The following commit has been merged into the perf/kprobes branch of tip: Commit-ID: f75dd136b65cccfaf3869be5380f401538fa9f72 Gitweb: https://git.kernel.org/tip/f75dd136b65cccfaf3869be5380f401538fa9f72 Author: Masami Hiramatsu <mhiramat@xxxxxxxxxx> AuthorDate: Sat, 29 Aug 2020 22:00:46 +09:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Tue, 08 Sep 2020 11:52:32 +02:00 arc: kprobes: Use generic kretprobe trampoline handler Use the generic kretprobe trampoline handler. Don't use framepointer verification. Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Link: https://lore.kernel.org/r/159870604671.1229682.13639386820521358456.stgit@devnote2 --- arch/arc/kernel/kprobes.c | 54 +------------------------------------- 1 file changed, 2 insertions(+), 52 deletions(-) diff --git a/arch/arc/kernel/kprobes.c b/arch/arc/kernel/kprobes.c index 7d3efe8..cabef45 100644 --- a/arch/arc/kernel/kprobes.c +++ b/arch/arc/kernel/kprobes.c @@ -388,6 +388,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, { ri->ret_addr = (kprobe_opcode_t *) regs->blink; + ri->fp = NULL; /* Replace the return addr with trampoline addr */ regs->blink = (unsigned long)&kretprobe_trampoline; @@ -396,58 +397,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, static int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - struct kretprobe_instance *ri = NULL; - struct hlist_head *head, empty_rp; - struct hlist_node *tmp; - unsigned long flags, orig_ret_address = 0; - unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline; - - INIT_HLIST_HEAD(&empty_rp); - kretprobe_hash_lock(current, &head, &flags); - - /* - * It is possible to have multiple instances associated with a given - * task either because an multiple functions in the call path - * have a return probe installed on them, and/or more than one return - * return probe was registered for a target function. - * - * We can handle this because: - * - instances are always inserted at the head of the list - * - when multiple return probes are registered for the same - * function, the first instance's ret_addr will point to the - * real return address, and all the rest will point to - * kretprobe_trampoline - */ - hlist_for_each_entry_safe(ri, tmp, head, hlist) { - if (ri->task != current) - /* another task is sharing our hash bucket */ - continue; - - if (ri->rp && ri->rp->handler) - ri->rp->handler(ri, regs); - - orig_ret_address = (unsigned long)ri->ret_addr; - recycle_rp_inst(ri, &empty_rp); - - if (orig_ret_address != trampoline_address) { - /* - * This is the real return address. Any other - * instances associated with this task are for - * other calls deeper on the call stack - */ - break; - } - } - - kretprobe_assert(ri, orig_ret_address, trampoline_address); - regs->ret = orig_ret_address; - - kretprobe_hash_unlock(current, &flags); - - hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { - hlist_del(&ri->hlist); - kfree(ri); - } + regs->ret = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); /* By returning a non zero value, we are telling the kprobe handler * that we don't want the post_handler to run
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