path: root/ashmemtest-basic/ashmemtest.c

/*******************************************************************************
 * Copyright (c) 2013 Linaro
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Linaro <linaro-dev@lists.linaro.org>
 *******************************************************************************/

/*
 * Test for Android shared memory (ashmem) driver.
 */

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <stdarg.h>

#ifdef ANDROID
/* In-tree compilation */
#include <linux/ashmem.h> 
#else
/* Freestanding compilation, use local copy */
#include "ashmem.h"
#endif /* ANDROID */

#ifndef ASHMEM_MAJOR
#define ASHMEM_MAJOR 10 /* misc device, should match MISC_DEVICE in linux/major.h */
#endif

/* Stolen from the kernel */
#define DEFAULT_PROT_MASK (PROT_READ | PROT_WRITE | PROT_EXEC)

#ifndef _LINUX_ASHMEM_H
#ifndef _UAPI_LINUX_ASHMEM_H
/* only if not defined already */
struct ashmem_pin {
    uint32_t offset;
    uint32_t len;
};
#endif
#endif

/* current test run */
char testname[32];

/* device name */
char ashmemdev[64];

/* guess what */
size_t pagesize;

void fatal (int error, const char *fmt, ...)
{
    va_list ap;

    va_start (ap, fmt);
    vfprintf (stderr, fmt, ap);
    if (error)
	fprintf (stderr, " (error %d [%s])", error, strerror (error));
    va_end (ap);
    fprintf (stderr, "\n");
    printf ("[%s]: test failed\n", testname);
    exit (1);
}

int test_open (char *name, mode_t mode)
{
    int fd;

    fd = open (name, mode);
    if (fd < 0)
	fatal (errno, "can't open %s", name);
    return fd;
}

int test_open_and_set_size (char *name, mode_t mode, size_t size)
{
    int ret, fd = test_open (name, mode);
    ret = ioctl (fd, ASHMEM_SET_SIZE, size);
    if (ret < 0)
	fatal (errno, "can''t set size to %ld bytes\n", size);
    return fd;
}

void test_close (int fd)
{
    if (close (fd) < 0)
	fatal (errno, "can't close fd %d", fd);
}

void ashmem_basic (void)
{
    int fd;
    struct stat st;

    strcpy(testname, __func__);

    /* make sure we can open it */
    fd = test_open (ashmemdev, O_RDWR);

    /* check whether it's a valid device file */
    if (fstat (fd, &st) < 0)
	fatal (errno, "can't stat %s (fd %d)", ashmemdev, fd);
    if (!S_ISCHR (st.st_mode))
	fatal (0, "%s is not a character device", ashmemdev);
    if (major (st.st_rdev) != ASHMEM_MAJOR)
	fatal (0, "%s is not a device with major %d", ashmemdev, ASHMEM_MAJOR);

    /* check that close works too */
    test_close (fd);

    printf ("[%s]: test passed\n", __func__);
}

void ashmem_anonymous_region (void)
{
    int fd, ret;
    char name[ASHMEM_NAME_LEN];
    size_t size;

    strcpy(testname, __func__);

    /* test max possible size */
    fd = test_open (ashmemdev, O_RDWR);
    size = (SIZE_MAX - pagesize - 1) & ~(pagesize - 1);
    ret = ioctl (fd, ASHMEM_SET_SIZE, size);
    if (ret < 0 && errno != ENOMEM)
	fatal (errno, "ENOMEM expected if too large size for ASHMEM_SET_SIZE is used");
    test_close (fd);

    /* test whether normal anonymous region has the default name */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, pagesize);
    ret = ioctl (fd, ASHMEM_GET_NAME, name);
    if (ret < 0)
	fatal (errno, "can't get region name");
    if (strcmp (name, ASHMEM_NAME_DEF))
	fatal (0, "expect %s, but got %s for anonymous region name", ASHMEM_NAME_DEF, name);
    test_close (fd);

    printf ("[%s]: test passed\n", __func__);
}

void ashmem_named_region (void)
{
    int fd, ret, i;
    char name[ASHMEM_NAME_LEN], name2[ASHMEM_NAME_LEN];

    strcpy(testname, __func__);

    /* test invalid name pointer */
    fd = test_open (ashmemdev, O_RDWR);
    ret = ioctl (fd, ASHMEM_SET_NAME, (char *) 0xdeadbeef);
    if (ret >= 0 || errno != EFAULT)
      fatal (errno, "ASHMEM_SET_NAME should not allow bad name pointer\n");
    test_close (fd);

    /* test whether normal name matches between set and get */
    snprintf (name, ASHMEM_NAME_LEN, "Test memory region");
    fd = test_open_and_set_size (ashmemdev, O_RDWR, pagesize);
    ret = ioctl (fd, ASHMEM_SET_NAME, name);
    if (ret < 0)
	fatal (errno, "can't set name '%s'", name);
    ret = ioctl (fd, ASHMEM_GET_NAME, name2);
    if (strcmp (name, name2))
	fatal (0, "name mismatch: expect '%s', got '%s'", name, name2);
    test_close (fd);

    printf ("[%s]: test passed\n", __func__);
}

void ashmem_pin_unpin (void)
{
    int fd, ret;
    size_t size;
    void *mem;
    struct ashmem_pin pin;

    strcpy(testname, __func__);

    /* note the memory is pinned by default */

    /* normal unpin/pin for the whole single-page region */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, pagesize);
    mem = mmap (NULL, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem == MAP_FAILED)
	fatal (errno, "can't map ashmem region");
    pin.offset = 0, pin.len = pagesize;
    ret = ioctl (fd, ASHMEM_UNPIN, &pin);
    if (ret < 0)
	fatal (errno, "can't unpin region with offset %ld and size %ld", 0, pagesize);
    ret = ioctl (fd, ASHMEM_PIN, &pin);
    if (ret < 0)
	fatal (errno, "can't pin region with offset %ld and size %ld", 0, pagesize);
    if (munmap (mem, pagesize))
	fatal (errno, "can't unmap ashmem region");
    test_close (fd);

    /* make sure we can unpin zero bytes (means everything onward) */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, pagesize);
    mem = mmap (NULL, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem == MAP_FAILED)
	fatal (errno, "can't map ashmem region");
    pin.offset = 0, pin.len = 0;
    ret = ioctl (fd, ASHMEM_UNPIN, &pin);
    if (ret < 0)
	fatal (errno, "should be able to unpin zero bytes");
    if (munmap (mem, pagesize))
	fatal (errno, "can't unmap ashmem region");
    test_close (fd);

    /* make sure we can't unpin across page boundaries */
    size = pagesize * 16;
    fd = test_open_and_set_size (ashmemdev, O_RDWR, size);
    mem = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem == MAP_FAILED)
	fatal (errno, "can't map ashmem region");
    pin.offset = pagesize + 7, pin.len = 3 * pagesize + 11;
    ret = ioctl (fd, ASHMEM_UNPIN, &pin);
    if (ret >= 0)
	fatal (errno, "should not be able to unpin across page boundaries");
    if (munmap (mem, size))
	fatal (errno, "can't unmap ashmem region");
    test_close (fd);

    /* make sure we can't unpin more than requested */
    size = pagesize * 8;
    fd = test_open_and_set_size (ashmemdev, O_RDWR, size);
    mem = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem == MAP_FAILED)
	fatal (errno, "can't map ashmem region");
    pin.offset = 0, pin.len = size * 2;
    ret = ioctl (fd, ASHMEM_UNPIN, &pin);
    if (ret >= 0)
	fatal (errno, "should not be able to unpin more than allocated");
    if (munmap (mem, size))
	fatal (errno, "can't unmap ashmem region");
    test_close (fd);

    /* make sure we can't unpin beyond the region */
    size = pagesize * 8;
    fd = test_open_and_set_size (ashmemdev, O_RDWR, size);
    mem = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem == MAP_FAILED)
	fatal (errno, "can't map ashmem region");
    pin.offset = size * 2, pin.len = pagesize;
    ret = ioctl (fd, ASHMEM_UNPIN, &pin);
    if (ret >= 0)
	fatal (errno, "should not be able to unpin beyond the region");
    if (munmap (mem, size))
	fatal (errno, "can't unmap ashmem region");
    test_close (fd);

    printf ("[%s]: test passed\n", __func__);
}

void ashmem_pin_status (void)
{
    int fd, ret;
    void *mem;
    struct ashmem_pin pin;
    size_t size = pagesize * 4;

    strcpy(testname, __func__);

    /* get 4-pages region */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, size);
    mem = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem == MAP_FAILED)
	fatal (errno, "can't map ashmem region");

    /* make sure we can examine zero-sized region (means everything onward) */
    pin.offset = 0, pin.len = 0;
    ret = ioctl (fd, ASHMEM_GET_PIN_STATUS, &pin);
    if (ret < 0)
	fatal (errno, "should be able to ask status of zero-sized region");

    /* make sure we can't examine across page boundaries */
    pin.offset = pagesize + 11, pin.len = pagesize + 17;
    ret = ioctl (fd, ASHMEM_GET_PIN_STATUS, &pin);
    if (ret >= 0)
	fatal (errno, "should not be able to ask across page boundaries");

    /* make sure we can't examine beyond the region */
    pin.offset = size * 2, pin.len = pagesize;
    ret = ioctl (fd, ASHMEM_GET_PIN_STATUS, &pin);
    if (ret >= 0)
	fatal (errno, "should not be able to ask beyond the region");

    /* make sure it's initially pinned */
    pin.offset = 0, pin.len = size;
    ret = ioctl (fd, ASHMEM_GET_PIN_STATUS, &pin);
    if (ret != ASHMEM_IS_PINNED)
	fatal (0, "expect initially pinned region");

    /* unpin it */
    pin.offset = 0, pin.len = size;
    ret = ioctl (fd, ASHMEM_UNPIN, &pin);
    if (ret < 0)
	fatal (errno, "can't unpin region");

    /* make sure it's not pinned now */
    pin.offset = 0, pin.len = size;
    ret = ioctl (fd, ASHMEM_GET_PIN_STATUS, &pin);
    if (ret != ASHMEM_IS_UNPINNED)
	fatal (0, "expect unpinned region");

    if (munmap (mem, size))
	fatal (errno, "can't unmap ashmem region\n");
    test_close (fd);

    printf ("[%s]: test passed\n", __func__);
}

void ashmem_size (void)
{
    int fd, ret;

    strcpy(testname, __func__);

    /* check whether set and get sizes match */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, pagesize);
    ret = ioctl (fd, ASHMEM_GET_SIZE, 0);
    if (ret != pagesize)
	fatal (0, "size mismatch: expect %ld, got %d", pagesize, ret);
    test_close (fd);

    printf ("[%s]: test passed\n", __func__);
}

void ashmem_mmap (void)
{
    void *mem;
    int i, fd, ret;
    size_t size = pagesize * 4;
    char *pattern = alloca (size);

    strcpy(testname, __func__);

    /* fill the random pattern */
    for (i = 0; i < size; i++)
	pattern[i] = 'a' + rand () % ('z' - 'a');

    /* write the pattern to ashmem region, then compare with origin */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, size);
    mem = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem == MAP_FAILED)
	fatal (errno, "can't map ashmem region");
    memcpy (mem, pattern, size);
    if (memcmp (mem, pattern, size))
	fatal (0, "pattern vs. ashmem mismatch");
    if (munmap (mem, size))
	fatal (errno, "can't unmap ashmem region");
    test_close (fd);

    /* make sure we can mmap a half in the middle */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, size);
    mem = mmap (NULL, size / 2, PROT_READ | PROT_WRITE, MAP_SHARED, fd, pagesize);
    if (mem == MAP_FAILED)
	fatal (errno, "can't map ashmem region in the middle");
    if (munmap (mem, size / 2))
	fatal (errno, "can't unmap ashmem region");
    test_close (fd);

    /* make sure we can't mmap read-only region for read/write */
    fd = test_open_and_set_size (ashmemdev, O_RDONLY, size);
    mem = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem != MAP_FAILED || errno != EACCES)
	fatal (errno, "should not allow read-write map for read-only region");
    test_close (fd);

    /* make sure we can't mmap write-only region for read/write */
    fd = test_open_and_set_size (ashmemdev, O_WRONLY, size);
    mem = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem != MAP_FAILED || errno != EACCES)
	fatal (errno, "should not allow read-write map for write-only region");
    test_close (fd);

    printf ("[%s]: test passed\n", __func__);
}

void ashmem_prot (void)
{
    void *mem;
    int fd, ret;

    strcpy(testname, __func__);

    /* check whether default protection is read/write/exec */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, pagesize);
    ret = ioctl (fd, ASHMEM_GET_PROT_MASK);
    if (ret != DEFAULT_PROT_MASK)
	fatal (0, "default protection mask mismatch (got %x expect %x)",
	       ret, DEFAULT_PROT_MASK);
    test_close (fd);

    /* check whether we can remove some protection bits */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, pagesize);
    ret = ioctl (fd, ASHMEM_GET_PROT_MASK);
    if (ret != DEFAULT_PROT_MASK)
	fatal (errno, "can't get protection mask or unexpected mask");
    ret &= ~(PROT_READ | PROT_WRITE);
    ret = ioctl (fd, ASHMEM_SET_PROT_MASK, ret);
    if (ret < 0)
	fatal (errno, "can't remove protection bits");
    ret = ioctl (fd, ASHMEM_GET_PROT_MASK);
    if (ret != PROT_EXEC)
	fatal (errno, "protection mask mismatch (expect %x got %x)", PROT_EXEC, ret);
    test_close (fd);

    /* check whether we can't map read/write after removing PROT_READ... */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, pagesize);
    ret = ioctl (fd, ASHMEM_GET_PROT_MASK);
    if (ret != DEFAULT_PROT_MASK)
	fatal (errno, "can't get protection mask or unexpected mask");
    ret &= ~PROT_READ;
    ret = ioctl (fd, ASHMEM_SET_PROT_MASK, ret);
    if (ret < 0)
	fatal (errno, "can't remove protection bits");
    mem = mmap (NULL, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem != MAP_FAILED || errno != EPERM)
	fatal (errno, "should not allow read/write map after removing PROT_READ");
    /* ...but can map write-only */
    mem = mmap (NULL, pagesize, PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem == MAP_FAILED)
	fatal (errno, "should allow write-only map after removing PROT_READ");
    if (munmap (mem, pagesize))
	fatal (errno, "can't unmap ashmem region");
    test_close (fd);

    /* likewise after removing PROT_WRITE... */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, pagesize);
    ret = ioctl (fd, ASHMEM_GET_PROT_MASK);
    if (ret != DEFAULT_PROT_MASK)
	fatal (errno, "can't get protection mask or unexpected mask");
    ret &= ~PROT_WRITE;
    ret = ioctl (fd, ASHMEM_SET_PROT_MASK, ret);
    if (ret < 0)
	fatal (errno, "can't remove protection bits");
    mem = mmap (NULL, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem != MAP_FAILED || errno != EPERM)
	fatal (errno, "should not allow read/write map after removing PROT_WRITE");
    /* ...still can map read-only */
    mem = mmap (NULL, pagesize, PROT_READ, MAP_SHARED, fd, 0);
    if (mem == MAP_FAILED)
	fatal (errno, "should allow read-only map after removing PROT_WRITE");
    if (munmap (mem, pagesize))
	fatal (errno, "can't unmap ashmem region");
    test_close (fd);

    printf ("[%s]: test passed\n", __func__);
}

void ashmem_purge (void)
{
    void *mem;
    struct ashmem_pin pin;
    const int count = 16;
    int i, fd, ret, size = pagesize * count;

    strcpy(testname, __func__);

    /* allocate 16 pages */
    fd = test_open_and_set_size (ashmemdev, O_RDWR, size);
    mem = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (mem == MAP_FAILED)
	fatal (errno, "can't map ashmem region");
    /* unpin all odd pages */
    for (i = 1; i < count; i += 2) {
	pin.offset = i * pagesize;
	pin.len = pagesize;
	ret = ioctl (fd, ASHMEM_UNPIN, &pin);
	if (ret < 0)
	    fatal (errno, "can't unpin page %d of %d", i, count);
    }
    /* purge should release 8 pages */
    ret = ioctl (fd, ASHMEM_PURGE_ALL_CACHES);
    if (ret != count / 2) {
	if (ret < 0)
	    fatal (errno, "can't purge caches");
	else if (ret < count / 2)
	    fatal (0, "purge %d pages, but expect %d", ret, count / 2);
	else
	    printf("[%s]: warning: purged more pages (%d) than expected (%d), probably somebody else does the same....",
			__func__, ret, count / 2);
    }
    if (munmap (mem, size))
	fatal (errno, "can't unmap ashmem region");
    test_close (fd);

    printf ("[%s]: test passed\n", __func__);
}

int main(int argc, char *argv[])
{
    snprintf (ashmemdev, sizeof (ashmemdev), "/%s", ASHMEM_NAME_DEF);
    pagesize = getpagesize ();

    ashmem_basic ();
    ashmem_anonymous_region ();
    ashmem_named_region ();
    ashmem_pin_unpin ();
    ashmem_pin_status ();
    ashmem_size ();
    ashmem_mmap ();
    ashmem_prot ();
    ashmem_purge ();

    return 0;
}