From: Pi-Hsun Shih <pihsun@chromium.org>
To: unlisted-recipients:; (no To-header on input)
Cc: Pi-Hsun Shih <pihsun@chromium.org>,
linux-wireless@vger.kernel.org,
Johannes Berg <johannes@sipsolutions.net>,
linux-kernel@vger.kernel.org (open list),
clang-built-linux@googlegroups.com (open list:CLANG/LLVM BUILD
SUPPORT)
Subject: [PATCH RESEND] wireless: Use offsetof instead of custom macro.
Date: Thu, 28 Nov 2019 11:39:58 +0800 [thread overview]
Message-ID: <20191128033959.87715-1-pihsun@chromium.org> (raw)
Use offsetof to calculate offset of a field to take advantage of
compiler built-in version when possible, and avoid UBSAN warning when
compiling with Clang:
==================================================================
UBSAN: Undefined behaviour in net/wireless/wext-core.c:525:14
member access within null pointer of type 'struct iw_point'
CPU: 3 PID: 165 Comm: kworker/u16:3 Tainted: G S W 4.19.23 #43
Workqueue: cfg80211 __cfg80211_scan_done [cfg80211]
Call trace:
dump_backtrace+0x0/0x194
show_stack+0x20/0x2c
__dump_stack+0x20/0x28
dump_stack+0x70/0x94
ubsan_epilogue+0x14/0x44
ubsan_type_mismatch_common+0xf4/0xfc
__ubsan_handle_type_mismatch_v1+0x34/0x54
wireless_send_event+0x3cc/0x470
___cfg80211_scan_done+0x13c/0x220 [cfg80211]
__cfg80211_scan_done+0x28/0x34 [cfg80211]
process_one_work+0x170/0x35c
worker_thread+0x254/0x380
kthread+0x13c/0x158
ret_from_fork+0x10/0x18
===================================================================
Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
---
include/uapi/linux/wireless.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/include/uapi/linux/wireless.h b/include/uapi/linux/wireless.h
index 86eca3208b6b..f259cca5cc2b 100644
--- a/include/uapi/linux/wireless.h
+++ b/include/uapi/linux/wireless.h
@@ -1090,8 +1090,7 @@ struct iw_event {
/* iw_point events are special. First, the payload (extra data) come at
* the end of the event, so they are bigger than IW_EV_POINT_LEN. Second,
* we omit the pointer, so start at an offset. */
-#define IW_EV_POINT_OFF (((char *) &(((struct iw_point *) NULL)->length)) - \
- (char *) NULL)
+#define IW_EV_POINT_OFF offsetof(struct iw_point, length)
#define IW_EV_POINT_LEN (IW_EV_LCP_LEN + sizeof(struct iw_point) - \
IW_EV_POINT_OFF)
base-commit: 1875ff320f14afe21731a6e4c7b46dd33e45dfaa
--
2.24.0.393.g34dc348eaf-goog
next reply other threads:[~2019-11-28 3:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-28 3:39 Pi-Hsun Shih [this message]
2019-11-28 3:53 ` [PATCH RESEND] wireless: Use offsetof instead of custom macro Joe Perches
2019-11-29 4:04 ` Pi-Hsun Shih
2019-12-02 17:27 ` Nick Desaulniers
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