Re: [PATCH v2 2/5] riscv: Use SYM_*() assembly macros instead of deprecated ones

From: Andrew Jones
Date: Wed Oct 25 2023 - 02:50:48 EST


On Tue, Oct 24, 2023 at 08:03:52PM +0200, Clément Léger wrote:
>
>
> On 24/10/2023 17:23, Andrew Jones wrote:
> > On Tue, Oct 24, 2023 at 03:26:52PM +0200, Clément Léger wrote:
> > ...
> >> diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S
> >> index 09b47ebacf2e..3ab438f30d13 100644
> >> --- a/arch/riscv/lib/uaccess.S
> >> +++ b/arch/riscv/lib/uaccess.S
> >> @@ -10,8 +10,7 @@
> >> _asm_extable 100b, \lbl
> >> .endm
> >>
> >> -ENTRY(__asm_copy_to_user)
> >> -ENTRY(__asm_copy_from_user)
> >> +SYM_FUNC_START(__asm_copy_to_user)
> >>
> >> /* Enable access to user memory */
> >> li t6, SR_SUM
> >> @@ -181,13 +180,13 @@ ENTRY(__asm_copy_from_user)
> >> csrc CSR_STATUS, t6
> >> sub a0, t5, a0
> >> ret
> >> -ENDPROC(__asm_copy_to_user)
> >> -ENDPROC(__asm_copy_from_user)
> >> +SYM_FUNC_END(__asm_copy_to_user)
> >> EXPORT_SYMBOL(__asm_copy_to_user)
> >> +SYM_FUNC_ALIAS(__asm_copy_from_user, __asm_copy_to_user)
> >> EXPORT_SYMBOL(__asm_copy_from_user)
> >
> > I didn't see any comment about the sharing of debug info among both the
> > from and to functions. Assuming it isn't confusing in some way, then
>
> Hi Andrew,
>
> I did some testing with gdb and it seems to correctly assume that
> __asm_copy_to_user maps to __asm_copy_from_user for debugging. The basic
> tests that I did (breakpoints, disasm, etc) seems to show no sign of
> problems for debugging. Were you thinking about other things specifically ?

Mostly just backtrace symbols, but I suppose we can live with it, since
it wouldn't be the only weird thing in a backtrace.

Thanks,
drew