于 2013年02月24日 18:55, Simon Horman 写道: > 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" <[email protected]> >> Cc: Andrew Morton <[email protected]> >> Cc: Simon Horman <[email protected]> >> Signed-off-by: Zhang Yanfei <[email protected]> >> --- >> 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 >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
