From: Helge Deller deller@gmx.de
[ Upstream commit 9cc2fa4f4a92ccc6760d764e7341be46ee8aaaa1 ]
The function end_of_stack() returns a pointer to the last entry of a stack. For architectures like parisc where the stack grows upwards return the pointer to the highest address in the stack.
Without this change I faced a crash on parisc, because the stackleak functionality wrote STACKLEAK_POISON to the lowest address and thus overwrote the first 4 bytes of the task_struct which included the TIF_FLAGS.
Signed-off-by: Helge Deller deller@gmx.de Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/sched/task_stack.h | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/include/linux/sched/task_stack.h b/include/linux/sched/task_stack.h index cb4828aaa34fd..3461beb89b040 100644 --- a/include/linux/sched/task_stack.h +++ b/include/linux/sched/task_stack.h @@ -25,7 +25,11 @@ static inline void *task_stack_page(const struct task_struct *task)
static inline unsigned long *end_of_stack(const struct task_struct *task) { +#ifdef CONFIG_STACK_GROWSUP + return (unsigned long *)((unsigned long)task->stack + THREAD_SIZE) - 1; +#else return task->stack; +#endif }
#elif !defined(__HAVE_THREAD_FUNCTIONS)