Commit 0d4b3ca1 authored by Ricky Ringler's avatar Ricky Ringler Committed by Max Filippov
Browse files

xtensa: align: validate access in fast_load_store 



access_ok() is used only in user mode and
branches to .Linvalid_instruction on fault.
Kernel mode skips access_ok().

Tested-by: default avatarRicky Ringler <richard.rringler@gmail.com>

Signed-off-by: default avatarRicky Ringler <richard.rringler@gmail.com>
Message-ID: <20251215143323.2771889-1-richard.rringler@gmail.com>
Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 7d0a66e4

arch/xtensa/kernel/align.S

+8 −2
Original line number Diff line number Diff line
@@ -21,6 +21,9 @@ 
#include <asm/asm-offsets.h>

#include <asm/asmmacro.h>

#include <asm/processor.h>

#ifdef CONFIG_MMU

#include <asm/asm-uaccess.h>

#endif



#if XCHAL_UNALIGNED_LOAD_EXCEPTION || defined CONFIG_XTENSA_LOAD_STORE

#define LOAD_EXCEPTION_HANDLER
@@ -185,8 +188,11 @@ ENTRY(fast_load_store) 


#ifdef CONFIG_MMU

	/* l32e can't be used here even when it's available. */

	/* TODO access_ok(a3) could be used here */

	j	.Linvalid_instruction

	rsr	a6, ps

	bbci.l	a6, PS_UM_BIT, 1f # kernel mode

	movi	a5, 8

	access_ok a3, a5, a6, a2, .Linvalid_instruction

1:

#endif

	l32i	a5, a3, 0

	l32i	a6, a3, 4