Re: [mmotm:master 141/230] include/linux/kernel.h:744:28: note: in expansion of macro 'min'

[Michal Nazarewicz <mina86@mina86.com>]

On Fri, Jun 20 2014, Fengguang Wu <fengguang.wu@intel.com> wrote:
>>> include/linux/kernel.h:744:28: note: in expansion of macro 'min'
>     #define clamp(val, lo, hi) min(max(val, lo), hi)
>                                ^
>>> drivers/net/ethernet/intel/i40e/i40e_debugfs.c:1901:11: note: in expansion of macro 'clamp'
>       bytes = clamp(bytes, (u16)1024, (u16)I40E_MAX_AQ_BUF_SIZE);
>               ^

The obvious fix:

----------- >8 --------------------------------------------------------------
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 44649e0..149864b 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -719,8 +719,8 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
        (void) (&_max1 == &_max2);              \
        _max1 > _max2 ? _max1 : _max2; })
 
-#define min3(x, y, z) min(min(x, y), z)
-#define max3(x, y, z) max(max(x, y), z)
+#define min3(x, y, z) min((typeof(x))min(x, y), z)
+#define max3(x, y, z) max((typeof(x))max(x, y), z)
 
 /**
  * min_not_zero - return the minimum that is _not_ zero, unless both are zero
@@ -741,7 +741,7 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
  * This macro does strict typechecking of min/max to make sure they are of the
  * same type as val.  See the unnecessary pointer comparisons.
  */
-#define clamp(val, lo, hi) min(max(val, lo), hi)
+#define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
 
 /*
  * ..and if you can't take the strict
----------- >8 --------------------------------------------------------------

increases size of the kernel:

-rwx------ 1 mpn eng 437026785 Jun 20 15:45 vmlinux.before
-rwx------ 1 mpn eng 437026881 Jun 20 15:30 vmlinux.after

even though it's still slightly smaller than w/o the patch all together:

-rwx------ 1 mpn eng 437027411 Jun 20 16:04 vmlinux.before.before

-- 
Best regards,                                         _     _
.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
..o | Computer Science,  Michał “mina86” Nazarewicz    (o o)
ooo +--<mpn@google.com>--<xmpp:mina86@jabber.org>--ooO--(_)--Ooo--

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