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 <[email protected]> --- Notes (jremus): Changes in v3: - Remove comment on #endif. (Ingo) Changes in v2: - Add parameter ws to ARCH_INIT_USER_{FP_FRAME|FP_ENTRY_FRAME}. - Provide common fallback of unwind_user_at_function_start(). - Provide common dummy of ARCH_INIT_USER_FP_ENTRY_FRAME. - Reword commit message accordingly. arch/x86/include/asm/unwind_user.h | 1 + include/linux/unwind_user.h | 18 ++++++++++++++++-- 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 f9a1c460150d..a528eee80dd6 100644 --- a/arch/x86/include/asm/unwind_user.h +++ b/arch/x86/include/asm/unwind_user.h @@ -37,6 +37,7 @@ 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 f81c36ab2861..fdb1001e3750 100644 --- a/kernel/unwind/user.c +++ b/kernel/unwind/user.c @@ -74,7 +74,6 @@ 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)) { @@ -88,9 +87,6 @@ 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_sframe(struct unwind_user_state *state) -- 2.51.0
