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author | Oleg Nesterov <oleg@redhat.com> | 2013-02-04 17:48:34 +0100 |
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committer | Oleg Nesterov <oleg@redhat.com> | 2013-02-08 18:28:07 +0100 |
commit | f42d24a1d20d2e72d1e5d48930f18b138dfad117 (patch) | |
tree | 10696fc2f0a21d60a7fb1581efecd172435f0408 /kernel/trace | |
parent | 31ba334836c0ac0039084859f14a5b96858493dc (diff) | |
download | blackbird-op-linux-f42d24a1d20d2e72d1e5d48930f18b138dfad117.tar.gz blackbird-op-linux-f42d24a1d20d2e72d1e5d48930f18b138dfad117.zip |
uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVE
Change uprobe_trace_func() and uprobe_perf_func() to return "int". Change
uprobe_dispatcher() to return "trace_ret | perf_ret" although this is not
needed, currently TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive.
The only functional change is that uprobe_perf_func() checks the filtering
too and returns UPROBE_HANDLER_REMOVE if nobody wants to trace current.
Testing:
# perf probe -x /lib/libc.so.6 syscall
# perf record -e probe_libc:syscall -i perl -e 'fork; syscall -1 for 1..10; wait'
# perf report --show-total-period
100.00% 10 perl libc-2.8.so [.] syscall
Before this patch:
# cat /sys/kernel/debug/tracing/uprobe_profile
/lib/libc.so.6 syscall 20
A child process doesn't have a counter, but still it hits this breakoint
"copied" by dup_mmap().
After the patch:
# cat /sys/kernel/debug/tracing/uprobe_profile
/lib/libc.so.6 syscall 11
The child process hits this int3 only once and does unapply_uprobe().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Diffstat (limited to 'kernel/trace')
-rw-r--r-- | kernel/trace/trace_uprobe.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index b7850f535acf..2399f1416555 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -486,7 +486,7 @@ static const struct file_operations uprobe_profile_ops = { }; /* uprobe handler */ -static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) +static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) { struct uprobe_trace_entry_head *entry; struct ring_buffer_event *event; @@ -504,7 +504,7 @@ static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) event = trace_current_buffer_lock_reserve(&buffer, call->event.type, size, irq_flags, pc); if (!event) - return; + return 0; entry = ring_buffer_event_data(event); entry->ip = instruction_pointer(task_pt_regs(current)); @@ -514,6 +514,8 @@ static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) if (!filter_current_check_discard(buffer, call, entry, event)) trace_buffer_unlock_commit(buffer, event, irq_flags, pc); + + return 0; } /* Event entry printers */ @@ -721,7 +723,7 @@ static bool uprobe_perf_filter(struct uprobe_consumer *uc, } /* uprobe profile handler */ -static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) +static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) { struct ftrace_event_call *call = &tu->call; struct uprobe_trace_entry_head *entry; @@ -730,11 +732,14 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) int size, __size, i; int rctx; + if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) + return UPROBE_HANDLER_REMOVE; + __size = sizeof(*entry) + tu->size; size = ALIGN(__size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) - return; + return 0; preempt_disable(); @@ -752,6 +757,7 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) out: preempt_enable(); + return 0; } #endif /* CONFIG_PERF_EVENTS */ @@ -792,18 +798,19 @@ int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) { struct trace_uprobe *tu; + int ret = 0; tu = container_of(con, struct trace_uprobe, consumer); tu->nhit++; if (tu->flags & TP_FLAG_TRACE) - uprobe_trace_func(tu, regs); + ret |= uprobe_trace_func(tu, regs); #ifdef CONFIG_PERF_EVENTS if (tu->flags & TP_FLAG_PROFILE) - uprobe_perf_func(tu, regs); + ret |= uprobe_perf_func(tu, regs); #endif - return 0; + return ret; } static struct trace_event_functions uprobe_funcs = { |