From b326e9560a28fc3e950637ef51847ed8f05c1335 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 5 Dec 2009 09:44:31 +0100 Subject: hw-breakpoints: Use overflow handler instead of the event callback struct perf_event::event callback was called when a breakpoint triggers. But this is a rather opaque callback, pretty tied-only to the breakpoint API and not really integrated into perf as it triggers even when we don't overflow. We prefer to use overflow_handler() as it fits into the perf events rules, being called only when we overflow. Reported-by: Peter Zijlstra Signed-off-by: Frederic Weisbecker Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: "K. Prasad" --- kernel/hw_breakpoint.c | 17 +++++------------ kernel/perf_event.c | 24 +++++++++--------------- kernel/trace/trace_ksym.c | 5 +++-- 3 files changed, 17 insertions(+), 29 deletions(-) (limited to 'kernel') diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index 2d10b012828..b600fc27f16 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -259,7 +259,7 @@ void release_bp_slot(struct perf_event *bp) } -int __register_perf_hw_breakpoint(struct perf_event *bp) +int register_perf_hw_breakpoint(struct perf_event *bp) { int ret; @@ -276,19 +276,12 @@ int __register_perf_hw_breakpoint(struct perf_event *bp) * This is a quick hack that will be removed soon, once we remove * the tmp breakpoints from ptrace */ - if (!bp->attr.disabled || bp->callback == perf_bp_event) + if (!bp->attr.disabled || !bp->overflow_handler) ret = arch_validate_hwbkpt_settings(bp, bp->ctx->task); return ret; } -int register_perf_hw_breakpoint(struct perf_event *bp) -{ - bp->callback = perf_bp_event; - - return __register_perf_hw_breakpoint(bp); -} - /** * register_user_hw_breakpoint - register a hardware breakpoint for user space * @attr: breakpoint attributes @@ -297,7 +290,7 @@ int register_perf_hw_breakpoint(struct perf_event *bp) */ struct perf_event * register_user_hw_breakpoint(struct perf_event_attr *attr, - perf_callback_t triggered, + perf_overflow_handler_t triggered, struct task_struct *tsk) { return perf_event_create_kernel_counter(attr, -1, tsk->pid, triggered); @@ -322,7 +315,7 @@ modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr) unregister_hw_breakpoint(bp); return perf_event_create_kernel_counter(attr, -1, bp->ctx->task->pid, - bp->callback); + bp->overflow_handler); } EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint); @@ -347,7 +340,7 @@ EXPORT_SYMBOL_GPL(unregister_hw_breakpoint); */ struct perf_event ** register_wide_hw_breakpoint(struct perf_event_attr *attr, - perf_callback_t triggered) + perf_overflow_handler_t triggered) { struct perf_event **cpu_events, **pevent, *bp; long err; diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 6b7ddba1dd6..fd43ff4ac86 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -4286,15 +4286,8 @@ static void bp_perf_event_destroy(struct perf_event *event) static const struct pmu *bp_perf_event_init(struct perf_event *bp) { int err; - /* - * The breakpoint is already filled if we haven't created the counter - * through perf syscall - * FIXME: manage to get trigerred to NULL if it comes from syscalls - */ - if (!bp->callback) - err = register_perf_hw_breakpoint(bp); - else - err = __register_perf_hw_breakpoint(bp); + + err = register_perf_hw_breakpoint(bp); if (err) return ERR_PTR(err); @@ -4390,7 +4383,7 @@ perf_event_alloc(struct perf_event_attr *attr, struct perf_event_context *ctx, struct perf_event *group_leader, struct perf_event *parent_event, - perf_callback_t callback, + perf_overflow_handler_t overflow_handler, gfp_t gfpflags) { const struct pmu *pmu; @@ -4433,10 +4426,10 @@ perf_event_alloc(struct perf_event_attr *attr, event->state = PERF_EVENT_STATE_INACTIVE; - if (!callback && parent_event) - callback = parent_event->callback; + if (!overflow_handler && parent_event) + overflow_handler = parent_event->overflow_handler; - event->callback = callback; + event->overflow_handler = overflow_handler; if (attr->disabled) event->state = PERF_EVENT_STATE_OFF; @@ -4776,7 +4769,8 @@ err_put_context: */ struct perf_event * perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, - pid_t pid, perf_callback_t callback) + pid_t pid, + perf_overflow_handler_t overflow_handler) { struct perf_event *event; struct perf_event_context *ctx; @@ -4793,7 +4787,7 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, } event = perf_event_alloc(attr, cpu, ctx, NULL, - NULL, callback, GFP_KERNEL); + NULL, overflow_handler, GFP_KERNEL); if (IS_ERR(event)) { err = PTR_ERR(event); goto err_put_context; diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c index ddfa0fd43bc..acb87d4a4ac 100644 --- a/kernel/trace/trace_ksym.c +++ b/kernel/trace/trace_ksym.c @@ -79,11 +79,12 @@ void ksym_collect_stats(unsigned long hbp_hit_addr) } #endif /* CONFIG_PROFILE_KSYM_TRACER */ -void ksym_hbp_handler(struct perf_event *hbp, void *data) +void ksym_hbp_handler(struct perf_event *hbp, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) { struct ring_buffer_event *event; struct ksym_trace_entry *entry; - struct pt_regs *regs = data; struct ring_buffer *buffer; int pc; -- cgit v1.2.3