bianbu-linux-6.6/arch/arm/include/asm/stacktrace.h
Masami Hiramatsu fed240d9c9 ARM: Recover kretprobe modified return address in stacktrace
Since the kretprobe replaces the function return address with
the kretprobe_trampoline on the stack, arm unwinder shows it
instead of the correct return address.

This finds the correct return address from the per-task
kretprobe_instances list and verify it is in between the
caller fp and callee fp.

Note that this supports both GCC and clang if CONFIG_FRAME_POINTER=y
and CONFIG_ARM_UNWIND=n. For the ARM unwinder, this is still
not working correctly.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-22 12:16:53 -04:00

40 lines
933 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_STACKTRACE_H
#define __ASM_STACKTRACE_H
#include <asm/ptrace.h>
#include <linux/llist.h>
struct stackframe {
/*
* FP member should hold R7 when CONFIG_THUMB2_KERNEL is enabled
* and R11 otherwise.
*/
unsigned long fp;
unsigned long sp;
unsigned long lr;
unsigned long pc;
#ifdef CONFIG_KRETPROBES
struct llist_node *kr_cur;
struct task_struct *tsk;
#endif
};
static __always_inline
void arm_get_current_stackframe(struct pt_regs *regs, struct stackframe *frame)
{
frame->fp = frame_pointer(regs);
frame->sp = regs->ARM_sp;
frame->lr = regs->ARM_lr;
frame->pc = regs->ARM_pc;
#ifdef CONFIG_KRETPROBES
frame->kr_cur = NULL;
frame->tsk = current;
#endif
}
extern int unwind_frame(struct stackframe *frame);
extern void walk_stackframe(struct stackframe *frame,
int (*fn)(struct stackframe *, void *), void *data);
#endif /* __ASM_STACKTRACE_H */