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From:   Josh Poimboeuf <jpoimboe@redhat.com>
To:     Al Viro <viro@zeniv.linux.org.uk>
Cc:     x86@kernel.org, linux-kernel@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Will Deacon <will@kernel.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Waiman Long <longman@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Andrew Cooper <andrew.cooper3@citrix.com>,
        Andy Lutomirski <luto@kernel.org>,
        Christoph Hellwig <hch@lst.de>,
        David Laight <David.Laight@aculab.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Borislav Petkov <bp@alien8.de>
Subject: [PATCH v4 2/4] uaccess: Fix __user annotations for copy_mc_to_user()
Date:   Tue,  4 May 2021 22:54:30 -0500
Message-Id: <5edbdb1ae63b0e3771fdf1a46ce1cb517f091b1a.1620186182.git.jpoimboe@redhat.com>
In-Reply-To: <cover.1620186182.git.jpoimboe@redhat.com>
References: <cover.1620186182.git.jpoimboe@redhat.com>
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The 'dst' field is a user pointer, so annotate it as such.  This is
consistent with what powerpc is already doing for this interface.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 arch/x86/include/asm/uaccess.h | 2 +-
 arch/x86/lib/copy_mc.c         | 8 ++++----
 lib/iov_iter.c                 | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index c9fa7be3df82..fb75657b5e56 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -445,7 +445,7 @@ copy_mc_to_kernel(void *to, const void *from, unsigned len);
 #define copy_mc_to_kernel copy_mc_to_kernel
 
 unsigned long __must_check
-copy_mc_to_user(void *to, const void *from, unsigned len);
+copy_mc_to_user(void __user *to, const void *from, unsigned len);
 #endif
 
 /*
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
index 80efd45a7761..6e8b7e600def 100644
--- a/arch/x86/lib/copy_mc.c
+++ b/arch/x86/lib/copy_mc.c
@@ -70,23 +70,23 @@ unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigne
 }
 EXPORT_SYMBOL_GPL(copy_mc_to_kernel);
 
-unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned len)
+unsigned long __must_check copy_mc_to_user(void __user *dst, const void *src, unsigned len)
 {
 	unsigned long ret;
 
 	if (copy_mc_fragile_enabled) {
 		__uaccess_begin();
-		ret = copy_mc_fragile(dst, src, len);
+		ret = copy_mc_fragile((__force void *)dst, src, len);
 		__uaccess_end();
 		return ret;
 	}
 
 	if (static_cpu_has(X86_FEATURE_ERMS)) {
 		__uaccess_begin();
-		ret = copy_mc_enhanced_fast_string(dst, src, len);
+		ret = copy_mc_enhanced_fast_string((__force void *)dst, src, len);
 		__uaccess_end();
 		return ret;
 	}
 
-	return copy_user_generic(dst, src, len);
+	return copy_user_generic((__force void *)dst, src, len);
 }
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 61228a6c69f8..26f87115133f 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -679,7 +679,7 @@ static int copyout_mc(void __user *to, const void *from, size_t n)
 {
 	if (access_ok(to, n)) {
 		instrument_copy_to_user(to, from, n);
-		n = copy_mc_to_user((__force void *) to, from, n);
+		n = copy_mc_to_user(to, from, n);
 	}
 	return n;
 }
-- 
2.31.1