From: 平松雅巳 / HIRAMATU，MASAMI [mailto:masami.hiramatsu.pt@xxxxxxxxxxx]
From: Sandeepa Prabhu <sandeepa.s.prabhu@xxxxxxxxx>
The pre-handler of this special 'trampoline' kprobe executes the return
probe handler functions and restores original return address in ELR_EL1.
This way the saved pt_regs still hold the original register context to be
carried back to the probed kernel function.
This patch seems not well separated.
diff --git a/arch/arm64/kernel/kprobes.c b/arch/arm64/kernel/kprobes.c
index bd3f233..13d3333 100644
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
+ struct pt_regs *regs)
+ ri->ret_addr = (kprobe_opcode_t *)regs->regs;
+ /* replace return addr (x30) with trampoline */
+ regs->regs = (long)&kretprobe_trampoline;
So, where is the kretprobe_trampoline? It seems that function is
defined in other patch.
+int __kprobes arch_trampoline_kprobe(struct kprobe *p)
+ return 0;
And what this function is for??
Ah, sorry, this was my fault. Yes, this function is required.
But this implementation also means there is an asm-based trampoline
function which should be included in this patch.
David, could you tell me the repository which I can get the latest
version of this series? I'd like to see the whole code of kprobes/arm64.