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Commit 15ad6ace authored by Luc Van Oostenryck's avatar Luc Van Oostenryck Committed by Will Deacon
Browse files

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: default avatarLuc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 67831edf

arch/arm64/kernel/alternative.c

+4 −4
Original line number Diff line number Diff line
@@ -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++) {