Re: [PATCH v2] kexec: Use min_t to simplify logic

From: Simon Horman
Date: Sun Feb 24 2013 - 19:37:05 EST


On Sun, Feb 24, 2013 at 10:37:21PM +0800, Zhang Yanfei wrote:
> From: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
>
> This is just a tweak: using min_t to simplify logic of variable
> assignments.
>
> v2:
> - Rewrite patch description as Simon suggested.
> - Fix an inappropriate if test introduced by v1. Thanks Simon.

Hi Zhang,

thanks for the update.

Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>

> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Simon Horman <horms@xxxxxxxxxxxx>
> Signed-off-by: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
> ---
> kernel/kexec.c | 22 ++++++----------------
> 1 files changed, 6 insertions(+), 16 deletions(-)
>
> diff --git a/kernel/kexec.c b/kernel/kexec.c
> index 2436ffc..effd655 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;
> - if (uchunk > ubytes) {
> - uchunk = ubytes;
> + mchunk = min_t(size_t, mbytes, 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 +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
>
> _______________________________________________
> kexec mailing list
> kexec@xxxxxxxxxxxxxxxxxxx
> http://lists.infradead.org/mailman/listinfo/kexec
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/