[PATCH 2/2] x86/dumpstack: Print registers for first stack frame

[Josh Poimboeuf]

In the stack dump code, if the frame after the starting pt_regs is also
a regs frame, the registers don't get printed.  Fix that.

Reported-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Tested-by: Alexander Tsoy <alexander@xxxxxxx>
Fixes: 3b3fa11bc700 ("x86/dumpstack: Print any pt_regs found on the stack")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
 arch/x86/kernel/dumpstack.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index e4c2c73bd99e..0c2f29e8a5a2 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -115,6 +115,7 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
 
 	unwind_start(&state, task, regs, stack);
 	stack = stack ? : get_stack_pointer(task, regs);
+	regs = unwind_get_entry_regs(&state, &partial);
 
 	/*
 	 * Iterate through the stacks, starting with the current stack pointer.
@@ -132,7 +133,7 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
 	 * - hardirq stack
 	 * - entry stack
 	 */
-	for (regs = NULL; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) {
+	for ( ; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) {
 		const char *stack_name;
 
 		if (get_stack_info(stack, task, &stack_info, &visit_mask)) {
-- 
2.13.6