diff options
Diffstat (limited to 'arch/arm64/lib/copy_to_user.S')
| -rw-r--r-- | arch/arm64/lib/copy_to_user.S | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S index a0aeeb9b7a28..a257b47e2dc4 100644 --- a/arch/arm64/lib/copy_to_user.S +++ b/arch/arm64/lib/copy_to_user.S @@ -15,7 +15,11 @@ */ #include <linux/linkage.h> + +#include <asm/alternative.h> #include <asm/assembler.h> +#include <asm/cpufeature.h> +#include <asm/sysreg.h> /* * Copy to user space from a kernel buffer (alignment handled by the hardware) @@ -28,14 +32,21 @@ * x0 - bytes not copied */ ENTRY(__copy_to_user) - add x4, x0, x2 // upper user buffer boundary - subs x2, x2, #8 +ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_HAS_PAN, \ + CONFIG_ARM64_PAN) + add x5, x0, x2 // upper user buffer boundary + subs x2, x2, #16 + b.mi 1f +0: + ldp x3, x4, [x1], #16 + subs x2, x2, #16 +USER(9f, stp x3, x4, [x0], #16) + b.pl 0b +1: adds x2, x2, #8 b.mi 2f -1: ldr x3, [x1], #8 - subs x2, x2, #8 + sub x2, x2, #8 USER(9f, str x3, [x0], #8 ) - b.pl 1b 2: adds x2, x2, #4 b.mi 3f ldr w3, [x1], #4 @@ -51,11 +62,13 @@ USER(9f, strh w3, [x0], #2 ) ldrb w3, [x1] USER(9f, strb w3, [x0] ) 5: mov x0, #0 +ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_HAS_PAN, \ + CONFIG_ARM64_PAN) ret ENDPROC(__copy_to_user) .section .fixup,"ax" .align 2 -9: sub x0, x4, x0 // bytes not copied +9: sub x0, x5, x0 // bytes not copied ret .previous |