linux-kernel - [PATCH v2] staging: comedi: rewrite macro function with GNU extension typeof

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20191104163331.68173-1-jbi.octave@gmail.com>
Date:   Mon,  4 Nov 2019 16:33:31 +0000
From:   Jules Irenge <jbi.octave@...il.com>
To:     outreachy-kernel@...glegroups.com
Cc:     gregkh@...uxfoundation.org, devel@...verdev.osuosl.org,
        linux-kernel@...r.kernel.org, hsweeten@...ionengravers.com,
        abbotti@....co.uk, Jules Irenge <jbi.octave@...il.com>
Subject: [PATCH v2] staging: comedi: rewrite macro function with GNU extension typeof

Rewrite macro function with the GNU extension typeof
to remove a possible side-effects of MACRO argument reuse "x".
 - Problem could rise if arguments have different types
and different use though.

Signed-off-by: Jules Irenge <jbi.octave@...il.com>
---
v1 - had no full commit log message, with changes not intended to be in the patch 
v2 - remove some changes not intended to be in this driver
     include note of a potential problem
 drivers/staging/comedi/comedi.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/comedi/comedi.h b/drivers/staging/comedi/comedi.h
index 09a940066c0e..a57691a2e8d8 100644
--- a/drivers/staging/comedi/comedi.h
+++ b/drivers/staging/comedi/comedi.h
@@ -1103,8 +1103,10 @@ enum ni_common_signal_names {
 
 /* *** END GLOBALLY-NAMED NI TERMINALS/SIGNALS *** */
 
-#define NI_USUAL_PFI_SELECT(x)	(((x) < 10) ? (0x1 + (x)) : (0xb + (x)))
-#define NI_USUAL_RTSI_SELECT(x)	(((x) < 7) ? (0xb + (x)) : 0x1b)
+#define NI_USUAL_PFI_SELECT(x)\
+	({typeof(x) x_ = (x); (x_ < 10) ? (0x1 + x_) : (0xb + x_); })
+#define NI_USUAL_RTSI_SELECT(x)\
+	({typeof(x) x_ = (x); (x_ < 7) ? (0xb + x_) : 0x1b; })
 
 /*
  * mode bits for NI general-purpose counters, set with
-- 
2.23.0