Re: [PATCH 2/3] x86: Macrofy resuable code

Abhishek Sagar
2008-01-27T13:31:41Z

Sam Ravnborg wrote:

> Small static functions are preferred over macros.
> Any particular reason to use a macro here?
>
> Sam

These macros have very limited(two) instantiations. But here's an alternative patch inlined.

Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
---

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index a99e764..b7c2d20 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -159,6 +159,16 @@ struct kretprobe_blackpoint kretprobe_blacklist[] = {
};
const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);

+static inline unsigned long kprobe_bkpt_addr(struct pt_regs *regs)
+{
+ return (instruction_pointer(regs) - sizeof(kprobe_opcode_t));
+}
+
+static inline int is_jprobe_bkpt(u8 *ptr)
+{
+ return (ptr > (u8 *)jprobe_return) && (ptr < (u8 *)jprobe_return_end);
+}
+
/* Insert a jump instruction at address 'from', which jumps to address 'to'.*/
static void __kprobes set_jmp_op(void *from, void *to)
{
@@ -519,7 +529,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
struct kprobe *p;
struct kprobe_ctlblk *kcb;

- addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t));
+ addr = (kprobe_opcode_t *)kprobe_bkpt_addr(regs);
if (*addr != BREAKPOINT_INSTRUCTION) {
/*
* The breakpoint instruction was removed right
@@ -1032,8 +1042,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
u8 *addr = (u8 *) (regs->ip - 1);
struct jprobe *jp = container_of(p, struct jprobe, kp);

- if ((addr > (u8 *) jprobe_return) &&
- (addr < (u8 *) jprobe_return_end)) {
+ if (is_jprobe_bkpt(addr)) {
if (stack_addr(regs) != kcb->jprobe_saved_sp) {
struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
printk(KERN_ERR