* [PATCH] asm-generic/ptrace.h: add a comment about frame_pointer
@ 2018-12-10 21:31 Dmitry V. Levin
2018-12-10 21:31 ` Dmitry V. Levin
0 siblings, 1 reply; 2+ messages in thread
From: Dmitry V. Levin @ 2018-12-10 21:31 UTC (permalink / raw)
To: Oleg Nesterov, Arnd Bergmann; +Cc: linux-arch, linux-kernel
I have been misled by comments in asm-generic/ptrace.h into thinking
that frame_pointer() is universally available across architectures,
which resulted in a wrong design decision.
Add a comment about frame_pointer in a hope that it will help others
to avoid this mistake in the future.
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
---
include/asm-generic/ptrace.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/asm-generic/ptrace.h b/include/asm-generic/ptrace.h
index 82e674f6b337..3186c30bd50d 100644
--- a/include/asm-generic/ptrace.h
+++ b/include/asm-generic/ptrace.h
@@ -59,6 +59,10 @@ static inline void user_stack_pointer_set(struct pt_regs *regs,
#define SET_FP(regs, val) (GET_FP(regs) = (val))
#endif
+/*
+ * Unlike instruction_pointer and user_stack_pointer,
+ * frame_pointer is not universally available across architectures.
+ */
static inline unsigned long frame_pointer(struct pt_regs *regs)
{
return GET_FP(regs);
--
ldv
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH] asm-generic/ptrace.h: add a comment about frame_pointer
2018-12-10 21:31 [PATCH] asm-generic/ptrace.h: add a comment about frame_pointer Dmitry V. Levin
@ 2018-12-10 21:31 ` Dmitry V. Levin
0 siblings, 0 replies; 2+ messages in thread
From: Dmitry V. Levin @ 2018-12-10 21:31 UTC (permalink / raw)
To: Oleg Nesterov, Arnd Bergmann; +Cc: linux-arch, linux-kernel
I have been misled by comments in asm-generic/ptrace.h into thinking
that frame_pointer() is universally available across architectures,
which resulted in a wrong design decision.
Add a comment about frame_pointer in a hope that it will help others
to avoid this mistake in the future.
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
---
include/asm-generic/ptrace.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/asm-generic/ptrace.h b/include/asm-generic/ptrace.h
index 82e674f6b337..3186c30bd50d 100644
--- a/include/asm-generic/ptrace.h
+++ b/include/asm-generic/ptrace.h
@@ -59,6 +59,10 @@ static inline void user_stack_pointer_set(struct pt_regs *regs,
#define SET_FP(regs, val) (GET_FP(regs) = (val))
#endif
+/*
+ * Unlike instruction_pointer and user_stack_pointer,
+ * frame_pointer is not universally available across architectures.
+ */
static inline unsigned long frame_pointer(struct pt_regs *regs)
{
return GET_FP(regs);
--
ldv
^ permalink raw reply related [flat|nested] 2+ messages in thread
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2018-12-10 21:31 [PATCH] asm-generic/ptrace.h: add a comment about frame_pointer Dmitry V. Levin
2018-12-10 21:31 ` Dmitry V. Levin
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