git/compat/mmap.c
Carlo Marcelo Arenas Belón bf1e6da791 compat: make sure git_mmap is not expected to write
in f48000fc ("Yank writing-back support from gitfakemmap.", 2005-10-08)
support for writting back changes was removed but the specific prot
flag that would be used was not checked for

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-25 18:51:03 +09:00

41 lines
711 B
C

#include "../git-compat-util.h"
void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
size_t n = 0;
if (start != NULL || flags != MAP_PRIVATE || prot != PROT_READ)
die("Invalid usage of mmap when built with NO_MMAP");
start = xmalloc(length);
if (start == NULL) {
errno = ENOMEM;
return MAP_FAILED;
}
while (n < length) {
ssize_t count = xpread(fd, (char *)start + n, length - n, offset + n);
if (count == 0) {
memset((char *)start+n, 0, length-n);
break;
}
if (count < 0) {
free(start);
errno = EACCES;
return MAP_FAILED;
}
n += count;
}
return start;
}
int git_munmap(void *start, size_t length)
{
free(start);
return 0;
}