This is a note to let you know that I've just added the patch titled ia64: kprobes: Fix to pass correct trampoline address to the handler to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ia64-kprobes-fix-to-pass-correct-trampoline-address-to-the-handler.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a7fe2378454cf46cd5e2776d05e72bbe8f0a468c Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Date: Tue, 14 Sep 2021 23:40:27 +0900 Subject: ia64: kprobes: Fix to pass correct trampoline address to the handler From: Masami Hiramatsu <mhiramat@xxxxxxxxxx> commit a7fe2378454cf46cd5e2776d05e72bbe8f0a468c upstream. 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@devnote2 Fixes: e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler") Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: X86 ML <x86@xxxxxxxxxx> Cc: Daniel Xu <dxu@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Abhishek Sagar <sagar.abhishek@xxxxxxxxx> Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> Cc: Paul McKenney <paulmck@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/ia64/kernel/kprobes.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -411,7 +411,8 @@ 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 @@ -427,7 +428,7 @@ void __kprobes arch_prepare_kretprobe(st 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 */ @@ -957,14 +958,14 @@ 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; Patches currently in stable-queue which might be from mhiramat@xxxxxxxxxx are queue-4.19/ia64-kprobes-fix-to-pass-correct-trampoline-address-to-the-handler.patch