[PATCH] ARM: Mark ret_fast_syscall as a function

[PATCH] ARM: Mark ret_fast_syscall as a function

[Drew Richardson]

ret_fast_syscall runs when user space makes a syscall. However it
needs to be marked as such so the ELF information is correct. Before
it was:

   101: 8000f300     0 NOTYPE  LOCAL  DEFAULT    2 ret_fast_syscall

But with this change it correctly shows as:

   101: 8000f300    96 FUNC    LOCAL  DEFAULT    2 ret_fast_syscall

I see this function when using perf to unwind call stacks from kernel
space to user space. Without this change I would need to add some
special case logic when using the vmlinux ELF information.

Signed-off-by: Drew Richardson <drew.richardson@arm.com>
---
 arch/arm/kernel/entry-common.S | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 92828a1dec80..b48dd4f37f80 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -61,6 +61,7 @@ work_pending:
 	movlt	scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)
 	ldmia	sp, {r0 - r6}			@ have to reload r0 - r6
 	b	local_restart			@ ... and off we go
+ENDPROC(ret_fast_syscall)
 
 /*
  * "slow" syscall return path.  "why" tells us if this was a real syscall.
-- 
2.1.4

Re: [PATCH] ARM: Mark ret_fast_syscall as a function

[Drew Richardson]

On Tue, Jul 14, 2015 at 01:45:57PM +0100, Drew Richardson wrote:
> ret_fast_syscall runs when user space makes a syscall. However it
> needs to be marked as such so the ELF information is correct. Before
> it was:
> 
>    101: 8000f300     0 NOTYPE  LOCAL  DEFAULT    2 ret_fast_syscall
> 
> But with this change it correctly shows as:
> 
>    101: 8000f300    96 FUNC    LOCAL  DEFAULT    2 ret_fast_syscall
> 
> I see this function when using perf to unwind call stacks from kernel
> space to user space. Without this change I would need to add some
> special case logic when using the vmlinux ELF information.
> 
> Signed-off-by: Drew Richardson <drew.richardson@arm.com>

I haven't heard any further comments on this, did this get merged and
I just didn't notice? Or did I forget to add someone?

Thanks,

Drew

Re: [PATCH] ARM: Mark ret_fast_syscall as a function

[Nicolas Pitre]

On Thu, 6 Aug 2015, Drew Richardson wrote:

> On Tue, Jul 14, 2015 at 01:45:57PM +0100, Drew Richardson wrote:
> > ret_fast_syscall runs when user space makes a syscall. However it
> > needs to be marked as such so the ELF information is correct. Before
> > it was:
> > 
> >    101: 8000f300     0 NOTYPE  LOCAL  DEFAULT    2 ret_fast_syscall
> > 
> > But with this change it correctly shows as:
> > 
> >    101: 8000f300    96 FUNC    LOCAL  DEFAULT    2 ret_fast_syscall
> > 
> > I see this function when using perf to unwind call stacks from kernel
> > space to user space. Without this change I would need to add some
> > special case logic when using the vmlinux ELF information.
> > 
> > Signed-off-by: Drew Richardson <drew.richardson@arm.com>
> 
> I haven't heard any further comments on this, did this get merged and
> I just didn't notice? Or did I forget to add someone?

Most likely that it is so trivial that nobody paid much attention.

FWIW, you can add

Acked-by: Nicolas Pitre <nico@linaro.org>

and submit it here: http://www.arm.linux.org.uk/developer/patches/


Nicolas

Re: [PATCH] ARM: Mark ret_fast_syscall as a function

[Drew Richardson]

On Thu, Aug 06, 2015 at 06:30:40PM +0100, Nicolas Pitre wrote:
> On Thu, 6 Aug 2015, Drew Richardson wrote:
> 
> > On Tue, Jul 14, 2015 at 01:45:57PM +0100, Drew Richardson wrote:
> > > ret_fast_syscall runs when user space makes a syscall. However it
> > > needs to be marked as such so the ELF information is correct. Before
> > > it was:
> > > 
> > >    101: 8000f300     0 NOTYPE  LOCAL  DEFAULT    2 ret_fast_syscall
> > > 
> > > But with this change it correctly shows as:
> > > 
> > >    101: 8000f300    96 FUNC    LOCAL  DEFAULT    2 ret_fast_syscall
> > > 
> > > I see this function when using perf to unwind call stacks from kernel
> > > space to user space. Without this change I would need to add some
> > > special case logic when using the vmlinux ELF information.
> > > 
> > > Signed-off-by: Drew Richardson <drew.richardson@arm.com>
> > 
> > I haven't heard any further comments on this, did this get merged and
> > I just didn't notice? Or did I forget to add someone?
> 
> Most likely that it is so trivial that nobody paid much attention.
> 
> FWIW, you can add
> 
> Acked-by: Nicolas Pitre <nico@linaro.org>
> 
> and submit it here: http://www.arm.linux.org.uk/developer/patches/
> 
> 
> Nicolas
> 

Done, thanks.