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| author | Ananth N Mavinakayanahalli <ananth@in.ibm.com> | 2005-11-07 01:00:07 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-07 07:53:45 -0800 |
| commit | e65845235c8120be63001fc1a4ac00c819194bbe (patch) | |
| tree | 209a081cc07375290743ceb45f52dc474f45382a /kernel/kprobes.c | |
| parent | 66ff2d0691e00e1e7bfdf398a970310c9a0fe671 (diff) | |
| download | lwn-e65845235c8120be63001fc1a4ac00c819194bbe.tar.gz lwn-e65845235c8120be63001fc1a4ac00c819194bbe.zip | |
[PATCH] Kprobes: Track kprobe on a per_cpu basis - base changes
Changes to the base kprobe infrastructure to track kprobe execution on a
per-cpu basis.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
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 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 43 |
1 files changed, 28 insertions, 15 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ce4915dd683a..6da8f9b33d1e 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -51,7 +51,7 @@ static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; unsigned int kprobe_cpu = NR_CPUS; static DEFINE_SPINLOCK(kprobe_lock); -static struct kprobe *curr_kprobe; +static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; /* * kprobe->ainsn.insn points to the copy of the instruction to be @@ -188,6 +188,17 @@ void __kprobes unlock_kprobes(void) local_irq_restore(flags); } +/* 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; +} + +static inline void reset_kprobe_instance(void) +{ + __get_cpu_var(kprobe_instance) = NULL; +} + /* You have to be holding the kprobe_lock */ struct kprobe __kprobes *get_kprobe(void *addr) { @@ -213,11 +224,11 @@ static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) list_for_each_entry(kp, &p->list, list) { if (kp->pre_handler) { - curr_kprobe = kp; + set_kprobe_instance(kp); if (kp->pre_handler(kp, regs)) return 1; } - curr_kprobe = NULL; + reset_kprobe_instance(); } return 0; } @@ -229,9 +240,9 @@ static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, list_for_each_entry(kp, &p->list, list) { if (kp->post_handler) { - curr_kprobe = kp; + set_kprobe_instance(kp); kp->post_handler(kp, regs, flags); - curr_kprobe = NULL; + reset_kprobe_instance(); } } return; @@ -240,12 +251,14 @@ static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, int trapnr) { + struct kprobe *cur = __get_cpu_var(kprobe_instance); + /* * if we faulted "during" the execution of a user specified * probe handler, invoke just that probe's fault handler */ - if (curr_kprobe && curr_kprobe->fault_handler) { - if (curr_kprobe->fault_handler(curr_kprobe, regs, trapnr)) + if (cur && cur->fault_handler) { + if (cur->fault_handler(cur, regs, trapnr)) return 1; } return 0; @@ -253,15 +266,15 @@ static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs) { - struct kprobe *kp = curr_kprobe; - if (curr_kprobe && kp->break_handler) { - if (kp->break_handler(kp, regs)) { - curr_kprobe = NULL; - return 1; - } + struct kprobe *cur = __get_cpu_var(kprobe_instance); + int ret = 0; + + if (cur && cur->break_handler) { + if (cur->break_handler(cur, regs)) + ret = 1; } - curr_kprobe = NULL; - return 0; + reset_kprobe_instance(); + return ret; } struct kretprobe_instance __kprobes *get_free_rp_inst(struct kretprobe *rp) |