From 42ac26d253ebe7a5f409443f2fbd239d66b65f57 Mon Sep 17 00:00:00 2001
From: Santosh Sivaraj <santosh@fossix.org>
Date: Tue, 20 Aug 2019 13:43:52 +0530
Subject: [PATCH] powerpc: add machine check safe copy_to_user
References: jsc#SLE-7730 jsc#SLE-8330
Patch-mainline: v5.4-rc1
Git-commit: 42ac26d253ebe7a5f409443f2fbd239d66b65f57
Use memcpy_mcsafe() implementation to define copy_to_user_mcsafe()
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820081352.8641-8-santosh@fossix.org
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/uaccess.h | 14 ++++++++++++++
2 files changed, 15 insertions(+)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -136,6 +136,7 @@ config PPC
select ARCH_HAS_STRICT_KERNEL_RWX if ((PPC_BOOK3S_64 || PPC32) && !RELOCATABLE && !HIBERNATION)
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE if PPC64
+ select ARCH_HAS_UACCESS_MCSAFE if PPC64
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_KEEP_MEMBLOCK
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 8b03eb44e876..15002b51ff18 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -387,6 +387,20 @@ static inline unsigned long raw_copy_to_user(void __user *to,
return ret;
}
+static __always_inline unsigned long __must_check
+copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n)
+{
+ if (likely(check_copy_size(from, n, true))) {
+ if (access_ok(to, n)) {
+ allow_write_to_user(to, n);
+ n = memcpy_mcsafe((void *)to, from, n);
+ prevent_write_to_user(to, n);
+ }
+ }
+
+ return n;
+}
+
extern unsigned long __clear_user(void __user *addr, unsigned long size);
static inline unsigned long clear_user(void __user *addr, unsigned long size)
--
2.23.0