Commit 91d7753a authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Arnaldo Carvalho de Melo
Browse files

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: default avatarJiri 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: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 4018994f

arch/x86/include/asm/perf_event.h

+2 −0
Original line number Diff line number Diff line
@@ -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 */

include/linux/perf_event.h

+1 −1
Original line number Diff line number Diff line
@@ -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);

kernel/events/internal.h

+41 −21
Original line number Diff line number Diff line
@@ -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)

{

	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);

#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;							\

}

	} while (len);



static inline int memcpy_common(void *dst, const void *src, size_t n)

{

	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);

kernel/events/ring_buffer.c

+2 −2
Original line number Diff line number Diff line
@@ -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)

CRA Git | Maintained and supported by SUSTech CRA and CCSE