mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2025-04-06 00:16:18 +00:00
Code Issues Packages Projects Releases Wiki Activity

objtool/loongarch: Add unwind hints in prepare_frametrace()

Browse Source 
If 'regs' points to a local stack variable, prepare_frametrace() stores
all registers to the stack.  This confuses objtool as it expects them to
be restored from the stack later.

The stores don't affect stack tracing, so use unwind hints to hide them
from objtool.

Fixes the following warnings:

  arch/loongarch/kernel/traps.o: warning: objtool: show_stack+0xe0: stack state mismatch: reg1[22]=-1+0 reg2[22]=-2-160
  arch/loongarch/kernel/traps.o: warning: objtool: show_stack+0xe0: stack state mismatch: reg1[23]=-1+0 reg2[23]=-2-152

Fixes: cb8a2ef0848c ("LoongArch: Add ORC stack unwinder support")
Reported-by: kernel test robot <lkp@intel.com>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/270cadd8040dda74db2307f23497bb68e65db98d.1743481539.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/oe-kbuild-all/202503280703.OARM8SrY-lkp@intel.com/
This commit is contained in:
Josh Poimboeuf 2025-03-31 21:26:43 -07:00 committed by Ingo Molnar
parent 6309a5c43b
commit 7c977393b8
2 changed files with 12 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/loongarch/include/asm/stacktrace.h
View File

@ -8,6 +8,7 @@
#include <asm/asm.h>
#include <asm/ptrace.h>
#include <asm/loongarch.h>
#include <asm/unwind_hints.h>
#include <linux/stringify.h>
enum stack_type {
@ -43,6 +44,7 @@ int get_stack_info(unsigned long stack, struct task_struct *task, struct stack_i
static __always_inline void prepare_frametrace(struct pt_regs *regs)
{
__asm__ __volatile__(
UNWIND_HINT_SAVE
/* Save $ra */
STORE_ONE_REG(1)
/* Use $ra to save PC */
@ -80,6 +82,7 @@ static __always_inline void prepare_frametrace(struct pt_regs *regs)
STORE_ONE_REG(29)
STORE_ONE_REG(30)
STORE_ONE_REG(31)
UNWIND_HINT_RESTORE
: "=m" (regs->csr_era)
: "r" (regs->regs)
: "memory");

10
arch/loongarch/include/asm/unwind_hints.h
View File

@ -23,6 +23,14 @@
UNWIND_HINT sp_reg=ORC_REG_SP type=UNWIND_HINT_TYPE_CALL
.endm
#endif /* __ASSEMBLY__ */
#else /* !__ASSEMBLY__ */
#define UNWIND_HINT_SAVE \
UNWIND_HINT(UNWIND_HINT_TYPE_SAVE, 0, 0, 0)
#define UNWIND_HINT_RESTORE \
UNWIND_HINT(UNWIND_HINT_TYPE_RESTORE, 0, 0, 0)
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_LOONGARCH_UNWIND_HINTS_H */