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authorDaniel Walter <dwalter@google.com>2014-08-20 13:56:00 +0400
committerRichard Weinberger <richard@nod.at>2014-10-13 23:46:25 +0400
commit970e51feaddbc33ed0e7d187af7f69d1a12c7b6a (patch)
treedbe47fda5a1271dc5404c9c96d7965a870320fc2 /arch/um/kernel/stacktrace.c
parent2a2361228c5e6d8c1733f00653481de918598e50 (diff)
downloadlinux-970e51feaddbc33ed0e7d187af7f69d1a12c7b6a.tar.xz
um: Add support for CONFIG_STACKTRACE
Add stacktrace support for User Mode Linux Signed-off-by: Daniel Walter <dwalter@google.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/kernel/stacktrace.c')
-rw-r--r--arch/um/kernel/stacktrace.c80
1 files changed, 80 insertions, 0 deletions
diff --git a/arch/um/kernel/stacktrace.c b/arch/um/kernel/stacktrace.c
new file mode 100644
index 000000000000..ebe7bcf62684
--- /dev/null
+++ b/arch/um/kernel/stacktrace.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright (C) 2013 Richard Weinberger <richard@nod.at>
+ * Copyright (C) 2014 Google Inc., Author: Daniel Walter <dwalter@google.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kallsyms.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <asm/stacktrace.h>
+
+void dump_trace(struct task_struct *tsk,
+ const struct stacktrace_ops *ops,
+ void *data)
+{
+ int reliable = 0;
+ unsigned long *sp, bp, addr;
+ struct pt_regs *segv_regs = tsk->thread.segv_regs;
+ struct stack_frame *frame;
+
+ bp = get_frame_pointer(tsk, segv_regs);
+ sp = get_stack_pointer(tsk, segv_regs);
+
+ frame = (struct stack_frame *)bp;
+ while (((long) sp & (THREAD_SIZE-1)) != 0) {
+ addr = *sp;
+ if (__kernel_text_address(addr)) {
+ reliable = 0;
+ if ((unsigned long) sp == bp + sizeof(long)) {
+ frame = frame ? frame->next_frame : NULL;
+ bp = (unsigned long)frame;
+ reliable = 1;
+ }
+ ops->address(data, addr, reliable);
+ }
+ sp++;
+ }
+}
+
+static void save_addr(void *data, unsigned long address, int reliable)
+{
+ struct stack_trace *trace = data;
+
+ if (!reliable)
+ return;
+ if (trace->nr_entries >= trace->max_entries)
+ return;
+
+ trace->entries[trace->nr_entries++] = address;
+}
+
+static const struct stacktrace_ops dump_ops = {
+ .address = save_addr
+};
+
+static void __save_stack_trace(struct task_struct *tsk, struct stack_trace *trace)
+{
+ dump_trace(tsk, &dump_ops, trace);
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+
+void save_stack_trace(struct stack_trace *trace)
+{
+ __save_stack_trace(current, trace);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+ __save_stack_trace(tsk, trace);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);