Re: [PATCH] freezer: fix freeze timeout on exec
Hi Chanho,
I love your patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v4.20-rc1 next-20181109]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Chanho-Min/freezer-fix-freeze-timeout-on-exec/2018-171200
config: i386-randconfig-x002-201845 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
kernel/signal.c: In function 'zap_other_threads':
>> kernel/signal.c:1283:3: error: implicit declaration of function
>> 'cancel_freezing_thaw_task' [-Werror=implicit-function-declaration]
cancel_freezing_thaw_task(t);
^
cc1: some warnings being treated as errors
vim +/cancel_freezing_thaw_task +1283 kernel/signal.c
1260
1261 /*
1262 * Nuke all other threads in the group.
1263 */
1264 int zap_other_threads(struct task_struct *p)
1265 {
1266 struct task_struct *t = p;
1267 int count = 0;
1268
1269 p->signal->group_stop_count = 0;
1270
1271 while_each_thread(p, t) {
1272 task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
1273 count++;
1274
1275 /* Don't bother with already dead threads */
1276 if (t->exit_state)
1277 continue;
1278
1279 /*
1280 * we can check sig->group_exit_task to detect
de_thread,
1281 * but perhaps it doesn't hurt if the caller is
do_group_exit
1282 */
> 1283 cancel_freezing_thaw_task(t);
1284 sigaddset(>pending.signal, SIGKILL);
1285 signal_wake_up(t, 1);
1286 }
1287
1288 return count;
1289 }
1290
---
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Re: [PATCH] freezer: fix freeze timeout on exec
Hi Chanho,
I love your patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v4.20-rc1 next-20181109]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Chanho-Min/freezer-fix-freeze-timeout-on-exec/2018-171200
config: i386-randconfig-x002-201845 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
kernel/signal.c: In function 'zap_other_threads':
>> kernel/signal.c:1283:3: error: implicit declaration of function
>> 'cancel_freezing_thaw_task' [-Werror=implicit-function-declaration]
cancel_freezing_thaw_task(t);
^
cc1: some warnings being treated as errors
vim +/cancel_freezing_thaw_task +1283 kernel/signal.c
1260
1261 /*
1262 * Nuke all other threads in the group.
1263 */
1264 int zap_other_threads(struct task_struct *p)
1265 {
1266 struct task_struct *t = p;
1267 int count = 0;
1268
1269 p->signal->group_stop_count = 0;
1270
1271 while_each_thread(p, t) {
1272 task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
1273 count++;
1274
1275 /* Don't bother with already dead threads */
1276 if (t->exit_state)
1277 continue;
1278
1279 /*
1280 * we can check sig->group_exit_task to detect
de_thread,
1281 * but perhaps it doesn't hurt if the caller is
do_group_exit
1282 */
> 1283 cancel_freezing_thaw_task(t);
1284 sigaddset(>pending.signal, SIGKILL);
1285 signal_wake_up(t, 1);
1286 }
1287
1288 return count;
1289 }
1290
---
0-DAY kernel test infrastructureOpen Source Technology Center
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Re: [PATCH] freezer: fix freeze timeout on exec
Hi Chanho,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.20-rc1 next-20181109]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Chanho-Min/freezer-fix-freeze-timeout-on-exec/2018-171200
config: i386-randconfig-x070-201845 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All warnings (new ones prefixed by >>):
In file included from arch/x86/include/asm/atomic.h:5:0,
from include/linux/atomic.h:7,
from include/linux/crypto.h:20,
from arch/x86/kernel/asm-offsets.c:9:
include/linux/freezer.h: In function 'try_to_freeze_unsafe':
include/linux/freezer.h:64:30: error: dereferencing pointer to incomplete
type 'struct signal_struct'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^
include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> include/linux/freezer.h:64:2: note: in expansion of macro 'if'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~
include/linux/compiler.h:48:24: note: in expansion of macro
'__branch_check__'
# define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
^~~~
include/linux/freezer.h:64:6: note: in expansion of macro 'unlikely'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~~~
include/linux/freezer.h:64:40: error: 'SIGNAL_GROUP_EXIT' undeclared (first
use in this function)
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^
include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> include/linux/freezer.h:64:2: note: in expansion of macro 'if'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~
include/linux/compiler.h:48:24: note: in expansion of macro
'__branch_check__'
# define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
^~~~
include/linux/freezer.h:64:6: note: in expansion of macro 'unlikely'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~~~
include/linux/freezer.h:64:40: note: each undeclared identifier is reported
only once for each function it appears in
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^
include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> include/linux/freezer.h:64:2: note: in expansion of macro 'if'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~
include/linux/compiler.h:48:24: note: in expansion of macro
'__branch_check__'
# define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
^~~~
include/linux/freezer.h:64:6: note: in expansion of macro 'unlikely'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~~~
make[2]: *** [arch/x86/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [sub-make] Error 2
vim +/if +64 include/linux/freezer.h
50
51 /*
52 * DO NOT ADD ANY NEW CALLERS OF THIS FUNCTION
53 * If try_to_freeze causes a lockdep warning it means the caller may
deadlock
54 */
55 static inline bool try_to_freeze_unsafe(void)
56 {
57 might_sleep();
58 if (likely(!freezing(current)))
59 return false;
60 /*
61 * we are going to call do_exit() really soon,
62 * we have a pending SIGKILL
63 */
> 64 if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
65 return false;
66 return __refrigerator(false);
67 }
68
---
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Description: application/gzip
Re: [PATCH] freezer: fix freeze timeout on exec
Hi Chanho,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.20-rc1 next-20181109]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Chanho-Min/freezer-fix-freeze-timeout-on-exec/2018-171200
config: i386-randconfig-x070-201845 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All warnings (new ones prefixed by >>):
In file included from arch/x86/include/asm/atomic.h:5:0,
from include/linux/atomic.h:7,
from include/linux/crypto.h:20,
from arch/x86/kernel/asm-offsets.c:9:
include/linux/freezer.h: In function 'try_to_freeze_unsafe':
include/linux/freezer.h:64:30: error: dereferencing pointer to incomplete
type 'struct signal_struct'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^
include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> include/linux/freezer.h:64:2: note: in expansion of macro 'if'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~
include/linux/compiler.h:48:24: note: in expansion of macro
'__branch_check__'
# define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
^~~~
include/linux/freezer.h:64:6: note: in expansion of macro 'unlikely'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~~~
include/linux/freezer.h:64:40: error: 'SIGNAL_GROUP_EXIT' undeclared (first
use in this function)
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^
include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> include/linux/freezer.h:64:2: note: in expansion of macro 'if'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~
include/linux/compiler.h:48:24: note: in expansion of macro
'__branch_check__'
# define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
^~~~
include/linux/freezer.h:64:6: note: in expansion of macro 'unlikely'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~~~
include/linux/freezer.h:64:40: note: each undeclared identifier is reported
only once for each function it appears in
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^
include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> include/linux/freezer.h:64:2: note: in expansion of macro 'if'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~
include/linux/compiler.h:48:24: note: in expansion of macro
'__branch_check__'
# define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
^~~~
include/linux/freezer.h:64:6: note: in expansion of macro 'unlikely'
if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
^~~~
make[2]: *** [arch/x86/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [sub-make] Error 2
vim +/if +64 include/linux/freezer.h
50
51 /*
52 * DO NOT ADD ANY NEW CALLERS OF THIS FUNCTION
53 * If try_to_freeze causes a lockdep warning it means the caller may
deadlock
54 */
55 static inline bool try_to_freeze_unsafe(void)
56 {
57 might_sleep();
58 if (likely(!freezing(current)))
59 return false;
60 /*
61 * we are going to call do_exit() really soon,
62 * we have a pending SIGKILL
63 */
> 64 if (unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
65 return false;
66 return __refrigerator(false);
67 }
68
---
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.config.gz
Description: application/gzip
RE: [PATCH] freezer: fix freeze timeout on exec
> >
> > Can't we simply change de_thread() to use freezable_schedule() ?
> >
> > Oleg.
>
> We need to change freezable_schedule_timeout() instead.
> freezable_schedule also can't be frozen if sub-threads can't stop
> schedule().
> Furthermore, I'm not sure if it is safe to freeze it at de_thread().
>
> diff --git a/fs/exec.c b/fs/exec.c
> index 9c5ee2a..291cbd6 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -942,7 +942,7 @@ static int de_thread(struct task_struct *tsk)
> while (sig->notify_count) {
> __set_current_state(TASK_KILLABLE);
> spin_unlock_irq(lock);
> - schedule();
> + while (!freezable_schedule_timeout(HZ));
> if (unlikely(__fatal_signal_pending(tsk)))
> goto killed;
> spin_lock_irq(lock);
>
> Chanho
Sorry, I might misunderstand freezer.
Changes to freezable_schedule() works fine. It looks safe.
I'll apply patch again.
Chanho
RE: [PATCH] freezer: fix freeze timeout on exec
> >
> > Can't we simply change de_thread() to use freezable_schedule() ?
> >
> > Oleg.
>
> We need to change freezable_schedule_timeout() instead.
> freezable_schedule also can't be frozen if sub-threads can't stop
> schedule().
> Furthermore, I'm not sure if it is safe to freeze it at de_thread().
>
> diff --git a/fs/exec.c b/fs/exec.c
> index 9c5ee2a..291cbd6 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -942,7 +942,7 @@ static int de_thread(struct task_struct *tsk)
> while (sig->notify_count) {
> __set_current_state(TASK_KILLABLE);
> spin_unlock_irq(lock);
> - schedule();
> + while (!freezable_schedule_timeout(HZ));
> if (unlikely(__fatal_signal_pending(tsk)))
> goto killed;
> spin_lock_irq(lock);
>
> Chanho
Sorry, I might misunderstand freezer.
Changes to freezable_schedule() works fine. It looks safe.
I'll apply patch again.
Chanho
RE: [PATCH] freezer: fix freeze timeout on exec
> >
> > To fix this, I suggest a patch by emboding the mentioned solution.
> > First, revive and rework cancel_freezing_and_thaw() function whitch
> > stops the task from sleeping in refrigirator reliably. And, The task
> > to be killed does not allow to freeze.
>
> Can't we simply change de_thread() to use freezable_schedule() ?
>
> Oleg.
We need to change freezable_schedule_timeout() instead.
freezable_schedule also can't be frozen if sub-threads can't stop
schedule().
Furthermore, I'm not sure if it is safe to freeze it at de_thread().
diff --git a/fs/exec.c b/fs/exec.c
index 9c5ee2a..291cbd6 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -942,7 +942,7 @@ static int de_thread(struct task_struct *tsk)
while (sig->notify_count) {
__set_current_state(TASK_KILLABLE);
spin_unlock_irq(lock);
- schedule();
+ while (!freezable_schedule_timeout(HZ));
if (unlikely(__fatal_signal_pending(tsk)))
goto killed;
spin_lock_irq(lock);
Chanho
RE: [PATCH] freezer: fix freeze timeout on exec
> >
> > To fix this, I suggest a patch by emboding the mentioned solution.
> > First, revive and rework cancel_freezing_and_thaw() function whitch
> > stops the task from sleeping in refrigirator reliably. And, The task
> > to be killed does not allow to freeze.
>
> Can't we simply change de_thread() to use freezable_schedule() ?
>
> Oleg.
We need to change freezable_schedule_timeout() instead.
freezable_schedule also can't be frozen if sub-threads can't stop
schedule().
Furthermore, I'm not sure if it is safe to freeze it at de_thread().
diff --git a/fs/exec.c b/fs/exec.c
index 9c5ee2a..291cbd6 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -942,7 +942,7 @@ static int de_thread(struct task_struct *tsk)
while (sig->notify_count) {
__set_current_state(TASK_KILLABLE);
spin_unlock_irq(lock);
- schedule();
+ while (!freezable_schedule_timeout(HZ));
if (unlikely(__fatal_signal_pending(tsk)))
goto killed;
spin_lock_irq(lock);
Chanho
Re: [PATCH] freezer: fix freeze timeout on exec
On 11/08, Chanho Min wrote: > > Suspend fails due to the exec family of fuctnions blocking the freezer. > This issue has been found that it is mentioned in the ancient mail thread. > The casue is that de_thread() sleeps in TASK_UNINTERRUPTIBLE waiting for all > sub-threads to die, and we have the "deadlock" if one of them is frozen. > It causes freeze timeout as bellows. > > Freezing of tasks failed after 20.010 seconds (1 tasks refusing to freeze, > wq_busy=0): > setcpushares-ls D ffc8ed70 0 5817 1483 0x004d > Call trace: > [] __switch_to+0x88/0xa0 > [] __schedule+0x1bc/0x720 > [] schedule+0x40/0xa8 > [] flush_old_exec+0xdc/0x640 > [] load_elf_binary+0x2a8/0x1090 > [] search_binary_handler+0x9c/0x240 > [] load_script+0x20c/0x228 > [] search_binary_handler+0x9c/0x240 > [] do_execveat_common.isra.14+0x4f8/0x6e8 > [] compat_SyS_execve+0x38/0x48 > [] el0_svc_naked+0x24/0x28 > > To fix this, I suggest a patch by emboding the mentioned solution. > First, revive and rework cancel_freezing_and_thaw() function whitch stops the > task from sleeping in refrigirator reliably. And, The task to be killed does > not > allow to freeze. Can't we simply change de_thread() to use freezable_schedule() ? Oleg.
Re: [PATCH] freezer: fix freeze timeout on exec
On 11/08, Chanho Min wrote: > > Suspend fails due to the exec family of fuctnions blocking the freezer. > This issue has been found that it is mentioned in the ancient mail thread. > The casue is that de_thread() sleeps in TASK_UNINTERRUPTIBLE waiting for all > sub-threads to die, and we have the "deadlock" if one of them is frozen. > It causes freeze timeout as bellows. > > Freezing of tasks failed after 20.010 seconds (1 tasks refusing to freeze, > wq_busy=0): > setcpushares-ls D ffc8ed70 0 5817 1483 0x004d > Call trace: > [] __switch_to+0x88/0xa0 > [] __schedule+0x1bc/0x720 > [] schedule+0x40/0xa8 > [] flush_old_exec+0xdc/0x640 > [] load_elf_binary+0x2a8/0x1090 > [] search_binary_handler+0x9c/0x240 > [] load_script+0x20c/0x228 > [] search_binary_handler+0x9c/0x240 > [] do_execveat_common.isra.14+0x4f8/0x6e8 > [] compat_SyS_execve+0x38/0x48 > [] el0_svc_naked+0x24/0x28 > > To fix this, I suggest a patch by emboding the mentioned solution. > First, revive and rework cancel_freezing_and_thaw() function whitch stops the > task from sleeping in refrigirator reliably. And, The task to be killed does > not > allow to freeze. Can't we simply change de_thread() to use freezable_schedule() ? Oleg.
