[PATCH v3 2/2] kexec: Use min_t to simplify logic

Zhang Yanfei
2013-02-26T05:32:31Z

This is just a tweak: using min_t to simplify logic of variable
assignments.

v3:
- cast type of (PAGE_SIZE - (maddr & ~PAGE_MASK)) into size_t.

v2:
- Rewrite patch description as Simon suggested.
- Fix an inappropriate if test introduced by v1. Thanks Simon.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
---
kernel/kexec.c | 24 ++++++++----------------
1 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 3cbfcc7..b6b16f9 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -822,13 +822,9 @@ 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,
+ (size_t)(PAGE_SIZE - (maddr & ~PAGE_MASK)));
+ uchunk = min_t(size_t, ubytes, mchunk);

result = copy_from_user(ptr, buf, uchunk);
kunmap(page);
@@ -874,13 +870,10 @@ 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;
- if (uchunk > ubytes) {
- uchunk = ubytes;
+ mchunk = min_t(size_t, mbytes,
+ (size_t)(PAGE_SIZE - (maddr & ~PAGE_MASK)));
+ uchunk = min_t(size_t, ubytes, mchunk);
+ if (mchunk > uchunk) {
/* Zero the trailing part of the page */
memset(ptr + uchunk, 0, mchunk - uchunk);
}
@@ -1461,8 +1454,7 @@ 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