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| author | Jens Remus <jremus@linux.ibm.com> | 2025-12-08 19:03:50 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-12-17 15:31:07 +0300 |
| commit | 2652f9a4b019e34fbbde8dcd1396f1f00ec4844f (patch) | |
| tree | 3e319f985fbb0671615e84034041b48b5195be4c | |
| parent | 2d6ad925fb2386f3ee1d26f5022f7ea71bbc1541 (diff) | |
| download | linux-2652f9a4b019e34fbbde8dcd1396f1f00ec4844f.tar.xz | |
unwind_user/fp: Use dummies instead of ifdef
This simplifies the code. unwind_user_next_fp() does not need to
return -EINVAL if config option HAVE_UNWIND_USER_FP is disabled, as
unwind_user_start() will then not select this unwind method and
unwind_user_next() will therefore not call it.
Provide (1) a dummy definition of ARCH_INIT_USER_FP_FRAME, if the unwind
user method HAVE_UNWIND_USER_FP is not enabled, (2) a common fallback
definition of unwind_user_at_function_start() which returns false, and
(3) a common dummy definition of ARCH_INIT_USER_FP_ENTRY_FRAME.
Note that enabling the config option HAVE_UNWIND_USER_FP without
defining ARCH_INIT_USER_FP_FRAME triggers a compile error, which is
helpful when implementing support for this unwind user method in an
architecture. Enabling the config option when providing an arch-
specific unwind_user_at_function_start() definition makes it necessary
to also provide an arch-specific ARCH_INIT_USER_FP_ENTRY_FRAME
definition.
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251208160352.1363040-3-jremus@linux.ibm.com
| -rw-r--r-- | arch/x86/include/asm/unwind_user.h | 1 | ||||
| -rw-r--r-- | include/linux/unwind_user.h | 18 | ||||
| -rw-r--r-- | kernel/unwind/user.c | 4 |
3 files changed, 17 insertions, 6 deletions
diff --git a/arch/x86/include/asm/unwind_user.h b/arch/x86/include/asm/unwind_user.h index 12064284bc4e..971ffe937d50 100644 --- a/arch/x86/include/asm/unwind_user.h +++ b/arch/x86/include/asm/unwind_user.h @@ -35,6 +35,7 @@ static inline bool unwind_user_at_function_start(struct pt_regs *regs) { return is_uprobe_at_func_entry(regs); } +#define unwind_user_at_function_start unwind_user_at_function_start #endif /* CONFIG_HAVE_UNWIND_USER_FP */ diff --git a/include/linux/unwind_user.h b/include/linux/unwind_user.h index 7f7282516bf5..64618618febd 100644 --- a/include/linux/unwind_user.h +++ b/include/linux/unwind_user.h @@ -5,8 +5,22 @@ #include <linux/unwind_user_types.h> #include <asm/unwind_user.h> -#ifndef ARCH_INIT_USER_FP_FRAME - #define ARCH_INIT_USER_FP_FRAME +#ifndef CONFIG_HAVE_UNWIND_USER_FP + +#define ARCH_INIT_USER_FP_FRAME(ws) + +#endif + +#ifndef ARCH_INIT_USER_FP_ENTRY_FRAME +#define ARCH_INIT_USER_FP_ENTRY_FRAME(ws) +#endif + +#ifndef unwind_user_at_function_start +static inline bool unwind_user_at_function_start(struct pt_regs *regs) +{ + return false; +} +#define unwind_user_at_function_start unwind_user_at_function_start #endif int unwind_user(struct unwind_stacktrace *trace, unsigned int max_entries); diff --git a/kernel/unwind/user.c b/kernel/unwind/user.c index 0ca434f86e73..90ab3c1a205e 100644 --- a/kernel/unwind/user.c +++ b/kernel/unwind/user.c @@ -67,7 +67,6 @@ static int unwind_user_next_common(struct unwind_user_state *state, static int unwind_user_next_fp(struct unwind_user_state *state) { -#ifdef CONFIG_HAVE_UNWIND_USER_FP struct pt_regs *regs = task_pt_regs(current); if (state->topmost && unwind_user_at_function_start(regs)) { @@ -81,9 +80,6 @@ static int unwind_user_next_fp(struct unwind_user_state *state) ARCH_INIT_USER_FP_FRAME(state->ws) }; return unwind_user_next_common(state, &fp_frame); -#else - return -EINVAL; -#endif } static int unwind_user_next(struct unwind_user_state *state) |