Re: [patch 1/8] Kprobes - do not use kprobes mutex in arch code

From: Ananth N Mavinakayanahalli
Date: Tue Jul 17 2007 - 01:36:41 EST


On Fri, Jul 13, 2007 at 09:21:34PM -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@xxxxxxxxxx>

Acked-by: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>

Thanks Mathieu.

> CC: prasanna@xxxxxxxxxx
> CC: ananth@xxxxxxxxxx
> CC: anil.s.keshavamurthy@xxxxxxxxx
> CC: davem@xxxxxxxxxxxxx
> ---
> 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 2007-07-13 18:42:08.000000000 -0400
> +++ linux-2.6-lttng/include/linux/kprobes.h 2007-07-13 18:42:52.000000000 -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 @@
> }
>
> 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 2007-07-13 18:42:08.000000000 -0400
> +++ linux-2.6-lttng/arch/i386/kernel/kprobes.c 2007-07-13 18:42:52.000000000 -0400
> @@ -209,9 +209,7 @@
>
> 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 2007-07-13 18:42:10.000000000 -0400
> +++ linux-2.6-lttng/kernel/kprobes.c 2007-07-13 18:43:17.000000000 -0400
> @@ -641,7 +641,9 @@
> 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 2007-07-13 18:43:59.000000000 -0400
> +++ linux-2.6-lttng/arch/ia64/kernel/kprobes.c 2007-07-13 18:44:03.000000000 -0400
> @@ -565,9 +565,7 @@
>
> 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 2007-07-13 18:44:20.000000000 -0400
> +++ linux-2.6-lttng/arch/powerpc/kernel/kprobes.c 2007-07-13 18:44:26.000000000 -0400
> @@ -86,9 +86,7 @@
>
> 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 2007-07-13 18:44:43.000000000 -0400
> +++ linux-2.6-lttng/arch/s390/kernel/kprobes.c 2007-07-13 18:44:46.000000000 -0400
> @@ -218,9 +218,7 @@
>
> 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 2007-07-13 18:45:08.000000000 -0400
> +++ linux-2.6-lttng/arch/x86_64/kernel/kprobes.c 2007-07-13 18:45:14.000000000 -0400
> @@ -249,9 +249,7 @@
>
> 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
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