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authorJulien Thierry <julien.thierry@arm.com>2019-11-08 13:35:46 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-11-10 11:21:35 +0100
commit56e635e9c9ba77f91523949037b2a13c3e99f67c (patch)
tree86d14ae6225a6ca826d36c560cc1ead40ce4d7b5 /arch/arm/include/asm/assembler.h
parent6bb42e6d14004f6535b404b377db9b0e14c770dd (diff)
ARM: 8796/1: spectre-v1,v1.1: provide helpers for address sanitization
Commit afaf6838f4bc896a711180b702b388b8cfa638fc upstream. Introduce C and asm helpers to sanitize user address, taking the address range they target into account. Use asm helper for existing sanitization in __copy_from_user(). Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/include/asm/assembler.h')
-rw-r--r--arch/arm/include/asm/assembler.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 483481c6937e..f2624fbd0336 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -461,6 +461,17 @@ THUMB( orr \reg , \reg , #PSR_T_BIT )
#endif
.endm
+ .macro uaccess_mask_range_ptr, addr:req, size:req, limit:req, tmp:req
+#ifdef CONFIG_CPU_SPECTRE
+ sub \tmp, \limit, #1
+ subs \tmp, \tmp, \addr @ tmp = limit - 1 - addr
+ addhs \tmp, \tmp, #1 @ if (tmp >= 0) {
+ subhss \tmp, \tmp, \size @ tmp = limit - (addr + size) }
+ movlo \addr, #0 @ if (tmp < 0) addr = NULL
+ csdb
+#endif
+ .endm
+
.macro uaccess_disable, tmp, isb=1
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
/*