[PATCH] Switch Kprobes inline functions to __kprobes for x86_64

Andrew Morton pointed out that compiler might not inline the functions
marked for inline in kprobes.  There-by allowing the insertion of probes
on these kprobes routines, which might cause recursion.

This patch removes all such inline and adds them to kprobes section
there by disallowing probes on all such routines.  Some of the routines
can even still be inlined, since these routines gets executed after the
kprobes had done necessay setup for reentrancy.

Signed-off-by: Prasanna S Panchamukhi <[email protected]>
Cc: Andi Kleen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

arch/x86_64/kernel/kprobes.c

@@ -53,7 +53,7 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 /*
  * returns non-zero if opcode modifies the interrupt flag.
  */
-static inline int is_IF_modifier(kprobe_opcode_t *insn)
+static __always_inline int is_IF_modifier(kprobe_opcode_t *insn)
 {
 	switch (*insn) {
 	case 0xfa:		/* cli */
@@ -84,7 +84,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
  * If it does, return the address of the 32-bit displacement word.
  * If not, return null.
  */
-static inline s32 *is_riprel(u8 *insn)
+static s32 __kprobes *is_riprel(u8 *insn)
 {
 #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) |   \
@@ -229,23 +229,23 @@ void __kprobes arch_remove_kprobe(struct kprobe *p)
 	mutex_unlock(&kprobe_mutex);
 }
 
-static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
+static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
 	kcb->prev_kprobe.kp = kprobe_running();
 	kcb->prev_kprobe.status = kcb->kprobe_status;
 	kcb->prev_kprobe.old_rflags = kcb->kprobe_old_rflags;
 	kcb->prev_kprobe.saved_rflags = kcb->kprobe_saved_rflags;
 }
 
-static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb)
+static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
 	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 	kcb->kprobe_old_rflags = kcb->prev_kprobe.old_rflags;
 	kcb->kprobe_saved_rflags = kcb->prev_kprobe.saved_rflags;
 }
 
-static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
+static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 				struct kprobe_ctlblk *kcb)
 {
 	__get_cpu_var(current_kprobe) = p;