From f869e8a7f753e3fd43d6483e796774776f645edb Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 15 Aug 2012 21:06:33 -0400 Subject: expose a low-level variant of fd_install() for binder Similar situation to that of __alloc_fd(); do not use unless you really have to. You should not touch any descriptor table other than your own; it's a sure sign of a really bad API design. As with __alloc_fd(), you *must* use a first-class reference to struct files_struct; something obtained by get_files_struct(some task) (let alone direct task->files) will not do. It must be either current->files, or obtained by get_files_struct(current) by the owner of that sucker and given to you. Signed-off-by: Al Viro --- fs/file.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'fs/file.c') diff --git a/fs/file.c b/fs/file.c index 78cf88f2a0e8..0d1bf0515111 100644 --- a/fs/file.c +++ b/fs/file.c @@ -599,11 +599,18 @@ EXPORT_SYMBOL(put_unused_fd); * * It should never happen - if we allow dup2() do it, _really_ bad things * will follow. + * + * NOTE: __fd_install() variant is really, really low-level; don't + * use it unless you are forced to by truly lousy API shoved down + * your throat. 'files' *MUST* be either current->files or obtained + * by get_files_struct(current) done by whoever had given it to you, + * or really bad things will happen. Normally you want to use + * fd_install() instead. */ -void fd_install(unsigned int fd, struct file *file) +void __fd_install(struct files_struct *files, unsigned int fd, + struct file *file) { - struct files_struct *files = current->files; struct fdtable *fdt; spin_lock(&files->file_lock); fdt = files_fdtable(files); @@ -612,4 +619,9 @@ void fd_install(unsigned int fd, struct file *file) spin_unlock(&files->file_lock); } +void fd_install(unsigned int fd, struct file *file) +{ + __fd_install(current->files, fd, file); +} + EXPORT_SYMBOL(fd_install); -- cgit