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

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@devnote2Signed-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
......@@ -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
......
......@@ -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,
......
......@@ -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,
......
......@@ -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,
......
......@@ -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
......
......@@ -485,8 +485,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
static int __kprobes trampoline_probe_handler(struct kprobe *p,
struct pt_regs *regs)
{
instruction_pointer(regs) = __kretprobe_trampoline_handler(regs,
kretprobe_trampoline, NULL);
instruction_pointer(regs) = __kretprobe_trampoline_handler(regs, NULL);
/*
* By returning a non-zero value, we are telling
* kprobe_handler() that we don't want the post_handler
......
......@@ -175,7 +175,7 @@ int __kprobes parisc_kprobe_ss_handler(struct pt_regs *regs)
return 1;
}
static inline void kretprobe_trampoline(void)
void kretprobe_trampoline(void)
{
asm volatile("nop");
asm volatile("nop");
......@@ -193,7 +193,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
{
unsigned long orig_ret_address;
orig_ret_address = __kretprobe_trampoline_handler(regs, trampoline_p.addr, NULL);
orig_ret_address = __kretprobe_trampoline_handler(regs, NULL);
instruction_pointer_set(regs, orig_ret_address);
return 1;
......
......@@ -417,7 +417,7 @@ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
{
unsigned long orig_ret_address;
orig_ret_address = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);
orig_ret_address = __kretprobe_trampoline_handler(regs, NULL);
/*
* We get here through one of two paths:
* 1. by taking a trap -> kprobe_handler() -> here
......
......@@ -347,7 +347,7 @@ 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,
......
......@@ -343,7 +343,7 @@ static void __used kretprobe_trampoline_holder(void)
*/
static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
{
regs->psw.addr = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);
regs->psw.addr = __kretprobe_trampoline_handler(regs, NULL);
/*
* By returning a non-zero value, we are telling
* kprobe_handler() that we don't want the post_handler
......
......@@ -303,7 +303,7 @@ static void __used kretprobe_trampoline_holder(void)
*/
int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
{
regs->pc = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);
regs->pc = __kretprobe_trampoline_handler(regs, NULL);
return 1;
}
......
......@@ -451,7 +451,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
{
unsigned long orig_ret_address = 0;
orig_ret_address = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);
orig_ret_address = __kretprobe_trampoline_handler(regs, NULL);
regs->tpc = orig_ret_address;
regs->tnpc = orig_ret_address + 4;
......
......@@ -49,7 +49,6 @@ extern __visible kprobe_opcode_t optprobe_template_end[];
extern const int kretprobe_blacklist_size;
void arch_remove_kprobe(struct kprobe *p);
asmlinkage void kretprobe_trampoline(void);
extern void arch_kprobe_override_function(struct pt_regs *regs);
......
......@@ -1064,7 +1064,7 @@ __used __visible void *trampoline_handler(struct pt_regs *regs)
regs->ip = (unsigned long)&kretprobe_trampoline;
regs->orig_ax = ~0UL;
return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, &regs->sp);
return (void *)kretprobe_trampoline_handler(regs, &regs->sp);
}
NOKPROBE_SYMBOL(trampoline_handler);
......
......@@ -188,15 +188,23 @@ extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs);
extern int arch_trampoline_kprobe(struct kprobe *p);
void kretprobe_trampoline(void);
/*
* Since some architecture uses structured function pointer,
* use dereference_function_descriptor() to get real function address.
*/
static nokprobe_inline void *kretprobe_trampoline_addr(void)
{
return dereference_kernel_function_descriptor(kretprobe_trampoline);
}
/* If the trampoline handler called from a kprobe, use this version */
unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs,
void *trampoline_address,
void *frame_pointer);
void *frame_pointer);
static nokprobe_inline
unsigned long kretprobe_trampoline_handler(struct pt_regs *regs,
void *trampoline_address,
void *frame_pointer)
void *frame_pointer)
{
unsigned long ret;
/*
......@@ -205,7 +213,7 @@ unsigned long kretprobe_trampoline_handler(struct pt_regs *regs,
* be running at this point.
*/
kprobe_busy_begin();
ret = __kretprobe_trampoline_handler(regs, trampoline_address, frame_pointer);
ret = __kretprobe_trampoline_handler(regs, frame_pointer);
kprobe_busy_end();
return ret;
......
......@@ -1864,7 +1864,6 @@ static struct notifier_block kprobe_exceptions_nb = {
#ifdef CONFIG_KRETPROBES
unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs,
void *trampoline_address,
void *frame_pointer)
{
kprobe_opcode_t *correct_ret_addr = NULL;
......@@ -1879,7 +1878,7 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs,
BUG_ON(ri->fp != frame_pointer);
if (ri->ret_addr != trampoline_address) {
if (ri->ret_addr != kretprobe_trampoline_addr()) {
correct_ret_addr = ri->ret_addr;
/*
* This is the real return address. Any other
......
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