Files
flexnbd-c/tests/acceptance/ld_preloads/msync_logger.c
2018-02-08 22:28:34 +00:00

34 lines
713 B
C

#define _GNU_SOURCE
#include <dlfcn.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
typedef int (*real_msync_t)(void *addr, size_t length, int flags);
int real_msync(void *addr, size_t length, int flags) {
return ((real_msync_t)dlsym(RTLD_NEXT, "msync"))(addr, length, flags);
}
/*
* Noddy LD_PRELOAD wrapper to catch msync calls, and log them to a file.
*/
int msync(void *addr, size_t length, int flags) {
FILE *fd;
char *fn;
int retval;
retval = real_msync(addr, length, flags);
fn = getenv("OUTPUT_msync_logger");
if ( fn != NULL ) {
fd = fopen(fn,"a");
fprintf(fd,"msync:%d:%i:%i:%i\n", addr, length, flags, retval);
fclose(fd);
}
return retval;
}