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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2016-11-17 00:04:58 -0600 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-11-17 07:48:39 +0100 |
| commit | f4474c9f0bba17857b1a47c8dc89c07a0845c2b2 (patch) | |
| tree | 57dc79aef94b80fe95c0a96f26908057ddc0b79d /arch/x86/kernel/dumpstack.c | |
| parent | adb402cd1461eef6e1a21db4532a3b9e6a6be853 (diff) | |
| download | lwn-f4474c9f0bba17857b1a47c8dc89c07a0845c2b2.tar.gz lwn-f4474c9f0bba17857b1a47c8dc89c07a0845c2b2.zip | |
x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl()
When show_trace_log_lvl() is called from show_regs(), it completely
fails to dump the stack. This bug was introduced when
show_stack_log_lvl() was removed with the following commit:
0ee1dd9f5e7e ("x86/dumpstack: Remove raw stack dump")
Previous callers of that function now call show_trace_log_lvl()
directly. That resulted in a subtle change, in that the 'stack'
argument can now be NULL in certain cases.
A NULL 'stack' pointer means that the stack dump should start from the
topmost stack frame unless 'regs' is valid, in which case it should
start from 'regs->sp'.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 0ee1dd9f5e7e ("x86/dumpstack: Remove raw stack dump")
Link: http://lkml.kernel.org/r/c551842302a9c222d96a14e42e4003f059509f69.1479362652.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/dumpstack.c')
| -rw-r--r-- | arch/x86/kernel/dumpstack.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 499aa6f0fde5..1e057b01b648 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -59,6 +59,7 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, printk("%sCall Trace:\n", log_lvl); unwind_start(&state, task, regs, stack); + stack = stack ? : get_stack_pointer(task, regs); /* * Iterate through the stacks, starting with the current stack pointer. |