Re: [patch 03/11] Kprobes - do not use kprobes mutex in arch code

Ananth N Mavinakayanahalli
2007-08-21T04:17:56Z

On Mon, Aug 20, 2007 at 04:19:05PM -0400, Mathieu Desnoyers wrote:
> Remove the kprobes mutex from kprobes.h, since it does not belong there. Also
> remove all use of this mutex in the architecture specific code, replacing it by
> a proper mutex lock/unlock in the architecture agnostic code.
>
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

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

> CC: prasanna@in.ibm.com
> CC: ananth@in.ibm.com
> CC: anil.s.keshavamurthy@intel.com
> CC: davem@davemloft.net
> ---
> arch/i386/kernel/kprobes.c | 2 --
> arch/ia64/kernel/kprobes.c | 2 --
> arch/powerpc/kernel/kprobes.c | 2 --
> arch/s390/kernel/kprobes.c | 2 --
> arch/x86_64/kernel/kprobes.c | 2 --
> include/linux/kprobes.h | 2 --
> kernel/kprobes.c | 2 ++
> 7 files changed, 2 insertions(+), 12 deletions(-)
>
> Index: linux-2.6-lttng/include/linux/kprobes.h
> ===================================================================
> --- linux-2.6-lttng.orig/include/linux/kprobes.h 2007-08-07 15:28:05.000000000 -0400
> +++ linux-2.6-lttng/include/linux/kprobes.h 2007-08-07 15:28:22.000000000 -0400
> @@ -35,7 +35,6 @@
> #include <linux/percpu.h>
> #include <linux/spinlock.h>
> #include <linux/rcupdate.h>
> -#include <linux/mutex.h>
>
> #ifdef CONFIG_KPROBES
> #include <asm/kprobes.h>
> @@ -177,7 +176,6 @@ static inline void kretprobe_assert(stru
> }
>
> extern spinlock_t kretprobe_lock;
> -extern struct mutex kprobe_mutex;
> extern int arch_prepare_kprobe(struct kprobe *p);
> extern void arch_arm_kprobe(struct kprobe *p);
> extern void arch_disarm_kprobe(struct kprobe *p);
> Index: linux-2.6-lttng/arch/i386/kernel/kprobes.c
> ===================================================================
> --- linux-2.6-lttng.orig/arch/i386/kernel/kprobes.c 2007-08-07 15:28:05.000000000 -0400
> +++ linux-2.6-lttng/arch/i386/kernel/kprobes.c 2007-08-07 15:28:22.000000000 -0400
> @@ -180,9 +180,7 @@ void __kprobes arch_disarm_kprobe(struct
>
> void __kprobes arch_remove_kprobe(struct kprobe *p)
> {
> - mutex_lock(&kprobe_mutex);
> free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1));
> - mutex_unlock(&kprobe_mutex);
> }
>
> static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
> Index: linux-2.6-lttng/kernel/kprobes.c
> ===================================================================
> --- linux-2.6-lttng.orig/kernel/kprobes.c 2007-08-07 15:28:22.000000000 -0400
> +++ linux-2.6-lttng/kernel/kprobes.c 2007-08-07 15:28:22.000000000 -0400
> @@ -656,7 +656,9 @@ valid_p:
> list_del_rcu(&p->list);
> kfree(old_p);
> }
> + mutex_lock(&kprobe_mutex);
> arch_remove_kprobe(p);
> + mutex_unlock(&kprobe_mutex);
> } else {
> mutex_lock(&kprobe_mutex);
> if (p->break_handler)
> Index: linux-2.6-lttng/arch/ia64/kernel/kprobes.c
> ===================================================================
> --- linux-2.6-lttng.orig/arch/ia64/kernel/kprobes.c 2007-08-07 15:28:05.000000000 -0400
> +++ linux-2.6-lttng/arch/ia64/kernel/kprobes.c 2007-08-07 15:28:22.000000000 -0400
> @@ -565,9 +565,7 @@ void __kprobes arch_disarm_kprobe(struct
>
> void __kprobes arch_remove_kprobe(struct kprobe *p)
> {
> - mutex_lock(&kprobe_mutex);
> free_insn_slot(p->ainsn.insn, 0);
> - mutex_unlock(&kprobe_mutex);
> }
> /*
> * We are resuming execution after a single step fault, so the pt_regs
> Index: linux-2.6-lttng/arch/powerpc/kernel/kprobes.c
> ===================================================================
> --- linux-2.6-lttng.orig/arch/powerpc/kernel/kprobes.c 2007-08-07 15:28:05.000000000 -0400
> +++ linux-2.6-lttng/arch/powerpc/kernel/kprobes.c 2007-08-07 15:28:22.000000000 -0400
> @@ -86,9 +86,7 @@ void __kprobes arch_disarm_kprobe(struct
>
> void __kprobes arch_remove_kprobe(struct kprobe *p)
> {
> - mutex_lock(&kprobe_mutex);
> free_insn_slot(p->ainsn.insn, 0);
> - mutex_unlock(&kprobe_mutex);
> }
>
> static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
> Index: linux-2.6-lttng/arch/s390/kernel/kprobes.c
> ===================================================================
> --- linux-2.6-lttng.orig/arch/s390/kernel/kprobes.c 2007-08-07 15:28:05.000000000 -0400
> +++ linux-2.6-lttng/arch/s390/kernel/kprobes.c 2007-08-07 15:28:22.000000000 -0400
> @@ -218,9 +218,7 @@ void __kprobes arch_disarm_kprobe(struct
>
> void __kprobes arch_remove_kprobe(struct kprobe *p)
> {
> - mutex_lock(&kprobe_mutex);
> free_insn_slot(p->ainsn.insn, 0);
> - mutex_unlock(&kprobe_mutex);
> }
>
> static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
> Index: linux-2.6-lttng/arch/x86_64/kernel/kprobes.c
> ===================================================================
> --- linux-2.6-lttng.orig/arch/x86_64/kernel/kprobes.c 2007-08-07 15:28:06.000000000 -0400
> +++ linux-2.6-lttng/arch/x86_64/kernel/kprobes.c 2007-08-07 15:28:22.000000000 -0400
> @@ -219,9 +219,7 @@ void __kprobes arch_disarm_kprobe(struct
>
> void __kprobes arch_remove_kprobe(struct kprobe *p)
> {
> - mutex_lock(&kprobe_mutex);
> free_insn_slot(p->ainsn.insn, 0);
> - mutex_unlock(&kprobe_mutex);
> }
>
> static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
>
> --
> Mathieu Desnoyers
> Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
> OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68