4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx> commit e27c310af5c05cf876d9cad006928076c27f54d4 upstream. 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 <bp@xxxxxxx> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: Borislav Petkov <bp@xxxxxxx> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: ricardo.neri@xxxxxxxxx Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx> Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx> Cc: Huang Rui <ray.huang@xxxxxxx> Cc: Qiaowei Ren <qiaowei.ren@xxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Jiri Slaby <jslaby@xxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: "Ravi V. Shankar" <ravi.v.shankar@xxxxxxxxx> Cc: Chris Metcalf <cmetcalf@xxxxxxxxxxxx> Cc: Brian Gerst <brgerst@xxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Colin Ian King <colin.king@xxxxxxxxxxxxx> Cc: Chen Yucong <slaoub@xxxxxxxxx> Cc: Adam Buchbinder <adam.buchbinder@xxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Thomas Garnier <thgarnie@xxxxxxxxxx> Link: https://lkml.kernel.org/r/1509135945-13762-4-git-send-email-ricardo.neri-calderon@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/ptrace.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -136,9 +136,9 @@ static inline int v8086_mode(struct pt_r #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 @@ -149,8 +149,12 @@ static inline bool user_64bit_mode(struc /* 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