use clamp_t in UNAME26 fix

kees · torvalds · commit 31fd84b95eb2 · 2012-10-19T18:51:17.000-07:00
The min/max call needed to have explicit types on some architectures
(e.g. mn10300). Use clamp_t instead to avoid the warning:

  kernel/sys.c: In function 'override_release':
  kernel/sys.c:1287:10: warning: comparison of distinct pointer types lacks a cast [enabled by default]

Reported-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
diff --git a/kernel/sys.c b/kernel/sys.c
@@ -1284,7 +1284,7 @@ static int override_release(char __user *release, size_t len)
 			rest++;
 		}
 		v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;
-		copy = min(sizeof(buf), max_t(size_t, 1, len));
+		copy = clamp_t(size_t, len, 1, sizeof(buf));
 		copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
 		ret = copy_to_user(release, buf, copy + 1);
 	}

Original file line number	Diff line number	Diff line change
`@@ -1284,7 +1284,7 @@ static int override_release(char __user *release, size_t len)`
`1284`	`1284`	`rest++;`
`1285`	`1285`	`}`
`1286`	`1286`	`v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;`
`1287`		`- copy = min(sizeof(buf), max_t(size_t, 1, len));`
	`1287`	`+ copy = clamp_t(size_t, len, 1, sizeof(buf));`
`1288`	`1288`	`copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);`
`1289`	`1289`	`ret = copy_to_user(release, buf, copy + 1);`
`1290`	`1290`	`}`