@@ -4,6 +4,7 @@
#include <linux/sched.h>
#include <linux/ftrace.h>
+#include <linux/llist.h>
#include <asm/ptrace.h>
#include <asm/stacktrace.h>
@@ -20,6 +21,9 @@ struct unwind_state {
bool signal, full_regs;
unsigned long sp, bp, ip;
struct pt_regs *regs, *prev_regs;
+#if defined(CONFIG_KRETPROBES)
+ struct llist_node *kr_iter;
+#endif
#elif defined(CONFIG_UNWINDER_FRAME_POINTER)
bool got_irq;
unsigned long *bp, *orig_sp, ip;
@@ -2,6 +2,7 @@
#include <linux/objtool.h>
#include <linux/module.h>
#include <linux/sort.h>
+#include <linux/kprobes.h>
#include <asm/ptrace.h>
#include <asm/stacktrace.h>
#include <asm/unwind.h>
@@ -536,6 +537,21 @@ bool unwind_next_frame(struct unwind_state *state)
state->ip = ftrace_graph_ret_addr(state->task, &state->graph_idx,
state->ip, (void *)ip_p);
+ /*
+ * When the stack unwinder is called from the kretprobe handler
+ * or the interrupt handler which occurs in the kretprobe
+ * trampoline code, %sp is shown on the stack instead of the
+ * return address because kretprobe_trampoline() does
+ * "push %sp" at first.
+ * And also the unwinder may find the kretprobe_trampoline
+ * instead of the real return address on stack.
+ * In those cases, find the correct return address from
+ * task->kretprobe_instances list.
+ */
+ if (state->ip == sp ||
+ is_kretprobe_trampoline(state->ip))
+ state->ip = kretprobe_find_ret_addr(state->task,
+ &state->kr_iter);
state->sp = sp;
state->regs = NULL;
Since the kretprobe replaces the function return address with the kretprobe_trampoline on the stack, the ORC unwinder can not continue the stack unwinding at that point. To fix this issue, correct state->ip as like as function-graph tracer in the unwind_next_frame(). Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> --- Changes in v2: - Remove kretprobe wrapper functions from unwind_orc.c - Do not fixup state->ip when unwinding with regs because kretprobe fixup instruction pointer before calling handler. --- arch/x86/include/asm/unwind.h | 4 ++++ arch/x86/kernel/unwind_orc.c | 16 ++++++++++++++++ 2 files changed, 20 insertions(+)