ARM: 8795/1: spectre-v1.1: use put_user() for __put_user()

Commit e3aa6243434fd9a82e84bb79ab1abd14f2d9a5a7 upstream.

When Spectre mitigation is required, __put_user() needs to include
check_uaccess. This is already the case for put_user(), so just make
__put_user() an alias of put_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>

diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 0404dd1..98bbf89 100644 (file)
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -408,6 +408,14 @@ do {                                                                       \
        __pu_err;                                                       \
 })
 
+#ifdef CONFIG_CPU_SPECTRE
+/*
+ * When mitigating Spectre variant 1.1, all accessors need to include
+ * verification of the address space.
+ */
+#define __put_user(x, ptr) put_user(x, ptr)
+
+#else
 #define __put_user(x, ptr)                                             \
 ({                                                                     \
        long __pu_err = 0;                                              \
@@ -415,12 +423,6 @@ do {                                                                       \
        __pu_err;                                                       \
 })
 
-#define __put_user_error(x, ptr, err)                                  \
-({                                                                     \
-       __put_user_switch((x), (ptr), (err), __put_user_nocheck);       \
-       (void) 0;                                                       \
-})
-
 #define __put_user_nocheck(x, __pu_ptr, __err, __size)                 \
        do {                                                            \
                unsigned long __pu_addr = (unsigned long)__pu_ptr;      \
@@ -500,6 +502,7 @@ do {                                                                        \
        : "r" (x), "i" (-EFAULT)                                \
        : "cc")
 
+#endif /* !CONFIG_CPU_SPECTRE */
 
 #ifdef CONFIG_MMU
 extern unsigned long __must_check