From: Masami Hiramatsu mhiramat@kernel.org

The following commit:

Commit e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler")

Passed the wrong trampoline address to __kretprobe_trampoline_handler(): it passes the descriptor address instead of function entry address.

Pass the right parameter.

Also use correct symbol dereference function to get the function address from 'kretprobe_trampoline' - an IA64 special.

Link: https://lkml.kernel.org/r/163163042696.489837.12551102356265354730.stgit@dev...

Fixes: e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler") Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Ingo Molnar mingo@kernel.org Cc: X86 ML x86@kernel.org Cc: Daniel Xu dxu@dxuuu.xyz Cc: Thomas Gleixner tglx@linutronix.de Cc: Borislav Petkov bp@alien8.de Cc: Peter Zijlstra peterz@infradead.org Cc: Abhishek Sagar sagar.abhishek@gmail.com Cc: Andrii Nakryiko andrii.nakryiko@gmail.com Cc: Paul McKenney paulmck@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org --- arch/ia64/kernel/kprobes.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 441ed04b1037..d4048518a1d7 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -398,7 +398,8 @@ static void kretprobe_trampoline(void)

int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->cr_iip = __kretprobe_trampoline_handler(regs, kretprobe_trampoline, NULL); + regs->cr_iip = __kretprobe_trampoline_handler(regs, + dereference_function_descriptor(kretprobe_trampoline), NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler @@ -414,7 +415,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, ri->fp = NULL;

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

/* Check the instruction in the slot is break */ @@ -902,14 +903,14 @@ static struct kprobe trampoline_p = { int __init arch_init_kprobes(void) { trampoline_p.addr = - (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip; + dereference_function_descriptor(kretprobe_trampoline); return register_kprobe(&trampoline_p); }

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

return 0;