int ringbuffer_init(struct ringbuffer *b, size_t size, bool roundup_ok) {
int err;
if (size == 0 || size*2 < size || (size%PAGE_SIZE) != 0) {
if (!roundup_ok) {
errno = EINVAL;
return -1;
}
size = ((size+PAGE_SIZE-1)/PAGE_SIZE)*PAGE_SIZE;
}
b->size = size;
b->start = b->buf = mmap(NULL, size*2, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0);
if (b->buf == NULL) return -1;
if (remap_file_pages(b->buf, size, 0, size/PAGE_SIZE, 0)) goto unmap;
*(char *)b->buf = 0x42;
if (*((char *)b->buf+size) != 0x42) {
fprintf(stderr, "ERROR: SOMETHING BORKED UP THE RINGBUFFER!\n");
assert(0);
}
*(char *)b->buf = 0;
return 0;
unmap:
err = errno;
munmap(b->buf, size*2);
errno = err;
return -1;
}
static void nonlinear(void)
{
int fd;
const int NPAGES = 10;
int i;
char *page;
char *tmp;
fd = tempfd();
tmp = xmalloc(PS);
for (i = 0; i < NPAGES; i++) {
memset(tmp, i, PS);
write(fd, tmp, PS);
}
free(tmp);
page = checked_mmap(NULL, PS*NPAGES, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
int k = NPAGES - 1;
for (i = 0; i < NPAGES; i++, k--) {
if (remap_file_pages(page + i*PS, PS, 0, k, 0))
perror("remap_file_pages");
}
*page = 1;
testmem("rfp file dirty", page, MREAD);
expecterr("rfp fsync expect error", fsync(fd) < 0);
optionalerr("rfp msync expect error", msync(page, PS, MS_SYNC) < 0);
close(fd);
}
int
main(int argc, char *argv[])
{
int fd, j;
char ch;
long pageSize;
char *addr;
fd = open("/tmp/tfile", O_CREAT | O_TRUNC | O_RDWR, S_IRUSR | S_IWUSR);
if (fd == -1)
errExit("open");
pageSize = sysconf(_SC_PAGESIZE);
if (pageSize == -1)
fatal("Couldn't determine page size");
for (ch = 'a'; ch < 'd'; ch++)
for (j = 0; j < pageSize; j++)
write(fd, &ch, 1);
system("od -a /tmp/tfile");
addr = mmap(0, 3 * pageSize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (addr == MAP_FAILED)
errExit("mmap");
printf("Mapped at address %p\n", addr);
/* The three pages of the file -- 0 1 2 -- are currently mapped
linearly. Now we rearrange the mapping to 2 1 0. */
if (remap_file_pages(addr, pageSize, 0, 2, 0) == -1)
errExit("remap_file_pages");
if (remap_file_pages(addr + 2 * pageSize, pageSize, 0, 0, 0) == -1)
errExit("remap_file_pages");
/* Now we modify the contents of the mapping */
for (j = 0; j < 0x100; j++) /* Modifies page 2 of file */
*(addr + j) = '0';
for (j = 0; j < 0x100; j++) /* Modifies page 0 of file */
*(addr + 2 * pageSize + j) = '2';
system("od -a /tmp/tfile");
exit(EXIT_SUCCESS);
}
int
Mono_Posix_Syscall_remap_file_pages (void *start, mph_size_t size,
int prot, mph_ssize_t pgoff, int flags)
{
int _prot, _flags;
mph_return_if_size_t_overflow (size);
mph_return_if_ssize_t_overflow (pgoff);
if (Mono_Posix_FromMmapProts (prot, &_prot) == -1)
return -1;
if (Mono_Posix_FromMmapFlags (flags, &_flags) == -1)
return -1;
return remap_file_pages (start, (size_t) size, _prot, (ssize_t) pgoff, _flags);
}
/**
* Allocates a buffer of the given size, but mapped consecutively twice in
* memory, to avoid wrapping at the (first) end of the buffer
* @param rb ring buffer
* @param size size requested for the buffer, must be a multiple of page_size
* @param page_size actual page_size in the system
* @return errno-compatible negative value on error, 0 otherwise
*/
static int allocate_mirrored_buffer(struct rs_rb *rb, size_t size,
long page_size)
{
int ret;
rb->base = mmap(NULL, 2 * size, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
if (rb->base == MAP_FAILED)
return -errno;
ret = remap_file_pages(rb->base, size, 0, (size / page_size), 0);
if (ret == -1)
return -errno;
return 0;
}
/*
* remap_order()
* remap based on given order
*/
static int remap_order(
const args_t *args,
const size_t stride,
mapdata_t *data,
const size_t *order,
const size_t page_size)
{
size_t i;
for (i = 0; i < N_PAGES; i++) {
int ret;
ret = remap_file_pages(data + (i * stride), page_size,
0, order[i], 0);
if (ret < 0) {
pr_fail_err("remap_file_pages");
return -1;
}
}
return 0;
}
int main(int ac, char **av)
{
int lc, i;
#if defined (__s390__) || (__s390x__) || (__ia64__)
/* Disables the test in case the kernel version is lower than 2.6.12 and arch is s390 */
if ((tst_kvercmp(2, 6, 12)) < 0) {
tst_resm(TWARN,
"This test can only run on kernels that are 2.6.12 and higher");
exit(0);
}
#endif
tst_parse_opts(ac, av, NULL, NULL);
setup();
for (lc = 0; TEST_LOOPING(lc); lc++) {
tst_count = 0;
for (i = 0; i < TST_TOTAL; i++) {
/* do the setup if the test have one */
if (testcase[i].setupfunc
&& testcase[i].setupfunc(i) == -1) {
tst_resm(TWARN,
"Failed to setup test %d"
" Skipping test", i);
continue;
}
/* run the test */
TEST(remap_file_pages
(testcase[i].start, testcase[i].size,
testcase[i].prot, testcase[i].pgoff,
testcase[i].flags));
/* do the cleanup if the test have one */
if (testcase[i].cleanfunc
&& testcase[i].cleanfunc(i) == -1) {
tst_brkm(TBROK, cleanup,
"Failed to cleanup test %d,"
" quitting the test", i);
}
/* verify the return code */
if ((TEST_RETURN == -1)
&& (TEST_ERRNO == testcase[i].exp_errno)) {
tst_resm(TPASS,
"remap_file_pages(2) expected failure;"
" Got errno - %s : %s",
testcase[i].exp_errval,
testcase[i].err_desc);
} else {
tst_resm(TFAIL,
"remap_file_pages(2) failed to produce"
" expected error: %d, errno: %s."
" because got error %d",
testcase[i].exp_errno,
testcase[i].exp_errval, TEST_ERRNO);
}
} /* end of test loops */
} /* end of test looping */
/* clean up and exit */
cleanup();
tst_exit();
}
/* test case function, that runs remap_file_pages */
static void test_nonlinear(int fd)
{
char *data = NULL;
int i, j, repeat = 2;
for (i = 0; i < cache_pages; i++) {
char *page = cache_contents + i * page_sz;
for (j = 0; j < page_words; j++)
page[j] = i;
}
if (write(fd, cache_contents, cache_sz) != cache_sz) {
tst_resm(TFAIL,
"Write Error for \"cache_contents\" to \"cache_sz\" of %zu (errno=%d : %s)",
cache_sz, errno, strerror(errno));
cleanup(NULL);
}
data = mmap((void *)WINDOW_START,
window_sz, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (data == MAP_FAILED) {
tst_resm(TFAIL, "mmap Error, errno=%d : %s", errno,
strerror(errno));
cleanup(NULL);
}
again:
for (i = 0; i < window_pages; i += 2) {
char *page = data + i * page_sz;
if (remap_file_pages(page, page_sz * 2, 0,
(window_pages - i - 2), 0) == -1) {
tst_resm(TFAIL | TERRNO,
"remap_file_pages error for page=%p, "
"page_sz=%d, window_pages=%zu",
page, (page_sz * 2), (window_pages - i - 2));
cleanup(data);
}
}
for (i = 0; i < window_pages; i++) {
/*
* Double-check the correctness of the mapping:
*/
if (i & 1) {
if (data[i * page_sz] != window_pages - i) {
tst_resm(TFAIL,
"hm, mapped incorrect data, "
"data[%d]=%d, (window_pages-%d)=%zu",
(i * page_sz), data[i * page_sz], i,
(window_pages - i));
cleanup(data);
}
} else {
if (data[i * page_sz] != window_pages - i - 2) {
tst_resm(TFAIL,
"hm, mapped incorrect data, "
"data[%d]=%d, (window_pages-%d-2)=%zu",
(i * page_sz), data[i * page_sz], i,
(window_pages - i - 2));
cleanup(data);
}
}
}
if (--repeat)
goto again;
munmap(data, window_sz);
}