Commit 44e9a3bb authored by Linus Walleij's avatar Linus Walleij Committed by Russell King (Oracle)
Browse files

ARM: 9430/1: entry: Do a dummy read from VMAP shadow 

When switching task, in addition to a dummy read from the new
VMAP stack, also do a dummy read from the VMAP stack's
corresponding KASAN shadow memory to sync things up in
the new MM context.

Cc: stable@vger.kernel.org
Fixes: a1c510d0 ("ARM: implement support for vmap'ed stacks")
Link: https://lore.kernel.org/linux-arm-kernel/a1a1d062-f3a2-4d05-9836-3b098de9db6d@foss.st.com/


Reported-by: default avatarClement LE GOFFIC <clement.legoffic@foss.st.com>
Suggested-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
parent d6e6a74d

arch/arm/kernel/entry-armv.S

+8 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <asm/tls.h>

#include <asm/system_info.h>

#include <asm/uaccess-asm.h>

#include <asm/kasan_def.h>



#include "entry-header.S"

#include <asm/probes.h>
@@ -561,6 +562,13 @@ ENTRY(__switch_to) 
	@ entries covering the vmalloc region.

	@

	ldr	r2, [ip]

#ifdef CONFIG_KASAN_VMALLOC

	@ Also dummy read from the KASAN shadow memory for the new stack if we

	@ are using KASAN

	mov_l	r2, KASAN_SHADOW_OFFSET

	add	r2, r2, ip, lsr #KASAN_SHADOW_SCALE_SHIFT

	ldr	r2, [r2]

#endif

#endif



	@ When CONFIG_THREAD_INFO_IN_TASK=n, the update of SP itself is what