shared: guard all the seal logic behind HAVE_MEMFD_CREATE

The initial version of os_ro_anonymous_file missed two guards around the
seal logic which leads to a compilation error on older systems.

Also make the check for a read-only file symmetric in
os_ro_anonymous_file_get_fd and os_ro_anonymous_file_put_fd.

Signed-off-by: Sebastian Wick <sebastian@sebastianwick.net>
dev
Sebastian Wick 5 years ago
parent 7bce28b543
commit f0d3a61491
  1. 15
      shared/os-compatibility.c

@ -340,6 +340,7 @@ os_ro_anonymous_file_get_fd(struct ro_anonymous_file *file,
void *src, *dst;
int seals, fd;
#ifdef HAVE_MEMFD_CREATE
seals = fcntl(file->fd, F_GET_SEALS);
/* file was sealed for read-only and we don't have to support MAP_SHARED
@ -348,6 +349,7 @@ os_ro_anonymous_file_get_fd(struct ro_anonymous_file *file,
if (seals != -1 && mapmode == RO_ANONYMOUS_FILE_MAPMODE_PRIVATE &&
(seals & READONLY_SEALS) == READONLY_SEALS)
return file->fd;
#endif
/* for all other cases we create a new anonymous file that can be mapped
* with MAP_SHARED and copy the contents to it and return that instead
@ -388,17 +390,18 @@ os_ro_anonymous_file_get_fd(struct ro_anonymous_file *file,
int
os_ro_anonymous_file_put_fd(int fd)
{
#ifdef HAVE_MEMFD_CREATE
int seals = fcntl(fd, F_GET_SEALS);
if (seals == -1 && errno != EINVAL)
return -1;
/* If the fd cannot be sealed seals is -1 at this point
* or the file can be sealed but has not been sealed for writing.
* In both cases we created a new anonymous file that we have to
* close.
/* The only case in which we do NOT have to close the file is when the file
* was sealed for read-only
*/
if (seals == -1 || !(seals & F_SEAL_WRITE))
close(fd);
if (seals != -1 && (seals & READONLY_SEALS) == READONLY_SEALS)
return 0;
#endif
close(fd);
return 0;
}

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