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From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 3.18 21/26] unifdef: use memcpy instead of strncpy
Date: Wed,  5 Dec 2018 04:54:25 -0500	[thread overview]
Message-ID: <20181205095430.8019-21-sashal@kernel.org> (raw)
In-Reply-To: <20181205095430.8019-1-sashal@kernel.org>

From: Linus Torvalds <torvalds@linux-foundation.org>

[ Upstream commit 38c7b224ce22c25fed04007839edf974bd13439d ]

New versions of gcc reasonably warn about the odd pattern of

	strncpy(p, q, strlen(q));

which really doesn't make sense: the strncpy() ends up being just a slow
and odd way to write memcpy() in this case.

There was a comment about _why_ the code used strncpy - to avoid the
terminating NUL byte, but memcpy does the same and avoids the warning.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 scripts/unifdef.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/unifdef.c b/scripts/unifdef.c
index 7493c0ee51cc..db00e3e30a59 100644
--- a/scripts/unifdef.c
+++ b/scripts/unifdef.c
@@ -395,7 +395,7 @@ usage(void)
  * When we have processed a group that starts off with a known-false
  * #if/#elif sequence (which has therefore been deleted) followed by a
  * #elif that we don't understand and therefore must keep, we edit the
- * latter into a #if to keep the nesting correct. We use strncpy() to
+ * latter into a #if to keep the nesting correct. We use memcpy() to
  * overwrite the 4 byte token "elif" with "if  " without a '\0' byte.
  *
  * When we find a true #elif in a group, the following block will
@@ -450,7 +450,7 @@ static void Idrop (void) { Fdrop();  ignoreon(); }
 static void Itrue (void) { Ftrue();  ignoreon(); }
 static void Ifalse(void) { Ffalse(); ignoreon(); }
 /* modify this line */
-static void Mpass (void) { strncpy(keyword, "if  ", 4); Pelif(); }
+static void Mpass (void) { memcpy(keyword, "if  ", 4); Pelif(); }
 static void Mtrue (void) { keywordedit("else");  state(IS_TRUE_MIDDLE); }
 static void Melif (void) { keywordedit("endif"); state(IS_FALSE_TRAILER); }
 static void Melse (void) { keywordedit("endif"); state(IS_FALSE_ELSE); }
-- 
2.17.1

  parent reply	other threads:[~2018-12-05  9:54 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-05  9:54 [PATCH AUTOSEL 3.18 01/26] ARM: OMAP2+: prm44xx: Fix section annotation on omap44xx_prm_enable_io_wakeup Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 02/26] ARM: OMAP1: ams-delta: Fix possible use of uninitialized field Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 03/26] sysv: return 'err' instead of 0 in __sysv_write_inode Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 04/26] s390/cpum_cf: Reject request for sampling in event initialization Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 05/26] hwmon: (w83795) temp4_type has writable permission Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 06/26] Btrfs: send, fix infinite loop due to directory rename dependencies Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 07/26] uprobes: Fix handle_swbp() vs. unregister() + register() race once more Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 08/26] ASoC: omap-mcpdm: Add pm_qos handling to avoid under/overruns with CPU_IDLE Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 09/26] ASoC: omap-dmic: Add pm_qos handling to avoid overruns " Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 10/26] exportfs: do not read dentry after free Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 11/26] USB: omap_udc: use devm_request_irq() Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 12/26] USB: omap_udc: fix crashes on probe error and module removal Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 13/26] USB: omap_udc: fix omap_udc_start() on 15xx machines Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 14/26] USB: omap_udc: fix USB gadget functionality on Palm Tungsten E Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 15/26] KVM: x86: fix empty-body warnings Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 16/26] rapidio/rionet: do not free skb before reading its length Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 17/26] s390/qeth: fix length check in SNMP processing Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 18/26] drm/ast: fixed reading monitor EDID not stable issue Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 19/26] fscache: fix race between enablement and dropping of object Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 20/26] fscache, cachefiles: remove redundant variable 'cache' Sasha Levin
2018-12-05  9:54 ` Sasha Levin [this message]
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 22/26] ocfs2: fix deadlock caused by ocfs2_defrag_extent() Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 23/26] hfs: do not free node before using Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 24/26] hfsplus: " Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 25/26] debugobjects: avoid recursive calls with kmemleak Sasha Levin
2018-12-05  9:54 ` [PATCH AUTOSEL 3.18 26/26] ocfs2: fix potential use after free Sasha Levin

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