[ARM PATCH] 1912/1: Wrong cache aliasing bit check

Catalin Marinas · Russell King · commit 1261c634fa14 · 2004-06-04T19:54:37.000+01:00
Patch from Catalin Marinas

arch/arm/mm/mmap.c: arch_get_unamapped_area() checks bit 9 in the cache type register for possible cache aliasing problems. Bit 11 should be checked instead.
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
@@ -40,7 +40,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 	 */
 	cache_type = read_cpuid(CPUID_CACHETYPE);
 	if (cache_type != read_cpuid(CPUID_ID)) {
-		aliasing = (cache_type | cache_type >> 12) & (1 << 9);
+		aliasing = (cache_type | cache_type >> 12) & (1 << 11);
 		if (aliasing)
 			do_align = filp || flags & MAP_SHARED;
 	}

Original file line number	Diff line number	Diff line change
`@@ -40,7 +40,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,`
`40`	`40`	`*/`
`41`	`41`	`cache_type = read_cpuid(CPUID_CACHETYPE);`
`42`	`42`	`if (cache_type != read_cpuid(CPUID_ID)) {`
`43`		`- aliasing = (cache_type \| cache_type >> 12) & (1 << 9);`
	`43`	`+ aliasing = (cache_type \| cache_type >> 12) & (1 << 11);`
`44`	`44`	`if (aliasing)`
`45`	`45`	`do_align = filp \|\| flags & MAP_SHARED;`
`46`	`46`	`}`