Commit-ID: f4474c9f0bba17857b1a47c8dc89c07a0845c2b2
Gitweb: http://git.kernel.org/tip/f4474c9f0bba17857b1a47c8dc89c07a0845c2b2
Author: Josh Poimboeuf <[email protected]>
AuthorDate: Thu, 17 Nov 2016 00:04:58 -0600
Committer: Ingo Molnar <[email protected]>
CommitDate: Thu, 17 Nov 2016 07:48:39 +0100
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 <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Fixes: 0ee1dd9f5e7e ("x86/dumpstack: Remove raw stack dump")
Link:
http://lkml.kernel.org/r/c551842302a9c222d96a14e42e4003f059509f69.1479362652.git.jpoim...@redhat.com
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/kernel/dumpstack.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 499aa6f..1e057b0 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.
