The following commit has been merged into the perf/kprobes branch of tip: Commit-ID: 26a24a6b43d51c6fc70bef9b9016d81e4cf75e6e Gitweb: https://git.kernel.org/tip/26a24a6b43d51c6fc70bef9b9016d81e4cf75e6e Author: Masami Hiramatsu <mhiramat@xxxxxxxxxx> AuthorDate: Sat, 29 Aug 2020 22:02:04 +09:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Tue, 08 Sep 2020 11:52:34 +02:00 s390: 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/159870612453.1229682.15950927742606892302.stgit@devnote2 --- arch/s390/kernel/kprobes.c | 79 +------------------------------------- 1 file changed, 2 insertions(+), 77 deletions(-) diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index d2a71d8..fc30e79 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -228,6 +228,7 @@ NOKPROBE_SYMBOL(pop_kprobe); void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14]; + ri->fp = NULL; /* Replace the return addr with trampoline addr */ regs->gprs[14] = (unsigned long) &kretprobe_trampoline; @@ -331,83 +332,7 @@ static void __used kretprobe_trampoline_holder(void) */ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - struct kretprobe_instance *ri; - struct hlist_head *head, empty_rp; - struct hlist_node *tmp; - unsigned long flags, orig_ret_address; - unsigned long trampoline_address; - kprobe_opcode_t *correct_ret_addr; - - 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 - */ - ri = NULL; - orig_ret_address = 0; - correct_ret_addr = NULL; - trampoline_address = (unsigned long) &kretprobe_trampoline; - hlist_for_each_entry_safe(ri, tmp, head, hlist) { - if (ri->task != current) - /* another task is sharing our hash bucket */ - continue; - - orig_ret_address = (unsigned long) ri->ret_addr; - - 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); - - correct_ret_addr = ri->ret_addr; - hlist_for_each_entry_safe(ri, tmp, head, hlist) { - if (ri->task != current) - /* another task is sharing our hash bucket */ - continue; - - orig_ret_address = (unsigned long) ri->ret_addr; - - if (ri->rp && ri->rp->handler) { - ri->ret_addr = correct_ret_addr; - ri->rp->handler(ri, regs); - } - - 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; - } - - regs->psw.addr = 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->psw.addr = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler
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