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authorAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>2006-01-09 20:52:43 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-10 08:01:40 -0800
commit49a2a1b83ba6fa40c41968d6a28ba16e7ed0c3f7 (patch)
treef257b535d0f09f9ac2531d40feb732349993665c /arch
parent41dead49ccb4d7f0a34d56478f487342a3c3ab2b (diff)
[PATCH] kprobes: changed from using spinlock to mutex
Since Kprobes runtime exception handlers is now lock free as this code path is now using RCU to walk through the list, there is no need for the register/unregister{_kprobe} to use spin_{lock/unlock}_isr{save/restore}. The serialization during registration/unregistration is now possible using just a mutex. In the above process, this patch also fixes a minor memory leak for x86_64 and powerpc. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/kernel/kprobes.c6
-rw-r--r--arch/powerpc/kernel/kprobes.c14
-rw-r--r--arch/sparc64/kernel/kprobes.c6
-rw-r--r--arch/x86_64/kernel/kprobes.c7
4 files changed, 10 insertions, 23 deletions
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c
index 19edcd526ba..68fe1025048 100644
--- a/arch/i386/kernel/kprobes.c
+++ b/arch/i386/kernel/kprobes.c
@@ -58,13 +58,9 @@ static inline int is_IF_modifier(kprobe_opcode_t opcode)
int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
- return 0;
-}
-
-void __kprobes arch_copy_kprobe(struct kprobe *p)
-{
memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
p->opcode = *p->addr;
+ return 0;
}
void __kprobes arch_arm_kprobe(struct kprobe *p)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 5368f9c2e6b..331e169e862 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -60,13 +60,13 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
if (!p->ainsn.insn)
ret = -ENOMEM;
}
- return ret;
-}
-void __kprobes arch_copy_kprobe(struct kprobe *p)
-{
- memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
- p->opcode = *p->addr;
+ if (!ret) {
+ memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
+ p->opcode = *p->addr;
+ }
+
+ return ret;
}
void __kprobes arch_arm_kprobe(struct kprobe *p)
@@ -85,9 +85,7 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
- down(&kprobe_mutex);
free_insn_slot(p->ainsn.insn);
- up(&kprobe_mutex);
}
static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c
index a97b0f0727a..bbd5aa6818e 100644
--- a/arch/sparc64/kernel/kprobes.c
+++ b/arch/sparc64/kernel/kprobes.c
@@ -43,14 +43,10 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
- return 0;
-}
-
-void __kprobes arch_copy_kprobe(struct kprobe *p)
-{
p->ainsn.insn[0] = *p->addr;
p->ainsn.insn[1] = BREAKPOINT_INSTRUCTION_2;
p->opcode = *p->addr;
+ return 0;
}
void __kprobes arch_arm_kprobe(struct kprobe *p)
diff --git a/arch/x86_64/kernel/kprobes.c b/arch/x86_64/kernel/kprobes.c
index afe11f4fbd1..8b8943bfb89 100644
--- a/arch/x86_64/kernel/kprobes.c
+++ b/arch/x86_64/kernel/kprobes.c
@@ -42,8 +42,8 @@
#include <asm/pgtable.h>
#include <asm/kdebug.h>
-static DECLARE_MUTEX(kprobe_mutex);
void jprobe_return_end(void);
+void __kprobes arch_copy_kprobe(struct kprobe *p);
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -69,12 +69,11 @@ static inline int is_IF_modifier(kprobe_opcode_t *insn)
int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
/* insn: must be on special executable page on x86_64. */
- down(&kprobe_mutex);
p->ainsn.insn = get_insn_slot();
- up(&kprobe_mutex);
if (!p->ainsn.insn) {
return -ENOMEM;
}
+ arch_copy_kprobe(p);
return 0;
}
@@ -223,9 +222,7 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
- down(&kprobe_mutex);
free_insn_slot(p->ainsn.insn);
- up(&kprobe_mutex);
}
static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)