Messages in this thread | | | Subject | Re: [PATCH] LoongArch: Define the symbol fault as a local label in fpu.S | From | Jinyang He <> | Date | Tue, 29 Aug 2023 16:33:14 +0800 |
| |
On 2023-08-29 14:28, Tiezhu Yang wrote:
> The initial aim is to silence the following objtool warnings: > > arch/loongarch/kernel/fpu.o: warning: objtool: _save_fp_context() falls through to next function fault() > arch/loongarch/kernel/fpu.o: warning: objtool: _restore_fp_context() falls through to next function fault() > arch/loongarch/kernel/fpu.o: warning: objtool: _save_lsx_context() falls through to next function fault() > arch/loongarch/kernel/fpu.o: warning: objtool: _restore_lsx_context() falls through to next function fault() > arch/loongarch/kernel/fpu.o: warning: objtool: _save_lasx_context() falls through to next function fault() > arch/loongarch/kernel/fpu.o: warning: objtool: _restore_lasx_context() falls through to next function fault() > > Obviously, the symbol fault is not a function, it is just a local label, > so use SYM_CODE_START_LOCAL and SYM_CODE_END to define the symbol fault. > > Before: > > $ readelf -s arch/loongarch/kernel/fpu.o | awk -F: /fault/'{print $2}' > 000000000000053c 8 FUNC GLOBAL DEFAULT 1 fault > > After: > > $ readelf -s arch/loongarch/kernel/fpu.o | awk -F: /fault/'{print $2}' > 000000000000053c 8 NOTYPE LOCAL DEFAULT 1 fault > > Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> > --- > arch/loongarch/kernel/fpu.S | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S > index b4032de..7defe50 100644 > --- a/arch/loongarch/kernel/fpu.S > +++ b/arch/loongarch/kernel/fpu.S > @@ -521,7 +521,7 @@ SYM_FUNC_START(_restore_lasx_context) > jr ra > SYM_FUNC_END(_restore_lasx_context) > > -SYM_FUNC_START(fault) > +SYM_CODE_START_LOCAL(fault)
Hi, Tiezhu,
The include/linux/linkage.h noted, * FUNC -- C-like functions (proper stack frame etc.) * CODE -- non-C code (e.g. irq handlers with different, special stack etc.) I think here should be SYM_FUNC_START_LOCAL. Thus, it may create debug info like sp_offset == 0 && ra == CFI_UNDEFINED, (just some impressions).
BTW, I've noticed some funcs should be marked as SYM_CODE.., e.g. handle_syscall, handle_tlb_xxx. If you are sure that changes are necessary, fix them.
Thanks!
Jinyang
> li.w a0, -EFAULT # failure > jr ra > -SYM_FUNC_END(fault) > +SYM_CODE_END(fault)
| |