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| author | Peter Zijlstra <peterz@infradead.org> | 2021-05-25 09:25:19 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-06-01 16:00:08 +0200 |
| commit | ec6aba3d2be1ed75b3f4c894bb64a36d40db1f55 (patch) | |
| tree | 0fd56814090efcd59ce2f2b29906043853764b23 /samples/kprobes | |
| parent | 9ce4d216fe8b581e4da4406461a4cfc9acbfa679 (diff) | |
| download | linux-ec6aba3d2be1ed75b3f4c894bb64a36d40db1f55.tar.bz2 | |
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
Diffstat (limited to 'samples/kprobes')
| -rw-r--r-- | samples/kprobes/kprobe_example.c | 15 |
1 files changed, 0 insertions, 15 deletions
diff --git a/samples/kprobes/kprobe_example.c b/samples/kprobes/kprobe_example.c index c495664c0a9b..4b2f31828951 100644 --- a/samples/kprobes/kprobe_example.c +++ b/samples/kprobes/kprobe_example.c @@ -94,26 +94,11 @@ static void __kprobes handler_post(struct kprobe *p, struct pt_regs *regs, #endif } -/* - * fault_handler: this is called if an exception is generated for any - * instruction within the pre- or post-handler, or when Kprobes - * single-steps the probed instruction. - */ -static int handler_fault(struct kprobe *p, struct pt_regs *regs, int trapnr) -{ - pr_info("fault_handler: p->addr = 0x%p, trap #%dn", p->addr, trapnr); - /* Return 0 because we don't handle the fault. */ - return 0; -} -/* NOKPROBE_SYMBOL() is also available */ -NOKPROBE_SYMBOL(handler_fault); - static int __init kprobe_init(void) { int ret; kp.pre_handler = handler_pre; kp.post_handler = handler_post; - kp.fault_handler = handler_fault; ret = register_kprobe(&kp); if (ret < 0) { |