2020-05-07 09:30:20

by Yunfeng Ye

Subject: [PATCH] arm64: stacktrace: Factor out some common code info on_stack()

There are some common codes for stack checking, so factors it out into
the function on_stack() and on_valid_stack().

No functional change.

Signed-off-by: Yunfeng Ye <[email protected]>
---
arch/arm64/include/asm/stacktrace.h | 53 +++++++++++++++++--------------------
arch/arm64/kernel/sdei.c | 28 ++------------------
2 files changed, 26 insertions(+), 55 deletions(-)

diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index fdb913cc0bcb..b92bef2fb6cd 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -69,27 +69,40 @@ extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,

DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);

-static inline bool on_irq_stack(unsigned long sp,
+static inline bool on_stack(unsigned long sp, unsigned long low,
+ unsigned long high, enum stack_type type,
struct stack_info *info)
{
- unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
- unsigned long high = low + IRQ_STACK_SIZE;
-
- if (!low)
- return false;
-
if (sp < low || sp >= high)
return false;

if (info) {
info->low = low;
info->high = high;
- info->type = STACK_TYPE_IRQ;
+ info->type = type;
}
-
return true;
}

+static inline bool on_valid_stack(unsigned long sp, unsigned long low,
+ unsigned long high, enum stack_type type,
+ struct stack_info *info)
+{
+ if (!low)
+ return false;
+
+ return on_stack(sp, low, high, type, info);
+}
+
+static inline bool on_irq_stack(unsigned long sp,
+ struct stack_info *info)
+{
+ unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
+ unsigned long high = low + IRQ_STACK_SIZE;
+
+ return on_valid_stack(sp, low, high, STACK_TYPE_IRQ, info);
+}
+
static inline bool on_task_stack(const struct task_struct *tsk,
unsigned long sp,
struct stack_info *info)
@@ -97,16 +110,7 @@ static inline bool on_task_stack(const struct task_struct *tsk,
unsigned long low = (unsigned long)task_stack_page(tsk);
unsigned long high = low + THREAD_SIZE;

- if (sp < low || sp >= high)
- return false;
-
- if (info) {
- info->low = low;
- info->high = high;
- info->type = STACK_TYPE_TASK;
- }
-
- return true;
+ return on_stack(sp, low, high, STACK_TYPE_TASK, info);
}

#ifdef CONFIG_VMAP_STACK
@@ -118,16 +122,7 @@ static inline bool on_overflow_stack(unsigned long sp,
unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
unsigned long high = low + OVERFLOW_STACK_SIZE;

- if (sp < low || sp >= high)
- return false;
-
- if (info) {
- info->low = low;
- info->high = high;
- info->type = STACK_TYPE_OVERFLOW;
- }
-
- return true;
+ return on_stack(sp, low, high, STACK_TYPE_OVERFLOW, info);
}
#else
static inline bool on_overflow_stack(unsigned long sp,
diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c
index d6259dac62b6..1758fcaa45dd 100644
--- a/arch/arm64/kernel/sdei.c
+++ b/arch/arm64/kernel/sdei.c
@@ -95,19 +95,7 @@ static bool on_sdei_normal_stack(unsigned long sp, struct stack_info *info)
unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr);
unsigned long high = low + SDEI_STACK_SIZE;

- if (!low)
- return false;
-
- if (sp < low || sp >= high)
- return false;
-
- if (info) {
- info->low = low;
- info->high = high;
- info->type = STACK_TYPE_SDEI_NORMAL;
- }
-
- return true;
+ return on_valid_stack(sp, low, high, STACK_TYPE_SDEI_NORMAL, info);
}

static bool on_sdei_critical_stack(unsigned long sp, struct stack_info *info)
@@ -115,19 +103,7 @@ static bool on_sdei_critical_stack(unsigned long sp, struct stack_info *info)
unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr);
unsigned long high = low + SDEI_STACK_SIZE;

- if (!low)
- return false;
-
- if (sp < low || sp >= high)
- return false;
-
- if (info) {
- info->low = low;
- info->high = high;
- info->type = STACK_TYPE_SDEI_CRITICAL;
- }
-
- return true;
+ return on_valid_stack(sp, low, high, STACK_TYPE_SDEI_CRITICAL, info);
}

bool _on_sdei_stack(unsigned long sp, struct stack_info *info)
--
1.8.3.1

2020-05-07 13:54:31

by Will Deacon

Subject: Re: [PATCH] arm64: stacktrace: Factor out some common code info on_stack()

On Thu, May 07, 2020 at 05:28:19PM +0800, Yunfeng Ye wrote:
> diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
> index fdb913cc0bcb..b92bef2fb6cd 100644
> --- a/arch/arm64/include/asm/stacktrace.h
> +++ b/arch/arm64/include/asm/stacktrace.h
> @@ -69,27 +69,40 @@ extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
>
> DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
>
> -static inline bool on_irq_stack(unsigned long sp,
> +static inline bool on_stack(unsigned long sp, unsigned long low,
> + unsigned long high, enum stack_type type,
> struct stack_info *info)
> {
> - unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
> - unsigned long high = low + IRQ_STACK_SIZE;
> -
> - if (!low)
> - return false;
> -
> if (sp < low || sp >= high)
> return false;
>
> if (info) {
> info->low = low;
> info->high = high;
> - info->type = STACK_TYPE_IRQ;
> + info->type = type;
> }
> -
> return true;
> }
>
> +static inline bool on_valid_stack(unsigned long sp, unsigned long low,
> + unsigned long high, enum stack_type type,
> + struct stack_info *info)
> +{
> + if (!low)
> + return false;
> +
> + return on_stack(sp, low, high, type, info);
> +}

Do we need this as distinct from on_stack()? Afaict, 'low' is never
going to be NULL for the on_stack() callers, so I suggest just having
on_stack() check 'low' and getting everybody to call that instead.

Make sense?

Will

2020-05-08 01:32:08

by Yunfeng Ye

Subject: Re: [PATCH] arm64: stacktrace: Factor out some common code info on_stack()

On 2020/5/7 21:52, Will Deacon wrote:
> On Thu, May 07, 2020 at 05:28:19PM +0800, Yunfeng Ye wrote:
>> diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
>> index fdb913cc0bcb..b92bef2fb6cd 100644
>> --- a/arch/arm64/include/asm/stacktrace.h
>> +++ b/arch/arm64/include/asm/stacktrace.h
>> @@ -69,27 +69,40 @@ extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
>>
>> DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
>>
>> -static inline bool on_irq_stack(unsigned long sp,
>> +static inline bool on_stack(unsigned long sp, unsigned long low,
>> + unsigned long high, enum stack_type type,
>> struct stack_info *info)
>> {
>> - unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
>> - unsigned long high = low + IRQ_STACK_SIZE;
>> -
>> - if (!low)
>> - return false;
>> -
>> if (sp < low || sp >= high)
>> return false;
>>
>> if (info) {
>> info->low = low;
>> info->high = high;
>> - info->type = STACK_TYPE_IRQ;
>> + info->type = type;
>> }
>> -
>> return true;
>> }
>>
>> +static inline bool on_valid_stack(unsigned long sp, unsigned long low,
>> + unsigned long high, enum stack_type type,
>> + struct stack_info *info)
>> +{
>> + if (!low)
>> + return false;
>> +
>> + return on_stack(sp, low, high, type, info);
>> +}
>
> Do we need this as distinct from on_stack()? Afaict, 'low' is never
> going to be NULL for the on_stack() callers, so I suggest just having
> on_stack() check 'low' and getting everybody to call that instead.
>
> Make sense?
>
ok, I will modify and send the patch v2, thanks.

> Will
>
> .
>