[PATCH 4.19 08/12] Revert "ia64: kprobes: Fix to pass correct trampoline address to the handler"

Greg Kroah-Hartman
2022-04-29T10:42:59Z

From: Masami Hiramatsu <mhiramat@kernel.org>

This reverts commit f5f96e3643dc33d6117cf7047e73512046e4858b.

The commit f5f96e3643dc ("ia64: kprobes: Fix to pass correct trampoline
address to the handler") was wrongly backported. It involves another
commit which is a part of another bigger series, so it should not be
backported to the stable tree.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/ia64/kernel/kprobes.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -411,8 +411,7 @@ static void kretprobe_trampoline(void)

int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
{
- regs->cr_iip = __kretprobe_trampoline_handler(regs,
- dereference_function_descriptor(kretprobe_trampoline), NULL);
+ regs->cr_iip = __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
@@ -428,7 +427,7 @@ void __kprobes arch_prepare_kretprobe(st
ri->fp = NULL;

/* Replace the return addr with trampoline addr */
- regs->b0 = (unsigned long)dereference_function_descriptor(kretprobe_trampoline);
+ regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip;
}

/* Check the instruction in the slot is break */
@@ -958,14 +957,14 @@ static struct kprobe trampoline_p = {
int __init arch_init_kprobes(void)
{
trampoline_p.addr =
- dereference_function_descriptor(kretprobe_trampoline);
+ (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip;
return register_kprobe(&trampoline_p);
}

int __kprobes arch_trampoline_kprobe(struct kprobe *p)
{
if (p->addr ==
- dereference_function_descriptor(kretprobe_trampoline))
+ (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip)
return 1;

return 0;