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authorDavid Howells <dhowells@redhat.com>2012-02-16 17:49:42 +0000
committerH. Peter Anvin <hpa@zytor.com>2012-02-19 10:30:52 -0800
commit1dce27c5aa6770e9d195f2bb7db1db3d4dde5591 (patch)
tree4ad3ffeee95cb5b10e047b7cb9bdbb48cfc734e0
parent8b3d1cda4f5ff0d7c2ae910ea8fd03493996912f (diff)
Wrap accesses to the fd_sets in struct fdtable
Wrap accesses to the fd_sets in struct fdtable (for recording open files and close-on-exec flags) so that we can move away from using fd_sets since we abuse the fd_set structs by not allocating the full-sized structure under normal circumstances and by non-core code looking at the internals of the fd_sets. The first abuse means that use of FD_ZERO() on these fd_sets is not permitted, since that cannot be told about their abnormal lengths. This introduces six wrapper functions for setting, clearing and testing close-on-exec flags and fd-is-open flags: void __set_close_on_exec(int fd, struct fdtable *fdt); void __clear_close_on_exec(int fd, struct fdtable *fdt); bool close_on_exec(int fd, const struct fdtable *fdt); void __set_open_fd(int fd, struct fdtable *fdt); void __clear_open_fd(int fd, struct fdtable *fdt); bool fd_is_open(int fd, const struct fdtable *fdt); Note that I've prepended '__' to the names of the set/clear functions because they require the caller to hold a lock to use them. Note also that I haven't added wrappers for looking behind the scenes at the the array. Possibly that should exist too. Signed-off-by: David Howells <dhowells@redhat.com> Link: http://lkml.kernel.org/r/20120216174942.23314.1364.stgit@warthog.procyon.org.uk Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--Documentation/filesystems/files.txt4
-rw-r--r--arch/powerpc/platforms/cell/spufs/coredump.c2
-rw-r--r--drivers/staging/android/binder.c10
-rw-r--r--fs/autofs4/dev-ioctl.c2
-rw-r--r--fs/exec.c4
-rw-r--r--fs/fcntl.c18
-rw-r--r--fs/file.c8
-rw-r--r--fs/open.c4
-rw-r--r--fs/proc/base.c2
-rw-r--r--include/linux/fdtable.h30
10 files changed, 57 insertions, 27 deletions
diff --git a/Documentation/filesystems/files.txt b/Documentation/filesystems/files.txt
index ac2facc50d2..46dfc6b038c 100644
--- a/Documentation/filesystems/files.txt
+++ b/Documentation/filesystems/files.txt
@@ -113,8 +113,8 @@ the fdtable structure -
if (fd >= 0) {
/* locate_fd() may have expanded fdtable, load the ptr */
fdt = files_fdtable(files);
- FD_SET(fd, fdt->open_fds);
- FD_CLR(fd, fdt->close_on_exec);
+ __set_open_fd(fd, fdt);
+ __clear_close_on_exec(fd, fdt);
spin_unlock(&files->file_lock);
.....
diff --git a/arch/powerpc/platforms/cell/spufs/coredump.c b/arch/powerpc/platforms/cell/spufs/coredump.c
index 03c5fce2a5b..c2c5b078ba8 100644
--- a/arch/powerpc/platforms/cell/spufs/coredump.c
+++ b/arch/powerpc/platforms/cell/spufs/coredump.c
@@ -122,7 +122,7 @@ static struct spu_context *coredump_next_context(int *fd)
struct spu_context *ctx = NULL;
for (; *fd < fdt->max_fds; (*fd)++) {
- if (!FD_ISSET(*fd, fdt->open_fds))
+ if (!fd_is_open(*fd, fdt))
continue;
file = fcheck(*fd);
diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index 7491801a661..35dd9c370e5 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -408,11 +408,11 @@ repeat:
goto repeat;
}
- FD_SET(fd, fdt->open_fds);
+ __set_open_fd(fd, fdt);
if (flags & O_CLOEXEC)
- FD_SET(fd, fdt->close_on_exec);
+ __set_close_on_exec(fd, fdt);
else
- FD_CLR(fd, fdt->close_on_exec);
+ __clear_close_on_exec(fd, fdt);
files->next_fd = fd + 1;
#if 1
/* Sanity check */
@@ -453,7 +453,7 @@ static void task_fd_install(
static void __put_unused_fd(struct files_struct *files, unsigned int fd)
{
struct fdtable *fdt = files_fdtable(files);
- __FD_CLR(fd, fdt->open_fds);
+ __clear_open_fd(fd, fdt);
if (fd < files->next_fd)
files->next_fd = fd;
}
@@ -479,7 +479,7 @@ static long task_close_fd(struct binder_proc *proc, unsigned int fd)
if (!filp)
goto out_unlock;
rcu_assign_pointer(fdt->fd[fd], NULL);
- FD_CLR(fd, fdt->close_on_exec);
+ __clear_close_on_exec(fd, fdt);
__put_unused_fd(files, fd);
spin_unlock(&files->file_lock);
retval = filp_close(filp, files);
diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 76741d8d778..3dfd615afb6 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -230,7 +230,7 @@ static void autofs_dev_ioctl_fd_install(unsigned int fd, struct file *file)
fdt = files_fdtable(files);
BUG_ON(fdt->fd[fd] != NULL);
rcu_assign_pointer(fdt->fd[fd], file);
- FD_SET(fd, fdt->close_on_exec);
+ __set_close_on_exec(fd, fdt);
spin_unlock(&files->file_lock);
}
diff --git a/fs/exec.c b/fs/exec.c
index 92ce83a11e9..22cc38d9e79 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -2078,8 +2078,8 @@ static int umh_pipe_setup(struct subprocess_info *info, struct cred *new)
fd_install(0, rp);
spin_lock(&cf->file_lock);
fdt = files_fdtable(cf);
- FD_SET(0, fdt->open_fds);
- FD_CLR(0, fdt->close_on_exec);
+ __set_open_fd(0, fdt);
+ __clear_close_on_exec(0, fdt);
spin_unlock(&cf->file_lock);
/* and disallow core files too */
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 22764c7c838..75e7c1f3a08 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -32,20 +32,20 @@ void set_close_on_exec(unsigned int fd, int flag)
spin_lock(&files->file_lock);
fdt = files_fdtable(files);
if (flag)
- FD_SET(fd, fdt->close_on_exec);
+ __set_close_on_exec(fd, fdt);
else
- FD_CLR(fd, fdt->close_on_exec);
+ __clear_close_on_exec(fd, fdt);
spin_unlock(&files->file_lock);
}
-static int get_close_on_exec(unsigned int fd)
+static bool get_close_on_exec(unsigned int fd)
{
struct files_struct *files = current->files;
struct fdtable *fdt;
- int res;
+ bool res;
rcu_read_lock();
fdt = files_fdtable(files);
- res = FD_ISSET(fd, fdt->close_on_exec);
+ res = close_on_exec(fd, fdt);
rcu_read_unlock();
return res;
}
@@ -90,15 +90,15 @@ SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags)
err = -EBUSY;
fdt = files_fdtable(files);
tofree = fdt->fd[newfd];
- if (!tofree && FD_ISSET(newfd, fdt->open_fds))
+ if (!tofree && fd_is_open(newfd, fdt))
goto out_unlock;
get_file(file);
rcu_assign_pointer(fdt->fd[newfd], file);
- FD_SET(newfd, fdt->open_fds);
+ __set_open_fd(newfd, fdt);
if (flags & O_CLOEXEC)
- FD_SET(newfd, fdt->close_on_exec);
+ __set_close_on_exec(newfd, fdt);
else
- FD_CLR(newfd, fdt->close_on_exec);
+ __clear_close_on_exec(newfd, fdt);
spin_unlock(&files->file_lock);
if (tofree)
diff --git a/fs/file.c b/fs/file.c
index 4c6992d8f3b..114fea0a2ce 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -366,7 +366,7 @@ struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)
* is partway through open(). So make sure that this
* fd is available to the new process.
*/
- FD_CLR(open_files - i, new_fdt->open_fds);
+ __clear_open_fd(open_files - i, new_fdt);
}
rcu_assign_pointer(*new_fds++, f);
}
@@ -460,11 +460,11 @@ repeat:
if (start <= files->next_fd)
files->next_fd = fd + 1;
- FD_SET(fd, fdt->open_fds);
+ __set_open_fd(fd, fdt);
if (flags & O_CLOEXEC)
- FD_SET(fd, fdt->close_on_exec);
+ __set_close_on_exec(fd, fdt);
else
- FD_CLR(fd, fdt->close_on_exec);
+ __clear_close_on_exec(fd, fdt);
error = fd;
#if 1
/* Sanity check */
diff --git a/fs/open.c b/fs/open.c
index 77becc04114..5720854156d 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -836,7 +836,7 @@ EXPORT_SYMBOL(dentry_open);
static void __put_unused_fd(struct files_struct *files, unsigned int fd)
{
struct fdtable *fdt = files_fdtable(files);
- __FD_CLR(fd, fdt->open_fds);
+ __clear_open_fd(fd, fdt);
if (fd < files->next_fd)
files->next_fd = fd;
}
@@ -1080,7 +1080,7 @@ SYSCALL_DEFINE1(close, unsigned int, fd)
if (!filp)
goto out_unlock;
rcu_assign_pointer(fdt->fd[fd], NULL);
- FD_CLR(fd, fdt->close_on_exec);
+ __clear_close_on_exec(fd, fdt);
__put_unused_fd(files, fd);
spin_unlock(&files->file_lock);
retval = filp_close(filp, files);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index d4548dd49b0..db6ab4b36a0 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1754,7 +1754,7 @@ static int proc_fd_info(struct inode *inode, struct path *path, char *info)
fdt = files_fdtable(files);
f_flags = file->f_flags & ~O_CLOEXEC;
- if (FD_ISSET(fd, fdt->close_on_exec))
+ if (close_on_exec(fd, fdt))
f_flags |= O_CLOEXEC;
if (path) {
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index 82163c4b32c..7675da2c18f 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -38,6 +38,36 @@ struct fdtable {
struct fdtable *next;
};
+static inline void __set_close_on_exec(int fd, struct fdtable *fdt)
+{
+ FD_SET(fd, fdt->close_on_exec);
+}
+
+static inline void __clear_close_on_exec(int fd, struct fdtable *fdt)
+{
+ FD_CLR(fd, fdt->close_on_exec);
+}
+
+static inline bool close_on_exec(int fd, const struct fdtable *fdt)
+{
+ return FD_ISSET(fd, fdt->close_on_exec);
+}
+
+static inline void __set_open_fd(int fd, struct fdtable *fdt)
+{
+ FD_SET(fd, fdt->open_fds);
+}
+
+static inline void __clear_open_fd(int fd, struct fdtable *fdt)
+{
+ FD_CLR(fd, fdt->open_fds);
+}
+
+static inline bool fd_is_open(int fd, const struct fdtable *fdt)
+{
+ return FD_ISSET(fd, fdt->open_fds);
+}
+
/*
* Open file table structure
*/