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-rw-r--r--arch/x86/include/asm/unwind.h73
-rw-r--r--arch/x86/kernel/Makefile6
-rw-r--r--arch/x86/kernel/unwind_frame.c93
-rw-r--r--arch/x86/kernel/unwind_guess.c43
4 files changed, 215 insertions, 0 deletions
diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h
new file mode 100644
index 000000000000..c4b6d1cafa46
--- /dev/null
+++ b/arch/x86/include/asm/unwind.h
@@ -0,0 +1,73 @@
+#ifndef _ASM_X86_UNWIND_H
+#define _ASM_X86_UNWIND_H
+
+#include <linux/sched.h>
+#include <linux/ftrace.h>
+#include <asm/ptrace.h>
+#include <asm/stacktrace.h>
+
+struct unwind_state {
+ struct stack_info stack_info;
+ unsigned long stack_mask;
+ struct task_struct *task;
+ int graph_idx;
+#ifdef CONFIG_FRAME_POINTER
+ unsigned long *bp;
+#else
+ unsigned long *sp;
+#endif
+};
+
+void __unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs, unsigned long *first_frame);
+
+bool unwind_next_frame(struct unwind_state *state);
+
+static inline bool unwind_done(struct unwind_state *state)
+{
+ return state->stack_info.type == STACK_TYPE_UNKNOWN;
+}
+
+static inline
+void unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs, unsigned long *first_frame)
+{
+ first_frame = first_frame ? : get_stack_pointer(task, regs);
+
+ __unwind_start(state, task, regs, first_frame);
+}
+
+#ifdef CONFIG_FRAME_POINTER
+
+static inline
+unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
+{
+ if (unwind_done(state))
+ return NULL;
+
+ return state->bp + 1;
+}
+
+unsigned long unwind_get_return_address(struct unwind_state *state);
+
+#else /* !CONFIG_FRAME_POINTER */
+
+static inline
+unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
+{
+ return NULL;
+}
+
+static inline
+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);
+}
+
+#endif /* CONFIG_FRAME_POINTER */
+
+#endif /* _ASM_X86_UNWIND_H */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 0503f5bfb18d..45257cf84370 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -125,6 +125,12 @@ obj-$(CONFIG_EFI) += sysfb_efi.o
obj-$(CONFIG_PERF_EVENTS) += perf_regs.o
obj-$(CONFIG_TRACING) += tracepoint.o
+ifdef CONFIG_FRAME_POINTER
+obj-y += unwind_frame.o
+else
+obj-y += unwind_guess.o
+endif
+
###
# 64 bit specific files
ifeq ($(CONFIG_X86_64),y)
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c
new file mode 100644
index 000000000000..a2456d4d286a
--- /dev/null
+++ b/arch/x86/kernel/unwind_frame.c
@@ -0,0 +1,93 @@
+#include <linux/sched.h>
+#include <asm/ptrace.h>
+#include <asm/bitops.h>
+#include <asm/stacktrace.h>
+#include <asm/unwind.h>
+
+#define FRAME_HEADER_SIZE (sizeof(long) * 2)
+
+unsigned long unwind_get_return_address(struct unwind_state *state)
+{
+ unsigned long addr;
+ unsigned long *addr_p = unwind_get_return_address_ptr(state);
+
+ if (unwind_done(state))
+ return 0;
+
+ addr = ftrace_graph_ret_addr(state->task, &state->graph_idx, *addr_p,
+ addr_p);
+
+ return __kernel_text_address(addr) ? addr : 0;
+}
+EXPORT_SYMBOL_GPL(unwind_get_return_address);
+
+static bool update_stack_state(struct unwind_state *state, void *addr,
+ size_t len)
+{
+ struct stack_info *info = &state->stack_info;
+
+ /*
+ * If addr isn't on the current stack, switch to the next one.
+ *
+ * We may have to traverse multiple stacks to deal with the possibility
+ * that 'info->next_sp' could point to an empty stack and 'addr' could
+ * be on a subsequent stack.
+ */
+ while (!on_stack(info, addr, len))
+ if (get_stack_info(info->next_sp, state->task, info,
+ &state->stack_mask))
+ return false;
+
+ return true;
+}
+
+bool unwind_next_frame(struct unwind_state *state)
+{
+ unsigned long *next_bp;
+
+ if (unwind_done(state))
+ return false;
+
+ next_bp = (unsigned long *)*state->bp;
+
+ /* make sure the next frame's data is accessible */
+ if (!update_stack_state(state, next_bp, FRAME_HEADER_SIZE))
+ return false;
+
+ /* move to the next frame */
+ state->bp = next_bp;
+ return true;
+}
+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;
+
+ /* don't even attempt to start from user mode regs */
+ if (regs && user_mode(regs)) {
+ state->stack_info.type = STACK_TYPE_UNKNOWN;
+ return;
+ }
+
+ /* set up the starting stack frame */
+ state->bp = get_frame_pointer(task, regs);
+
+ /* initialize stack info and make sure the frame data is accessible */
+ get_stack_info(state->bp, state->task, &state->stack_info,
+ &state->stack_mask);
+ update_stack_state(state, state->bp, FRAME_HEADER_SIZE);
+
+ /*
+ * The caller can provide the address of the first frame directly
+ * (first_frame) or indirectly (regs->sp) to indicate which stack frame
+ * to start unwinding at. Skip ahead until we reach it.
+ */
+ while (!unwind_done(state) &&
+ (!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
+ state->bp < first_frame))
+ unwind_next_frame(state);
+}
+EXPORT_SYMBOL_GPL(__unwind_start);
diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c
new file mode 100644
index 000000000000..b5a834c93065
--- /dev/null
+++ b/arch/x86/kernel/unwind_guess.c
@@ -0,0 +1,43 @@
+#include <linux/sched.h>
+#include <linux/ftrace.h>
+#include <asm/ptrace.h>
+#include <asm/bitops.h>
+#include <asm/stacktrace.h>
+#include <asm/unwind.h>
+
+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);
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-29 02:39:26 +0000