kprobes: Remove kprobe::fault_handler

The reason for kprobe::fault_handler(), as given by their comment:

 * We come here because instructions in the pre/post
 * handler caused the page_fault, this could happen
 * if handler tries to access user space by
 * copy_from_user(), get_user() etc. Let the
 * user-specified handler try to fix it first.

Is just plain bad. Those other handlers are ran from non-preemptible
context and had better use _nofault() functions. Also, there is no
upstream usage of this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20210525073213.561116662@infradead.org
This commit is contained in:
Peter Zijlstra 2021-05-25 09:25:19 +02:00
parent 9ce4d216fe
commit ec6aba3d2b
16 changed files with 5 additions and 172 deletions

View file

@ -403,9 +403,6 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
return 1;
if (kcb->kprobe_status & KPROBE_HIT_SS) {
resume_execution(cur, regs, kcb);
regs->cp0_status |= kcb->kprobe_old_SR;