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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 /kernel/kprobes.c | |
| parent | uprobes: Update uprobe_write_opcode() kernel-doc comment (diff) | |
| download | linux-dev-ec6aba3d2be1ed75b3f4c894bb64a36d40db1f55.tar.xz linux-dev-ec6aba3d2be1ed75b3f4c894bb64a36d40db1f55.zip | |
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 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 19 |
1 files changed, 0 insertions, 19 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 745f08fdd7a6..e41385afe79d 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1183,23 +1183,6 @@ static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs, } NOKPROBE_SYMBOL(aggr_post_handler); -static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, - int trapnr) -{ - struct kprobe *cur = __this_cpu_read(kprobe_instance); - - /* - * if we faulted "during" the execution of a user specified - * probe handler, invoke just that probe's fault handler - */ - if (cur && cur->fault_handler) { - if (cur->fault_handler(cur, regs, trapnr)) - return 1; - } - return 0; -} -NOKPROBE_SYMBOL(aggr_fault_handler); - /* Walks the list and increments nmissed count for multiprobe case */ void kprobes_inc_nmissed_count(struct kprobe *p) { @@ -1330,7 +1313,6 @@ static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) ap->addr = p->addr; ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED; ap->pre_handler = aggr_pre_handler; - ap->fault_handler = aggr_fault_handler; /* We don't care the kprobe which has gone. */ if (p->post_handler && !kprobe_gone(p)) ap->post_handler = aggr_post_handler; @@ -2014,7 +1996,6 @@ int register_kretprobe(struct kretprobe *rp) rp->kp.pre_handler = pre_handler_kretprobe; rp->kp.post_handler = NULL; - rp->kp.fault_handler = NULL; /* Pre-allocate memory for max kretprobe instances */ if (rp->maxactive <= 0) { |