From: Michael Ellerman
> Currently when we back trace something that is in a syscall we see
> something like this:
>
> [c000000000000000] [c000000000000000] SyS_read+0x6c/0x110
> [c000000000000000] [c000000000000000] syscall_exit+0x0/0x98
>
> Although it's entirely correct, seeing syscall_exit at the bottom can be
> confusing - we were exiting from a syscall and then called SyS_read() ?
>
> If we instead change syscall_exit to be a local label we get something
> more intuitive:
>
> [c0000001fa46fde0] [c00000000026719c] SyS_read+0x6c/0x110
> [c0000001fa46fe30] [c000000000009264] system_call+0x38/0xd0
>
> ie. we were handling a system call, and it was SyS_read().
>
> Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
> ---
> arch/powerpc/kernel/entry_64.S | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
> index 0905c8da90f1..d8828e50dbef 100644
> --- a/arch/powerpc/kernel/entry_64.S
> +++ b/arch/powerpc/kernel/entry_64.S
> @@ -178,7 +178,7 @@ system_call: /* label this so stack
> traces look sane */
> mtctr r12
> bctrl /* Call handler */
Why not add a 'nop' here instead?
> -syscall_exit:
> +.Lsyscall_exit:
> std r3,RESULT(r1)
> #ifdef SHOW_SYSCALLS
> bl do_show_syscall_exit
> @@ -270,7 +270,7 @@ syscall_dotrace:
...
David
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