In its current form, user_64bit_mode() can only be used when CONFIG_X86_64 is selected. This implies that code built with CONFIG_X86_64=n cannot use it. If a piece of code needs to be built for both CONFIG_X86_64=y and CONFIG_X86_64=n and wants to use this function, it needs to wrap it in an #ifdef/#endif; potentially, in multiple places.
This can be easily avoided with a single #ifdef/#endif pair within user_64bit_mode() itself. Suggested-by: Borislav Petkov <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Adam Buchbinder <[email protected]> Cc: Colin Ian King <[email protected]> Cc: Lorenzo Stoakes <[email protected]> Cc: Qiaowei Ren <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Kees Cook <[email protected]> Cc: Thomas Garnier <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Ravi V. Shankar <[email protected]> Cc: [email protected] Signed-off-by: Ricardo Neri <[email protected]> --- arch/x86/include/asm/ptrace.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 2b5d686..ea78a84 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -115,9 +115,9 @@ static inline int v8086_mode(struct pt_regs *regs) #endif } -#ifdef CONFIG_X86_64 static inline bool user_64bit_mode(struct pt_regs *regs) { +#ifdef CONFIG_X86_64 #ifndef CONFIG_PARAVIRT /* * On non-paravirt systems, this is the only long mode CPL 3 @@ -128,8 +128,12 @@ static inline bool user_64bit_mode(struct pt_regs *regs) /* Headers are too twisted for this to go in paravirt.h. */ return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs; #endif +#else /* !CONFIG_X86_64 */ + return false; +#endif } +#ifdef CONFIG_X86_64 #define current_user_stack_pointer() current_pt_regs()->sp #define compat_user_stack_pointer() current_pt_regs()->sp #endif -- 2.9.3
