From 30de14b1884ba609fc1acfba5b40309e3a6ccefe Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Fri, 8 Apr 2022 14:51:26 +0200 Subject: s390: current_stack_pointer shouldn't be a function s390 defines current_stack_pointer as function while all other architectures use 'register unsigned long asm(""). This make codes like the following from check_stack_object() fail: if (IS_ENABLED(CONFIG_STACK_GROWSUP)) { if ((void *)current_stack_pointer < obj + len) return BAD_STACK; } else { if (obj < (void *)current_stack_pointer) return BAD_STACK; } because this would compare the address of current_stack_pointer() and not the stackpointer value. Reported-by: Karsten Graul Fixes: 2792d84e6da5 ("usercopy: Check valid lifetime via stack depth") Cc: Kees Cook Cc: Vasily Gorbik Cc: Alexander Gordeev Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens --- arch/s390/include/asm/processor.h | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'arch/s390/include/asm/processor.h') diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index eee8d96fb38e..ff1e25d515a8 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -200,13 +200,7 @@ unsigned long __get_wchan(struct task_struct *p); /* Has task runtime instrumentation enabled ? */ #define is_ri_task(tsk) (!!(tsk)->thread.ri_cb) -static __always_inline unsigned long current_stack_pointer(void) -{ - unsigned long sp; - - asm volatile("la %0,0(15)" : "=a" (sp)); - return sp; -} +register unsigned long current_stack_pointer asm("r15"); static __always_inline unsigned short stap(void) { -- cgit