diff options
| author | Will Deacon <will.deacon@arm.com> | 2019-04-08 17:56:34 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-17 08:37:54 +0200 |
| commit | 6ed78eba4b5474add9c534f25f0dfdfd5a8df38d (patch) | |
| tree | 12c67c7384dbd12585f913a8055303bf5c267b2b | |
| parent | 9e5c0620db8bda12c235548a891f0aadb93ed5a2 (diff) | |
arm64: backtrace: Don't bother trying to unwind the userspace stack
commit 1e6f5440a6814d28c32d347f338bfef68bc3e69d upstream.
Calling dump_backtrace() with a pt_regs argument corresponding to
userspace doesn't make any sense and our unwinder will simply print
"Call trace:" before unwinding the stack looking for user frames.
Rather than go through this song and dance, just return early if we're
passed a user register state.
Cc: <stable@vger.kernel.org>
Fixes: 1149aad10b1e ("arm64: Add dump_backtrace() in show_regs")
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm64/kernel/traps.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 4fc0e958770b..4cacc33d07ce 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -145,10 +145,16 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) { struct stackframe frame; - int skip; + int skip = 0; pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk); + if (regs) { + if (user_mode(regs)) + return; + skip = 1; + } + if (!tsk) tsk = current; @@ -169,7 +175,6 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) frame.graph = tsk->curr_ret_stack; #endif - skip = !!regs; printk("Call trace:\n"); while (1) { unsigned long stack; @@ -232,15 +237,13 @@ static int __die(const char *str, int err, struct pt_regs *regs) return ret; print_modules(); - __show_regs(regs); pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n", TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), end_of_stack(tsk)); + show_regs(regs); - if (!user_mode(regs)) { - dump_backtrace(regs, tsk); + if (!user_mode(regs)) dump_instr(KERN_EMERG, regs); - } return ret; } |