11dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 21dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Copyright (C) 2008 The Android Open Source Project 31dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * All rights reserved. 41dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 51dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Redistribution and use in source and binary forms, with or without 61dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * modification, are permitted provided that the following conditions 71dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * are met: 81dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * * Redistributions of source code must retain the above copyright 91dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer. 101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * * Redistributions in binary form must reproduce the above copyright 111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer in 121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * the documentation and/or other materials provided with the 131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * distribution. 141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 161dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 171dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 221dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * SUCH DAMAGE. 271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 28107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes 291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <errno.h> 301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <sys/mman.h> 31107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes#include <unistd.h> 32107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes 33107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes#include "private/ErrnoRestorer.h" 341dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 35107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes// mmap2(2) is like mmap(2), but the offset is in 4096-byte blocks, not bytes. 36107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughesextern "C" void* __mmap2(void*, size_t, int, int, int, size_t); 371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 38107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes#define MMAP2_SHIFT 12 // 2**12 == 4096 39e459bba398e8a9eee0958d418e9b16dfabdb1515Rom Lemarchand 409bd9b7dd205e79577f5cd1d9488aabe0f213ce35Elliott Hughesstatic bool kernel_has_MADV_MERGEABLE = true; 419bd9b7dd205e79577f5cd1d9488aabe0f213ce35Elliott Hughes 42afcc0cccdafef0c67600cbbc72cee0e7a41f3f04Daniel Leungvoid* mmap64(void* addr, size_t size, int prot, int flags, int fd, off64_t offset) { 43431166d99519f6794f10c48694913d2fe864b841Elliott Hughes if (offset < 0 || (offset & ((1UL << MMAP2_SHIFT)-1)) != 0) { 44107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes errno = EINVAL; 45107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes return MAP_FAILED; 46107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes } 47b8e1e9685efc82d6ac112b9aa316e7f6bf5186caJP Abgrall 489bd9b7dd205e79577f5cd1d9488aabe0f213ce35Elliott Hughes bool is_private_anonymous = (flags & (MAP_PRIVATE | MAP_ANONYMOUS)) != 0; 49431166d99519f6794f10c48694913d2fe864b841Elliott Hughes void* result = __mmap2(addr, size, prot, flags, fd, offset >> MMAP2_SHIFT); 509bd9b7dd205e79577f5cd1d9488aabe0f213ce35Elliott Hughes 519bd9b7dd205e79577f5cd1d9488aabe0f213ce35Elliott Hughes if (result != MAP_FAILED && kernel_has_MADV_MERGEABLE && is_private_anonymous) { 52107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes ErrnoRestorer errno_restorer; 539bd9b7dd205e79577f5cd1d9488aabe0f213ce35Elliott Hughes int rc = madvise(result, size, MADV_MERGEABLE); 549bd9b7dd205e79577f5cd1d9488aabe0f213ce35Elliott Hughes if (rc == -1 && errno == EINVAL) { 559bd9b7dd205e79577f5cd1d9488aabe0f213ce35Elliott Hughes kernel_has_MADV_MERGEABLE = false; 569bd9b7dd205e79577f5cd1d9488aabe0f213ce35Elliott Hughes } 57107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes } 58e459bba398e8a9eee0958d418e9b16dfabdb1515Rom Lemarchand 59107cdd406b8e404af4d552498076cfe2dfe5efbfElliott Hughes return result; 601dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 61afcc0cccdafef0c67600cbbc72cee0e7a41f3f04Daniel Leung 62afcc0cccdafef0c67600cbbc72cee0e7a41f3f04Daniel Leungvoid* mmap(void* addr, size_t size, int prot, int flags, int fd, off_t offset) { 63431166d99519f6794f10c48694913d2fe864b841Elliott Hughes return mmap64(addr, size, prot, flags, fd, static_cast<off64_t>(offset)); 64afcc0cccdafef0c67600cbbc72cee0e7a41f3f04Daniel Leung} 65