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authorFrederic Weisbecker <fweisbec@gmail.com>2012-08-07 15:20:38 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2012-08-10 11:44:06 -0300
commit91d7753a45f8525dc75b6be01e427dc1c378dc16 (patch)
tree906a2c335d4403a39bd0f09ed3e338865d3df49b
parent4018994f3d8785275ef0e7391b75c3462c029e56 (diff)
perf: Factor __output_copy to be usable with specific copy function
Adding a generic way to use __output_copy function with specific copy function via DEFINE_PERF_OUTPUT_COPY macro. Using this to add new __output_copy_user function, that provides output copy from user pointers. For x86 the copy_from_user_nmi function is used and __copy_from_user_inatomic for the rest of the architectures. This new function will be used in user stack dump on sample, coming in next patches. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Arun Sharma <asharma@fb.com> Cc: Benjamin Redelings <benjamin.redelings@nescent.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Ulrich Drepper <drepper@gmail.com> Link: http://lkml.kernel.org/r/1344345647-11536-4-git-send-email-jolsa@redhat.com Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r--arch/x86/include/asm/perf_event.h2
-rw-r--r--include/linux/perf_event.h2
-rw-r--r--kernel/events/internal.h62
-rw-r--r--kernel/events/ring_buffer.c4
4 files changed, 46 insertions, 24 deletions
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index cb4e43bce98..4fabcdf1cfa 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -262,4 +262,6 @@ static inline void perf_check_microcode(void) { }
static inline void amd_pmu_disable_virt(void) { }
#endif
+#define arch_perf_out_copy_user copy_from_user_nmi
+
#endif /* _ASM_X86_PERF_EVENT_H */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 3d4d84745f0..d41394a1af3 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1319,7 +1319,7 @@ static inline bool has_branch_stack(struct perf_event *event)
extern int perf_output_begin(struct perf_output_handle *handle,
struct perf_event *event, unsigned int size);
extern void perf_output_end(struct perf_output_handle *handle);
-extern void perf_output_copy(struct perf_output_handle *handle,
+extern unsigned int perf_output_copy(struct perf_output_handle *handle,
const void *buf, unsigned int len);
extern int perf_swevent_get_recursion_context(void);
extern void perf_swevent_put_recursion_context(int rctx);
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index a096c19f2c2..7fd5408493d 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -2,6 +2,7 @@
#define _KERNEL_EVENTS_INTERNAL_H
#include <linux/hardirq.h>
+#include <linux/uaccess.h>
/* Buffer handling */
@@ -76,30 +77,49 @@ static inline unsigned long perf_data_size(struct ring_buffer *rb)
return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
}
-static inline void
-__output_copy(struct perf_output_handle *handle,
- const void *buf, unsigned int len)
+#define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \
+static inline unsigned int \
+func_name(struct perf_output_handle *handle, \
+ const void *buf, unsigned int len) \
+{ \
+ unsigned long size, written; \
+ \
+ do { \
+ size = min_t(unsigned long, handle->size, len); \
+ \
+ written = memcpy_func(handle->addr, buf, size); \
+ \
+ len -= written; \
+ handle->addr += written; \
+ buf += written; \
+ handle->size -= written; \
+ if (!handle->size) { \
+ struct ring_buffer *rb = handle->rb; \
+ \
+ handle->page++; \
+ handle->page &= rb->nr_pages - 1; \
+ handle->addr = rb->data_pages[handle->page]; \
+ handle->size = PAGE_SIZE << page_order(rb); \
+ } \
+ } while (len && written == size); \
+ \
+ return len; \
+}
+
+static inline int memcpy_common(void *dst, const void *src, size_t n)
{
- do {
- unsigned long size = min_t(unsigned long, handle->size, len);
-
- memcpy(handle->addr, buf, size);
-
- len -= size;
- handle->addr += size;
- buf += size;
- handle->size -= size;
- if (!handle->size) {
- struct ring_buffer *rb = handle->rb;
-
- handle->page++;
- handle->page &= rb->nr_pages - 1;
- handle->addr = rb->data_pages[handle->page];
- handle->size = PAGE_SIZE << page_order(rb);
- }
- } while (len);
+ memcpy(dst, src, n);
+ return n;
}
+DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
+
+#ifndef arch_perf_out_copy_user
+#define arch_perf_out_copy_user __copy_from_user_inatomic
+#endif
+
+DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
+
/* Callchain handling */
extern struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs);
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 6ddaba43fb7..b4c2ad3dee7 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -182,10 +182,10 @@ out:
return -ENOSPC;
}
-void perf_output_copy(struct perf_output_handle *handle,
+unsigned int perf_output_copy(struct perf_output_handle *handle,
const void *buf, unsigned int len)
{
- __output_copy(handle, buf, len);
+ return __output_copy(handle, buf, len);
}
void perf_output_end(struct perf_output_handle *handle)