linux-ide.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] ata: Eliminate usage of uninitialized_var() macro
@ 2020-06-15  4:02 Jason Yan
  0 siblings, 0 replies; only message in thread
From: Jason Yan @ 2020-06-15  4:02 UTC (permalink / raw)
  To: axboe, b.zolnierkie, linux-ide, linux-kernel
  Cc: kernel-hardening, Jason Yan, Kees Cook

This is an effort to eliminate the uninitialized_var() macro[1].

The use of this macro is the wrong solution because it forces off ANY
analysis by the compiler for a given variable. It even masks "unused
variable" warnings.

Quoted from Linus[2]:

"It's a horrible thing to use, in that it adds extra cruft to the
source code, and then shuts up a compiler warning (even the _reliable_
warnings from gcc)."

The gcc option "-Wmaybe-uninitialized" has been disabled and this change
will not produce any warnnings even with "make W=1".

[1] https://github.com/KSPP/linux/issues/81
[2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
---
 drivers/ata/libata-scsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 435781a16875..fcb00f2825fe 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -93,7 +93,7 @@ static ssize_t ata_scsi_park_show(struct device *device,
 	struct ata_link *link;
 	struct ata_device *dev;
 	unsigned long now;
-	unsigned int uninitialized_var(msecs);
+	unsigned int msecs;
 	int rc = 0;
 
 	ap = ata_shost_to_port(sdev->host);
-- 
2.25.4


^ permalink raw reply related	[flat|nested] only message in thread

only message in thread, other threads:[~2020-06-15  4:01 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-06-15  4:02 [PATCH] ata: Eliminate usage of uninitialized_var() macro Jason Yan

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).