platform_bionic/libc/bionic/name_mem.c
Colin Cross 6771b9cef6 bionic: add function to name memory
Only works on some kernels, and only on page-aligned regions of
anonymous memory.  It will show up in /proc/pid/maps as
[anon:<name>] and in /proc/pid/smaps as Name: <name>

Change-Id: If31667cf45ff41cc2a79a140ff68707526def80e
2013-08-07 15:41:30 -07:00

53 lines
2.4 KiB
C

/*
* Copyright (C) 2013 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "private/bionic_name_mem.h"
/*
* Local definitions of custom prctl arguments to set a vma name in some kernels
*/
#define BIONIC_PR_SET_VMA 0x53564d41
#define BIONIC_PR_SET_VMA_ANON_NAME 0
/*
* Names a region of memory. The name is expected to show up in /proc/pid/maps
* and /proc/pid/smaps. There is no guarantee that it will work, and it if it
* does work it is likely to only work on memory that was allocated with
* mmap(MAP_ANONYMOUS), and only on regions that are page aligned. name should
* be a pointer to a string that is valid for as long as the memory is mapped,
* preferably a compile-time constant string.
*
* Returns -1 on error and sets errno. If it returns an error naming page
* aligned anonymous memory the kernel doesn't support naming, and an alternate
* method of naming memory should be used (like ashmem).
*/
int __bionic_name_mem(void *addr, size_t len, const char *name)
{
return prctl(BIONIC_PR_SET_VMA, BIONIC_PR_SET_VMA_ANON_NAME,
addr, len, name);
}