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authorSven Schnelle <svens@linux.ibm.com>2022-04-08 14:51:26 +0200
committerHeiko Carstens <hca@linux.ibm.com>2022-04-12 11:56:08 +0200
commit30de14b1884ba609fc1acfba5b40309e3a6ccefe (patch)
tree6196ce347eb977a4d787615260264a3255274d4d /arch
parenta25d5887821e242e5ea8388d8461ff20bedb0729 (diff)
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("<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: 2792d84e6da5 ("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>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/include/asm/entry-common.h2
-rw-r--r--arch/s390/include/asm/processor.h8
-rw-r--r--arch/s390/include/asm/stacktrace.h2
-rw-r--r--arch/s390/lib/test_unwind.c2
4 files changed, 4 insertions, 10 deletions
diff --git a/arch/s390/include/asm/entry-common.h b/arch/s390/include/asm/entry-common.h
index eabab24b71dd..2f0a1cacdf85 100644
--- a/arch/s390/include/asm/entry-common.h
+++ b/arch/s390/include/asm/entry-common.h
@@ -58,7 +58,7 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
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
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)
{
diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h
index 275f4258fbd5..f8500191993d 100644
--- a/arch/s390/include/asm/stacktrace.h
+++ b/arch/s390/include/asm/stacktrace.h
@@ -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
* %r15 upon function invocation. It may differ from %r15 later if function
* allocates stack for local variables or new stack frame to call other
diff --git a/arch/s390/lib/test_unwind.c b/arch/s390/lib/test_unwind.c
index 9bb067321ab4..5a053b393d5c 100644
--- a/arch/s390/lib/test_unwind.c
+++ b/arch/s390/lib/test_unwind.c
@@ -147,7 +147,7 @@ static __always_inline struct pt_regs fake_pt_regs(void)
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
- regs.gprs[15] = current_stack_pointer();
+ regs.gprs[15] = current_stack_pointer;
asm volatile(
"basr %[psw_addr],0\n"