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-rw-r--r--arch/s390/kernel/stacktrace.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
index 0787010139..94f440e383 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();
+}