[Use cpuops V1 07/11] kprobes: Use this_cpu_ops

From: Christoph Lameter
Date: Mon Dec 06 2010 - 12:17:55 EST


Use this_cpu ops in various places to optimize per cpu data access.

Cc: Jason Baron <jbaron@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>

---
arch/x86/kernel/kprobes.c | 14 +++++++-------
include/linux/kprobes.h | 4 ++--
kernel/kprobes.c | 8 ++++----
3 files changed, 13 insertions(+), 13 deletions(-)

Index: linux-2.6/arch/x86/kernel/kprobes.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/kprobes.c 2010-12-03 14:48:27.000000000 -0600
+++ linux-2.6/arch/x86/kernel/kprobes.c 2010-12-06 10:29:03.000000000 -0600
@@ -403,7 +403,7 @@ static void __kprobes save_previous_kpro

static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
{
- __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+ __this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
kcb->kprobe_status = kcb->prev_kprobe.status;
kcb->kprobe_old_flags = kcb->prev_kprobe.old_flags;
kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags;
@@ -412,7 +412,7 @@ static void __kprobes restore_previous_k
static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{
- __get_cpu_var(current_kprobe) = p;
+ __this_cpu_write(current_kprobe, p);
kcb->kprobe_saved_flags = kcb->kprobe_old_flags
= (regs->flags & (X86_EFLAGS_TF | X86_EFLAGS_IF));
if (is_IF_modifier(p->ainsn.insn))
@@ -586,7 +586,7 @@ static int __kprobes kprobe_handler(stru
preempt_enable_no_resched();
return 1;
} else if (kprobe_running()) {
- p = __get_cpu_var(current_kprobe);
+ p = __this_cpu_read(current_kprobe);
if (p->break_handler && p->break_handler(p, regs)) {
setup_singlestep(p, regs, kcb, 0);
return 1;
@@ -759,11 +759,11 @@ static __used __kprobes void *trampoline

orig_ret_address = (unsigned long)ri->ret_addr;
if (ri->rp && ri->rp->handler) {
- __get_cpu_var(current_kprobe) = &ri->rp->kp;
+ __this_cpu_write(current_kprobe, &ri->rp->kp);
get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
ri->ret_addr = correct_ret_addr;
ri->rp->handler(ri, regs);
- __get_cpu_var(current_kprobe) = NULL;
+ __this_cpu_write(current_kprobe, NULL);
}

recycle_rp_inst(ri, &empty_rp);
@@ -1198,10 +1198,10 @@ static void __kprobes optimized_callback
regs->ip = (unsigned long)op->kp.addr + INT3_SIZE;
regs->orig_ax = ~0UL;

- __get_cpu_var(current_kprobe) = &op->kp;
+ __this_cpu_write(current_kprobe, &op->kp);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
opt_pre_handler(&op->kp, regs);
- __get_cpu_var(current_kprobe) = NULL;
+ __this_cpu_write(current_kprobe, NULL);
}
preempt_enable_no_resched();
}
Index: linux-2.6/include/linux/kprobes.h
===================================================================
--- linux-2.6.orig/include/linux/kprobes.h 2010-12-03 14:48:27.000000000 -0600
+++ linux-2.6/include/linux/kprobes.h 2010-12-06 10:29:03.000000000 -0600
@@ -303,12 +303,12 @@ struct hlist_head * kretprobe_inst_table
/* kprobe_running() will just return the current_kprobe on this CPU */
static inline struct kprobe *kprobe_running(void)
{
- return (__get_cpu_var(current_kprobe));
+ return (__this_cpu_read(current_kprobe));
}

static inline void reset_current_kprobe(void)
{
- __get_cpu_var(current_kprobe) = NULL;
+ __this_cpu_write(current_kprobe, NULL);
}

static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
Index: linux-2.6/kernel/kprobes.c
===================================================================
--- linux-2.6.orig/kernel/kprobes.c 2010-12-03 14:48:27.000000000 -0600
+++ linux-2.6/kernel/kprobes.c 2010-12-06 10:29:03.000000000 -0600
@@ -317,12 +317,12 @@ void __kprobes free_optinsn_slot(kprobe_
/* We have preemption disabled.. so it is safe to use __ versions */
static inline void set_kprobe_instance(struct kprobe *kp)
{
- __get_cpu_var(kprobe_instance) = kp;
+ __this_cpu_write(kprobe_instance, kp);
}

static inline void reset_kprobe_instance(void)
{
- __get_cpu_var(kprobe_instance) = NULL;
+ __this_cpu_write(kprobe_instance, NULL);
}

/*
@@ -775,7 +775,7 @@ static void __kprobes aggr_post_handler(
static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs,
int trapnr)
{
- struct kprobe *cur = __get_cpu_var(kprobe_instance);
+ struct kprobe *cur = __this_cpu_read(kprobe_instance);

/*
* if we faulted "during" the execution of a user specified
@@ -790,7 +790,7 @@ static int __kprobes aggr_fault_handler(

static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs)
{
- struct kprobe *cur = __get_cpu_var(kprobe_instance);
+ struct kprobe *cur = __this_cpu_read(kprobe_instance);
int ret = 0;

if (cur && cur->break_handler) {

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