diff options
Diffstat (limited to 'utils.c')
| -rw-r--r-- | utils.c | 48 |
1 files changed, 47 insertions, 1 deletions
@@ -16,10 +16,11 @@ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ -#include "utils.h" +#include <sys/mman.h> #include <stdarg.h> #include <stdlib.h> #include <stdio.h> +#include "utils.h" #define foreach_arg(_arg, _addr, _len, _first_addr, _first_len) \ for (_addr = (_first_addr), _len = (_first_len); \ @@ -103,3 +104,48 @@ out: } #endif + +void *cbuf_alloc(unsigned int order) +{ + char path[] = "/tmp/cbuf-XXXXXX"; + unsigned long size = cbuf_size(order); + void *ret = NULL; + int fd; + + fd = mkstemp(path); + if (fd < 0) + return NULL; + + if (unlink(path)) + goto close; + + if (ftruncate(fd, cbuf_size(order))) + goto close; + +#ifndef MAP_ANONYMOUS +#define MAP_ANONYMOUS MAP_ANON +#endif + + ret = mmap(NULL, size * 2, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0); + if (ret == MAP_FAILED) { + ret = NULL; + goto close; + } + + if (mmap(ret, size, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, + fd, 0) != ret || + mmap(ret + size, size, PROT_READ | PROT_WRITE, + MAP_FIXED | MAP_SHARED, fd, 0) != ret + size) { + munmap(ret, size * 2); + ret = NULL; + } + +close: + close(fd); + return ret; +} + +void cbuf_free(void *ptr, unsigned int order) +{ + munmap(ptr, cbuf_size(order) * 2); +} |