Re: IS_ERR Threshold Value

[Ralf Baechle <ralf@linux-mips.org>]

On Wed, Jun 28, 2006 at 02:08:25PM -0700, Randy.Dunlap wrote:

> Hi,
> Peter Anvin mentioned just a few days ago that this threshold value
> should be 4095 for all arches.  I think we need to get that patch
> done & submitted to Andrew for -mm.

So here the patch is:

 o Raise the maximum error number in IS_ERR_VALUE to 4095.
 o Make that number available as a new constant MAX_ERRNO.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/include/linux/err.h b/include/linux/err.h
index ff71d2a..cd3b367 100644
--- a/include/linux/err.h
+++ b/include/linux/err.h
@@ -13,7 +13,9 @@ #include <asm/errno.h>
  * This should be a per-architecture thing, to allow different
  * error and pointer decisions.
  */
-#define IS_ERR_VALUE(x) unlikely((x) > (unsigned long)-1000L)
+#define MAX_ERRNO	4095
+
+#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
 
 static inline void *ERR_PTR(long error)
 {