diff options
| author | Catalin Marinas <catalin.marinas@arm.com> | 2016-07-01 14:58:21 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-11-21 17:33:47 +0000 |
| commit | bd38967d406fb4f9fca67d612db71b5d74cfb0f5 (patch) | |
| tree | fbcc9bd2e2f70c40387fe166de6f4e874c0d0bdb /arch/arm64/lib/copy_from_user.S | |
| parent | a8ada146f5179793bbaff3c936d73147ccd47ba2 (diff) | |
| download | lwn-bd38967d406fb4f9fca67d612db71b5d74cfb0f5.tar.gz lwn-bd38967d406fb4f9fca67d612db71b5d74cfb0f5.zip | |
arm64: Factor out PAN enabling/disabling into separate uaccess_* macros
This patch moves the directly coded alternatives for turning PAN on/off
into separate uaccess_{enable,disable} macros or functions. The asm
macros take a few arguments which will be used in subsequent patches.
Note that any (unlikely) access that the compiler might generate between
uaccess_enable() and uaccess_disable(), other than those explicitly
specified by the user access code, will not be protected by PAN.
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/lib/copy_from_user.S')
| -rw-r--r-- | arch/arm64/lib/copy_from_user.S | 11 |
1 files changed, 3 insertions, 8 deletions
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S index 4fd67ea03bb0..cfe13396085b 100644 --- a/arch/arm64/lib/copy_from_user.S +++ b/arch/arm64/lib/copy_from_user.S @@ -16,11 +16,8 @@ #include <linux/linkage.h> -#include <asm/alternative.h> -#include <asm/assembler.h> #include <asm/cache.h> -#include <asm/cpufeature.h> -#include <asm/sysreg.h> +#include <asm/uaccess.h> /* * Copy from user space to a kernel buffer (alignment handled by the hardware) @@ -67,12 +64,10 @@ end .req x5 ENTRY(__arch_copy_from_user) -ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \ - CONFIG_ARM64_PAN) + uaccess_enable_not_uao x3, x4 add end, x0, x2 #include "copy_template.S" -ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \ - CONFIG_ARM64_PAN) + uaccess_disable_not_uao x3 mov x0, #0 // Nothing to copy ret ENDPROC(__arch_copy_from_user) |