Merge the 32bit and 64bit version.
Halve the check constants on 32bit.
Use STACK_TOP since it is defined.
Passing is_64 is now redundant since is_32bit_task() is used to
determine which callchain variant should be used. Use STACK_TOP and
is_32bit_task() directly.
This removes a page from the valid 32bit area on 64bit:
#define TASK_SIZE_USER32 (0x0000000100000000UL - (1 * PAGE_SIZE))
#define STACK_TOP_USER32 TASK_SIZE_USER32
Signed-off-by: Michal Suchanek <[email protected]>
---
v8: new patch
v11: simplify by using is_32bit_task()
---
arch/powerpc/perf/callchain.c | 27 +++++++++++----------------
1 file changed, 11 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index c9a78c6e4361..194c7fd933e6 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -102,6 +102,15 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
}
}
+static inline int valid_user_sp(unsigned long sp)
+{
+ bool is_64 = !is_32bit_task();
+
+ if (!sp || (sp & (is_64 ? 7 : 3)) || sp > STACK_TOP - (is_64 ? 32 : 16))
+ return 0;
+ return 1;
+}
+
#ifdef CONFIG_PPC64
/*
* On 64-bit we don't want to invoke hash_page on user addresses from
@@ -161,13 +170,6 @@ static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret)
return read_user_stack_slow(ptr, ret, 8);
}
-static inline int valid_user_sp(unsigned long sp, int is_64)
-{
- if (!sp || (sp & 7) || sp > (is_64 ? TASK_SIZE : 0x100000000UL) - 32)
- return 0;
- return 1;
-}
-
/*
* 64-bit user processes use the same stack frame for RT and non-RT signals.
*/
@@ -226,7 +228,7 @@ static void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
while (entry->nr < entry->max_stack) {
fp = (unsigned long __user *) sp;
- if (!valid_user_sp(sp, 1) || read_user_stack_64(fp, &next_sp))
+ if (!valid_user_sp(sp) || read_user_stack_64(fp, &next_sp))
return;
if (level > 0 && read_user_stack_64(&fp[2], &next_ip))
return;
@@ -275,13 +277,6 @@ static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry
{
}
-static inline int valid_user_sp(unsigned long sp, int is_64)
-{
- if (!sp || (sp & 7) || sp > TASK_SIZE - 32)
- return 0;
- return 1;
-}
-
#define __SIGNAL_FRAMESIZE32 __SIGNAL_FRAMESIZE
#define sigcontext32 sigcontext
#define mcontext32 mcontext
@@ -423,7 +418,7 @@ static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
while (entry->nr < entry->max_stack) {
fp = (unsigned int __user *) (unsigned long) sp;
- if (!valid_user_sp(sp, 0) || read_user_stack_32(fp, &next_sp))
+ if (!valid_user_sp(sp) || read_user_stack_32(fp, &next_sp))
return;
if (level > 0 && read_user_stack_32(&fp[1], &next_ip))
return;
--
2.23.0
On Thu, Mar 19, 2020 at 1:54 PM Michal Suchanek <[email protected]> wrote:
>
> Merge the 32bit and 64bit version.
>
> Halve the check constants on 32bit.
>
> Use STACK_TOP since it is defined.
>
> Passing is_64 is now redundant since is_32bit_task() is used to
> determine which callchain variant should be used. Use STACK_TOP and
> is_32bit_task() directly.
>
> This removes a page from the valid 32bit area on 64bit:
> #define TASK_SIZE_USER32 (0x0000000100000000UL - (1 * PAGE_SIZE))
> #define STACK_TOP_USER32 TASK_SIZE_USER32
...
> +static inline int valid_user_sp(unsigned long sp)
> +{
> + bool is_64 = !is_32bit_task();
> +
> + if (!sp || (sp & (is_64 ? 7 : 3)) || sp > STACK_TOP - (is_64 ? 32 : 16))
> + return 0;
> + return 1;
> +}
Perhaps better to read
if (!sp)
return 0;
if (is_32bit_task()) {
if (sp & 0x03)
return 0;
if (sp > STACK_TOP - 16)
return 0;
} else {
...
}
return 1;
Other possibility:
unsigned long align = is_32bit_task() ? 3 : 7;
unsigned long top = STACK_TOP - (is_32bit_task() ? 16 : 32);
return !(!sp || (sp & align) || sp > top);
--
With Best Regards,
Andy Shevchenko
On Thu, Mar 19, 2020 at 03:35:03PM +0200, Andy Shevchenko wrote:
> On Thu, Mar 19, 2020 at 1:54 PM Michal Suchanek <[email protected]> wrote:
> >
> > Merge the 32bit and 64bit version.
> >
> > Halve the check constants on 32bit.
> >
> > Use STACK_TOP since it is defined.
> >
> > Passing is_64 is now redundant since is_32bit_task() is used to
> > determine which callchain variant should be used. Use STACK_TOP and
> > is_32bit_task() directly.
> >
> > This removes a page from the valid 32bit area on 64bit:
> > #define TASK_SIZE_USER32 (0x0000000100000000UL - (1 * PAGE_SIZE))
> > #define STACK_TOP_USER32 TASK_SIZE_USER32
>
> ...
>
> > +static inline int valid_user_sp(unsigned long sp)
> > +{
> > + bool is_64 = !is_32bit_task();
> > +
> > + if (!sp || (sp & (is_64 ? 7 : 3)) || sp > STACK_TOP - (is_64 ? 32 : 16))
> > + return 0;
> > + return 1;
> > +}
>
> Perhaps better to read
>
> if (!sp)
> return 0;
>
> if (is_32bit_task()) {
> if (sp & 0x03)
> return 0;
> if (sp > STACK_TOP - 16)
> return 0;
> } else {
> ...
> }
>
> return 1;
>
> Other possibility:
>
> unsigned long align = is_32bit_task() ? 3 : 7;
> unsigned long top = STACK_TOP - (is_32bit_task() ? 16 : 32);
>
> return !(!sp || (sp & align) || sp > top);
Sounds reasonale.
Thanks
Michal
>
> --
> With Best Regards,
> Andy Shevchenko
Le 19/03/2020 à 14:35, Andy Shevchenko a écrit :
> On Thu, Mar 19, 2020 at 1:54 PM Michal Suchanek <[email protected]> wrote:
>>
>> Merge the 32bit and 64bit version.
>>
>> Halve the check constants on 32bit.
>>
>> Use STACK_TOP since it is defined.
>>
>> Passing is_64 is now redundant since is_32bit_task() is used to
>> determine which callchain variant should be used. Use STACK_TOP and
>> is_32bit_task() directly.
>>
>> This removes a page from the valid 32bit area on 64bit:
>> #define TASK_SIZE_USER32 (0x0000000100000000UL - (1 * PAGE_SIZE))
>> #define STACK_TOP_USER32 TASK_SIZE_USER32
>
> ...
>
>> +static inline int valid_user_sp(unsigned long sp)
>> +{
>> + bool is_64 = !is_32bit_task();
>> +
>> + if (!sp || (sp & (is_64 ? 7 : 3)) || sp > STACK_TOP - (is_64 ? 32 : 16))
>> + return 0;
>> + return 1;
>> +}
>
> Perhaps better to read
>
> if (!sp)
> return 0;
>
> if (is_32bit_task()) {
> if (sp & 0x03)
> return 0;
> if (sp > STACK_TOP - 16)
> return 0;
> } else {
> ...
> }
>
> return 1;
>
> Other possibility:
I prefer this one.
>
> unsigned long align = is_32bit_task() ? 3 : 7;
I would call it mask instead of align
> unsigned long top = STACK_TOP - (is_32bit_task() ? 16 : 32);
>
> return !(!sp || (sp & align) || sp > top);
>
Christophe
On Thu, Mar 19, 2020 at 03:16:03PM +0100, Christophe Leroy wrote:
>
>
> Le 19/03/2020 ? 14:35, Andy Shevchenko a ?crit?:
> > On Thu, Mar 19, 2020 at 1:54 PM Michal Suchanek <[email protected]> wrote:
> > >
> > > Merge the 32bit and 64bit version.
> > >
> > > Halve the check constants on 32bit.
> > >
> > > Use STACK_TOP since it is defined.
> > >
> > > Passing is_64 is now redundant since is_32bit_task() is used to
> > > determine which callchain variant should be used. Use STACK_TOP and
> > > is_32bit_task() directly.
> > >
> > > This removes a page from the valid 32bit area on 64bit:
> > > #define TASK_SIZE_USER32 (0x0000000100000000UL - (1 * PAGE_SIZE))
> > > #define STACK_TOP_USER32 TASK_SIZE_USER32
> >
> > ...
> >
> > > +static inline int valid_user_sp(unsigned long sp)
> > > +{
> > > + bool is_64 = !is_32bit_task();
> > > +
> > > + if (!sp || (sp & (is_64 ? 7 : 3)) || sp > STACK_TOP - (is_64 ? 32 : 16))
> > > + return 0;
> > > + return 1;
> > > +}
> >
> > Other possibility:
>
> I prefer this one.
>
> >
> > unsigned long align = is_32bit_task() ? 3 : 7;
>
> I would call it mask instead of align
>
> > unsigned long top = STACK_TOP - (is_32bit_task() ? 16 : 32);
> >
> > return !(!sp || (sp & align) || sp > top);
And we can avoid the inversion here as well as in !valid_user_sp(sp) by
changing to invalid_user_sp.
Thanks
Michal