Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML update from Richard Weinberger:
 "Besides of fixes this contains also support for CONFIG_STACKTRACE by
  Daniel Walter"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: net: Eliminate NULL test after alloc_bootmem
  um: Add support for CONFIG_STACKTRACE
  um: ubd: Fix for processes stuck in D state forever
  um: delete unnecessary bootmem struct page array
  um: remove csum_partial_copy_generic_i386 to clean up exception table

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);