[RFC PATCH 4/6] kprobes: remove global kprobe_lock - ppc64 changes

[Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>]

Changes for ppc64 kprobes

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>

 arch/ppc64/kernel/kprobes.c |   16 +++++++++-------
 1 files changed, 9 insertions(+), 7 deletions(-)

Index: linux-2.6.13-rc3/arch/ppc64/kernel/kprobes.c
===================================================================
--- linux-2.6.13-rc3.orig/arch/ppc64/kernel/kprobes.c	2005-07-29 13:00:59.000000000 -0400
+++ linux-2.6.13-rc3/arch/ppc64/kernel/kprobes.c	2005-07-29 13:01:58.000000000 -0400
@@ -30,7 +30,6 @@
 #include <linux/config.h>
 #include <linux/kprobes.h>
 #include <linux/ptrace.h>
-#include <linux/spinlock.h>
 #include <linux/preempt.h>
 #include <asm/cacheflush.h>
 #include <asm/kdebug.h>
@@ -141,6 +140,7 @@ static inline void set_current_kprobe(st
 	kcb->kprobe_saved_msr = regs->msr;
 }
 
+/* Called with kretprobe_lock held */
 void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
 				      struct pt_regs *regs)
 {
@@ -175,7 +175,7 @@ static inline int kprobe_handler(struct 
 			if (kcb->kprobe_status == KPROBE_HIT_SS) {
 				regs->msr &= ~MSR_SE;
 				regs->msr |= kcb->kprobe_saved_msr;
-				unlock_kprobes();
+				read_unlock(&kprobe_lock);
 				goto no_kprobe;
 			}
 			/* We have reentered the kprobe_handler(), since
@@ -201,10 +201,10 @@ static inline int kprobe_handler(struct 
 		goto no_kprobe;
 	}
 
-	lock_kprobes();
+	read_lock(&kprobe_lock);
 	p = get_kprobe(addr);
 	if (!p) {
-		unlock_kprobes();
+		read_unlock(&kprobe_lock);
 		if (*addr != BREAKPOINT_INSTRUCTION) {
 			/*
 			 * PowerPC has multiple variants of the "trap"
@@ -272,6 +272,7 @@ int __kprobes trampoline_probe_handler(s
 	unsigned long orig_ret_address = 0;
 	unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline;
 
+	spin_lock(&kretprobe_lock);
         head = kretprobe_inst_table_head(current);
 
 	/*
@@ -310,7 +311,8 @@ int __kprobes trampoline_probe_handler(s
 	BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address));
 	regs->nip = orig_ret_address;
 
-	unlock_kprobes();
+	spin_unlock(&kretprobe_lock);
+	read_unlock(&kprobe_lock);
 
         /*
          * By returning a non-zero value, we are telling
@@ -361,7 +363,7 @@ static inline int post_kprobe_handler(st
 		goto out;
 	}
 	reset_current_kprobe();
-	unlock_kprobes();
+	read_unlock(&kprobe_lock);
 out:
 	preempt_enable_no_resched();
 
@@ -391,7 +393,7 @@ static inline int kprobe_fault_handler(s
 		regs->msr |= kcb->kprobe_saved_msr;
 
 		reset_current_kprobe();
-		unlock_kprobes();
+		read_unlock(&kprobe_lock);
 		preempt_enable_no_resched();
 	}
 	return 0;