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authorLinus Torvalds <torvalds@linux-foundation.org>2010-02-28 10:20:25 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2010-02-28 10:20:25 -0800
commit6556a6743549defc32e5f90ee2cb1ecd833a44c3 (patch)
tree622306583d4a3c13235a8bfc012854c125c597f1 /kernel/trace/trace_event_profile.c
parente0d272429a34ff143bfa04ee8e29dd4eed2964c7 (diff)
parent1dd2980d990068e20045b90c424518cc7f3657ff (diff)
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (172 commits) perf_event, amd: Fix spinlock initialization perf_event: Fix preempt warning in perf_clock() perf tools: Flush maps on COMM events perf_events, x86: Split PMU definitions into separate files perf annotate: Handle samples not at objdump output addr boundaries perf_events, x86: Remove superflous MSR writes perf_events: Simplify code by removing cpu argument to hw_perf_group_sched_in() perf_events, x86: AMD event scheduling perf_events: Add new start/stop PMU callbacks perf_events: Report the MMAP pgoff value in bytes perf annotate: Defer allocating sym_priv->hist array perf symbols: Improve debugging information about symtab origins perf top: Use a macro instead of a constant variable perf symbols: Check the right return variable perf/scripts: Tag syscall_name helper as not yet available perf/scripts: Add perf-trace-python Documentation perf/scripts: Remove unnecessary PyTuple resizes perf/scripts: Add syscall tracing scripts perf/scripts: Add Python scripting engine perf/scripts: Remove check-perf-trace from listed scripts ... Fix trivial conflict in tools/perf/util/probe-event.c
Diffstat (limited to 'kernel/trace/trace_event_profile.c')
-rw-r--r--kernel/trace/trace_event_profile.c52
1 files changed, 47 insertions, 5 deletions
diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
index 9e25573242c..f0d69300507 100644
--- a/kernel/trace/trace_event_profile.c
+++ b/kernel/trace/trace_event_profile.c
@@ -6,14 +6,12 @@
*/
#include <linux/module.h>
+#include <linux/kprobes.h>
#include "trace.h"
-char *perf_trace_buf;
-EXPORT_SYMBOL_GPL(perf_trace_buf);
-
-char *perf_trace_buf_nmi;
-EXPORT_SYMBOL_GPL(perf_trace_buf_nmi);
+static char *perf_trace_buf;
+static char *perf_trace_buf_nmi;
typedef typeof(char [FTRACE_MAX_PROFILE_SIZE]) perf_trace_t ;
@@ -120,3 +118,47 @@ void ftrace_profile_disable(int event_id)
}
mutex_unlock(&event_mutex);
}
+
+__kprobes void *ftrace_perf_buf_prepare(int size, unsigned short type,
+ int *rctxp, unsigned long *irq_flags)
+{
+ struct trace_entry *entry;
+ char *trace_buf, *raw_data;
+ int pc, cpu;
+
+ pc = preempt_count();
+
+ /* Protect the per cpu buffer, begin the rcu read side */
+ local_irq_save(*irq_flags);
+
+ *rctxp = perf_swevent_get_recursion_context();
+ if (*rctxp < 0)
+ goto err_recursion;
+
+ cpu = smp_processor_id();
+
+ if (in_nmi())
+ trace_buf = rcu_dereference(perf_trace_buf_nmi);
+ else
+ trace_buf = rcu_dereference(perf_trace_buf);
+
+ if (!trace_buf)
+ goto err;
+
+ raw_data = per_cpu_ptr(trace_buf, cpu);
+
+ /* zero the dead bytes from align to not leak stack to user */
+ *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+ entry = (struct trace_entry *)raw_data;
+ tracing_generic_entry_update(entry, *irq_flags, pc);
+ entry->type = type;
+
+ return raw_data;
+err:
+ perf_swevent_put_recursion_context(*rctxp);
+err_recursion:
+ local_irq_restore(*irq_flags);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(ftrace_perf_buf_prepare);