From: Jason Yan <yanaijie@huawei.com>
To: <rjw@rjwysocki.net>, <lenb@kernel.org>,
<linux-acpi@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: <kernel-hardening@lists.openwall.com>,
Jason Yan <yanaijie@huawei.com>,
Kees Cook <keescook@chromium.org>
Subject: [PATCH] ACPI: Eliminate usage of uninitialized_var() macro
Date: Mon, 15 Jun 2020 12:00:47 +0800 [thread overview]
Message-ID: <20200615040047.3535543-1-yanaijie@huawei.com> (raw)
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/acpi/acpi_pad.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index e7dc0133f817..6cc4c92d9ff9 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -88,7 +88,7 @@ static void round_robin_cpu(unsigned int tsk_index)
cpumask_var_t tmp;
int cpu;
unsigned long min_weight = -1;
- unsigned long uninitialized_var(preferred_cpu);
+ unsigned long preferred_cpu;
if (!alloc_cpumask_var(&tmp, GFP_KERNEL))
return;
--
2.25.4
next reply other threads:[~2020-06-15 4:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-15 4:00 Jason Yan [this message]
2020-06-24 15:49 ` [PATCH] ACPI: Eliminate usage of uninitialized_var() macro Rafael J. Wysocki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200615040047.3535543-1-yanaijie@huawei.com \
--to=yanaijie@huawei.com \
--cc=keescook@chromium.org \
--cc=kernel-hardening@lists.openwall.com \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rjw@rjwysocki.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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 read-only IMAP folder(s) and NNTP newsgroup(s).