[RFC PATCH v3 03/17] x86/unwind_user: Guard unwind_user_word_size() by UNWIND_USER
From: Jens Remus <hidden>
Date: 2025-12-08 17:16:41
Also in:
bpf, linux-s390, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 stack unwinding · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Josh Poimboeuf, Peter Zijlstra
The unwind user framework in general requires an architecture-specific implementation of unwind_user_word_size() to be present for any unwind method, whether that is fp or a future other method, such as potentially sframe. Guard unwind_user_word_size() by the availability of the UNWIND_USER framework instead of the specific HAVE_UNWIND_USER_FP method. This facilitates to selectively disable HAVE_UNWIND_USER_FP on x86 (e.g. for test purposes) once a new unwind method is added to unwind user. Signed-off-by: Jens Remus <redacted> --- arch/x86/include/asm/unwind_user.h | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/arch/x86/include/asm/unwind_user.h b/arch/x86/include/asm/unwind_user.h
index a528eee80dd6..4d699e4954ed 100644
--- a/arch/x86/include/asm/unwind_user.h
+++ b/arch/x86/include/asm/unwind_user.h@@ -2,11 +2,27 @@ #ifndef _ASM_X86_UNWIND_USER_H #define _ASM_X86_UNWIND_USER_H -#ifdef CONFIG_HAVE_UNWIND_USER_FP +#ifdef CONFIG_UNWIND_USER #include <asm/ptrace.h> #include <asm/uprobes.h> +static inline int unwind_user_word_size(struct pt_regs *regs) +{ + /* We can't unwind VM86 stacks */ + if (regs->flags & X86_VM_MASK) + return 0; +#ifdef CONFIG_X86_64 + if (!user_64bit_mode(regs)) + return sizeof(int); +#endif + return sizeof(long); +} + +#endif /* CONFIG_UNWIND_USER */ + +#ifdef CONFIG_HAVE_UNWIND_USER_FP + #define ARCH_INIT_USER_FP_FRAME(ws) \ .cfa_off = 2*(ws), \ .ra_off = -1*(ws), \
@@ -21,18 +37,6 @@ .use_fp = false, \ .outermost = false, -static inline int unwind_user_word_size(struct pt_regs *regs) -{ - /* We can't unwind VM86 stacks */ - if (regs->flags & X86_VM_MASK) - return 0; -#ifdef CONFIG_X86_64 - if (!user_64bit_mode(regs)) - return sizeof(int); -#endif - return sizeof(long); -} - static inline bool unwind_user_at_function_start(struct pt_regs *regs) { return is_uprobe_at_func_entry(regs);
--
2.51.0