On Wed, 2007-04-11 at 11:24 -0700, Andrew Morton wrote:
> I suspect we would benefit from a proper suite of tools for comparing a
> single number against a range, and for comparing ranges.
How about this ambition-reduction patch, instead?
===
range_within() was too ambitious: it started inspiring people. Remove it.
val_outside() was a terrible name, too. Try range_over_limit().
Signed-off-by: Rusty Russell <[EMAIL PROTECTED]>
diff -r 2f617843ce25 include/asm-generic/range.h
--- a/include/asm-generic/range.h Thu Apr 12 09:32:53 2007 +1000
+++ b/include/asm-generic/range.h Thu Apr 12 09:36:20 2007 +1000
@@ -2,18 +2,18 @@
#define _ASM_GENERIC_RANGE_H
/**
- * val_outside - is a value and length past a limit?
- * @val: the start value
+ * range_over_limit() - is a start and length past a limit?
+ * @start: the start value
* @len: the length from the start
* @limit: the first invalid value
*
- * Like val + len > limit, except with overflow checking.
+ * Like start + len > limit, except with overflow checking.
*/
-static inline bool val_outside(unsigned long val, unsigned long len,
- unsigned long limit)
+static inline bool range_over_limit(unsigned long start, unsigned long len,
+ unsigned long limit)
{
- return val + len > limit || val + len < val;
+ return start + len > limit || start + len < start;
}
#endif /* _ASM_GENERIC_RANGE_H */
diff -r 2f617843ce25 include/asm-i386/range.h
--- a/include/asm-i386/range.h Thu Apr 12 09:32:53 2007 +1000
+++ b/include/asm-i386/range.h Thu Apr 12 09:36:37 2007 +1000
@@ -1,14 +1,14 @@
#ifndef __ASM_RANGE_H
#define __ASM_RANGE_H
-/* Is val + size > limit? This needs 33-bit arithmetic. We have a carry... */
-static inline bool val_outside(unsigned long val, unsigned long len,
- unsigned long limit)
+/* Is start + size > limit? This needs 33-bit arithmetic. We have a carry... */
+static inline bool range_over_limit(unsigned long start, unsigned long len,
+ unsigned long limit)
{
unsigned long flag, roksum;
asm("addl %3,%1 ; sbbl %0,%0; cmpl %1,%4; sbbl $0,%0"
:"=&r" (flag), "=r" (roksum)
- :"1" (val), "g" (len), "rm" (limit));
+ :"1" (start), "g" (len), "rm" (limit));
return flag;
}
#endif /* __ASM_RANGE_H */
diff -r 2f617843ce25 include/asm-i386/uaccess.h
--- a/include/asm-i386/uaccess.h Thu Apr 12 09:32:53 2007 +1000
+++ b/include/asm-i386/uaccess.h Thu Apr 12 09:37:07 2007 +1000
@@ -51,10 +51,10 @@ extern struct movsl_mask {
* This is equivalent to the following test:
* (u33)addr + (u33)size > (u33)current->addr_limit.seg
*/
-#define __range_ok(addr, size) ({ \
- __chk_user_ptr(addr); \
- val_outside((int)(addr), (size), \
- current_thread_info()->addr_limit.seg); \
+#define __range_ok(addr, size) ({ \
+ __chk_user_ptr(addr); \
+ range_over_limit((int)(addr), (size), \
+ current_thread_info()->addr_limit.seg); \
})
/**
diff -r 2f617843ce25 include/linux/kernel.h
--- a/include/linux/kernel.h Thu Apr 12 09:32:53 2007 +1000
+++ b/include/linux/kernel.h Thu Apr 12 09:35:13 2007 +1000
@@ -16,7 +16,6 @@
#include <linux/log2.h>
#include <asm/byteorder.h>
#include <asm/bug.h>
-#include <asm/range.h>
extern const char linux_banner[];
extern const char linux_proc_banner[];
@@ -312,26 +311,6 @@ static inline int __attribute__ ((format
(void)__tmp; \
})
-/**
- * range_within - is one range within another?
- * @start: the start value
- * @len: the length from the start
- * @base: the first valid value
- * @limit: the first invalid value
- *
- * This is usually used for memory range testing. The common cases of
- * constant 0 start and constant 0 len cases are optimized out.
- */
-static inline bool range_within(unsigned long start, unsigned long len,
- unsigned long base, unsigned long limit)
-{
- if (start < base)
- return false;
- if (__builtin_constant_p(len) && len == 0)
- return start - base <= limit - base;
- return !val_outside(limit, start, len);
-}
-
struct sysinfo;
extern int do_sysinfo(struct sysinfo *info);
-
To unsubscribe from this list: send the line "unsubscribe linux-arch" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
