x86/kprobes: Restore BTF if the single-stepping is cancelled
Fix to restore BTF if single-stepping causes a page fault and
it is cancelled.
Usually the BTF flag was restored when the single stepping is done
(in resume_execution()). However, if a page fault happens on the
single stepping instruction, the fault handler is invoked and
the single stepping is cancelled. Thus, the BTF flag is not
restored.
Fixes: 1ecc798c67
("x86: debugctlmsr kprobes")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/160389546985.106936.12727996109376240993.stgit@devnote2
zero-sugar-mainline-defconfig
parent
78af4dc949
commit
78ff2733ff
|
@ -937,6 +937,11 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
|
||||||
* So clear it by resetting the current kprobe:
|
* So clear it by resetting the current kprobe:
|
||||||
*/
|
*/
|
||||||
regs->flags &= ~X86_EFLAGS_TF;
|
regs->flags &= ~X86_EFLAGS_TF;
|
||||||
|
/*
|
||||||
|
* Since the single step (trap) has been cancelled,
|
||||||
|
* we need to restore BTF here.
|
||||||
|
*/
|
||||||
|
restore_btf();
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* If the TF flag was set before the kprobe hit,
|
* If the TF flag was set before the kprobe hit,
|
||||||
|
|
Loading…
Reference in New Issue