2021-06-17 01:39:16

by Gustavo A. R. Silva

Subject: [PATCH][next] xfs: Fix multiple fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix
the following warnings by replacing /* fallthrough */ comments,
and its variants, with the new pseudo-keyword macro fallthrough:

fs/xfs/libxfs/xfs_attr.c:487:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:500:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:532:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:594:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:607:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:1410:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:1445:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:1473:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

Notice that Clang doesn't recognize /* fallthrough */ comments as
implicit fall-through markings, so in order to globally enable
-Wimplicit-fallthrough for Clang, these comments need to be
replaced with fallthrough; in the whole codebase.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---

I'm taking this in my -next[1] branch for v5.14.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/log/?h=for-next/kspp

fs/xfs/libxfs/xfs_attr.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index 611dc67234a6..7994e80358f7 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -483,7 +483,7 @@ xfs_attr_set_iter(
if (error)
return error;

- /* fallthrough */
+ fallthrough;
case XFS_DAS_RM_LBLK:
/* Set state in case xfs_attr_rmtval_remove returns -EAGAIN */
dac->dela_state = XFS_DAS_RM_LBLK;
@@ -496,7 +496,7 @@ xfs_attr_set_iter(
return -EAGAIN;
}

- /* fallthrough */
+ fallthrough;
case XFS_DAS_RD_LEAF:
/*
* This is the last step for leaf format. Read the block with
@@ -528,7 +528,7 @@ xfs_attr_set_iter(
return error;
}

- /* fallthrough */
+ fallthrough;
case XFS_DAS_ALLOC_NODE:
/*
* If there was an out-of-line value, allocate the blocks we
@@ -590,7 +590,7 @@ xfs_attr_set_iter(
if (error)
return error;

- /* fallthrough */
+ fallthrough;
case XFS_DAS_RM_NBLK:
/* Set state in case xfs_attr_rmtval_remove returns -EAGAIN */
dac->dela_state = XFS_DAS_RM_NBLK;
@@ -603,7 +603,7 @@ xfs_attr_set_iter(
return -EAGAIN;
}

- /* fallthrough */
+ fallthrough;
case XFS_DAS_CLR_FLAG:
/*
* The last state for node format. Look up the old attr and
@@ -1406,7 +1406,7 @@ xfs_attr_remove_iter(
state = dac->da_state;
}

- /* fallthrough */
+ fallthrough;
case XFS_DAS_RMTBLK:
dac->dela_state = XFS_DAS_RMTBLK;

@@ -1441,7 +1441,7 @@ xfs_attr_remove_iter(
return -EAGAIN;
}

- /* fallthrough */
+ fallthrough;
case XFS_DAS_RM_NAME:
/*
* If we came here fresh from a transaction roll, reattach all
@@ -1469,7 +1469,7 @@ xfs_attr_remove_iter(
return -EAGAIN;
}

- /* fallthrough */
+ fallthrough;
case XFS_DAS_RM_SHRINK:
/*
* If the result is small enough, push it all into the inode.
--
2.27.0

2021-06-19 15:43:37

by Kees Cook

Subject: Re: [PATCH][next] xfs: Fix multiple fall-through warnings for Clang

On Wed, Jun 16, 2021 at 02:17:14PM -0500, Gustavo A. R. Silva wrote:
> In preparation to enable -Wimplicit-fallthrough for Clang, fix
> the following warnings by replacing /* fallthrough */ comments,
> and its variants, with the new pseudo-keyword macro fallthrough:
>
> fs/xfs/libxfs/xfs_attr.c:487:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
> fs/xfs/libxfs/xfs_attr.c:500:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
> fs/xfs/libxfs/xfs_attr.c:532:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
> fs/xfs/libxfs/xfs_attr.c:594:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
> fs/xfs/libxfs/xfs_attr.c:607:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
> fs/xfs/libxfs/xfs_attr.c:1410:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
> fs/xfs/libxfs/xfs_attr.c:1445:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
> fs/xfs/libxfs/xfs_attr.c:1473:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
>
> Notice that Clang doesn't recognize /* fallthrough */ comments as
> implicit fall-through markings, so in order to globally enable
> -Wimplicit-fallthrough for Clang, these comments need to be
> replaced with fallthrough; in the whole codebase.
>
> Link: https://github.com/KSPP/linux/issues/115
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

Thanks for carrying these!

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook