Commit 96fed8ac authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)
Browse files

kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler() 

The __kretprobe_trampoline_handler() callback, called from low level
arch kprobes methods, has the 'trampoline_address' parameter, which is
entirely superfluous as it basically just replicates:

  dereference_kernel_function_descriptor(kretprobe_trampoline)

In fact we had bugs in arch code where it wasn't replicated correctly.

So remove this superfluous parameter and use kretprobe_trampoline_addr()
instead.

Link: https://lkml.kernel.org/r/163163044546.489837.13505751885476015002.stgit@devnote2



Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Tested-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent f2ec8d9a

arch/arc/kernel/kprobes.c

+1 −1
Original line number Diff line number Diff line
@@ -381,7 +381,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, 
static int __kprobes trampoline_probe_handler(struct kprobe *p,

					      struct pt_regs *regs)

{

	regs->ret = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);

	regs->ret = __kretprobe_trampoline_handler(regs, NULL);



	/* By returning a non zero value, we are telling the kprobe handler

	 * that we don't want the post_handler to run

arch/arm/probes/kprobes/core.c

+1 −2
Original line number Diff line number Diff line
@@ -392,8 +392,7 @@ void __naked __kprobes kretprobe_trampoline(void) 
/* Called from kretprobe_trampoline */

static __used __kprobes void *trampoline_handler(struct pt_regs *regs)

{

	return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline,

						    (void *)regs->ARM_fp);

	return (void *)kretprobe_trampoline_handler(regs, (void *)regs->ARM_fp);

}



void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,

arch/arm64/kernel/probes/kprobes.c

+1 −2
Original line number Diff line number Diff line
@@ -401,8 +401,7 @@ int __init arch_populate_kprobe_blacklist(void) 


void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs)

{

	return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline,

					(void *)kernel_stack_pointer(regs));

	return (void *)kretprobe_trampoline_handler(regs, (void *)kernel_stack_pointer(regs));

}



void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,

arch/csky/kernel/probes/kprobes.c

+1 −1
Original line number Diff line number Diff line
@@ -386,7 +386,7 @@ int __init arch_populate_kprobe_blacklist(void) 


void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs)

{

	return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);

	return (void *)kretprobe_trampoline_handler(regs, NULL);

}



void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,

arch/ia64/kernel/kprobes.c

+2 −3
Original line number Diff line number Diff line
@@ -392,14 +392,13 @@ static void __kprobes set_current_kprobe(struct kprobe *p, 
	__this_cpu_write(current_kprobe, p);

}



static void kretprobe_trampoline(void)

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, NULL);

	/*

	 * By returning a non-zero value, we are telling

	 * kprobe_handler() that we don't want the post_handler