arm64: fix endianness annotation for __apply_alternatives()/get_alt_insn()

get_alt_insn() is used to read and create ARM instructions, which
are always stored in memory in little-endian order. These values
are thus correctly converted to/from native order when processed
but the pointers used to hold the address of these instructions
are declared as for native order values.

Fix this by declaring the pointers as __le32* instead of u32* and
make the few appropriate needed changes like removing the unneeded
cast '(u32*)' in front of __ALT_PTR()'s definition.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c
index 8840c10..6dd0a3a 100644 (file)
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@ -28,7 +28,7 @@
 #include <asm/sections.h>
 #include <linux/stop_machine.h>
 
-#define __ALT_PTR(a,f)         (u32 *)((void *)&(a)->f + (a)->f)
+#define __ALT_PTR(a,f)         ((void *)&(a)->f + (a)->f)
 #define ALT_ORIG_PTR(a)                __ALT_PTR(a, orig_offset)
 #define ALT_REPL_PTR(a)                __ALT_PTR(a, alt_offset)
 
@@ -60,7 +60,7 @@ static bool branch_insn_requires_update(struct alt_instr *alt, unsigned long pc)
 
 #define align_down(x, a)       ((unsigned long)(x) & ~(((unsigned long)(a)) - 1))
 
-static u32 get_alt_insn(struct alt_instr *alt, u32 *insnptr, u32 *altinsnptr)
+static u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnptr)
 {
        u32 insn;
 
@@ -109,7 +109,7 @@ static void __apply_alternatives(void *alt_region, bool use_linear_alias)
 {
        struct alt_instr *alt;
        struct alt_region *region = alt_region;
-       u32 *origptr, *replptr, *updptr;
+       __le32 *origptr, *replptr, *updptr;
 
        for (alt = region->begin; alt < region->end; alt++) {
                u32 insn;
@@ -124,7 +124,7 @@ static void __apply_alternatives(void *alt_region, bool use_linear_alias)
 
                origptr = ALT_ORIG_PTR(alt);
                replptr = ALT_REPL_PTR(alt);
-               updptr = use_linear_alias ? (u32 *)lm_alias(origptr) : origptr;
+               updptr = use_linear_alias ? lm_alias(origptr) : origptr;
                nr_inst = alt->alt_len / sizeof(insn);
 
                for (i = 0; i < nr_inst; i++) {