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Commit f972eb63 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Jiri Olsa
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perf: Pass protection and flags bits through mmap2 interface 



The mmap2 interface was missing the protection and flags bits needed to
accurately determine if a mmap memory area was shared or private and
if it was readable or not.

Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
[tweaked patch to compile and wrote changelog]
Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/1400526833-141779-2-git-send-email-dzickus@redhat.com


Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
parent e646fe73

include/uapi/linux/perf_event.h

+1 −0
Original line number Diff line number Diff line
@@ -705,6 +705,7 @@ enum perf_event_type { 
	 *	u32				min;

	 *	u64				ino;

	 *	u64				ino_generation;

	 *	u32				prot, flags;

	 *	char				filename[];

	 * 	struct sample_id		sample_id;

	 * };

kernel/events/core.c

+33 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 
#include <linux/mm_types.h>

#include <linux/cgroup.h>

#include <linux/module.h>

#include <linux/mman.h>



#include "internal.h"
@@ -5127,6 +5128,7 @@ struct perf_mmap_event { 
	int			maj, min;

	u64			ino;

	u64			ino_generation;

	u32			prot, flags;



	struct {

		struct perf_event_header	header;
@@ -5168,6 +5170,8 @@ static void perf_event_mmap_output(struct perf_event *event, 
		mmap_event->event_id.header.size += sizeof(mmap_event->min);

		mmap_event->event_id.header.size += sizeof(mmap_event->ino);

		mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation);

		mmap_event->event_id.header.size += sizeof(mmap_event->prot);

		mmap_event->event_id.header.size += sizeof(mmap_event->flags);

	}



	perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
@@ -5186,6 +5190,8 @@ static void perf_event_mmap_output(struct perf_event *event, 
		perf_output_put(&handle, mmap_event->min);

		perf_output_put(&handle, mmap_event->ino);

		perf_output_put(&handle, mmap_event->ino_generation);

		perf_output_put(&handle, mmap_event->prot);

		perf_output_put(&handle, mmap_event->flags);

	}



	__output_copy(&handle, mmap_event->file_name,
@@ -5204,6 +5210,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) 
	struct file *file = vma->vm_file;

	int maj = 0, min = 0;

	u64 ino = 0, gen = 0;

	u32 prot = 0, flags = 0;

	unsigned int size;

	char tmp[16];

	char *buf = NULL;
@@ -5234,6 +5241,28 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) 
		gen = inode->i_generation;

		maj = MAJOR(dev);

		min = MINOR(dev);



		if (vma->vm_flags & VM_READ)

			prot |= PROT_READ;

		if (vma->vm_flags & VM_WRITE)

			prot |= PROT_WRITE;

		if (vma->vm_flags & VM_EXEC)

			prot |= PROT_EXEC;



		if (vma->vm_flags & VM_MAYSHARE)

			flags = MAP_SHARED;

		else

			flags = MAP_PRIVATE;



		if (vma->vm_flags & VM_DENYWRITE)

			flags |= MAP_DENYWRITE;

		if (vma->vm_flags & VM_MAYEXEC)

			flags |= MAP_EXECUTABLE;

		if (vma->vm_flags & VM_LOCKED)

			flags |= MAP_LOCKED;

		if (vma->vm_flags & VM_HUGETLB)

			flags |= MAP_HUGETLB;



		goto got_name;

	} else {

		name = (char *)arch_vma_name(vma);
@@ -5274,6 +5303,8 @@ got_name: 
	mmap_event->min = min;

	mmap_event->ino = ino;

	mmap_event->ino_generation = gen;

	mmap_event->prot = prot;

	mmap_event->flags = flags;



	if (!(vma->vm_flags & VM_EXEC))

		mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;
@@ -5314,6 +5345,8 @@ void perf_event_mmap(struct vm_area_struct *vma) 
		/* .min (attr_mmap2 only) */

		/* .ino (attr_mmap2 only) */

		/* .ino_generation (attr_mmap2 only) */

		/* .prot (attr_mmap2 only) */

		/* .flags (attr_mmap2 only) */

	};



	perf_event_mmap_event(&mmap_event);