From: Rasmus Villemoes linux@rasmusvillemoes.dk
[ Upstream commit 38f087de8947700d3b06d3d1594490e0f611c5d1 ]
Calling complete() from within the __init function is wrong - theoretically, the init process could proceed all the way to freeing the init mem before the devtmpfsd thread gets to execute the return instruction in devtmpfs_setup().
In practice, it seems to be harmless as gcc inlines devtmpfs_setup() into devtmpfsd(). So the calls of the __init functions init_chdir() etc. actually happen from devtmpfs_setup(), but the __ref on that one silences modpost (it's all right, because those calls happen before the complete()). But it does make the __init annotation of the setup function moot, which we'll fix in a subsequent patch.
Fixes: bcbacc4909f1 ("devtmpfs: refactor devtmpfsd()") Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Rasmus Villemoes linux@rasmusvillemoes.dk Link: https://lore.kernel.org/r/20210312103027.2701413-1-linux@rasmusvillemoes.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/base/devtmpfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index 653c8c6ac7a7..aedeb2dc1a18 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -419,7 +419,6 @@ static int __init devtmpfs_setup(void *p) init_chroot("."); out: *(int *)p = err; - complete(&setup_done); return err; }
@@ -432,6 +431,7 @@ static int __ref devtmpfsd(void *p) { int err = devtmpfs_setup(p);
+ complete(&setup_done); if (err) return err; devtmpfs_work_loop();