MIPS: KASLR: Correct valid bits in apply_r_mips_26_rel()

Apply_r_mips_26_rel() relocates instructions like j, jal and etc. These
instructions consist of 6bits function field and 26bits address field.
The value of target_addr as follows,
=================================================================
|     high 4bits           |            low 28bits              |
=================================================================
|the high 4bits of this PC | the low 26bits of instructions << 2|
=================================================================
Thus, loc_orig and log_new both need high 4bits rather than high 6bits.

Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

diff --git a/arch/mips/kernel/relocate.c b/arch/mips/kernel/relocate.c
index 3d80a51..8561c7a 100644 (file)
--- a/arch/mips/kernel/relocate.c
+++ b/arch/mips/kernel/relocate.c
@@ -95,7 +95,7 @@ static int __init apply_r_mips_26_rel(u32 *loc_orig, u32 *loc_new, long offset)
 
        /* Original target address */
        target_addr <<= 2;
-       target_addr += (unsigned long)loc_orig & ~0x03ffffff;
+       target_addr += (unsigned long)loc_orig & 0xf0000000;
 
        /* Get the new target address */
        target_addr += offset;
@@ -105,7 +105,7 @@ static int __init apply_r_mips_26_rel(u32 *loc_orig, u32 *loc_new, long offset)
                return -ENOEXEC;
        }
 
-       target_addr -= (unsigned long)loc_new & ~0x03ffffff;
+       target_addr -= (unsigned long)loc_new & 0xf0000000;
        target_addr >>= 2;
 
        *loc_new = (*loc_new & ~0x03ffffff) | (target_addr & 0x03ffffff);