diff options
| -rw-r--r-- | arch/s390/kernel/process.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 2ff90a1a105..008c74526fd 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -58,10 +58,18 @@ asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); */ unsigned long thread_saved_pc(struct task_struct *tsk) { - struct stack_frame *sf; + struct stack_frame *sf, *low, *high; - sf = (struct stack_frame *) tsk->thread.ksp; - sf = (struct stack_frame *) sf->back_chain; + if (!tsk || !task_stack_page(tsk)) + return 0; + low = task_stack_page(tsk); + high = (struct stack_frame *) task_pt_regs(tsk); + sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN); + if (sf <= low || sf > high) + return 0; + sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); + if (sf <= low || sf > high) + return 0; return sf->gprs[8]; } |