[PATCH] fix RLIM_NOFILE handling
* dup2() should return -EBADF on exceeded sysctl_nr_open
* dup() should *not* return -EINVAL even if you have rlimit set to 0;
it should get -EMFILE instead.
Check for orig_start exceeding rlimit taken to sys_fcntl().
Failing expand_files() in dup{2,3}() now gets -EMFILE remapped to -EBADF.
Consequently, remaining checks for rlimit are taken to expand_files().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 3deec98..61d6251 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -64,11 +64,6 @@
struct fdtable *fdt;
spin_lock(&files->file_lock);
-
- error = -EINVAL;
- if (orig_start >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
- goto out;
-
repeat:
fdt = files_fdtable(files);
/*
@@ -83,10 +78,6 @@
if (start < fdt->max_fds)
newfd = find_next_zero_bit(fdt->open_fds->fds_bits,
fdt->max_fds, start);
-
- error = -EMFILE;
- if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
- goto out;
error = expand_files(files, newfd);
if (error < 0)
@@ -141,13 +132,14 @@
spin_lock(&files->file_lock);
if (!(file = fcheck(oldfd)))
goto out_unlock;
- if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
- goto out_unlock;
get_file(file); /* We are now finished with oldfd */
err = expand_files(files, newfd);
- if (err < 0)
+ if (unlikely(err < 0)) {
+ if (err == -EMFILE)
+ err = -EBADF;
goto out_fput;
+ }
/* To avoid races with open() and dup(), we will mark the fd as
* in-use in the open-file bitmap throughout the entire dup2()
@@ -328,6 +320,8 @@
switch (cmd) {
case F_DUPFD:
case F_DUPFD_CLOEXEC:
+ if (arg >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
+ break;
get_file(filp);
err = dupfd(filp, arg, cmd == F_DUPFD_CLOEXEC);
break;
diff --git a/fs/file.c b/fs/file.c
index 7b3887e..d8773b1 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -250,9 +250,18 @@
struct fdtable *fdt;
fdt = files_fdtable(files);
+
+ /*
+ * N.B. For clone tasks sharing a files structure, this test
+ * will limit the total number of files that can be opened.
+ */
+ if (nr >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
+ return -EMFILE;
+
/* Do we need to expand? */
if (nr < fdt->max_fds)
return 0;
+
/* Can we expand? */
if (nr >= sysctl_nr_open)
return -EMFILE;
diff --git a/fs/open.c b/fs/open.c
index 3fe1a68..52647be 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -972,7 +972,6 @@
int fd, error;
struct fdtable *fdt;
- error = -EMFILE;
spin_lock(&files->file_lock);
repeat:
@@ -980,13 +979,6 @@
fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds,
files->next_fd);
- /*
- * N.B. For clone tasks sharing a files structure, this test
- * will limit the total number of files that can be opened.
- */
- if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
- goto out;
-
/* Do we need to expand the fd array or fd set? */
error = expand_files(files, fd);
if (error < 0)
@@ -997,7 +989,6 @@
* If we needed to expand the fs array we
* might have blocked - try again.
*/
- error = -EMFILE;
goto repeat;
}