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x86: Macrofy resuable code

PATCH In review Abhishek Sagar 2 participants 3 messages Jan 27, 2008 x86

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Abhishek Sagar

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#0 lore raw

PATCH 2/3 x86: Macrofy resuable code

Encapsulate reusable code .

Signed-off-by Abhishek Sagar <[email protected]>

---

arch/x86/kernel/kprobes.c +9 -3
index a99e764..45f2949 100644
@@ -74,6 +74,13 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 #define stack_addr(regs) ((unsigned long *)&regs->sp)
 #endif
 
+#define kprobe_bkpt_addr(regs) \
+	((unsigned long)(regs->ip - sizeof(kprobe_opcode_t)))
+
+#define is_jprobe_bkpt(ptr) \
+	((ptr > (u8 *)jprobe_return) && (ptr < (u8 *)jprobe_return_end))
+
+
 #define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\
 	(((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) |   \
 	  (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) |   \

@@ -519,7 +526,7 @@ 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 +1039,7 @@ 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
#1 lore raw
Quoted 10 lines · Abhishek Sagar

Encapsulate reusable code .

Signed-off-by Abhishek Sagar <[email protected]>

---

arch/x86/kernel/kprobes.c +0 -0
index a99e764..45f2949 100644

arch/x86/kernel/kprobes.c DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); · line 83

Quoted 10 lines
arch/x86/kernel/kprobes.c +7 -0
@@ -74,6 +74,13 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 #define stack_addr(regs) ((unsigned long *)&regs->sp)
 #endif
 
+#define kprobe_bkpt_addr(regs) \
+	((unsigned long)(regs->ip - sizeof(kprobe_opcode_t)))
+
+#define is_jprobe_bkpt(ptr) \
+	((ptr > (u8 *)jprobe_return) && (ptr < (u8 *)jprobe_return_end))
+
+

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

Sam

author
#2 lore raw
Quoted 4 lines · Sam Ravnborg

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 <[email protected]>

---

arch/x86/kernel/kprobes.c +12 -3
index a99e764..b7c2d20 100644
@@ -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