abf7a57fa3a644386df330e18c11b0
# bad: [f0bb4c0ab064a8aeeffbda1cee380151a594eaab] Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect bad f0bb4c0ab064a8aeeffbda1cee380151a594eaab
# good: [3e42dee676e8cf5adca817b1518b2e99d1c138ff] Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect good 3e42dee676e8cf5adca817b1518b2e99d1c138ff
# good: [130768b8c93cd8d21390a136ec8cef417153ca14] perf/x86/intel: Add Haswell PEBS record support
git bisect good 130768b8c93cd8d21390a136ec8cef417153ca14
# bad: [ab3d681e9d41816f90836ea8fe235168d973207f] Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect bad ab3d681e9d41816f90836ea8fe235168d973207f
# good: [14961444696effb2e660fe876e5c1880f8bc3932] rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs
git bisect good 14961444696effb2e660fe876e5c1880f8bc3932
# good: [be77f87c001b770f13fe742becb08b847d9542f1] Merge branches 'cbnum.2013.06.10a', 'doc.2013.06.10a', 'fixes.2013.06.10a', 'srcu.2013.06.10a' and 'tiny.2013.06.10a' into HEAD
git bisect good be77f87c001b770f13fe742becb08b847d9542f1
# bad: [2fe3d4b149ccebbb384062fbbe6634439f2bf120] mutex: Add more tests to lib/locking-selftest.c
git bisect bad 2fe3d4b149ccebbb384062fbbe6634439f2bf120
# bad: [040a0a37100563754bb1fee6ff6427420bcfa609] mutex: Add support for wound/wait style locks
git bisect bad 040a0a37100563754bb1fee6ff6427420bcfa609
# good: [a41b56efa70e060f650aeb54740aaf52044a1ead] arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
git bisect good a41b56efa70e060f650aeb54740aaf52044a1ead
---------- bisection log end ----------
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootable kernel.
2013-09-07 16:00 [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootable kernel Tetsuo Handa
@ 2013-09-08 4:32 ` Tetsuo Handa
2013-09-08 5:28 ` Ilia Mirkin
0 siblings, 1 reply; 15+ messages in thread
From: Tetsuo Handa @ 2013-09-08 4:32 UTC (permalink / raw)
To: maarten.lankhorst
Cc: linux-kernel, daniel.vetter, robdclark, a.p.zijlstra, mingo
Hello.
I found what is wrong.
---------- bad patch start ----------
>From 3c56dfbd32a9b67ba824ce96128bb513eb65de4b Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Sun, 8 Sep 2013 12:44:20 +0900
Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
"!__builtin_constant_p(p == NULL)" which I guess the author meant that
"__builtin_constant_p(p) && p", but gcc 3.x cannot handle such expression
correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: <stable@kernel.org> [3.11+]
---
kernel/mutex.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/mutex.c b/kernel/mutex.c
index a52ee7bb..0a6f14f 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -448,7 +448,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct task_struct *owner;
struct mspin_node node;
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (__builtin_constant_p(ww_ctx) && ww_ctx && ww_ctx->acquired > 0) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -478,7 +478,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
if ((atomic_read(&lock->count) == 1) &&
(atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
lock_acquired(&lock->dep_map, ip);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (__builtin_constant_p(ww_ctx) && ww_ctx) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -548,7 +548,7 @@ slowpath:
goto err;
}
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (__builtin_constant_p(ww_ctx) && ww_ctx && ww_ctx->acquired > 0) {
ret = __mutex_lock_check_stamp(lock, ww_ctx);
if (ret)
goto err;
@@ -568,7 +568,7 @@ done:
mutex_remove_waiter(lock, &waiter, current_thread_info());
mutex_set_owner(lock);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (__builtin_constant_p(ww_ctx) && ww_ctx) {
struct ww_mutex *ww = container_of(lock,
struct ww_mutex,
base);
--
1.7.8
---------- bad patch end ----------
However, after applying the patch above, I get problems (both gcc 3.x and 4.x)
with locking selftests.
---------- gcc version 3.3.5 start ----------
[ 0.000000] Linux version 3.11.0-dirty (root@aqua) (gcc version 3.3.5 (Debian 1:3.3.5-13)) #124 SMP Sun Sep 8 12:05:18 JST 2013
(...snipped...)
[ 0.000000] --------------------------------------------------------------------------
[ 0.000000] | Wound/wait tests |
[ 0.000000] ---------------------
[ 0.000000] ww api failures:
[ 0.000000] ------------[ cut here ]------------
[ 0.000000] WARNING: CPU: 0 PID: 0 at lib/locking-selftest.c:1143 ww_test_fail_acquire+0x112/0x2c0()
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.11.0-dirty #124
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000477 00000000 c1577f18 c11e6736 c1577f24 c11e677d c11ffeb2 c1577f50
[ 0.000000] c1041af9 c14f5ea0 00000000 00000000 c15114fa 00000477 c11ffeb2 c1cd9360
[ 0.000000] 00000000 00000001 c1577f60 c1041bbd 00000009 00000000 c1577f84 c11ffeb2
[ 0.000000] Call Trace:
[ 0.000000] [<c11e6736>] __dump_stack+0x16/0x20
[ 0.000000] [<c11e677d>] dump_stack+0x3d/0x60
[ 0.000000] [<c11ffeb2>] ? ww_test_fail_acquire+0x112/0x2c0
[ 0.000000] [<c1041af9>] warn_slowpath_common+0x79/0xa0
[ 0.000000] [<c11ffeb2>] ? ww_test_fail_acquire+0x112/0x2c0
[ 0.000000] [<c1041bbd>] warn_slowpath_null+0x1d/0x30
[ 0.000000] [<c11ffeb2>] ww_test_fail_acquire+0x112/0x2c0
[ 0.000000] [<c11ffce2>] ? dotest+0x42/0x100
[ 0.000000] [<c11ffda0>] ? dotest+0x100/0x100
[ 0.000000] [<c11ffce2>] dotest+0x42/0x100
[ 0.000000] [<c1084f95>] ? printk+0x35/0x40
[ 0.000000] [<c12030b3>] ww_tests+0x53/0x410
[ 0.000000] [<c1204e14>] locking_selftest+0x19a4/0x1ab0
[ 0.000000] [<c15c2a0c>] start_kernel+0x1ec/0x2c0
[ 0.000000] [<c15c2480>] ? repair_env_string+0x70/0x70
[ 0.000000] [<c15c2275>] i386_start_kernel+0x25/0x30
[ 0.000000] ---[ end trace 74d4202eb2b56266 ]---
[ 0.000000] ok | ok | ok |
[ 0.000000] ww contexts mixing: ok |FAILED|
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #124
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1577f78 c11e6736 c1577f84 c11e677d c1200480 c1577fac
[ 0.000000] c11ffd01 c151157d c1084f95 00000000 ffffffff 00000010 00000000 00020800
[ 0.000000] c1788800 c1577fbc c120311b c15115f7 c151160d c1577fd0 c1204e14 c1504b06
[ 0.000000] Call Trace:
[ 0.000000] [<c11e6736>] __dump_stack+0x16/0x20
[ 0.000000] [<c11e677d>] dump_stack+0x3d/0x60
[ 0.000000] [<c1200480>] ? ww_test_two_contexts+0x160/0x160
[ 0.000000] [<c11ffd01>] dotest+0x61/0x100
[ 0.000000] [<c1084f95>] ? printk+0x35/0x40
[ 0.000000] [<c120311b>] ww_tests+0xbb/0x410
[ 0.000000] [<c1204e14>] locking_selftest+0x19a4/0x1ab0
[ 0.000000] [<c15c2a0c>] start_kernel+0x1ec/0x2c0
[ 0.000000] [<c15c2480>] ? repair_env_string+0x70/0x70
[ 0.000000] [<c15c2275>] i386_start_kernel+0x25/0x30
[ 0.000000]
[ 0.000000] finishing ww context: ok | ok | ok |FAILED|
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #124
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1577f78 c11e6736 c1577f84 c11e677d c1200ba0 c1577fac
[ 0.000000] c11ffd01 c151157d c1084f95 00000000 ffffffff 00000010 00000000 00020800
[ 0.000000] c1788800 c1577fbc c1203180 c15115f7 c1511620 c1577fd0 c1204e14 c1504b06
[ 0.000000] Call Trace:
[ 0.000000] [<c11e6736>] __dump_stack+0x16/0x20
[ 0.000000] [<c11e677d>] dump_stack+0x3d/0x60
[ 0.000000] [<c1200ba0>] ? ww_test_context_fini_early+0x1e0/0x1e0
[ 0.000000] [<c11ffd01>] dotest+0x61/0x100
[ 0.000000] [<c1084f95>] ? printk+0x35/0x40
[ 0.000000] [<c1203180>] ww_tests+0x120/0x410
[ 0.000000] [<c1204e14>] locking_selftest+0x19a4/0x1ab0
[ 0.000000] [<c15c2a0c>] start_kernel+0x1ec/0x2c0
[ 0.000000] [<c15c2480>] ? repair_env_string+0x70/0x70
[ 0.000000] [<c15c2275>] i386_start_kernel+0x25/0x30
[ 0.000000]
[ 0.000000] locking mismatches: ok |FAILED|
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #124
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1577f78 c11e6736 c1577f84 c11e677d c1200d40 c1577fac
[ 0.000000] c11ffd01 c151157d c1084f95 00000000 ffffffff 00000010 00000000 00020800
[ 0.000000] c1788800 c1577fbc c12031c3 c15115f7 c1511635 c1577fd0 c1204e14 c1504b06
[ 0.000000] Call Trace:
[ 0.000000] [<c11e6736>] __dump_stack+0x16/0x20
[ 0.000000] [<c11e677d>] dump_stack+0x3d/0x60
[ 0.000000] [<c1200d40>] ? ww_test_object_unlock_twice+0x30/0x30
[ 0.000000] [<c11ffd01>] dotest+0x61/0x100
[ 0.000000] [<c1084f95>] ? printk+0x35/0x40
[ 0.000000] [<c12031c3>] ww_tests+0x163/0x410
[ 0.000000] [<c1204e14>] locking_selftest+0x19a4/0x1ab0
[ 0.000000] [<c15c2a0c>] start_kernel+0x1ec/0x2c0
[ 0.000000] [<c15c2480>] ? repair_env_string+0x70/0x70
[ 0.000000] [<c15c2275>] i386_start_kernel+0x25/0x30
[ 0.000000] FAILED|
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #124
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1577f78 c11e6736 c1577f84 c11e677d c1200ea0 c1577fac
[ 0.000000] c11ffd01 c151157d c1084f95 00000000 ffffffff 00000010 00000000 00020800
[ 0.000000] c1788800 c1577fbc c12031d4 c15115f7 c1511635 c1577fd0 c1204e14 c1504b06
[ 0.000000] Call Trace:
[ 0.000000] [<c11e6736>] __dump_stack+0x16/0x20
[ 0.000000] [<c11e677d>] dump_stack+0x3d/0x60
[ 0.000000] [<c1200ea0>] ? ww_test_object_lock_unbalanced+0x160/0x160
[ 0.000000] [<c11ffd01>] dotest+0x61/0x100
[ 0.000000] [<c1084f95>] ? printk+0x35/0x40
[ 0.000000] [<c12031d4>] ww_tests+0x174/0x410
[ 0.000000] [<c1204e14>] locking_selftest+0x19a4/0x1ab0
[ 0.000000] [<c15c2a0c>] start_kernel+0x1ec/0x2c0
[ 0.000000] [<c15c2480>] ? repair_env_string+0x70/0x70
[ 0.000000] [<c15c2275>] i386_start_kernel+0x25/0x30
[ 0.000000]
[ 0.000000] EDEADLK handling:
[ 0.000000] BUG: scheduling while atomic: swapper/0/0/0x00000002
[ 0.000000] 2 locks held by swapper/0/0:
[ 0.000000] #0: (ww_lockdep_acquire){+.+...}, at: [<c11ffce2>] dotest+0x42/0x100
[ 0.000000] #1: (ww_lockdep_mutex){+.+...}, at: [<c1201093>] ww_test_edeadlk_normal+0x103/0x210
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #124
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00200246 00000000 c1577e04 c11e6736 c1577e10 c11e677d c1581160 c1577e2c
[ 0.000000] c106cd05 c14f7440 c1581430 00000000 00000002 00000000 c1577efc c13c0a57
[ 0.000000] c17b56a8 00000001 c1581608 c1577e80 c109363e 00000000 c1577e78 c100470e
[ 0.000000] Call Trace:
[ 0.000000] [<c11e6736>] __dump_stack+0x16/0x20
[ 0.000000] [<c11e677d>] dump_stack+0x3d/0x60
[ 0.000000] [<c106cd05>] __schedule_bug+0x75/0xa0
[ 0.000000] [<c13c0a57>] __schedule+0x67/0x790
[ 0.000000] [<c109363e>] ? validate_chain+0x49e/0x540
[ 0.000000] [<c100470e>] ? dump_trace+0x9e/0xd0
[ 0.000000] [<c1090ab9>] ? save_trace+0x39/0xa0
[ 0.000000] [<c109438a>] ? mark_held_locks+0xca/0x100
[ 0.000000] [<c13bfb2c>] ? __ww_mutex_lock+0x1cc/0x380
[ 0.000000] [<c10945ce>] ? trace_hardirqs_on_caller+0x14e/0x160
[ 0.000000] [<c13c11e5>] schedule+0x65/0x70
[ 0.000000] [<c13c1202>] schedule_preempt_disabled+0x12/0x20
[ 0.000000] [<c13bfb33>] __ww_mutex_lock+0x1d3/0x380
[ 0.000000] [<c12010e3>] ? ww_test_edeadlk_normal+0x153/0x210
[ 0.000000] [<c12010e3>] ? ww_test_edeadlk_normal+0x153/0x210
[ 0.000000] [<c12010e3>] ww_test_edeadlk_normal+0x153/0x210
[ 0.000000] [<c11ffce2>] ? dotest+0x42/0x100
[ 0.000000] [<c1200f90>] ? ww_test_object_lock_stale_context+0xf0/0xf0
[ 0.000000] [<c11ffce2>] dotest+0x42/0x100
[ 0.000000] [<c1084f95>] ? printk+0x35/0x40
[ 0.000000] [<c1203209>] ww_tests+0x1a9/0x410
[ 0.000000] [<c1204e14>] locking_selftest+0x19a4/0x1ab0
[ 0.000000] [<c15c2a0c>] start_kernel+0x1ec/0x2c0
[ 0.000000] [<c15c2480>] ? repair_env_string+0x70/0x70
[ 0.000000] [<c15c2275>] i386_start_kernel+0x25/0x30
[ 0.000000] BUG: unable to handle kernel NULL pointer dereference at 00000008
[ 0.000000] IP: [<c11ebce3>] rb_next+0x3/0x60
[ 0.000000] *pde = 00000000
[ 0.000000] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #124
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] task: c1581160 ti: c1576000 task.ti: c1576000
[ 0.000000] EIP: 0060:[<c11ebce3>] EFLAGS: 00210002 CPU: 0
[ 0.000000] EIP is at rb_next+0x3/0x60
[ 0.000000] EAX: 00000008 EBX: dffed47c ECX: fffffff8 EDX: 00000008
[ 0.000000] ESI: 00000000 EDI: c15813e0 EBP: c1577e04 ESP: c1577dfc
[ 0.000000] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[ 0.000000] CR0: 8005003b CR2: 00000008 CR3: 01787000 CR4: 00000690
[ 0.000000] Stack:
[ 0.000000] c1577e04 c1073ceb c1577e1c c10759a5 00000000 dffed420 dffed47c c15813e0
[ 0.000000] c1577e2c c1077937 dffed420 ffffffff c1577efc c13c0bf5 c17b56a8 00000001
[ 0.000000] c1581608 c1577e80 c109363e 00000000 c1577e78 c100470e c13c6f68 c1905be0
[ 0.000000] Call Trace:
[ 0.000000] [<c1073ceb>] ? __pick_next_entity+0xb/0x20
[ 0.000000] [<c10759a5>] pick_next_entity+0x25/0xa0
[ 0.000000] [<c1077937>] pick_next_task_fair+0x27/0x40
[ 0.000000] [<c13c0bf5>] __schedule+0x205/0x790
[ 0.000000] [<c109363e>] ? validate_chain+0x49e/0x540
[ 0.000000] [<c100470e>] ? dump_trace+0x9e/0xd0
[ 0.000000] [<c1090ab9>] ? save_trace+0x39/0xa0
[ 0.000000] [<c109438a>] ? mark_held_locks+0xca/0x100
[ 0.000000] [<c13bfb2c>] ? __ww_mutex_lock+0x1cc/0x380
[ 0.000000] [<c10945ce>] ? trace_hardirqs_on_caller+0x14e/0x160
[ 0.000000] [<c13c11e5>] schedule+0x65/0x70
[ 0.000000] [<c13c1202>] schedule_preempt_disabled+0x12/0x20
[ 0.000000] [<c13bfb33>] __ww_mutex_lock+0x1d3/0x380
[ 0.000000] [<c12010e3>] ? ww_test_edeadlk_normal+0x153/0x210
[ 0.000000] [<c12010e3>] ? ww_test_edeadlk_normal+0x153/0x210
[ 0.000000] [<c12010e3>] ww_test_edeadlk_normal+0x153/0x210
[ 0.000000] [<c11ffce2>] ? dotest+0x42/0x100
[ 0.000000] [<c1200f90>] ? ww_test_object_lock_stale_context+0xf0/0xf0
[ 0.000000] [<c11ffce2>] dotest+0x42/0x100
[ 0.000000] [<c1084f95>] ? printk+0x35/0x40
[ 0.000000] [<c1203209>] ww_tests+0x1a9/0x410
[ 0.000000] [<c1204e14>] locking_selftest+0x19a4/0x1ab0
[ 0.000000] [<c15c2a0c>] start_kernel+0x1ec/0x2c0
[ 0.000000] [<c15c2480>] ? repair_env_string+0x70/0x70
[ 0.000000] [<c15c2275>] i386_start_kernel+0x25/0x30
[ 0.000000] Code: d2 74 20 8b 42 04 85 c0 74 17 8d b4 26 00 00 00 00 8d bc 27 00 00 00 00 89 c2 8b 40 04 85 c0 75 f7 89 d0 5d c3 8d 76 00 55 89 c2 <8b> 08 31 c0 89 e5 39 d1 74 43 8b 42 04 85 c0 74 1c 89 c2 8b 40
[ 0.000000] EIP: [<c11ebce3>] rb_next+0x3/0x60 SS:ESP 0068:c1577dfc
[ 0.000000] CR2: 0000000000000008
[ 0.000000] ---[ end trace 74d4202eb2b56267 ]---
[ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
---------- gcc version 3.3.5 end ----------
---------- gcc version 4.6.3 start ----------
[ 0.000000] Linux version 3.11.0-dirty (root@aqua) (gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #125 SMP Sun Sep 8 12:13:43 JST 2013
(...snipped...)
[ 0.000000] --------------------------------------------------------------------------
[ 0.000000] | Wound/wait tests |
[ 0.000000] ---------------------
[ 0.000000] ww api failures:
[ 0.000000] ------------[ cut here ]------------
[ 0.000000] WARNING: CPU: 0 PID: 0 at lib/locking-selftest.c:1143 ww_test_fail_acquire+0xee/0x280()
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.11.0-dirty #125
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1505f2c c13938a3 c14a89d9 c1505f5c c103a47a c1492b9c
[ 0.000000] 00000000 00000000 c14a89d9 00000477 c11e16de c11e16de c11e15f0 00000001
[ 0.000000] 00000001 c1505f6c c103a4bd 00000009 00000000 c1505f84 c11e16de 00000000
[ 0.000000] Call Trace:
[ 0.000000] [<c13938a3>] dump_stack+0x4b/0x66
[ 0.000000] [<c103a47a>] warn_slowpath_common+0x7a/0xa0
[ 0.000000] [<c11e16de>] ? ww_test_fail_acquire+0xee/0x280
[ 0.000000] [<c11e16de>] ? ww_test_fail_acquire+0xee/0x280
[ 0.000000] [<c11e15f0>] ? ww_test_edeadlk_no_unlock_slow+0x270/0x270
[ 0.000000] [<c103a4bd>] warn_slowpath_null+0x1d/0x20
[ 0.000000] [<c11e16de>] ww_test_fail_acquire+0xee/0x280
[ 0.000000] [<c1393e84>] ? dotest+0x32/0xcf
[ 0.000000] [<c1393e84>] dotest+0x32/0xcf
[ 0.000000] [<c1393f67>] ww_tests+0x46/0x398
[ 0.000000] [<c11e464c>] locking_selftest+0x168c/0x1720
[ 0.000000] [<c154a939>] start_kernel+0x249/0x325
[ 0.000000] [<c154a52e>] ? obsolete_checksetup+0x95/0x95
[ 0.000000] [<c154a358>] i386_start_kernel+0x12e/0x131
[ 0.000000] ---[ end trace 614b89df0eea1b4a ]---
[ 0.000000] ok | ok | ok |
[ 0.000000] ww contexts mixing: ok |FAILED|
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #125
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1505f84 c13938a3 c11e29a0 c1505fac c1393ea3 c14a89f0
[ 0.000000] 00000000 c14a893c c1505fa8 00000010 c157e100 00020800 c1707800 c1505fb8
[ 0.000000] c1393fc4 c14a4e60 c1505fcc c11e464c c14a4e60 c1495b4c 00000780 c1505fec
[ 0.000000] Call Trace:
[ 0.000000] [<c13938a3>] dump_stack+0x4b/0x66
[ 0.000000] [<c11e29a0>] ? ww_test_try_context+0x110/0x110
[ 0.000000] [<c1393ea3>] dotest+0x51/0xcf
[ 0.000000] [<c1393fc4>] ww_tests+0xa3/0x398
[ 0.000000] [<c11e464c>] locking_selftest+0x168c/0x1720
[ 0.000000] [<c154a939>] start_kernel+0x249/0x325
[ 0.000000] [<c154a52e>] ? obsolete_checksetup+0x95/0x95
[ 0.000000] [<c154a358>] i386_start_kernel+0x12e/0x131
[ 0.000000]
[ 0.000000] finishing ww context: ok | ok | ok |FAILED|
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #125
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1505f84 c13938a3 c11e0b70 c1505fac c1393ea3 c14a89f0
[ 0.000000] 00000000 c14a893c c1505fa8 00000010 c157e100 00020800 c1707800 c1505fb8
[ 0.000000] c139401e c14a4e60 c1505fcc c11e464c c14a4e60 c1495b4c 00000780 c1505fec
[ 0.000000] Call Trace:
[ 0.000000] [<c13938a3>] dump_stack+0x4b/0x66
[ 0.000000] [<c11e0b70>] ? ww_test_context_fini_early+0x1c0/0x1c0
[ 0.000000] [<c1393ea3>] dotest+0x51/0xcf
[ 0.000000] [<c139401e>] ww_tests+0xfd/0x398
[ 0.000000] [<c11e464c>] locking_selftest+0x168c/0x1720
[ 0.000000] [<c154a939>] start_kernel+0x249/0x325
[ 0.000000] [<c154a52e>] ? obsolete_checksetup+0x95/0x95
[ 0.000000] [<c154a358>] i386_start_kernel+0x12e/0x131
[ 0.000000]
[ 0.000000] locking mismatches: ok |FAILED|
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #125
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1505f84 c13938a3 c11e1870 c1505fac c1393ea3 c14a89f0
[ 0.000000] 00000000 c14a893c c1505fa8 00000010 c157e100 00020800 c1707800 c1505fb8
[ 0.000000] c1394056 c14a4e60 c1505fcc c11e464c c14a4e60 c1495b4c 00000780 c1505fec
[ 0.000000] Call Trace:
[ 0.000000] [<c13938a3>] dump_stack+0x4b/0x66
[ 0.000000] [<c11e1870>] ? ww_test_fail_acquire+0x280/0x280
[ 0.000000] [<c1393ea3>] dotest+0x51/0xcf
[ 0.000000] [<c1394056>] ww_tests+0x135/0x398
[ 0.000000] [<c11e464c>] locking_selftest+0x168c/0x1720
[ 0.000000] [<c154a939>] start_kernel+0x249/0x325
[ 0.000000] [<c154a52e>] ? obsolete_checksetup+0x95/0x95
[ 0.000000] [<c154a358>] i386_start_kernel+0x12e/0x131
[ 0.000000] FAILED|
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #125
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1505f84 c13938a3 c11e2a80 c1505fac c1393ea3 c14a89f0
[ 0.000000] 00000000 c14a893c c1505fa8 00000010 c157e100 00020800 c1707800 c1505fb8
[ 0.000000] c1394067 c14a4e60 c1505fcc c11e464c c14a4e60 c1495b4c 00000780 c1505fec
[ 0.000000] Call Trace:
[ 0.000000] [<c13938a3>] dump_stack+0x4b/0x66
[ 0.000000] [<c11e2a80>] ? ww_test_diff_class+0xe0/0xe0
[ 0.000000] [<c1393ea3>] dotest+0x51/0xcf
[ 0.000000] [<c1394067>] ww_tests+0x146/0x398
[ 0.000000] [<c11e464c>] locking_selftest+0x168c/0x1720
[ 0.000000] [<c154a939>] start_kernel+0x249/0x325
[ 0.000000] [<c154a52e>] ? obsolete_checksetup+0x95/0x95
[ 0.000000] [<c154a358>] i386_start_kernel+0x12e/0x131
[ 0.000000]
[ 0.000000] EDEADLK handling:
[ 0.000000] BUG: scheduling while atomic: swapper/0/0/0x00000002
[ 0.000000] 2 locks held by swapper/0/0:
[ 0.000000] #0: (ww_lockdep_acquire){+.+...}, at: [<c1393e84>] dotest+0x32/0xcf
[ 0.000000] #1: (ww_lockdep_mutex){+.+...}, at: [<c11e0e51>] ww_test_edeadlk_normal+0x181/0x220
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #125
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1505e6c c13938a3 c150e920 c1505e88 c138e482 c1493b04
[ 0.000000] c150ebf0 00000000 00000002 dffed440 c1505f10 c139a565 00000000 003c41e1
[ 0.000000] 00000000 c150edc8 c1505eec c150e920 00000006 00000001 c16fe440 c16fe440
[ 0.000000] Call Trace:
[ 0.000000] [<c13938a3>] dump_stack+0x4b/0x66
[ 0.000000] [<c138e482>] __schedule_bug+0x5f/0x71
[ 0.000000] [<c139a565>] __schedule+0x65/0x5d0
[ 0.000000] [<c10896bf>] ? mark_held_locks+0xcf/0x100
[ 0.000000] [<c13994f5>] ? __ww_mutex_lock+0x1b5/0x370
[ 0.000000] [<c1089976>] ? trace_hardirqs_on_caller+0x146/0x170
[ 0.000000] [<c139ab9d>] schedule+0x4d/0x50
[ 0.000000] [<c139add3>] schedule_preempt_disabled+0x13/0x20
[ 0.000000] [<c1399505>] __ww_mutex_lock+0x1c5/0x370
[ 0.000000] [<c11e0e77>] ? ww_test_edeadlk_normal+0x1a7/0x220
[ 0.000000] [<c11e0e77>] ? ww_test_edeadlk_normal+0x1a7/0x220
[ 0.000000] [<c11e0cd0>] ? ww_test_context_lock_after_done+0x160/0x160
[ 0.000000] [<c11e0e77>] ww_test_edeadlk_normal+0x1a7/0x220
[ 0.000000] [<c1393e84>] ? dotest+0x32/0xcf
[ 0.000000] [<c1393e84>] dotest+0x32/0xcf
[ 0.000000] [<c1394091>] ww_tests+0x170/0x398
[ 0.000000] [<c11e464c>] locking_selftest+0x168c/0x1720
[ 0.000000] [<c154a939>] start_kernel+0x249/0x325
[ 0.000000] [<c154a52e>] ? obsolete_checksetup+0x95/0x95
[ 0.000000] [<c154a358>] i386_start_kernel+0x12e/0x131
[ 0.000000] ------------[ cut here ]------------
[ 0.000000] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/cpu/common.c:1371 warn_pre_alternatives+0x22/0x30()
[ 0.000000] You're using static_cpu_has before alternatives have run!
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #125
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] 00000000 00000000 c1505d38 c13938a3 c1484b96 c1505d68 c103a47a c1488bf8
[ 0.000000] c1505d94 00000000 c1484b96 0000055b c100f502 c100f502 c1505e20 00000008
[ 0.000000] c1032a90 c1505d80 c103a51e 00000009 c1505d78 c1488bf8 c1505d94 c1505d94
[ 0.000000] Call Trace:
[ 0.000000] [<c13938a3>] dump_stack+0x4b/0x66
[ 0.000000] [<c103a47a>] warn_slowpath_common+0x7a/0xa0
[ 0.000000] [<c100f502>] ? warn_pre_alternatives+0x22/0x30
[ 0.000000] [<c100f502>] ? warn_pre_alternatives+0x22/0x30
[ 0.000000] [<c1032a90>] ? vmalloc_sync_all+0x120/0x120
[ 0.000000] [<c103a51e>] warn_slowpath_fmt+0x2e/0x30
[ 0.000000] [<c100f502>] warn_pre_alternatives+0x22/0x30
[ 0.000000] [<c1032655>] __do_page_fault+0xe5/0x400
[ 0.000000] [<c1088ee0>] ? validate_chain.isra.23+0x5d0/0x6c0
[ 0.000000] [<c106c5e0>] ? dequeue_entity+0x420/0x4f0
[ 0.000000] [<c1032a90>] ? vmalloc_sync_all+0x120/0x120
[ 0.000000] [<c1032a98>] do_page_fault+0x8/0x10
[ 0.000000] [<c139cb97>] error_code+0x5f/0x64
[ 0.000000] [<c1032a90>] ? vmalloc_sync_all+0x120/0x120
[ 0.000000] [<c11cc966>] ? rb_next+0x6/0x50
[ 0.000000] [<c106a0cd>] pick_next_entity+0x2d/0xb0
[ 0.000000] [<c106a16f>] pick_next_task_fair+0x1f/0x40
[ 0.000000] [<c139a725>] __schedule+0x225/0x5d0
[ 0.000000] [<c10896bf>] ? mark_held_locks+0xcf/0x100
[ 0.000000] [<c13994f5>] ? __ww_mutex_lock+0x1b5/0x370
[ 0.000000] [<c1089976>] ? trace_hardirqs_on_caller+0x146/0x170
[ 0.000000] [<c139ab9d>] schedule+0x4d/0x50
[ 0.000000] [<c139add3>] schedule_preempt_disabled+0x13/0x20
[ 0.000000] [<c1399505>] __ww_mutex_lock+0x1c5/0x370
[ 0.000000] [<c11e0e77>] ? ww_test_edeadlk_normal+0x1a7/0x220
[ 0.000000] [<c11e0e77>] ? ww_test_edeadlk_normal+0x1a7/0x220
[ 0.000000] [<c11e0cd0>] ? ww_test_context_lock_after_done+0x160/0x160
[ 0.000000] [<c11e0e77>] ww_test_edeadlk_normal+0x1a7/0x220
[ 0.000000] [<c1393e84>] ? dotest+0x32/0xcf
[ 0.000000] [<c1393e84>] dotest+0x32/0xcf
[ 0.000000] [<c1394091>] ww_tests+0x170/0x398
[ 0.000000] [<c11e464c>] locking_selftest+0x168c/0x1720
[ 0.000000] [<c154a939>] start_kernel+0x249/0x325
[ 0.000000] [<c154a52e>] ? obsolete_checksetup+0x95/0x95
[ 0.000000] [<c154a358>] i386_start_kernel+0x12e/0x131
[ 0.000000] ---[ end trace 614b89df0eea1b4b ]---
[ 0.000000] BUG: unable to handle kernel NULL pointer dereference at 00000008
[ 0.000000] IP: [<c11cc966>] rb_next+0x6/0x50
[ 0.000000] *pde = 00000000
[ 0.000000] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.11.0-dirty #125
[ 0.000000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 0.000000] task: c150e920 ti: c1504000 task.ti: c1504000
[ 0.000000] EIP: 0060:[<c11cc966>] EFLAGS: 00210046 CPU: 0
[ 0.000000] EIP is at rb_next+0x6/0x50
[ 0.000000] EAX: 00000008 EBX: dffed4a0 ECX: 00000000 EDX: fffffff8
[ 0.000000] ESI: 00000000 EDI: 00000000 EBP: c1505e60 ESP: c1505e5c
[ 0.000000] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[ 0.000000] CR0: 8005003b CR2: 00000008 CR3: 01706000 CR4: 00000690
[ 0.000000] Stack:
[ 0.000000] dffed4a0 c1505e78 c106a0cd 0112a880 00000000 dffed4a0 00000000 c1505e88
[ 0.000000] c106a16f dffed440 c150eba0 c1505f10 c139a725 00000000 003c41e1 00000000
[ 0.000000] c150edc8 c1505eec c150e920 00000006 00000001 c16fe440 c16fe440 c150e920
[ 0.000000] Call Trace:
[ 0.000000] [<c106a0cd>] pick_next_entity+0x2d/0xb0
[ 0.000000] [<c106a16f>] pick_next_task_fair+0x1f/0x40
[ 0.000000] [<c139a725>] __schedule+0x225/0x5d0
[ 0.000000] [<c10896bf>] ? mark_held_locks+0xcf/0x100
[ 0.000000] [<c13994f5>] ? __ww_mutex_lock+0x1b5/0x370
[ 0.000000] [<c1089976>] ? trace_hardirqs_on_caller+0x146/0x170
[ 0.000000] [<c139ab9d>] schedule+0x4d/0x50
[ 0.000000] [<c139add3>] schedule_preempt_disabled+0x13/0x20
[ 0.000000] [<c1399505>] __ww_mutex_lock+0x1c5/0x370
[ 0.000000] [<c11e0e77>] ? ww_test_edeadlk_normal+0x1a7/0x220
[ 0.000000] [<c11e0e77>] ? ww_test_edeadlk_normal+0x1a7/0x220
[ 0.000000] [<c11e0cd0>] ? ww_test_context_lock_after_done+0x160/0x160
[ 0.000000] [<c11e0e77>] ww_test_edeadlk_normal+0x1a7/0x220
[ 0.000000] [<c1393e84>] ? dotest+0x32/0xcf
[ 0.000000] [<c1393e84>] dotest+0x32/0xcf
[ 0.000000] [<c1394091>] ww_tests+0x170/0x398
[ 0.000000] [<c11e464c>] locking_selftest+0x168c/0x1720
[ 0.000000] [<c154a939>] start_kernel+0x249/0x325
[ 0.000000] [<c154a52e>] ? obsolete_checksetup+0x95/0x95
[ 0.000000] [<c154a358>] i386_start_kernel+0x12e/0x131
[ 0.000000] Code: 90 8d 74 26 00 55 8b 00 89 e5 85 c0 75 09 eb 0e 90 8d 74 26 00 89 d0 8b 50 04 85 d2 75 f7 5d c3 90 8d 74 26 00 55 31 c9 89 e5 53 <8b> 10 39 d0 74 3c 8b 48 04 85 c9 75 07 eb 13 8d 76 00 89 d1 8b
[ 0.000000] EIP: [<c11cc966>] rb_next+0x6/0x50 SS:ESP 0068:c1505e5c
[ 0.000000] CR2: 0000000000000008
[ 0.000000] ---[ end trace 614b89df0eea1b4c ]---
[ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
---------- gcc version 4.6.3 end ----------
The patch below can fix "boot failure on gcc 3.x" and avoid "locking selftests
failure on gcc 3.x / 4.x".
---------- good patch start ----------
>From 04a2739f00822a4ca59128501b1f3f5bf4981af7 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Sun, 8 Sep 2013 13:06:42 +0900
Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
"!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
But changing from "!__builtin_constant_p(p == NULL)" to
"__builtin_constant_p(p) && p" causes locking selftest failures when built with
CONFIG_DEBUG_LOCKING_API_SELFTESTS=y. Therefore, change from
"!__builtin_constant_p(p == NULL)" to "p".
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: <stable@kernel.org> [3.11+]
---
kernel/mutex.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/mutex.c b/kernel/mutex.c
index a52ee7bb..3b04d6a 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -448,7 +448,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct task_struct *owner;
struct mspin_node node;
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (ww_ctx && ww_ctx->acquired > 0) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -478,7 +478,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
if ((atomic_read(&lock->count) == 1) &&
(atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
lock_acquired(&lock->dep_map, ip);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (ww_ctx) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -548,7 +548,7 @@ slowpath:
goto err;
}
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (ww_ctx && ww_ctx->acquired > 0) {
ret = __mutex_lock_check_stamp(lock, ww_ctx);
if (ret)
goto err;
@@ -568,7 +568,7 @@ done:
mutex_remove_waiter(lock, &waiter, current_thread_info());
mutex_set_owner(lock);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (ww_ctx) {
struct ww_mutex *ww = container_of(lock,
struct ww_mutex,
base);
--
1.7.8
---------- good patch end ----------
We need to give up __builtin_constant_p() optimization after all?
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootable kernel.
2013-09-08 4:32 ` Tetsuo Handa
@ 2013-09-08 5:28 ` Ilia Mirkin
2013-09-08 7:24 ` Tetsuo Handa
0 siblings, 1 reply; 15+ messages in thread
From: Ilia Mirkin @ 2013-09-08 5:28 UTC (permalink / raw)
To: Tetsuo Handa
Cc: Maarten Lankhorst, linux-kernel@vger.kernel.org, Daniel Vetter,
Rob Clark, a.p.zijlstra, mingo
On Sun, Sep 8, 2013 at 12:32 AM, Tetsuo Handa
<penguin-kernel@i-love.sakura.ne.jp> wrote:
> Hello.
>
> I found what is wrong.
>
> ---------- bad patch start ----------
> >From 3c56dfbd32a9b67ba824ce96128bb513eb65de4b Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Date: Sun, 8 Sep 2013 12:44:20 +0900
> Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
>
> Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
> "!__builtin_constant_p(p == NULL)" which I guess the author meant that
> "__builtin_constant_p(p) && p", but gcc 3.x cannot handle such expression
> correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
I think that !__builtin_constant_p(p == NULL) is basically saying "I
am unable to conclude that p == NULL at build time", which would
translate to something along the lines of
(__builtin_constant_p(p) && p) || !__builtin_constant_p(p)
Your logic will be be false for non-built-in-constants supplied as p.
Or perhaps it's just equivalent to !__builtin_constant_p(p), since the
compiler's ability to conclude whether it is NULL at build-time should
be unaffected by whether it actually is NULL or not. Some simple
experimentation with recent gcc's should be able to determine this.
The more I think about it, the more likely the latter interpretation
is correct and you can just drop the == NULL's. (Although perhaps the
original intent was more like the former.)
-ilia
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootable kernel.
2013-09-08 5:28 ` Ilia Mirkin
@ 2013-09-08 7:24 ` Tetsuo Handa
2013-09-08 7:42 ` Ilia Mirkin
2013-09-08 8:11 ` Maarten Lankhorst
0 siblings, 2 replies; 15+ messages in thread
From: Tetsuo Handa @ 2013-09-08 7:24 UTC (permalink / raw)
To: imirkin, maarten.lankhorst
Cc: linux-kernel, daniel.vetter, robdclark, a.p.zijlstra, mingo
Hello.
Ilia Mirkin wrote:
> > Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
> > "!__builtin_constant_p(p == NULL)" which I guess the author meant that
> > "__builtin_constant_p(p) && p", but gcc 3.x cannot handle such expression
> > correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
>
> I think that !__builtin_constant_p(p == NULL) is basically saying "I
> am unable to conclude that p == NULL at build time", which would
> translate to something along the lines of
>
> (__builtin_constant_p(p) && p) || !__builtin_constant_p(p)
>
I think
(__builtin_constant_p(p) && p) && p->acquired > 0
is safe but
(!__builtin_constant_p(p)) && p->acquired > 0
is not safe, for "p != NULL" check is required for avoiding NULL pointer
dereference.
It seems to me that
(!__builtin_constant_p(p == NULL))
need to be translated to something along the lines of
(__builtin_constant_p(p) && p) || (!__builtin_constant_p(p) && p)
which can be simplified as
(p)
.
> Or perhaps it's just equivalent to !__builtin_constant_p(p), since the
> compiler's ability to conclude whether it is NULL at build-time should
> be unaffected by whether it actually is NULL or not.
Likewise, it seems to me that
(!__builtin_constant_p(p == NULL))
need to be translated to something along the lines of
(!__builtin_constant_p(p) && p)
. Well this change as well can fix "boot failure on gcc 3.x" and avoid "locking
selftests failure on gcc 3.x / 4.x". OK, let's wait for answer from the author.
Can I add "Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>" to below patch?
---------- good patch start ----------
>From a8bbf6b3c2d44cb90d63820f146aaff119d871c9 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Sun, 8 Sep 2013 16:09:27 +0900
Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
"!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
Fix it by changing from "!__builtin_constant_p(p == NULL)" to
"!__builtin_constant_p(p) && p".
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: <stable@kernel.org> [3.11+]
---
kernel/mutex.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/mutex.c b/kernel/mutex.c
index a52ee7bb..ef02003 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -448,7 +448,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct task_struct *owner;
struct mspin_node node;
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (!__builtin_constant_p(ww_ctx) && ww_ctx && ww_ctx->acquired > 0) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -478,7 +478,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
if ((atomic_read(&lock->count) == 1) &&
(atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
lock_acquired(&lock->dep_map, ip);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (!__builtin_constant_p(ww_ctx) && ww_ctx) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -548,7 +548,7 @@ slowpath:
goto err;
}
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (!__builtin_constant_p(ww_ctx) && ww_ctx && ww_ctx->acquired > 0) {
ret = __mutex_lock_check_stamp(lock, ww_ctx);
if (ret)
goto err;
@@ -568,7 +568,7 @@ done:
mutex_remove_waiter(lock, &waiter, current_thread_info());
mutex_set_owner(lock);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (!__builtin_constant_p(ww_ctx) && ww_ctx) {
struct ww_mutex *ww = container_of(lock,
struct ww_mutex,
base);
--
1.7.8
---------- good patch end ----------
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootable kernel.
2013-09-08 7:24 ` Tetsuo Handa
@ 2013-09-08 7:42 ` Ilia Mirkin
2013-09-08 8:11 ` Maarten Lankhorst
1 sibling, 0 replies; 15+ messages in thread
From: Ilia Mirkin @ 2013-09-08 7:42 UTC (permalink / raw)
To: Tetsuo Handa
Cc: Maarten Lankhorst, linux-kernel@vger.kernel.org, Daniel Vetter,
Rob Clark, a.p.zijlstra, mingo
On Sun, Sep 8, 2013 at 3:24 AM, Tetsuo Handa
<penguin-kernel@i-love.sakura.ne.jp> wrote:
> Hello.
>
> Ilia Mirkin wrote:
>> > Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
>> > "!__builtin_constant_p(p == NULL)" which I guess the author meant that
>> > "__builtin_constant_p(p) && p", but gcc 3.x cannot handle such expression
>> > correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
>>
>> I think that !__builtin_constant_p(p == NULL) is basically saying "I
>> am unable to conclude that p == NULL at build time", which would
>> translate to something along the lines of
>>
>> (__builtin_constant_p(p) && p) || !__builtin_constant_p(p)
>>
>
> I think
>
> (__builtin_constant_p(p) && p) && p->acquired > 0
>
> is safe but
>
> (!__builtin_constant_p(p)) && p->acquired > 0
>
> is not safe, for "p != NULL" check is required for avoiding NULL pointer
> dereference.
>
> It seems to me that
>
> (!__builtin_constant_p(p == NULL))
>
> need to be translated to something along the lines of
>
> (__builtin_constant_p(p) && p) || (!__builtin_constant_p(p) && p)
>
> which can be simplified as
>
> (p)
>
> .
>
>> Or perhaps it's just equivalent to !__builtin_constant_p(p), since the
>> compiler's ability to conclude whether it is NULL at build-time should
>> be unaffected by whether it actually is NULL or not.
>
> Likewise, it seems to me that
>
> (!__builtin_constant_p(p == NULL))
>
> need to be translated to something along the lines of
>
> (!__builtin_constant_p(p) && p)
Well, I think the theory is that if p is not a compile-time constant
then it must not be null. At least that's the implication of the
current code. As I understand it, the == NULL is a no-op as far as gcc
is concerned, since it's not evaluating the expr, only checking if it
can be evaluated. Unless there can be a situation where it can know
whether a value is null or not, but not know its actual value, in
which case the && p is warranted.
>
> . Well this change as well can fix "boot failure on gcc 3.x" and avoid "locking
> selftests failure on gcc 3.x / 4.x". OK, let's wait for answer from the author.
Probably best to do that, yes. Maarten?
>
> Can I add "Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>" to below patch?
I don't think that's the correct usage of "Signed-off-by", since I
neither wrote the patch nor am I on the upstream path. If you really
want to give credit, you could invent a "Suggested-by" tag, but I
really don't care.
>
> ---------- good patch start ----------
> >From a8bbf6b3c2d44cb90d63820f146aaff119d871c9 Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Date: Sun, 8 Sep 2013 16:09:27 +0900
> Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
>
> Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
> "!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
> correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
>
> Fix it by changing from "!__builtin_constant_p(p == NULL)" to
> "!__builtin_constant_p(p) && p".
>
> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Cc: <stable@kernel.org> [3.11+]
> ---
> kernel/mutex.c | 8 ++++----
> 1 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/mutex.c b/kernel/mutex.c
> index a52ee7bb..ef02003 100644
> --- a/kernel/mutex.c
> +++ b/kernel/mutex.c
> @@ -448,7 +448,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> struct task_struct *owner;
> struct mspin_node node;
>
> - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> + if (!__builtin_constant_p(ww_ctx) && ww_ctx && ww_ctx->acquired > 0) {
> struct ww_mutex *ww;
>
> ww = container_of(lock, struct ww_mutex, base);
> @@ -478,7 +478,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> if ((atomic_read(&lock->count) == 1) &&
> (atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
> lock_acquired(&lock->dep_map, ip);
> - if (!__builtin_constant_p(ww_ctx == NULL)) {
> + if (!__builtin_constant_p(ww_ctx) && ww_ctx) {
> struct ww_mutex *ww;
> ww = container_of(lock, struct ww_mutex, base);
>
> @@ -548,7 +548,7 @@ slowpath:
> goto err;
> }
>
> - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> + if (!__builtin_constant_p(ww_ctx) && ww_ctx && ww_ctx->acquired > 0) {
> ret = __mutex_lock_check_stamp(lock, ww_ctx);
> if (ret)
> goto err;
> @@ -568,7 +568,7 @@ done:
> mutex_remove_waiter(lock, &waiter, current_thread_info());
> mutex_set_owner(lock);
>
> - if (!__builtin_constant_p(ww_ctx == NULL)) {
> + if (!__builtin_constant_p(ww_ctx) && ww_ctx) {
> struct ww_mutex *ww = container_of(lock,
> struct ww_mutex,
> base);
> --
> 1.7.8
> ---------- good patch end ----------
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootable kernel.
2013-09-08 7:24 ` Tetsuo Handa
2013-09-08 7:42 ` Ilia Mirkin
@ 2013-09-08 8:11 ` Maarten Lankhorst
2013-09-08 11:53 ` [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootablekernel Tetsuo Handa
1 sibling, 1 reply; 15+ messages in thread
From: Maarten Lankhorst @ 2013-09-08 8:11 UTC (permalink / raw)
To: Tetsuo Handa
Cc: imirkin, linux-kernel, daniel.vetter, robdclark, a.p.zijlstra,
mingo
Op 08-09-13 09:24, Tetsuo Handa schreef:
> Hello.
>
> Ilia Mirkin wrote:
>>> Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
>>> "!__builtin_constant_p(p == NULL)" which I guess the author meant that
>>> "__builtin_constant_p(p) && p", but gcc 3.x cannot handle such expression
>>> correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
>> I think that !__builtin_constant_p(p == NULL) is basically saying "I
>> am unable to conclude that p == NULL at build time", which would
>> translate to something along the lines of
>>
>> (__builtin_constant_p(p) && p) || !__builtin_constant_p(p)
>>
> I think
>
> (__builtin_constant_p(p) && p) && p->acquired > 0
>
> is safe but
>
> (!__builtin_constant_p(p)) && p->acquired > 0
>
> is not safe, for "p != NULL" check is required for avoiding NULL pointer
> dereference.
>
> It seems to me that
>
> (!__builtin_constant_p(p == NULL))
>
> need to be translated to something along the lines of
>
> (__builtin_constant_p(p) && p) || (!__builtin_constant_p(p) && p)
>
> which can be simplified as
>
> (p)
>
> .
>
>> Or perhaps it's just equivalent to !__builtin_constant_p(p), since the
>> compiler's ability to conclude whether it is NULL at build-time should
>> be unaffected by whether it actually is NULL or not.
> Likewise, it seems to me that
>
> (!__builtin_constant_p(p == NULL))
>
> need to be translated to something along the lines of
>
> (!__builtin_constant_p(p) && p)
>
> . Well this change as well can fix "boot failure on gcc 3.x" and avoid "locking
> selftests failure on gcc 3.x / 4.x". OK, let's wait for answer from the author.
>
> Can I add "Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>" to below patch?
>
> ---------- good patch start ----------
> >From a8bbf6b3c2d44cb90d63820f146aaff119d871c9 Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Date: Sun, 8 Sep 2013 16:09:27 +0900
> Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
>
> Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
> "!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
> correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
>
> Fix it by changing from "!__builtin_constant_p(p == NULL)" to
> "!__builtin_constant_p(p) && p".
>
> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Cc: <stable@kernel.org> [3.11+]
> ---
> kernel/mutex.c | 8 ++++----
> 1 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/mutex.c b/kernel/mutex.c
> index a52ee7bb..ef02003 100644
> --- a/kernel/mutex.c
> +++ b/kernel/mutex.c
> @@ -448,7 +448,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> struct task_struct *owner;
> struct mspin_node node;
>
> - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> + if (!__builtin_constant_p(ww_ctx) && ww_ctx && ww_ctx->acquired > 0) {
> struct ww_mutex *ww;
>
> ww = container_of(lock, struct ww_mutex, base);
> @@ -478,7 +478,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> if ((atomic_read(&lock->count) == 1) &&
> (atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
> lock_acquired(&lock->dep_map, ip);
> - if (!__builtin_constant_p(ww_ctx == NULL)) {
> + if (!__builtin_constant_p(ww_ctx) && ww_ctx) {
> struct ww_mutex *ww;
> ww = container_of(lock, struct ww_mutex, base);
>
> @@ -548,7 +548,7 @@ slowpath:
> goto err;
> }
>
> - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> + if (!__builtin_constant_p(ww_ctx) && ww_ctx && ww_ctx->acquired > 0) {
> ret = __mutex_lock_check_stamp(lock, ww_ctx);
> if (ret)
> goto err;
> @@ -568,7 +568,7 @@ done:
> mutex_remove_waiter(lock, &waiter, current_thread_info());
> mutex_set_owner(lock);
>
> - if (!__builtin_constant_p(ww_ctx == NULL)) {
> + if (!__builtin_constant_p(ww_ctx) && ww_ctx) {
> struct ww_mutex *ww = container_of(lock,
> struct ww_mutex,
> base);
Wrong. Wrong. Wrong.
The builtin_constant_p was explicitly added to NOT do a null pointer check in the ww_ctx case, and now you re-introduce it for ALL
compilers. Gcc will still think ww_ctx may be NULL in the ww_mutex_lock case.
__builtin_constant_p(ww_ctx) always evaluates to false, and is not equivalent to __builtin_constant_p(ww_ctx != NULL) in gcc 4.6 at least,
I have no idea why gcc treats pointers differently like that. Explicitly testing against NULL fixes it.
__builtin_constant_p(ww_ctx == NULL) should return the same value as __builtin_constant_p(ww_ctx != NULL), but I did the == NULL check for clarity,
if it's broken for your compiler, please add a bool use_ww_ctx or something to __mutex_lock_common that's set directly instead, the __builtin_constant_p trick
might be too gcc version specific.
~Maarten
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootablekernel.
2013-09-08 8:11 ` Maarten Lankhorst
@ 2013-09-08 11:53 ` Tetsuo Handa
2013-09-08 20:36 ` Maarten Lankhorst
0 siblings, 1 reply; 15+ messages in thread
From: Tetsuo Handa @ 2013-09-08 11:53 UTC (permalink / raw)
To: maarten.lankhorst
Cc: imirkin, linux-kernel, daniel.vetter, robdclark, a.p.zijlstra,
mingo
Hello.
Maarten Lankhorst wrote:
> if it's broken for your compiler, please add a bool use_ww_ctx or something to __mutex_lock_common that's set directly instead, the __builtin_constant_p trick
> might be too gcc version specific.
I see. I tested that both gcc 3.x and gcc 4.x can generate bootable kernel
using below fix.
----------
>From f71fb89bccaa7ed5b3a14e735a1b9cc1a0e7112d Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Sun, 8 Sep 2013 20:37:19 +0900
Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p()
usage.
Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
"!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: <stable@kernel.org> [3.11+]
---
kernel/mutex.c | 9 +++++----
1 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/kernel/mutex.c b/kernel/mutex.c
index a52ee7bb..2e7984e 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -414,6 +414,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct mutex_waiter waiter;
unsigned long flags;
int ret;
+ const bool use_ww_ctx = !!ww_ctx;
preempt_disable();
mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip);
@@ -448,7 +449,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct task_struct *owner;
struct mspin_node node;
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (use_ww_ctx && ww_ctx->acquired > 0) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -478,7 +479,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
if ((atomic_read(&lock->count) == 1) &&
(atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
lock_acquired(&lock->dep_map, ip);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (use_ww_ctx) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -548,7 +549,7 @@ slowpath:
goto err;
}
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (use_ww_ctx && ww_ctx->acquired > 0) {
ret = __mutex_lock_check_stamp(lock, ww_ctx);
if (ret)
goto err;
@@ -568,7 +569,7 @@ done:
mutex_remove_waiter(lock, &waiter, current_thread_info());
mutex_set_owner(lock);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (use_ww_ctx) {
struct ww_mutex *ww = container_of(lock,
struct ww_mutex,
base);
--
1.7.8
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootablekernel.
2013-09-08 11:53 ` [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootablekernel Tetsuo Handa
@ 2013-09-08 20:36 ` Maarten Lankhorst
2013-09-09 11:56 ` Tetsuo Handa
0 siblings, 1 reply; 15+ messages in thread
From: Maarten Lankhorst @ 2013-09-08 20:36 UTC (permalink / raw)
To: Tetsuo Handa
Cc: imirkin, linux-kernel, daniel.vetter, robdclark, a.p.zijlstra,
mingo
Op 08-09-13 13:53, Tetsuo Handa schreef:
> Hello.
>
> Maarten Lankhorst wrote:
>> if it's broken for your compiler, please add a bool use_ww_ctx or something to __mutex_lock_common that's set directly instead, the __builtin_constant_p trick
>> might be too gcc version specific.
> I see. I tested that both gcc 3.x and gcc 4.x can generate bootable kernel
> using below fix.
> ----------
> >From f71fb89bccaa7ed5b3a14e735a1b9cc1a0e7112d Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Date: Sun, 8 Sep 2013 20:37:19 +0900
> Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p()
> usage.
>
> Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
> "!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
> correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
>
> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Cc: <stable@kernel.org> [3.11+]
> ---
> kernel/mutex.c | 9 +++++----
> 1 files changed, 5 insertions(+), 4 deletions(-)
Almost correct. I meant passing it as parameter to __mutex_lock_common. Your version will still cause an extra pointless null check in the ww_mutex_lock case.
> diff --git a/kernel/mutex.c b/kernel/mutex.c
> index a52ee7bb..2e7984e 100644
> --- a/kernel/mutex.c
> +++ b/kernel/mutex.c
> @@ -414,6 +414,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> struct mutex_waiter waiter;
> unsigned long flags;
> int ret;
> + const bool use_ww_ctx = !!ww_ctx;
>
> preempt_disable();
> mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip);
> @@ -448,7 +449,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> struct task_struct *owner;
> struct mspin_node node;
>
> - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> + if (use_ww_ctx && ww_ctx->acquired > 0) {
> struct ww_mutex *ww;
>
> ww = container_of(lock, struct ww_mutex, base);
> @@ -478,7 +479,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> if ((atomic_read(&lock->count) == 1) &&
> (atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
> lock_acquired(&lock->dep_map, ip);
> - if (!__builtin_constant_p(ww_ctx == NULL)) {
> + if (use_ww_ctx) {
> struct ww_mutex *ww;
> ww = container_of(lock, struct ww_mutex, base);
>
> @@ -548,7 +549,7 @@ slowpath:
> goto err;
> }
>
> - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> + if (use_ww_ctx && ww_ctx->acquired > 0) {
> ret = __mutex_lock_check_stamp(lock, ww_ctx);
> if (ret)
> goto err;
> @@ -568,7 +569,7 @@ done:
> mutex_remove_waiter(lock, &waiter, current_thread_info());
> mutex_set_owner(lock);
>
> - if (!__builtin_constant_p(ww_ctx == NULL)) {
> + if (use_ww_ctx) {
> struct ww_mutex *ww = container_of(lock,
> struct ww_mutex,
> base);
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootablekernel.
2013-09-08 20:36 ` Maarten Lankhorst
@ 2013-09-09 11:56 ` Tetsuo Handa
2013-09-09 12:07 ` Maarten Lankhorst
2013-09-09 12:58 ` Peter Zijlstra
0 siblings, 2 replies; 15+ messages in thread
From: Tetsuo Handa @ 2013-09-09 11:56 UTC (permalink / raw)
To: maarten.lankhorst
Cc: imirkin, linux-kernel, daniel.vetter, robdclark, a.p.zijlstra,
mingo
Maarten Lankhorst wrote:
> Almost correct. I meant passing it as parameter to __mutex_lock_common. Your version will still cause an extra pointless null check in the ww_mutex_lock case.
Ah, I see.
----------
>From 95f189eb37c25ddf8e48d5dfc2f9f1185c52b6a8 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Mon, 9 Sep 2013 20:48:13 +0900
Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
"!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
Fix it by explicitly passing a bool which tells whether p != NULL or not.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: <stable@kernel.org> [3.11+]
---
kernel/mutex.c | 32 ++++++++++++++++----------------
1 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/kernel/mutex.c b/kernel/mutex.c
index a52ee7bb..a2b80f1 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -408,7 +408,7 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock,
static __always_inline int __sched
__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct lockdep_map *nest_lock, unsigned long ip,
- struct ww_acquire_ctx *ww_ctx)
+ struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
{
struct task_struct *task = current;
struct mutex_waiter waiter;
@@ -448,7 +448,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct task_struct *owner;
struct mspin_node node;
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (use_ww_ctx && ww_ctx->acquired > 0) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -478,7 +478,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
if ((atomic_read(&lock->count) == 1) &&
(atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
lock_acquired(&lock->dep_map, ip);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (use_ww_ctx) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -548,7 +548,7 @@ slowpath:
goto err;
}
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (use_ww_ctx && ww_ctx->acquired > 0) {
ret = __mutex_lock_check_stamp(lock, ww_ctx);
if (ret)
goto err;
@@ -568,7 +568,7 @@ done:
mutex_remove_waiter(lock, &waiter, current_thread_info());
mutex_set_owner(lock);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (use_ww_ctx) {
struct ww_mutex *ww = container_of(lock,
struct ww_mutex,
base);
@@ -618,7 +618,7 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
- subclass, NULL, _RET_IP_, NULL);
+ subclass, NULL, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(mutex_lock_nested);
@@ -628,7 +628,7 @@ _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
{
might_sleep();
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
- 0, nest, _RET_IP_, NULL);
+ 0, nest, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock);
@@ -638,7 +638,7 @@ mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
return __mutex_lock_common(lock, TASK_KILLABLE,
- subclass, NULL, _RET_IP_, NULL);
+ subclass, NULL, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(mutex_lock_killable_nested);
@@ -647,7 +647,7 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
return __mutex_lock_common(lock, TASK_INTERRUPTIBLE,
- subclass, NULL, _RET_IP_, NULL);
+ subclass, NULL, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
@@ -685,7 +685,7 @@ __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
might_sleep();
ret = __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE,
- 0, &ctx->dep_map, _RET_IP_, ctx);
+ 0, &ctx->dep_map, _RET_IP_, ctx, 1);
if (!ret && ctx->acquired > 1)
return ww_mutex_deadlock_injection(lock, ctx);
@@ -700,7 +700,7 @@ __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
might_sleep();
ret = __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE,
- 0, &ctx->dep_map, _RET_IP_, ctx);
+ 0, &ctx->dep_map, _RET_IP_, ctx, 1);
if (!ret && ctx->acquired > 1)
return ww_mutex_deadlock_injection(lock, ctx);
@@ -812,28 +812,28 @@ __mutex_lock_slowpath(atomic_t *lock_count)
struct mutex *lock = container_of(lock_count, struct mutex, count);
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0,
- NULL, _RET_IP_, NULL);
+ NULL, _RET_IP_, NULL, 0);
}
static noinline int __sched
__mutex_lock_killable_slowpath(struct mutex *lock)
{
return __mutex_lock_common(lock, TASK_KILLABLE, 0,
- NULL, _RET_IP_, NULL);
+ NULL, _RET_IP_, NULL, 0);
}
static noinline int __sched
__mutex_lock_interruptible_slowpath(struct mutex *lock)
{
return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0,
- NULL, _RET_IP_, NULL);
+ NULL, _RET_IP_, NULL, 0);
}
static noinline int __sched
__ww_mutex_lock_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
{
return __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE, 0,
- NULL, _RET_IP_, ctx);
+ NULL, _RET_IP_, ctx, 1);
}
static noinline int __sched
@@ -841,7 +841,7 @@ __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock,
struct ww_acquire_ctx *ctx)
{
return __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE, 0,
- NULL, _RET_IP_, ctx);
+ NULL, _RET_IP_, ctx, 1);
}
#endif
--
1.7.8
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootablekernel.
2013-09-09 11:56 ` Tetsuo Handa
@ 2013-09-09 12:07 ` Maarten Lankhorst
2013-09-09 13:22 ` Tetsuo Handa
2013-09-09 12:58 ` Peter Zijlstra
1 sibling, 1 reply; 15+ messages in thread
From: Maarten Lankhorst @ 2013-09-09 12:07 UTC (permalink / raw)
To: Tetsuo Handa
Cc: imirkin, linux-kernel, daniel.vetter, robdclark, a.p.zijlstra,
mingo
Op 09-09-13 13:56, Tetsuo Handa schreef:
> Maarten Lankhorst wrote:
>> Almost correct. I meant passing it as parameter to __mutex_lock_common. Your version will still cause an extra pointless null check in the ww_mutex_lock case.
> Ah, I see.
> ----------
> >From 95f189eb37c25ddf8e48d5dfc2f9f1185c52b6a8 Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Date: Mon, 9 Sep 2013 20:48:13 +0900
> Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
>
> Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
> "!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
> correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
>
> Fix it by explicitly passing a bool which tells whether p != NULL or not.
>
Yeah looks ok, did you run the selftests from CONFIG_DEBUG_LOCKING_API_SELFTESTS,
with/without CONFIG_PROVE_LOCKING and once more with DEBUG_MUTEXES also unset?
~Maarten
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootablekernel.
2013-09-09 11:56 ` Tetsuo Handa
2013-09-09 12:07 ` Maarten Lankhorst
@ 2013-09-09 12:58 ` Peter Zijlstra
2013-10-03 14:02 ` [PATCH for 3.12-rcX] mutex: Avoid gcc version dependent __builtin_constant_p() usage Tetsuo Handa
1 sibling, 1 reply; 15+ messages in thread
From: Peter Zijlstra @ 2013-09-09 12:58 UTC (permalink / raw)
To: Tetsuo Handa
Cc: maarten.lankhorst, imirkin, linux-kernel, daniel.vetter,
robdclark, mingo
On Mon, Sep 09, 2013 at 08:56:53PM +0900, Tetsuo Handa wrote:
> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Date: Mon, 9 Sep 2013 20:48:13 +0900
> Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
>
> Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
> "!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
> correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
>
> Fix it by explicitly passing a bool which tells whether p != NULL or not.
>
> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Cc: <stable@kernel.org> [3.11+]
> ---
> kernel/mutex.c | 32 ++++++++++++++++----------------
> 1 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/kernel/mutex.c b/kernel/mutex.c
> index a52ee7bb..a2b80f1 100644
> --- a/kernel/mutex.c
> +++ b/kernel/mutex.c
> @@ -408,7 +408,7 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock,
> static __always_inline int __sched
> __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> struct lockdep_map *nest_lock, unsigned long ip,
> - struct ww_acquire_ctx *ww_ctx)
> + struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
> {
> struct task_struct *task = current;
> struct mutex_waiter waiter;
> @@ -448,7 +448,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> struct task_struct *owner;
> struct mspin_node node;
>
> - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> + if (use_ww_ctx && ww_ctx->acquired > 0) {
> struct ww_mutex *ww;
>
> ww = container_of(lock, struct ww_mutex, base);
> @@ -478,7 +478,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> if ((atomic_read(&lock->count) == 1) &&
> (atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
> lock_acquired(&lock->dep_map, ip);
> - if (!__builtin_constant_p(ww_ctx == NULL)) {
> + if (use_ww_ctx) {
> struct ww_mutex *ww;
> ww = container_of(lock, struct ww_mutex, base);
>
> @@ -548,7 +548,7 @@ slowpath:
> goto err;
> }
>
> - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> + if (use_ww_ctx && ww_ctx->acquired > 0) {
> ret = __mutex_lock_check_stamp(lock, ww_ctx);
> if (ret)
> goto err;
> @@ -568,7 +568,7 @@ done:
> mutex_remove_waiter(lock, &waiter, current_thread_info());
> mutex_set_owner(lock);
>
> - if (!__builtin_constant_p(ww_ctx == NULL)) {
> + if (use_ww_ctx) {
> struct ww_mutex *ww = container_of(lock,
> struct ww_mutex,
> base);
> @@ -618,7 +618,7 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass)
> {
> might_sleep();
> __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
> - subclass, NULL, _RET_IP_, NULL);
> + subclass, NULL, _RET_IP_, NULL, 0);
> }
>
> EXPORT_SYMBOL_GPL(mutex_lock_nested);
This is a sad patch, but provided it actually generates similar code I
suppose its the best we can do bar whole sale deprecating gcc-3.
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootablekernel.
2013-09-09 12:07 ` Maarten Lankhorst
@ 2013-09-09 13:22 ` Tetsuo Handa
2013-09-24 14:51 ` Tetsuo Handa
0 siblings, 1 reply; 15+ messages in thread
From: Tetsuo Handa @ 2013-09-09 13:22 UTC (permalink / raw)
To: maarten.lankhorst
Cc: imirkin, linux-kernel, daniel.vetter, robdclark, a.p.zijlstra,
mingo
Maarten Lankhorst wrote:
> Yeah looks ok, did you run the selftests from CONFIG_DEBUG_LOCKING_API_SELFTESTS,
> with/without CONFIG_PROVE_LOCKING and once more with DEBUG_MUTEXES also unset?
Since CONFIG_DEBUG_MUTEXES=n && CONFIG_PROVE_LOCKING=y is impossible, I tested
CONFIG_DEBUG_MUTEXES=y
CONFIG_PROVE_LOCKING=y
CONFIG_DEBUG_LOCKING_API_SELFTESTS=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_PROVE_LOCKING=n
CONFIG_DEBUG_LOCKING_API_SELFTESTS=y
CONFIG_DEBUG_MUTEXES=n
CONFIG_PROVE_LOCKING=n
CONFIG_DEBUG_LOCKING_API_SELFTESTS=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_PROVE_LOCKING=y
CONFIG_DEBUG_LOCKING_API_SELFTESTS=n
CONFIG_DEBUG_MUTEXES=y
CONFIG_PROVE_LOCKING=n
CONFIG_DEBUG_LOCKING_API_SELFTESTS=n
CONFIG_DEBUG_MUTEXES=n
CONFIG_PROVE_LOCKING=n
CONFIG_DEBUG_LOCKING_API_SELFTESTS=n
and all works OK.
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootablekernel.
2013-09-09 13:22 ` Tetsuo Handa
@ 2013-09-24 14:51 ` Tetsuo Handa
0 siblings, 0 replies; 15+ messages in thread
From: Tetsuo Handa @ 2013-09-24 14:51 UTC (permalink / raw)
To: maarten.lankhorst
Cc: imirkin, linux-kernel, daniel.vetter, robdclark, a.p.zijlstra,
mingo
Hello, Maarten.
Is this patch already queued for 3.12-rcX ?
I expect this patch be committed before sending a patch for 3.11-stable.
Regards.
----------
>From a1b01c858143c2c2c92b17e7df096042bfe0df6b Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Tue, 24 Sep 2013 23:44:17 +0900
Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
"!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
Fix it by explicitly passing a bool which tells whether p != NULL or not.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
kernel/mutex.c | 32 ++++++++++++++++----------------
1 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/kernel/mutex.c b/kernel/mutex.c
index 6d647ae..d24105b 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -410,7 +410,7 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock,
static __always_inline int __sched
__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct lockdep_map *nest_lock, unsigned long ip,
- struct ww_acquire_ctx *ww_ctx)
+ struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
{
struct task_struct *task = current;
struct mutex_waiter waiter;
@@ -450,7 +450,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct task_struct *owner;
struct mspin_node node;
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (use_ww_ctx && ww_ctx->acquired > 0) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -480,7 +480,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
if ((atomic_read(&lock->count) == 1) &&
(atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
lock_acquired(&lock->dep_map, ip);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (use_ww_ctx) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -551,7 +551,7 @@ slowpath:
goto err;
}
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (use_ww_ctx && ww_ctx->acquired > 0) {
ret = __mutex_lock_check_stamp(lock, ww_ctx);
if (ret)
goto err;
@@ -575,7 +575,7 @@ skip_wait:
lock_acquired(&lock->dep_map, ip);
mutex_set_owner(lock);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (use_ww_ctx) {
struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
struct mutex_waiter *cur;
@@ -615,7 +615,7 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
- subclass, NULL, _RET_IP_, NULL);
+ subclass, NULL, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(mutex_lock_nested);
@@ -625,7 +625,7 @@ _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
{
might_sleep();
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
- 0, nest, _RET_IP_, NULL);
+ 0, nest, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock);
@@ -635,7 +635,7 @@ mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
return __mutex_lock_common(lock, TASK_KILLABLE,
- subclass, NULL, _RET_IP_, NULL);
+ subclass, NULL, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(mutex_lock_killable_nested);
@@ -644,7 +644,7 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
return __mutex_lock_common(lock, TASK_INTERRUPTIBLE,
- subclass, NULL, _RET_IP_, NULL);
+ subclass, NULL, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
@@ -682,7 +682,7 @@ __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
might_sleep();
ret = __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE,
- 0, &ctx->dep_map, _RET_IP_, ctx);
+ 0, &ctx->dep_map, _RET_IP_, ctx, 1);
if (!ret && ctx->acquired > 1)
return ww_mutex_deadlock_injection(lock, ctx);
@@ -697,7 +697,7 @@ __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
might_sleep();
ret = __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE,
- 0, &ctx->dep_map, _RET_IP_, ctx);
+ 0, &ctx->dep_map, _RET_IP_, ctx, 1);
if (!ret && ctx->acquired > 1)
return ww_mutex_deadlock_injection(lock, ctx);
@@ -809,28 +809,28 @@ __mutex_lock_slowpath(atomic_t *lock_count)
struct mutex *lock = container_of(lock_count, struct mutex, count);
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0,
- NULL, _RET_IP_, NULL);
+ NULL, _RET_IP_, NULL, 0);
}
static noinline int __sched
__mutex_lock_killable_slowpath(struct mutex *lock)
{
return __mutex_lock_common(lock, TASK_KILLABLE, 0,
- NULL, _RET_IP_, NULL);
+ NULL, _RET_IP_, NULL, 0);
}
static noinline int __sched
__mutex_lock_interruptible_slowpath(struct mutex *lock)
{
return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0,
- NULL, _RET_IP_, NULL);
+ NULL, _RET_IP_, NULL, 0);
}
static noinline int __sched
__ww_mutex_lock_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
{
return __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE, 0,
- NULL, _RET_IP_, ctx);
+ NULL, _RET_IP_, ctx, 1);
}
static noinline int __sched
@@ -838,7 +838,7 @@ __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock,
struct ww_acquire_ctx *ctx)
{
return __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE, 0,
- NULL, _RET_IP_, ctx);
+ NULL, _RET_IP_, ctx, 1);
}
#endif
--
1.7.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH for 3.12-rcX] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
2013-09-09 12:58 ` Peter Zijlstra
@ 2013-10-03 14:02 ` Tetsuo Handa
2013-10-16 20:20 ` Tetsuo Handa
0 siblings, 1 reply; 15+ messages in thread
From: Tetsuo Handa @ 2013-10-03 14:02 UTC (permalink / raw)
To: peterz, maarten.lankhorst
Cc: imirkin, linux-kernel, daniel.vetter, robdclark, mingo
Peter Zijlstra wrote:
> On Mon, Sep 09, 2013 at 08:56:53PM +0900, Tetsuo Handa wrote:
> > From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> > Date: Mon, 9 Sep 2013 20:48:13 +0900
> > Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
> >
> > Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
> > "!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
> > correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
> >
> > Fix it by explicitly passing a bool which tells whether p != NULL or not.
> >
> > Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> > Cc: <stable@kernel.org> [3.11+]
> > ---
> > kernel/mutex.c | 32 ++++++++++++++++----------------
> > 1 files changed, 16 insertions(+), 16 deletions(-)
> >
> > diff --git a/kernel/mutex.c b/kernel/mutex.c
> > index a52ee7bb..a2b80f1 100644
> > --- a/kernel/mutex.c
> > +++ b/kernel/mutex.c
> > @@ -408,7 +408,7 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock,
> > static __always_inline int __sched
> > __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> > struct lockdep_map *nest_lock, unsigned long ip,
> > - struct ww_acquire_ctx *ww_ctx)
> > + struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
> > {
> > struct task_struct *task = current;
> > struct mutex_waiter waiter;
> > @@ -448,7 +448,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> > struct task_struct *owner;
> > struct mspin_node node;
> >
> > - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> > + if (use_ww_ctx && ww_ctx->acquired > 0) {
> > struct ww_mutex *ww;
> >
> > ww = container_of(lock, struct ww_mutex, base);
> > @@ -478,7 +478,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> > if ((atomic_read(&lock->count) == 1) &&
> > (atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
> > lock_acquired(&lock->dep_map, ip);
> > - if (!__builtin_constant_p(ww_ctx == NULL)) {
> > + if (use_ww_ctx) {
> > struct ww_mutex *ww;
> > ww = container_of(lock, struct ww_mutex, base);
> >
> > @@ -548,7 +548,7 @@ slowpath:
> > goto err;
> > }
> >
> > - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> > + if (use_ww_ctx && ww_ctx->acquired > 0) {
> > ret = __mutex_lock_check_stamp(lock, ww_ctx);
> > if (ret)
> > goto err;
> > @@ -568,7 +568,7 @@ done:
> > mutex_remove_waiter(lock, &waiter, current_thread_info());
> > mutex_set_owner(lock);
> >
> > - if (!__builtin_constant_p(ww_ctx == NULL)) {
> > + if (use_ww_ctx) {
> > struct ww_mutex *ww = container_of(lock,
> > struct ww_mutex,
> > base);
> > @@ -618,7 +618,7 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass)
> > {
> > might_sleep();
> > __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
> > - subclass, NULL, _RET_IP_, NULL);
> > + subclass, NULL, _RET_IP_, NULL, 0);
> > }
> >
> > EXPORT_SYMBOL_GPL(mutex_lock_nested);
>
> This is a sad patch, but provided it actually generates similar code I
> suppose its the best we can do bar whole sale deprecating gcc-3.
>
Can the patch below go to 3.12-rcX (and the patch above to 3.11-stable which
does the same thing)?
Regards.
----------
>From a1b01c858143c2c2c92b17e7df096042bfe0df6b Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Tue, 24 Sep 2013 23:44:17 +0900
Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
"!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
Fix it by explicitly passing a bool which tells whether p != NULL or not.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
kernel/mutex.c | 32 ++++++++++++++++----------------
1 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/kernel/mutex.c b/kernel/mutex.c
index 6d647ae..d24105b 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -410,7 +410,7 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock,
static __always_inline int __sched
__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct lockdep_map *nest_lock, unsigned long ip,
- struct ww_acquire_ctx *ww_ctx)
+ struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
{
struct task_struct *task = current;
struct mutex_waiter waiter;
@@ -450,7 +450,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct task_struct *owner;
struct mspin_node node;
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (use_ww_ctx && ww_ctx->acquired > 0) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -480,7 +480,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
if ((atomic_read(&lock->count) == 1) &&
(atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
lock_acquired(&lock->dep_map, ip);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (use_ww_ctx) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);
@@ -551,7 +551,7 @@ slowpath:
goto err;
}
- if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+ if (use_ww_ctx && ww_ctx->acquired > 0) {
ret = __mutex_lock_check_stamp(lock, ww_ctx);
if (ret)
goto err;
@@ -575,7 +575,7 @@ skip_wait:
lock_acquired(&lock->dep_map, ip);
mutex_set_owner(lock);
- if (!__builtin_constant_p(ww_ctx == NULL)) {
+ if (use_ww_ctx) {
struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
struct mutex_waiter *cur;
@@ -615,7 +615,7 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
- subclass, NULL, _RET_IP_, NULL);
+ subclass, NULL, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(mutex_lock_nested);
@@ -625,7 +625,7 @@ _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
{
might_sleep();
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
- 0, nest, _RET_IP_, NULL);
+ 0, nest, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock);
@@ -635,7 +635,7 @@ mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
return __mutex_lock_common(lock, TASK_KILLABLE,
- subclass, NULL, _RET_IP_, NULL);
+ subclass, NULL, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(mutex_lock_killable_nested);
@@ -644,7 +644,7 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
return __mutex_lock_common(lock, TASK_INTERRUPTIBLE,
- subclass, NULL, _RET_IP_, NULL);
+ subclass, NULL, _RET_IP_, NULL, 0);
}
EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
@@ -682,7 +682,7 @@ __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
might_sleep();
ret = __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE,
- 0, &ctx->dep_map, _RET_IP_, ctx);
+ 0, &ctx->dep_map, _RET_IP_, ctx, 1);
if (!ret && ctx->acquired > 1)
return ww_mutex_deadlock_injection(lock, ctx);
@@ -697,7 +697,7 @@ __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
might_sleep();
ret = __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE,
- 0, &ctx->dep_map, _RET_IP_, ctx);
+ 0, &ctx->dep_map, _RET_IP_, ctx, 1);
if (!ret && ctx->acquired > 1)
return ww_mutex_deadlock_injection(lock, ctx);
@@ -809,28 +809,28 @@ __mutex_lock_slowpath(atomic_t *lock_count)
struct mutex *lock = container_of(lock_count, struct mutex, count);
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0,
- NULL, _RET_IP_, NULL);
+ NULL, _RET_IP_, NULL, 0);
}
static noinline int __sched
__mutex_lock_killable_slowpath(struct mutex *lock)
{
return __mutex_lock_common(lock, TASK_KILLABLE, 0,
- NULL, _RET_IP_, NULL);
+ NULL, _RET_IP_, NULL, 0);
}
static noinline int __sched
__mutex_lock_interruptible_slowpath(struct mutex *lock)
{
return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0,
- NULL, _RET_IP_, NULL);
+ NULL, _RET_IP_, NULL, 0);
}
static noinline int __sched
__ww_mutex_lock_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
{
return __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE, 0,
- NULL, _RET_IP_, ctx);
+ NULL, _RET_IP_, ctx, 1);
}
static noinline int __sched
@@ -838,7 +838,7 @@ __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock,
struct ww_acquire_ctx *ctx)
{
return __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE, 0,
- NULL, _RET_IP_, ctx);
+ NULL, _RET_IP_, ctx, 1);
}
#endif
--
1.7.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [PATCH for 3.12-rcX] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
2013-10-03 14:02 ` [PATCH for 3.12-rcX] mutex: Avoid gcc version dependent __builtin_constant_p() usage Tetsuo Handa
@ 2013-10-16 20:20 ` Tetsuo Handa
0 siblings, 0 replies; 15+ messages in thread
From: Tetsuo Handa @ 2013-10-16 20:20 UTC (permalink / raw)
To: mingo; +Cc: linux-kernel, torvalds
I'm worrying that this patch becomes too late for backporting to 3.11-stable.
Since there is no objection, can this patch go?
Peter Zijlstra wrote:
> This is a sad patch, but provided it actually generates similar code I
> suppose its the best we can do bar whole sale deprecating gcc-3.
Tetsuo Handa wrote:
> Can the patch below go to 3.12-rcX (and the patch above to 3.11-stable which
> does the same thing)?
>
> Regards.
> ----------
> >From a1b01c858143c2c2c92b17e7df096042bfe0df6b Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Date: Tue, 24 Sep 2013 23:44:17 +0900
> Subject: [PATCH] mutex: Avoid gcc version dependent __builtin_constant_p() usage.
>
> Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
> "!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
> correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
>
> Fix it by explicitly passing a bool which tells whether p != NULL or not.
>
> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> ---
> kernel/mutex.c | 32 ++++++++++++++++----------------
> 1 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/kernel/mutex.c b/kernel/mutex.c
> index 6d647ae..d24105b 100644
> --- a/kernel/mutex.c
> +++ b/kernel/mutex.c
> @@ -410,7 +410,7 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock,
> static __always_inline int __sched
> __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> struct lockdep_map *nest_lock, unsigned long ip,
> - struct ww_acquire_ctx *ww_ctx)
> + struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
> {
> struct task_struct *task = current;
> struct mutex_waiter waiter;
> @@ -450,7 +450,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> struct task_struct *owner;
> struct mspin_node node;
>
> - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> + if (use_ww_ctx && ww_ctx->acquired > 0) {
> struct ww_mutex *ww;
>
> ww = container_of(lock, struct ww_mutex, base);
> @@ -480,7 +480,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
> if ((atomic_read(&lock->count) == 1) &&
> (atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
> lock_acquired(&lock->dep_map, ip);
> - if (!__builtin_constant_p(ww_ctx == NULL)) {
> + if (use_ww_ctx) {
> struct ww_mutex *ww;
> ww = container_of(lock, struct ww_mutex, base);
>
> @@ -551,7 +551,7 @@ slowpath:
> goto err;
> }
>
> - if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
> + if (use_ww_ctx && ww_ctx->acquired > 0) {
> ret = __mutex_lock_check_stamp(lock, ww_ctx);
> if (ret)
> goto err;
> @@ -575,7 +575,7 @@ skip_wait:
> lock_acquired(&lock->dep_map, ip);
> mutex_set_owner(lock);
>
> - if (!__builtin_constant_p(ww_ctx == NULL)) {
> + if (use_ww_ctx) {
> struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
> struct mutex_waiter *cur;
>
> @@ -615,7 +615,7 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass)
> {
> might_sleep();
> __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
> - subclass, NULL, _RET_IP_, NULL);
> + subclass, NULL, _RET_IP_, NULL, 0);
> }
>
> EXPORT_SYMBOL_GPL(mutex_lock_nested);
> @@ -625,7 +625,7 @@ _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
> {
> might_sleep();
> __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
> - 0, nest, _RET_IP_, NULL);
> + 0, nest, _RET_IP_, NULL, 0);
> }
>
> EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock);
> @@ -635,7 +635,7 @@ mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass)
> {
> might_sleep();
> return __mutex_lock_common(lock, TASK_KILLABLE,
> - subclass, NULL, _RET_IP_, NULL);
> + subclass, NULL, _RET_IP_, NULL, 0);
> }
> EXPORT_SYMBOL_GPL(mutex_lock_killable_nested);
>
> @@ -644,7 +644,7 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
> {
> might_sleep();
> return __mutex_lock_common(lock, TASK_INTERRUPTIBLE,
> - subclass, NULL, _RET_IP_, NULL);
> + subclass, NULL, _RET_IP_, NULL, 0);
> }
>
> EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
> @@ -682,7 +682,7 @@ __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
>
> might_sleep();
> ret = __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE,
> - 0, &ctx->dep_map, _RET_IP_, ctx);
> + 0, &ctx->dep_map, _RET_IP_, ctx, 1);
> if (!ret && ctx->acquired > 1)
> return ww_mutex_deadlock_injection(lock, ctx);
>
> @@ -697,7 +697,7 @@ __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
>
> might_sleep();
> ret = __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE,
> - 0, &ctx->dep_map, _RET_IP_, ctx);
> + 0, &ctx->dep_map, _RET_IP_, ctx, 1);
>
> if (!ret && ctx->acquired > 1)
> return ww_mutex_deadlock_injection(lock, ctx);
> @@ -809,28 +809,28 @@ __mutex_lock_slowpath(atomic_t *lock_count)
> struct mutex *lock = container_of(lock_count, struct mutex, count);
>
> __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0,
> - NULL, _RET_IP_, NULL);
> + NULL, _RET_IP_, NULL, 0);
> }
>
> static noinline int __sched
> __mutex_lock_killable_slowpath(struct mutex *lock)
> {
> return __mutex_lock_common(lock, TASK_KILLABLE, 0,
> - NULL, _RET_IP_, NULL);
> + NULL, _RET_IP_, NULL, 0);
> }
>
> static noinline int __sched
> __mutex_lock_interruptible_slowpath(struct mutex *lock)
> {
> return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0,
> - NULL, _RET_IP_, NULL);
> + NULL, _RET_IP_, NULL, 0);
> }
>
> static noinline int __sched
> __ww_mutex_lock_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
> {
> return __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE, 0,
> - NULL, _RET_IP_, ctx);
> + NULL, _RET_IP_, ctx, 1);
> }
>
> static noinline int __sched
> @@ -838,7 +838,7 @@ __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock,
> struct ww_acquire_ctx *ctx)
> {
> return __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE, 0,
> - NULL, _RET_IP_, ctx);
> + NULL, _RET_IP_, ctx, 1);
> }
>
> #endif
> --
> 1.7.1
>
^ permalink raw reply [flat|nested] 15+ messages in thread
end of thread, other threads:[~2013-10-16 20:20 UTC | newest]
Thread overview: 15+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-09-07 16:00 [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootable kernel Tetsuo Handa
2013-09-08 4:32 ` Tetsuo Handa
2013-09-08 5:28 ` Ilia Mirkin
2013-09-08 7:24 ` Tetsuo Handa
2013-09-08 7:42 ` Ilia Mirkin
2013-09-08 8:11 ` Maarten Lankhorst
2013-09-08 11:53 ` [3.11-rc1] CONFIG_DEBUG_MUTEXES=y using gcc 3.x makes unbootablekernel Tetsuo Handa
2013-09-08 20:36 ` Maarten Lankhorst
2013-09-09 11:56 ` Tetsuo Handa
2013-09-09 12:07 ` Maarten Lankhorst
2013-09-09 13:22 ` Tetsuo Handa
2013-09-24 14:51 ` Tetsuo Handa
2013-09-09 12:58 ` Peter Zijlstra
2013-10-03 14:02 ` [PATCH for 3.12-rcX] mutex: Avoid gcc version dependent __builtin_constant_p() usage Tetsuo Handa
2013-10-16 20:20 ` Tetsuo Handa
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