1 files changed, 34 insertions, 45 deletions

diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 4738f5e0f2ab..0653788026e2 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -8,80 +8,69 @@
 #include <linux/export.h>
 #include <linux/uaccess.h>
 #include <asm/stacktrace.h>
+#include <asm/unwind.h>
 
-static int save_stack_stack(void *data, char *name)
+static int save_stack_address(struct stack_trace *trace, unsigned long addr,
+                              bool nosched)
 {
-        return 0;
-}
-
-static int
-__save_stack_address(void *data, unsigned long addr, bool reliable, bool nosched)
-{
-        struct stack_trace *trace = data;
-#ifdef CONFIG_FRAME_POINTER
-        if (!reliable)
-                return 0;
-#endif
         if (nosched && in_sched_functions(addr))
                 return 0;
+
         if (trace->skip > 0) {
                 trace->skip--;
                 return 0;
         }
-        if (trace->nr_entries < trace->max_entries) {
-                trace->entries[trace->nr_entries++] = addr;
-                return 0;
-        } else {
-                return -1; /* no more room, stop walking the stack */
-        }
-}
 
-static int save_stack_address(void *data, unsigned long addr, int reliable)
-{
-        return __save_stack_address(data, addr, reliable, false);
+        if (trace->nr_entries >= trace->max_entries)
+                return -1;
+
+        trace->entries[trace->nr_entries++] = addr;
+        return 0;
 }
 
-static int
-save_stack_address_nosched(void *data, unsigned long addr, int reliable)
+static void __save_stack_trace(struct stack_trace *trace,
+                               struct task_struct *task, struct pt_regs *regs,
+                               bool nosched)
 {
-        return __save_stack_address(data, addr, reliable, true);
-}
+        struct unwind_state state;
+        unsigned long addr;
 
-static const struct stacktrace_ops save_stack_ops = {
-        .stack          = save_stack_stack,
-        .address        = save_stack_address,
-        .walk_stack     = print_context_stack,
-};
+        if (regs)
+                save_stack_address(trace, regs->ip, nosched);
 
-static const struct stacktrace_ops save_stack_ops_nosched = {
-        .stack          = save_stack_stack,
-        .address        = save_stack_address_nosched,
-        .walk_stack     = print_context_stack,
-};
+        for (unwind_start(&state, task, regs, NULL); !unwind_done(&state);
+             unwind_next_frame(&state)) {
+                addr = unwind_get_return_address(&state);
+                if (!addr || save_stack_address(trace, addr, nosched))
+                        break;
+        }
+
+        if (trace->nr_entries < trace->max_entries)
+                trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
 
 /*
  * Save stack-backtrace addresses into a stack_trace buffer.
  */
 void save_stack_trace(struct stack_trace *trace)
 {
-        dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace);
-        if (trace->nr_entries < trace->max_entries)
-                trace->entries[trace->nr_entries++] = ULONG_MAX;
+        __save_stack_trace(trace, current, NULL, false);
 }
 EXPORT_SYMBOL_GPL(save_stack_trace);
 
 void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
 {
-        dump_trace(current, regs, NULL, 0, &save_stack_ops, trace);
-        if (trace->nr_entries < trace->max_entries)
-                trace->entries[trace->nr_entries++] = ULONG_MAX;
+        __save_stack_trace(trace, current, regs, false);
 }
 
 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 {
-        dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace);
-        if (trace->nr_entries < trace->max_entries)
-                trace->entries[trace->nr_entries++] = ULONG_MAX;
+        if (!try_get_task_stack(tsk))
+                return;
+
+        __save_stack_trace(trace, tsk, NULL, true);
+
+        put_task_stack(tsk);
 }
 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);