| From 93b9cb7e3ba69526abcd046ade07197307dcdb20 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 12 Mar 2021 11:30:26 +0100 |
| Subject: devtmpfs: fix placement of complete() call |
| |
| 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 eac184e6d657..a71d14117943 100644 |
| --- a/drivers/base/devtmpfs.c |
| +++ b/drivers/base/devtmpfs.c |
| @@ -416,7 +416,6 @@ static int __init devtmpfs_setup(void *p) |
| init_chroot("."); |
| out: |
| *(int *)p = err; |
| - complete(&setup_done); |
| return err; |
| } |
| |
| @@ -429,6 +428,7 @@ static int __ref devtmpfsd(void *p) |
| { |
| int err = devtmpfs_setup(p); |
| |
| + complete(&setup_done); |
| if (err) |
| return err; |
| devtmpfs_work_loop(); |
| -- |
| 2.30.2 |
| |