? 2013?02?24? 18:55, Simon Horman ??:
> On Sun, Feb 24, 2013 at 12:03:00PM +0800, Zhang Yanfei wrote:
>> This is just a tweak: using min_t/max_t to avoid `if (foo = bar)' thing.
>
> - s/=/==/; s/[/]max_t//
>
>
> But in any case the change is more than that.
> I'd be happier with something like:
>
> kexec: Use min_t to simplify logic
Hmm, agreed.
>
>> Cc: "Eric W. Biederman" <ebiederm at xmission.com>
>> Cc: Andrew Morton <akpm at linux-foundation.org>
>> Cc: Simon Horman <horms at verge.net.au>
>> Signed-off-by: Zhang Yanfei <zhangyanfei at cn.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);
>
> The line above means that uchunk can now never be greater than ubytes.
>
>> if (uchunk > ubytes) {
>
> So the following seems more appropriate to me:
>
> if (mchunk > uchunk) {
Oops, this is really a mistake. Thanks.
I will send the v2 patch.
>
>
>> - 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
>>
> --
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