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authorDaniel Vetter <daniel.vetter@ffwll.ch>2016-10-25 10:06:04 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2016-10-25 10:06:04 +0200
commit0fc4f78f44e6c6148cee32456f0d0023ec1c1fd8 (patch)
tree71c906207227dd8753a0191db9304035ec3471a4 /arch/x86/kernel/unwind_guess.c
parent78010cd9736ec571796f4404524ed575b81238b9 (diff)
parent5481e27f6fd06b7cb902072e81d6b083db8155eb (diff)
Merge remote-tracking branch 'airlied/drm-next' into topic/drm-misc
Backmerge latest drm-next to have a baseline for the s/fence/dma_fence/ patch from Chris. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Diffstat (limited to 'arch/x86/kernel/unwind_guess.c')
-rw-r--r--arch/x86/kernel/unwind_guess.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c
new file mode 100644
index 000000000000..9298993dc8b7
--- /dev/null
+++ b/arch/x86/kernel/unwind_guess.c
@@ -0,0 +1,53 @@
+#include <linux/sched.h>
+#include <linux/ftrace.h>
+#include <asm/ptrace.h>
+#include <asm/bitops.h>
+#include <asm/stacktrace.h>
+#include <asm/unwind.h>
+
+unsigned long unwind_get_return_address(struct unwind_state *state)
+{
+ if (unwind_done(state))
+ return 0;
+
+ return ftrace_graph_ret_addr(state->task, &state->graph_idx,
+ *state->sp, state->sp);
+}
+EXPORT_SYMBOL_GPL(unwind_get_return_address);
+
+bool unwind_next_frame(struct unwind_state *state)
+{
+ struct stack_info *info = &state->stack_info;
+
+ if (unwind_done(state))
+ return false;
+
+ do {
+ for (state->sp++; state->sp < info->end; state->sp++)
+ if (__kernel_text_address(*state->sp))
+ return true;
+
+ state->sp = info->next_sp;
+
+ } while (!get_stack_info(state->sp, state->task, info,
+ &state->stack_mask));
+
+ return false;
+}
+EXPORT_SYMBOL_GPL(unwind_next_frame);
+
+void __unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs, unsigned long *first_frame)
+{
+ memset(state, 0, sizeof(*state));
+
+ state->task = task;
+ state->sp = first_frame;
+
+ get_stack_info(first_frame, state->task, &state->stack_info,
+ &state->stack_mask);
+
+ if (!__kernel_text_address(*first_frame))
+ unwind_next_frame(state);
+}
+EXPORT_SYMBOL_GPL(__unwind_start);