From: Helge Deller <deller@gmx.de> stable inclusion from linux-4.19.218 commit ca6b1b3e032cf6ae2a61303eba04848b10bd6efc -------------------------------- [ 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> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- 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 6a841929073f9..4f099d3fed3a9 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) -- 2.25.1