Remove stack unwinder for now

It has caused more problems than it ever really solved, and is
apparently not getting cleaned up and fixed.  We can put it back when
it's stable and isn't likely to make warning or bug events worse.

In the meantime, enable frame pointers for more readable stack traces.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 1 insertions, 49 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 818e4589f718..5c2681875b9a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -354,24 +354,6 @@ config FRAME_POINTER
           some architectures or if you use external debuggers.
           If you don't debug the kernel, you can say N.
 
-config UNWIND_INFO
-        bool "Compile the kernel with frame unwind information"
-        depends on !IA64 && !PARISC && !ARM
-        depends on !MODULES || !(MIPS || PPC || SUPERH || V850)
-        help
-          If you say Y here the resulting kernel image will be slightly larger
-          but not slower, and it will give very useful debugging information.
-          If you don't debug the kernel, you can say N, but we may not be able
-          to solve problems without frame unwind information or frame pointers.
-
-config STACK_UNWIND
-        bool "Stack unwind support"
-        depends on UNWIND_INFO
-        depends on X86
-        help
-          This enables more precise stack traces, omitting all unrelated
-          occurrences of pointers into kernel code from the dump.
-
 config FORCED_INLINING
         bool "Force gcc to inline functions marked 'inline'"
         depends on DEBUG_KERNEL
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index d143c0faf248..b5a90fc056d3 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -55,37 +55,7 @@ static bool fail_task(struct fault_attr *attr, struct task_struct *task)
 
 #define MAX_STACK_TRACE_DEPTH 32
 
-#ifdef CONFIG_STACK_UNWIND
-
-static asmlinkage int fail_stacktrace_callback(struct unwind_frame_info *info,
-                                                void *arg)
-{
-        int depth;
-        struct fault_attr *attr = arg;
-        bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX);
-
-        for (depth = 0; depth < attr->stacktrace_depth
-                        && unwind(info) == 0 && UNW_PC(info); depth++) {
-                if (arch_unw_user_mode(info))
-                        break;
-                if (attr->reject_start <= UNW_PC(info) &&
-                               UNW_PC(info) < attr->reject_end)
-                        return false;
-                if (attr->require_start <= UNW_PC(info) &&
-                               UNW_PC(info) < attr->require_end)
-                        found = true;
-        }
-        return found;
-}
-
-static bool fail_stacktrace(struct fault_attr *attr)
-{
-        struct unwind_frame_info info;
-
-        return unwind_init_running(&info, fail_stacktrace_callback, attr);
-}
-
-#elif defined(CONFIG_STACKTRACE)
+#if defined(CONFIG_STACKTRACE)
 
 static bool fail_stacktrace(struct fault_attr *attr)
 {