linux-kernel - [PATCH] kexec: use min_t/max_t to avoid 'if (foo == bar)' thing

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: <512990F4.3030203@cn.fujitsu.com>
Date:	Sun, 24 Feb 2013 12:03:00 +0800
From:	Zhang Yanfei <zhangyanfei@...fujitsu.com>
To:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Andrew Morton <akpm@...ux-foundation.org>
CC:	Simon Horman <horms@...ge.net.au>,
	"kexec@...ts.infradead.org" <kexec@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: [PATCH] kexec: use min_t/max_t to avoid 'if (foo == bar)' thing

This is just a tweak: using min_t/max_t to avoid `if (foo = bar)' thing.

Cc: "Eric W. Biederman" <ebiederm@...ssion.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Simon Horman <horms@...ge.net.au>
Signed-off-by: Zhang Yanfei <zhangyanfei@...fujitsu.com>
---
 kernel/kexec.c |   20 +++++---------------
 1 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 2436ffc..065db87 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -822,13 +822,8 @@ static int kimage_load_normal_segment(struct kimage *image,
 		/* Start with a clear page */
 		clear_page(ptr);
 		ptr += maddr & ~PAGE_MASK;
-		mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
-		if (mchunk > mbytes)
-			mchunk = mbytes;
-
-		uchunk = mchunk;
-		if (uchunk > ubytes)
-			uchunk = ubytes;
+		mchunk = min_t(size_t, mbytes, PAGE_SIZE - (maddr & ~PAGE_MASK));
+		uchunk = min_t(size_t, ubytes, mchunk);
 
 		result = copy_from_user(ptr, buf, uchunk);
 		kunmap(page);
@@ -874,13 +869,9 @@ static int kimage_load_crash_segment(struct kimage *image,
 		}
 		ptr = kmap(page);
 		ptr += maddr & ~PAGE_MASK;
-		mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
-		if (mchunk > mbytes)
-			mchunk = mbytes;
-
-		uchunk = mchunk;
+		mchunk = min_t(size_t, mbytes, PAGE_SIZE - (maddr & ~PAGE_MASK));
+		uchunk = min_t(size_t, ubytes, mchunk);
 		if (uchunk > ubytes) {
-			uchunk = ubytes;
 			/* Zero the trailing part of the page */
 			memset(ptr + uchunk, 0, mchunk - uchunk);
 		}
@@ -1461,8 +1452,7 @@ void vmcoreinfo_append_str(const char *fmt, ...)
 	r = vsnprintf(buf, sizeof(buf), fmt, args);
 	va_end(args);
 
-	if (r + vmcoreinfo_size > vmcoreinfo_max_size)
-		r = vmcoreinfo_max_size - vmcoreinfo_size;
+	r = min_t(size_t, r, vmcoreinfo_max_size - vmcoreinfo_size);
 
 	memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
 
-- 
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/