7be52b1a0e
This is needed by the MemoryFile changes in https://android-git.corp.google.com/g/2714 where it is used to find out whether a file descriptor refers to an ashmem region.
90 lines
2.1 KiB
C
90 lines
2.1 KiB
C
/*
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* Copyright (C) 2008 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/*
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* Implementation of the user-space ashmem API for devices, which have our
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* ashmem-enabled kernel. See ashmem-sim.c for the "fake" tmp-based version,
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* used by the simulator.
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*/
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#include <unistd.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/ioctl.h>
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#include <fcntl.h>
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#include <linux/ashmem.h>
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#include <cutils/ashmem.h>
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#define ASHMEM_DEVICE "/dev/ashmem"
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/*
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* ashmem_create_region - creates a new ashmem region and returns the file
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* descriptor, or <0 on error
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*
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* `name' is an optional label to give the region (visible in /proc/pid/maps)
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* `size' is the size of the region, in page-aligned bytes
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*/
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int ashmem_create_region(const char *name, size_t size)
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{
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int fd, ret;
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fd = open(ASHMEM_DEVICE, O_RDWR);
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if (fd < 0)
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return fd;
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if (name) {
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char buf[ASHMEM_NAME_LEN];
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strlcpy(buf, name, sizeof(buf));
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ret = ioctl(fd, ASHMEM_SET_NAME, buf);
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if (ret < 0)
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goto error;
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}
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ret = ioctl(fd, ASHMEM_SET_SIZE, size);
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if (ret < 0)
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goto error;
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return fd;
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error:
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close(fd);
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return ret;
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}
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int ashmem_set_prot_region(int fd, int prot)
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{
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return ioctl(fd, ASHMEM_SET_PROT_MASK, prot);
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}
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int ashmem_pin_region(int fd, size_t offset, size_t len)
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{
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struct ashmem_pin pin = { offset, len };
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return ioctl(fd, ASHMEM_PIN, &pin);
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}
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int ashmem_unpin_region(int fd, size_t offset, size_t len)
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{
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struct ashmem_pin pin = { offset, len };
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return ioctl(fd, ASHMEM_UNPIN, &pin);
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}
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int ashmem_get_size_region(int fd)
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{
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return ioctl(fd, ASHMEM_GET_SIZE, NULL);
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}
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