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| author | Tiezhu Yang <yangtiezhu@loongson.cn> | 2023-09-06 22:53:10 +0800 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2023-09-06 22:53:10 +0800 |
| commit | 8f58c571bf3095278ebda49ce95df5ead27ebb42 (patch) | |
| tree | 34421e9ed2c4c444ef3122f9501c72db2b3977bc | |
| parent | 937f65935950a0346292120acc5d98033f90e61c (diff) | |
| download | linux-aarch64-8f58c571bf3095278ebda49ce95df5ead27ebb42.tar.gz | |
LoongArch: Define symbol 'fault' as a local label in fpu.S
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()
Currently, SYM_FUNC_START()/SYM_FUNC_END() defines the symbol 'fault' as
SYM_T_FUNC which is STT_FUNC, the objtool warnings are generated through
the following code:
tools/objtool/include/objtool/check.h:
static inline struct symbol *insn_func(struct instruction *insn)
{
struct symbol *sym = insn->sym;
if (sym && sym->type != STT_FUNC)
sym = NULL;
return sym;
}
tools/objtool/check.c:
static int validate_branch(struct objtool_file *file, struct symbol *func,
struct instruction *insn, struct insn_state state)
{
...
if (func && insn_func(insn) && func != insn_func(insn)->pfunc) {
...
WARN("%s() falls through to next function %s()",
func->name, insn_func(insn)->name);
return 1;
}
...
}
We can see that the fixup can be a local label in the following code:
arch/loongarch/include/asm/asm-extable.h:
.pushsection __ex_table, "a"; \
.balign 4; \
.long ((insn) - .); \
.long ((fixup) - .); \
.short (type); \
.short (data); \
.popsection;
.macro _asm_extable, insn, fixup
__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_FIXUP, 0)
.endm
Like arch/loongarch/lib/*.S, just define the symbol 'fault' as a local
label in fpu.S.
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 0 NOTYPE LOCAL DEFAULT 1 .L_fpu_fault
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| -rw-r--r-- | arch/loongarch/kernel/fpu.S | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S index 501094a09f5d89..80dccf8e39a747 100644 --- a/arch/loongarch/kernel/fpu.S +++ b/arch/loongarch/kernel/fpu.S @@ -22,7 +22,7 @@ .macro EX insn, reg, src, offs .ex\@: \insn \reg, \src, \offs - _asm_extable .ex\@, fault + _asm_extable .ex\@, .L_fpu_fault .endm .macro sc_save_fp base @@ -514,7 +514,6 @@ SYM_FUNC_START(_restore_lasx_context) jr ra SYM_FUNC_END(_restore_lasx_context) -SYM_FUNC_START(fault) +.L_fpu_fault: li.w a0, -EFAULT # failure jr ra -SYM_FUNC_END(fault) |