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s390: current_stack_pointer shouldn't be a function

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s390 defines current_stack_pointer as function while all other
architectures use 'register unsigned long asm("<stackptr reg>").

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 <kgraul@linux.ibm.com>
Fixes: 2792d84e6d ("usercopy: Check valid lifetime via stack depth")
Cc: Kees Cook <keescook@chromium.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Sven Schnelle 2022-04-08 14:51:26 +02:00 committed by Heiko Carstens
parent a25d588782
commit 30de14b188
4 changed files with 4 additions and 10 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

2
arch/s390/include/asm/entry-common.h
View file

@ -58,7 +58,7 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
static inline bool on_thread_stack(void) static inline bool on_thread_stack(void)
{ {
return !(((unsigned long)(current->stack) ^ current_stack_pointer()) & ~(THREAD_SIZE - 1)); return !(((unsigned long)(current->stack) ^ current_stack_pointer) & ~(THREAD_SIZE - 1));
} }
#endif #endif

8
arch/s390/include/asm/processor.h
View file

@ -200,13 +200,7 @@ unsigned long __get_wchan(struct task_struct *p);
/* Has task runtime instrumentation enabled ? */ /* Has task runtime instrumentation enabled ? */
#define is_ri_task(tsk) (!!(tsk)->thread.ri_cb) #define is_ri_task(tsk) (!!(tsk)->thread.ri_cb)
static __always_inline unsigned long current_stack_pointer(void) register unsigned long current_stack_pointer asm("r15");
{
unsigned long sp;
asm volatile("la %0,0(15)" : "=a" (sp));
return sp;
}
static __always_inline unsigned short stap(void) static __always_inline unsigned short stap(void)
{ {

2
arch/s390/include/asm/stacktrace.h
View file

@ -46,7 +46,7 @@ struct stack_frame {
}; };
/* /*
* Unlike current_stack_pointer() which simply returns current value of %r15 * Unlike current_stack_pointer which simply contains the current value of %r15
* current_frame_address() returns function stack frame address, which matches * current_frame_address() returns function stack frame address, which matches
* %r15 upon function invocation. It may differ from %r15 later if function * %r15 upon function invocation. It may differ from %r15 later if function
* allocates stack for local variables or new stack frame to call other * allocates stack for local variables or new stack frame to call other

2
arch/s390/lib/test_unwind.c
View file

@ -147,7 +147,7 @@ static __always_inline struct pt_regs fake_pt_regs(void)
struct pt_regs regs; struct pt_regs regs;
memset(&regs, 0, sizeof(regs)); memset(&regs, 0, sizeof(regs));
regs.gprs[15] = current_stack_pointer(); regs.gprs[15] = current_stack_pointer;
asm volatile( asm volatile(
"basr %[psw_addr],0\n" "basr %[psw_addr],0\n"