arm64: kernel: Add support for Privileged Access Never

[mirror_ubuntu-zesty-kernel.git] / arch / arm64 / include / asm / futex.h

diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h
index 74069b3bd919c7ff3c5722f9f2c1dce212abd3fd..775e85b9d1f25ed64bf877c5e43defb3c839714b 100644 (file)
--- a/arch/arm64/include/asm/futex.h
+++ b/arch/arm64/include/asm/futex.h
@@ -20,10 +20,16 @@
 
 #include <linux/futex.h>
 #include <linux/uaccess.h>
+
+#include <asm/alternative.h>
+#include <asm/cpufeature.h>
 #include <asm/errno.h>
+#include <asm/sysreg.h>
 
 #define __futex_atomic_op(insn, ret, oldval, uaddr, tmp, oparg)                \
        asm volatile(                                                   \
+       ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN,            \
+                   CONFIG_ARM64_PAN)                                   \
 "1:    ldxr    %w1, %2\n"                                              \
        insn "\n"                                                       \
 "2:    stlxr   %w3, %w0, %2\n"                                         \
@@ -39,6 +45,8 @@
 "      .align  3\n"                                                    \
 "      .quad   1b, 4b, 2b, 4b\n"                                       \
 "      .popsection\n"                                                  \
+       ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN,            \
+                   CONFIG_ARM64_PAN)                                   \
        : "=&r" (ret), "=&r" (oldval), "+Q" (*uaddr), "=&r" (tmp)       \
        : "r" (oparg), "Ir" (-EFAULT)                                   \
        : "memory")