1 files changed, 94 insertions, 31 deletions

diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index c28c342c162..fdd0c6430e5 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -1,32 +1,29 @@
 /*
  * Stack trace management functions
  *
- *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2006-2009 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
  */
 #include <linux/sched.h>
 #include <linux/stacktrace.h>
 #include <linux/module.h>
+#include <linux/uaccess.h>
 #include <asm/stacktrace.h>
 
-static void save_stack_warning(void *data, char *msg)
-{
-}
-
-static void
-save_stack_warning_symbol(void *data, char *msg, unsigned long symbol)
-{
-}
-
 static int save_stack_stack(void *data, char *name)
 {
-	return -1;
+	return 0;
 }
 
-static void save_stack_address(void *data, unsigned long addr, int reliable)
+static void
+__save_stack_address(void *data, unsigned long addr, bool reliable, bool nosched)
 {
 	struct stack_trace *trace = data;
+#ifdef CONFIG_FRAME_POINTER
 	if (!reliable)
 		return;
+#endif
+	if (nosched && in_sched_functions(addr))
+		return;
 	if (trace->skip > 0) {
 		trace->skip--;
 		return;
@@ -35,34 +32,27 @@ static void save_stack_address(void *data, unsigned long addr, int reliable)
 		trace->entries[trace->nr_entries++] = addr;
 }
 
+static void save_stack_address(void *data, unsigned long addr, int reliable)
+{
+	return __save_stack_address(data, addr, reliable, false);
+}
+
 static void
 save_stack_address_nosched(void *data, unsigned long addr, int reliable)
 {
-	struct stack_trace *trace = (struct stack_trace *)data;
-	if (!reliable)
-		return;
-	if (in_sched_functions(addr))
-		return;
-	if (trace->skip > 0) {
-		trace->skip--;
-		return;
-	}
-	if (trace->nr_entries < trace->max_entries)
-		trace->entries[trace->nr_entries++] = addr;
+	return __save_stack_address(data, addr, reliable, true);
 }
 
 static const struct stacktrace_ops save_stack_ops = {
-	.warning = save_stack_warning,
-	.warning_symbol = save_stack_warning_symbol,
-	.stack = save_stack_stack,
-	.address = save_stack_address,
+	.stack		= save_stack_stack,
+	.address	= save_stack_address,
+	.walk_stack	= print_context_stack,
 };
 
 static const struct stacktrace_ops save_stack_ops_nosched = {
-	.warning = save_stack_warning,
-	.warning_symbol = save_stack_warning_symbol,
-	.stack = save_stack_stack,
-	.address = save_stack_address_nosched,
+	.stack		= save_stack_stack,
+	.address	= save_stack_address_nosched,
+	.walk_stack	= print_context_stack,
 };
 
 /*
@@ -74,6 +64,14 @@ void save_stack_trace(struct stack_trace *trace)
 	if (trace->nr_entries < trace->max_entries)
 		trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
+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;
+}
 
 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 {
@@ -81,3 +79,68 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 	if (trace->nr_entries < trace->max_entries)
 		trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+
+/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
+
+struct stack_frame_user {
+	const void __user	*next_fp;
+	unsigned long		ret_addr;
+};
+
+static int
+copy_stack_frame(const void __user *fp, struct stack_frame_user *frame)
+{
+	int ret;
+
+	if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
+		return 0;
+
+	ret = 1;
+	pagefault_disable();
+	if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
+		ret = 0;
+	pagefault_enable();
+
+	return ret;
+}
+
+static inline void __save_stack_trace_user(struct stack_trace *trace)
+{
+	const struct pt_regs *regs = task_pt_regs(current);
+	const void __user *fp = (const void __user *)regs->bp;
+
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = regs->ip;
+
+	while (trace->nr_entries < trace->max_entries) {
+		struct stack_frame_user frame;
+
+		frame.next_fp = NULL;
+		frame.ret_addr = 0;
+		if (!copy_stack_frame(fp, &frame))
+			break;
+		if ((unsigned long)fp < regs->sp)
+			break;
+		if (frame.ret_addr) {
+			trace->entries[trace->nr_entries++] =
+				frame.ret_addr;
+		}
+		if (fp == frame.next_fp)
+			break;
+		fp = frame.next_fp;
+	}
+}
+
+void save_stack_trace_user(struct stack_trace *trace)
+{
+	/*
+	 * Trace user stack if we are not a kernel thread
+	 */
+	if (current->mm) {
+		__save_stack_trace_user(trace);
+	}
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+