Merging upstream version 6.7.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
index 078701013..94f440e38 100644
--- a/arch/s390/kernel/stacktrace.c
+++ b/arch/s390/kernel/stacktrace.c
@@ -6,9 +6,12 @@
  */
 
 #include <linux/stacktrace.h>
+#include <linux/uaccess.h>
+#include <linux/compat.h>
 #include <asm/stacktrace.h>
 #include <asm/unwind.h>
 #include <asm/kprobes.h>
+#include <asm/ptrace.h>
 
 void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
 		     struct task_struct *task, struct pt_regs *regs)
@@ -58,3 +61,43 @@ int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
 		return -EINVAL;
 	return 0;
 }
+
+void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
+			  const struct pt_regs *regs)
+{
+	struct stack_frame_user __user *sf;
+	unsigned long ip, sp;
+	bool first = true;
+
+	if (is_compat_task())
+		return;
+	if (!consume_entry(cookie, instruction_pointer(regs)))
+		return;
+	sf = (void __user *)user_stack_pointer(regs);
+	pagefault_disable();
+	while (1) {
+		if (__get_user(sp, &sf->back_chain))
+			break;
+		if (__get_user(ip, &sf->gprs[8]))
+			break;
+		if (ip & 0x1) {
+			/*
+			 * If the instruction address is invalid, and this
+			 * is the first stack frame, assume r14 has not
+			 * been written to the stack yet. Otherwise exit.
+			 */
+			if (first && !(regs->gprs[14] & 0x1))
+				ip = regs->gprs[14];
+			else
+				break;
+		}
+		if (!consume_entry(cookie, ip))
+			break;
+		/* Sanity check: ABI requires SP to be aligned 8 bytes. */
+		if (!sp || sp & 0x7)
+			break;
+		sf = (void __user *)sp;
+		first = false;
+	}
+	pagefault_enable();
+}