From 88f7a890d74137ab0d126a5d65679cd620f1a289 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 30 Dec 2009 14:22:22 +0800 Subject: [PATCH] ksym_tracer: Fix to make the tracer work ksym tracer doesn't work: # echo tasklist_lock:rw- > ksym_trace_filter -bash: echo: write error: No such device It's because we pass to perf_event_create_kernel_counter() a cpu number which is not present. Signed-off-by: Li Zefan Cc: Steven Rostedt Cc: K.Prasad Cc: Frederic Weisbecker LKML-Reference: <4B3AF19E.1010201@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/hw_breakpoint.c | 10 +++++++--- kernel/trace/trace_ksym.c | 1 - 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index 366eedf949c0..48fb0bb6992a 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include @@ -388,7 +389,8 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, if (!cpu_events) return ERR_PTR(-ENOMEM); - for_each_possible_cpu(cpu) { + get_online_cpus(); + for_each_online_cpu(cpu) { pevent = per_cpu_ptr(cpu_events, cpu); bp = perf_event_create_kernel_counter(attr, cpu, -1, triggered); @@ -399,18 +401,20 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, goto fail; } } + put_online_cpus(); return cpu_events; fail: - for_each_possible_cpu(cpu) { + for_each_online_cpu(cpu) { pevent = per_cpu_ptr(cpu_events, cpu); if (IS_ERR(*pevent)) break; unregister_hw_breakpoint(*pevent); } + put_online_cpus(); + free_percpu(cpu_events); - /* return the error if any */ return ERR_PTR(err); } EXPORT_SYMBOL_GPL(register_wide_hw_breakpoint); diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c index faf37fa4408c..340b6ff193e0 100644 --- a/kernel/trace/trace_ksym.c +++ b/kernel/trace/trace_ksym.c @@ -197,7 +197,6 @@ int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) entry->attr.bp_addr = addr; entry->attr.bp_len = HW_BREAKPOINT_LEN_4; - ret = -EAGAIN; entry->ksym_hbp = register_wide_hw_breakpoint(&entry->attr, ksym_hbp_handler); -- 2.20.1