* [PATCH -mm] oprofile: BUG: using smp_processor_id() in preemptible code
@ 2008-09-20 10:58 Andrea Righi
2008-09-22 10:25 ` Ingo Molnar
0 siblings, 1 reply; 5+ messages in thread
From: Andrea Righi @ 2008-09-20 10:58 UTC (permalink / raw)
To: robert.richter, akpm; +Cc: oprofile-list, linux-kernel
Add local_irq_save() / local_irq_restore() before setting per cpu variable
switch_index, to avoid the following BUG:
[ 449.166827] BUG: using smp_processor_id() in preemptible [00000000] code: modprobe/6998
[ 449.166848] caller is op_nmi_init+0xf0/0x2b0 [oprofile]
[ 449.166855] Pid: 6998, comm: modprobe Not tainted 2.6.27-rc5-mm1 #29
[ 449.166860] Call Trace:
[ 449.166872] [<ffffffff80362d67>] debug_smp_processor_id+0xd7/0xe0
[ 449.166887] [<ffffffffa00181c0>] op_nmi_init+0xf0/0x2b0 [oprofile]
[ 449.166902] [<ffffffffa0018000>] oprofile_init+0x0/0x60 [oprofile]
[ 449.166915] [<ffffffffa00180a9>] oprofile_arch_init+0x9/0x30 [oprofile]
[ 449.166928] [<ffffffffa001801e>] oprofile_init+0x1e/0x60 [oprofile]
[ 449.166937] [<ffffffff8020903b>] _stext+0x3b/0x160
[ 449.166946] [<ffffffff80477985>] __mutex_unlock_slowpath+0xe5/0x190
[ 449.166955] [<ffffffff80262c1a>] trace_hardirqs_on_caller+0xca/0x140
[ 449.166965] [<ffffffff8026f7fc>] sys_init_module+0xdc/0x210
[ 449.166972] [<ffffffff8020b7cb>] system_call_fastpath+0x16/0x1b
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
---
arch/x86/oprofile/nmi_int.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index d4c2f2d..2e63357 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -520,6 +520,7 @@ int __init op_nmi_init(struct oprofile_operations *ops)
__u8 vendor = boot_cpu_data.x86_vendor;
__u8 family = boot_cpu_data.x86;
char *cpu_type;
+ unsigned long flags;
int ret = 0;
if (!cpu_has_apic)
@@ -580,7 +581,9 @@ int __init op_nmi_init(struct oprofile_operations *ops)
register_cpu_notifier(&oprofile_cpu_nb);
#endif
/* default values, can be overwritten by model */
+ local_irq_save(flags);
__get_cpu_var(switch_index) = 0;
+ local_irq_restore(flags);
ops->create_files = nmi_create_files;
ops->setup = nmi_setup;
ops->shutdown = nmi_shutdown;
--
1.5.4.3
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH -mm] oprofile: BUG: using smp_processor_id() in preemptible code
2008-09-20 10:58 [PATCH -mm] oprofile: BUG: using smp_processor_id() in preemptible code Andrea Righi
@ 2008-09-22 10:25 ` Ingo Molnar
2008-09-22 10:28 ` Ingo Molnar
0 siblings, 1 reply; 5+ messages in thread
From: Ingo Molnar @ 2008-09-22 10:25 UTC (permalink / raw)
To: Andrea Righi; +Cc: robert.richter, akpm, oprofile-list, linux-kernel
* Andrea Righi <righi.andrea@gmail.com> wrote:
> Add local_irq_save() / local_irq_restore() before setting per cpu
> variable switch_index, to avoid the following BUG:
that just papers over the bug:
> + local_irq_save(flags);
> __get_cpu_var(switch_index) = 0;
> + local_irq_restore(flags);
either use __raw_get_cpu_var() if we are for sure not preemptible here,
or fix the preemption status of this codepath.
Ingo
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH -mm] oprofile: BUG: using smp_processor_id() in preemptible code
2008-09-22 10:25 ` Ingo Molnar
@ 2008-09-22 10:28 ` Ingo Molnar
2008-09-22 13:15 ` Robert Richter
2008-09-22 15:13 ` Andrea Righi
0 siblings, 2 replies; 5+ messages in thread
From: Ingo Molnar @ 2008-09-22 10:28 UTC (permalink / raw)
To: Andrea Righi; +Cc: robert.richter, akpm, oprofile-list, linux-kernel
* Ingo Molnar <mingo@elte.hu> wrote:
> > + local_irq_save(flags);
> > __get_cpu_var(switch_index) = 0;
> > + local_irq_restore(flags);
>
> either use __raw_get_cpu_var() if we are for sure not preemptible
> here, or fix the preemption status of this codepath.
i've applied the patch below instead to tip/oprofile - agreed?
Ingo
------------>
>From 45f197ade73ba95681b9803680c75352fc0a1c0a Mon Sep 17 00:00:00 2001
From: Andrea Righi <righi.andrea@gmail.com>
Date: Sat, 20 Sep 2008 12:58:40 +0200
Subject: [PATCH] x86, oprofile: BUG: using smp_processor_id() in preemptible code
Add __raw access before setting per cpu variable switch_index, to avoid
the following BUG:
[ 449.166827] BUG: using smp_processor_id() in preemptible [00000000] code: modprobe/6998
[ 449.166848] caller is op_nmi_init+0xf0/0x2b0 [oprofile]
[ 449.166855] Pid: 6998, comm: modprobe Not tainted 2.6.27-rc5-mm1 #29
[ 449.166860] Call Trace:
[ 449.166872] [<ffffffff80362d67>] debug_smp_processor_id+0xd7/0xe0
[ 449.166887] [<ffffffffa00181c0>] op_nmi_init+0xf0/0x2b0 [oprofile]
[ 449.166902] [<ffffffffa0018000>] oprofile_init+0x0/0x60 [oprofile]
[ 449.166915] [<ffffffffa00180a9>] oprofile_arch_init+0x9/0x30 [oprofile]
[ 449.166928] [<ffffffffa001801e>] oprofile_init+0x1e/0x60 [oprofile]
[ 449.166937] [<ffffffff8020903b>] _stext+0x3b/0x160
[ 449.166946] [<ffffffff80477985>] __mutex_unlock_slowpath+0xe5/0x190
[ 449.166955] [<ffffffff80262c1a>] trace_hardirqs_on_caller+0xca/0x140
[ 449.166965] [<ffffffff8026f7fc>] sys_init_module+0xdc/0x210
[ 449.166972] [<ffffffff8020b7cb>] system_call_fastpath+0x16/0x1b
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Acked-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/oprofile/nmi_int.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index fb4902b..4108d02 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -551,7 +551,7 @@ int __init op_nmi_init(struct oprofile_operations *ops)
}
/* default values, can be overwritten by model */
- __get_cpu_var(switch_index) = 0;
+ __raw_get_cpu_var(switch_index) = 0;
ops->create_files = nmi_create_files;
ops->setup = nmi_setup;
ops->shutdown = nmi_shutdown;
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH -mm] oprofile: BUG: using smp_processor_id() in preemptible code
2008-09-22 10:28 ` Ingo Molnar
@ 2008-09-22 13:15 ` Robert Richter
2008-09-22 15:13 ` Andrea Righi
1 sibling, 0 replies; 5+ messages in thread
From: Robert Richter @ 2008-09-22 13:15 UTC (permalink / raw)
To: Ingo Molnar; +Cc: Andrea Righi, akpm, oprofile-list, linux-kernel
On 22.09.08 12:28:34, Ingo Molnar wrote:
>
> * Ingo Molnar <mingo@elte.hu> wrote:
>
> > > + local_irq_save(flags);
> > > __get_cpu_var(switch_index) = 0;
> > > + local_irq_restore(flags);
> >
> > either use __raw_get_cpu_var() if we are for sure not preemptible
> > here, or fix the preemption status of this codepath.
>
> i've applied the patch below instead to tip/oprofile - agreed?
Acked-by: Robert Richter <robert.richter@amd.com>
>
> Ingo
>
> ------------>
> From 45f197ade73ba95681b9803680c75352fc0a1c0a Mon Sep 17 00:00:00 2001
> From: Andrea Righi <righi.andrea@gmail.com>
> Date: Sat, 20 Sep 2008 12:58:40 +0200
> Subject: [PATCH] x86, oprofile: BUG: using smp_processor_id() in preemptible code
>
> Add __raw access before setting per cpu variable switch_index, to avoid
> the following BUG:
>
> [ 449.166827] BUG: using smp_processor_id() in preemptible [00000000] code: modprobe/6998
> [ 449.166848] caller is op_nmi_init+0xf0/0x2b0 [oprofile]
> [ 449.166855] Pid: 6998, comm: modprobe Not tainted 2.6.27-rc5-mm1 #29
> [ 449.166860] Call Trace:
> [ 449.166872] [<ffffffff80362d67>] debug_smp_processor_id+0xd7/0xe0
> [ 449.166887] [<ffffffffa00181c0>] op_nmi_init+0xf0/0x2b0 [oprofile]
> [ 449.166902] [<ffffffffa0018000>] oprofile_init+0x0/0x60 [oprofile]
> [ 449.166915] [<ffffffffa00180a9>] oprofile_arch_init+0x9/0x30 [oprofile]
> [ 449.166928] [<ffffffffa001801e>] oprofile_init+0x1e/0x60 [oprofile]
> [ 449.166937] [<ffffffff8020903b>] _stext+0x3b/0x160
> [ 449.166946] [<ffffffff80477985>] __mutex_unlock_slowpath+0xe5/0x190
> [ 449.166955] [<ffffffff80262c1a>] trace_hardirqs_on_caller+0xca/0x140
> [ 449.166965] [<ffffffff8026f7fc>] sys_init_module+0xdc/0x210
> [ 449.166972] [<ffffffff8020b7cb>] system_call_fastpath+0x16/0x1b
>
> Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
> Acked-by: Robert Richter <robert.richter@amd.com>
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
> ---
> arch/x86/oprofile/nmi_int.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
> index fb4902b..4108d02 100644
> --- a/arch/x86/oprofile/nmi_int.c
> +++ b/arch/x86/oprofile/nmi_int.c
> @@ -551,7 +551,7 @@ int __init op_nmi_init(struct oprofile_operations *ops)
> }
>
> /* default values, can be overwritten by model */
> - __get_cpu_var(switch_index) = 0;
> + __raw_get_cpu_var(switch_index) = 0;
> ops->create_files = nmi_create_files;
> ops->setup = nmi_setup;
> ops->shutdown = nmi_shutdown;
>
--
Advanced Micro Devices, Inc.
Operating System Research Center
email: robert.richter@amd.com
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH -mm] oprofile: BUG: using smp_processor_id() in preemptible code
2008-09-22 10:28 ` Ingo Molnar
2008-09-22 13:15 ` Robert Richter
@ 2008-09-22 15:13 ` Andrea Righi
1 sibling, 0 replies; 5+ messages in thread
From: Andrea Righi @ 2008-09-22 15:13 UTC (permalink / raw)
To: Ingo Molnar; +Cc: robert.richter, akpm, oprofile-list, linux-kernel
Ingo Molnar wrote:
> * Ingo Molnar <mingo@elte.hu> wrote:
>
>>> + local_irq_save(flags);
>>> __get_cpu_var(switch_index) = 0;
>>> + local_irq_restore(flags);
>> either use __raw_get_cpu_var() if we are for sure not preemptible
>> here, or fix the preemption status of this codepath.
>
> i've applied the patch below instead to tip/oprofile - agreed?
>
> Ingo
Seems to work fine.
Thanks,
-Andrea
>
> ------------>
> From 45f197ade73ba95681b9803680c75352fc0a1c0a Mon Sep 17 00:00:00 2001
> From: Andrea Righi <righi.andrea@gmail.com>
> Date: Sat, 20 Sep 2008 12:58:40 +0200
> Subject: [PATCH] x86, oprofile: BUG: using smp_processor_id() in preemptible code
>
> Add __raw access before setting per cpu variable switch_index, to avoid
> the following BUG:
>
> [ 449.166827] BUG: using smp_processor_id() in preemptible [00000000] code: modprobe/6998
> [ 449.166848] caller is op_nmi_init+0xf0/0x2b0 [oprofile]
> [ 449.166855] Pid: 6998, comm: modprobe Not tainted 2.6.27-rc5-mm1 #29
> [ 449.166860] Call Trace:
> [ 449.166872] [<ffffffff80362d67>] debug_smp_processor_id+0xd7/0xe0
> [ 449.166887] [<ffffffffa00181c0>] op_nmi_init+0xf0/0x2b0 [oprofile]
> [ 449.166902] [<ffffffffa0018000>] oprofile_init+0x0/0x60 [oprofile]
> [ 449.166915] [<ffffffffa00180a9>] oprofile_arch_init+0x9/0x30 [oprofile]
> [ 449.166928] [<ffffffffa001801e>] oprofile_init+0x1e/0x60 [oprofile]
> [ 449.166937] [<ffffffff8020903b>] _stext+0x3b/0x160
> [ 449.166946] [<ffffffff80477985>] __mutex_unlock_slowpath+0xe5/0x190
> [ 449.166955] [<ffffffff80262c1a>] trace_hardirqs_on_caller+0xca/0x140
> [ 449.166965] [<ffffffff8026f7fc>] sys_init_module+0xdc/0x210
> [ 449.166972] [<ffffffff8020b7cb>] system_call_fastpath+0x16/0x1b
>
> Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
> Acked-by: Robert Richter <robert.richter@amd.com>
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
> ---
> arch/x86/oprofile/nmi_int.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
> index fb4902b..4108d02 100644
> --- a/arch/x86/oprofile/nmi_int.c
> +++ b/arch/x86/oprofile/nmi_int.c
> @@ -551,7 +551,7 @@ int __init op_nmi_init(struct oprofile_operations *ops)
> }
>
> /* default values, can be overwritten by model */
> - __get_cpu_var(switch_index) = 0;
> + __raw_get_cpu_var(switch_index) = 0;
> ops->create_files = nmi_create_files;
> ops->setup = nmi_setup;
> ops->shutdown = nmi_shutdown;
^ permalink raw reply [flat|nested] 5+ messages in thread
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2008-09-20 10:58 [PATCH -mm] oprofile: BUG: using smp_processor_id() in preemptible code Andrea Righi
2008-09-22 10:25 ` Ingo Molnar
2008-09-22 10:28 ` Ingo Molnar
2008-09-22 13:15 ` Robert Richter
2008-09-22 15:13 ` Andrea Righi
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