From f33ff9927f42045116d738ee47ff7bc59f739bd7 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun, 12 Aug 2012 16:17:59 -0400
Subject: [PATCH] take rlimit check to callers of expand_files()
... except for one in android, where the check is different
and already done in caller. No need to recalculate rlimit
many times in alloc_fd() either.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/fcntl.c | 3 +++
fs/file.c | 16 +++++++++-------
2 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 887b5ba8c9b5..08e6af5c1b1f 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -64,6 +64,9 @@ SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags)
if (unlikely(oldfd == newfd))
return -EINVAL;
+ if (newfd >= rlimit(RLIMIT_NOFILE))
+ return -EMFILE;
+
spin_lock(&files->file_lock);
err = expand_files(files, newfd);
file = fcheck(oldfd);
diff --git a/fs/file.c b/fs/file.c
index 5b46e9970a7a..08922af4a62c 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -251,13 +251,6 @@ int expand_files(struct files_struct *files, int nr)
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 >= rlimit(RLIMIT_NOFILE))
- return -EMFILE;
-
/* Do we need to expand? */
if (nr < fdt->max_fds)
return 0;
@@ -431,6 +424,7 @@ int alloc_fd(unsigned start, unsigned flags)
{
struct files_struct *files = current->files;
unsigned int fd;
+ unsigned end = rlimit(RLIMIT_NOFILE);
int error;
struct fdtable *fdt;
@@ -444,6 +438,14 @@ repeat:
if (fd < fdt->max_fds)
fd = find_next_zero_bit(fdt->open_fds, fdt->max_fds, fd);
+ /*
+ * N.B. For clone tasks sharing a files structure, this test
+ * will limit the total number of files that can be opened.
+ */
+ error = -EMFILE;
+ if (fd >= end)
+ goto out;
+
error = expand_files(files, fd);
if (error < 0)
goto out;
--
2.20.1