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From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v1 2/8] powerpc/uaccess: Swap clear_user() and __clear_user()
Date: Wed, 10 Mar 2021 17:57:01 +0000 (UTC)	[thread overview]
Message-ID: <d8ec01fb22f33d87321451d5e5f01cb56dacaa39.1615398498.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1615398498.git.christophe.leroy@csgroup.eu>

It is clear_user() which is expected to call __clear_user(),
not the reverse.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/uaccess.h | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 2c09cff205ef..1c1d404514b1 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -414,21 +414,20 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 
 unsigned long __arch_clear_user(void __user *addr, unsigned long size);
 
-static inline unsigned long clear_user(void __user *addr, unsigned long size)
+static inline unsigned long __clear_user(void __user *addr, unsigned long size)
 {
-	unsigned long ret = size;
+	unsigned long ret;
+
 	might_fault();
-	if (likely(access_ok(addr, size))) {
-		allow_write_to_user(addr, size);
-		ret = __arch_clear_user(addr, size);
-		prevent_write_to_user(addr, size);
-	}
+	allow_write_to_user(addr, size);
+	ret = __arch_clear_user(addr, size);
+	prevent_write_to_user(addr, size);
 	return ret;
 }
 
-static inline unsigned long __clear_user(void __user *addr, unsigned long size)
+static inline unsigned long clear_user(void __user *addr, unsigned long size)
 {
-	return clear_user(addr, size);
+	return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size;
 }
 
 extern long strncpy_from_user(char *dst, const char __user *src, long count);
-- 
2.25.0


WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH v1 2/8] powerpc/uaccess: Swap clear_user() and __clear_user()
Date: Wed, 10 Mar 2021 17:57:01 +0000 (UTC)	[thread overview]
Message-ID: <d8ec01fb22f33d87321451d5e5f01cb56dacaa39.1615398498.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1615398498.git.christophe.leroy@csgroup.eu>

It is clear_user() which is expected to call __clear_user(),
not the reverse.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/uaccess.h | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 2c09cff205ef..1c1d404514b1 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -414,21 +414,20 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 
 unsigned long __arch_clear_user(void __user *addr, unsigned long size);
 
-static inline unsigned long clear_user(void __user *addr, unsigned long size)
+static inline unsigned long __clear_user(void __user *addr, unsigned long size)
 {
-	unsigned long ret = size;
+	unsigned long ret;
+
 	might_fault();
-	if (likely(access_ok(addr, size))) {
-		allow_write_to_user(addr, size);
-		ret = __arch_clear_user(addr, size);
-		prevent_write_to_user(addr, size);
-	}
+	allow_write_to_user(addr, size);
+	ret = __arch_clear_user(addr, size);
+	prevent_write_to_user(addr, size);
 	return ret;
 }
 
-static inline unsigned long __clear_user(void __user *addr, unsigned long size)
+static inline unsigned long clear_user(void __user *addr, unsigned long size)
 {
-	return clear_user(addr, size);
+	return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size;
 }
 
 extern long strncpy_from_user(char *dst, const char __user *src, long count);
-- 
2.25.0


  parent reply	other threads:[~2021-03-10 17:57 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-10 17:56 [PATCH v1 0/8] Miscellaneous user access improvement Christophe Leroy
2021-03-10 17:56 ` Christophe Leroy
2021-03-10 17:57 ` [PATCH v1 1/8] powerpc/uaccess: Also perform 64 bits copies in unsafe_copy_to_user() on ppc32 Christophe Leroy
2021-03-10 17:57   ` Christophe Leroy
2021-03-10 17:57 ` Christophe Leroy [this message]
2021-03-10 17:57   ` [PATCH v1 2/8] powerpc/uaccess: Swap clear_user() and __clear_user() Christophe Leroy
2021-03-10 17:57 ` [PATCH v1 3/8] powerpc/uaccess: Move copy_mc_xxx() functions down Christophe Leroy
2021-03-10 17:57   ` Christophe Leroy
2021-03-10 17:57 ` [PATCH v1 4/8] powerpc/syscalls: Use sys_old_select() in ppc_select() Christophe Leroy
2021-03-10 17:57   ` Christophe Leroy
2021-03-10 17:57 ` [PATCH v1 5/8] powerpc/lib: Don't use __put_user_asm_goto() outside of uaccess.h Christophe Leroy
2021-03-10 17:57   ` Christophe Leroy
2021-03-10 17:57 ` [PATCH v1 6/8] powerpc/net: Switch csum_and_copy_{to/from}_user to user_access block Christophe Leroy
2021-03-10 17:57   ` Christophe Leroy
2021-03-10 17:57 ` [PATCH v1 7/8] powerpc/futex: Switch " Christophe Leroy
2021-03-10 17:57   ` Christophe Leroy
2021-03-10 17:57 ` [PATCH v1 8/8] powerpc/ptrace: Convert gpr32_set_common() to user access block Christophe Leroy
2021-03-10 17:57   ` Christophe Leroy
2021-03-31  1:09 ` [PATCH v1 0/8] Miscellaneous user access improvement Michael Ellerman
2021-03-31  1:09   ` Michael Ellerman

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