From 4e1e018ecc6f7bfd10fc75b3ff9715cc8164e0a2 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 26 Jul 2008 16:01:20 -0400 Subject: [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 --- fs/fcntl.c | 18 ++++++------------ fs/file.c | 9 +++++++++ fs/open.c | 9 --------- 3 files changed, 15 insertions(+), 21 deletions(-) diff --git a/fs/fcntl.c b/fs/fcntl.c index 3deec988708..61d62513681 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -64,11 +64,6 @@ static int locate_fd(unsigned int orig_start, int cloexec) 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 @@ repeat: 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 @@ asmlinkage long sys_dup3(unsigned int oldfd, unsigned int newfd, int flags) 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 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, 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 7b3887e054d..d8773b19fe4 100644 --- a/fs/file.c +++ b/fs/file.c @@ -250,9 +250,18 @@ int expand_files(struct files_struct *files, int nr) 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 3fe1a6857c7..52647be277a 100644 --- a/fs/open.c +++ b/fs/open.c @@ -972,7 +972,6 @@ int get_unused_fd_flags(int flags) int fd, error; struct fdtable *fdt; - error = -EMFILE; spin_lock(&files->file_lock); repeat: @@ -980,13 +979,6 @@ repeat: 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 @@ repeat: * If we needed to expand the fs array we * might have blocked - try again. */ - error = -EMFILE; goto repeat; } -- cgit v1.2.3-18-g5258