aboutsummaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/unwind_bc.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/s390/kernel/unwind_bc.c')
-rw-r--r--arch/s390/kernel/unwind_bc.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/arch/s390/kernel/unwind_bc.c b/arch/s390/kernel/unwind_bc.c
index ea00f703f951..f515aa7cc9e5 100644
--- a/arch/s390/kernel/unwind_bc.c
+++ b/arch/s390/kernel/unwind_bc.c
@@ -50,19 +50,24 @@ bool unwind_next_frame(struct unwind_state *state)
sp = state->sp;
state->reuse_sp = false;
} else {
- sp = READ_ONCE_TASK_STACK(state->task, regs->gprs[15]);
+ sp = READ_ONCE_NOCHECK(regs->gprs[15]);
if (unlikely(outside_of_stack(state, sp))) {
if (!update_stack_info(state, sp))
goto out_err;
}
}
sf = (struct stack_frame *) sp;
- ip = READ_ONCE_TASK_STACK(state->task, sf->gprs[8]);
+ ip = READ_ONCE_NOCHECK(sf->gprs[8]);
reliable = false;
regs = NULL;
+ if (!__kernel_text_address(ip)) {
+ /* skip bogus %r14 */
+ state->regs = NULL;
+ return unwind_next_frame(state);
+ }
} else {
sf = (struct stack_frame *) state->sp;
- sp = READ_ONCE_TASK_STACK(state->task, sf->back_chain);
+ sp = READ_ONCE_NOCHECK(sf->back_chain);
if (likely(sp)) {
/* Non-zero back-chain points to the previous frame */
if (unlikely(outside_of_stack(state, sp))) {
@@ -70,7 +75,7 @@ bool unwind_next_frame(struct unwind_state *state)
goto out_err;
}
sf = (struct stack_frame *) sp;
- ip = READ_ONCE_TASK_STACK(state->task, sf->gprs[8]);
+ ip = READ_ONCE_NOCHECK(sf->gprs[8]);
reliable = true;
} else {
/* No back-chain, look for a pt_regs structure */
@@ -78,9 +83,9 @@ bool unwind_next_frame(struct unwind_state *state)
if (!on_stack(info, sp, sizeof(struct pt_regs)))
goto out_stop;
regs = (struct pt_regs *) sp;
- if (user_mode(regs))
+ if (READ_ONCE_NOCHECK(regs->psw.mask) & PSW_MASK_PSTATE)
goto out_stop;
- ip = READ_ONCE_TASK_STACK(state->task, regs->psw.addr);
+ ip = READ_ONCE_NOCHECK(regs->psw.addr);
reliable = true;
}
}
@@ -137,12 +142,12 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
/* Get the instruction pointer from pt_regs or the stack frame */
if (regs) {
- ip = READ_ONCE_TASK_STACK(state->task, regs->psw.addr);
+ ip = READ_ONCE_NOCHECK(regs->psw.addr);
reliable = true;
reuse_sp = true;
} else {
sf = (struct stack_frame *) sp;
- ip = READ_ONCE_TASK_STACK(state->task, sf->gprs[8]);
+ ip = READ_ONCE_NOCHECK(sf->gprs[8]);
reliable = false;
reuse_sp = false;
}