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From: Christoph Hellwig <hch@lst.de>
To: x86@kernel.org, Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: linux-parisc@vger.kernel.org, linux-um@lists.infradead.org,
	netdev@vger.kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 09/20] maccess: remove probe_read_common and probe_write_common
Date: Tue, 19 May 2020 15:44:38 +0200	[thread overview]
Message-ID: <20200519134449.1466624-10-hch@lst.de> (raw)
In-Reply-To: <20200519134449.1466624-1-hch@lst.de>

Each of the helpers has just two callers, which also different in
dealing with kernel or userspace pointers.  Just open code the logic
in the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 mm/maccess.c | 63 ++++++++++++++++++++++++----------------------------
 1 file changed, 29 insertions(+), 34 deletions(-)

diff --git a/mm/maccess.c b/mm/maccess.c
index e783ebfccd542..31cf6604e7fff 100644
--- a/mm/maccess.c
+++ b/mm/maccess.c
@@ -6,30 +6,6 @@
 #include <linux/mm.h>
 #include <linux/uaccess.h>
 
-static __always_inline long
-probe_read_common(void *dst, const void __user *src, size_t size)
-{
-	long ret;
-
-	pagefault_disable();
-	ret = __copy_from_user_inatomic(dst, src, size);
-	pagefault_enable();
-
-	return ret ? -EFAULT : 0;
-}
-
-static __always_inline long
-probe_write_common(void __user *dst, const void *src, size_t size)
-{
-	long ret;
-
-	pagefault_disable();
-	ret = __copy_to_user_inatomic(dst, src, size);
-	pagefault_enable();
-
-	return ret ? -EFAULT : 0;
-}
-
 /**
  * probe_kernel_read(): safely attempt to read from any location
  * @dst: pointer to the buffer that shall take the data
@@ -69,10 +45,15 @@ long __probe_kernel_read(void *dst, const void *src, size_t size)
 	mm_segment_t old_fs = get_fs();
 
 	set_fs(KERNEL_DS);
-	ret = probe_read_common(dst, (__force const void __user *)src, size);
+	pagefault_disable();
+	ret = __copy_from_user_inatomic(dst, (__force const void __user *)src,
+			size);
+	pagefault_enable();
 	set_fs(old_fs);
 
-	return ret;
+	if (ret)
+		return -EFAULT;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(probe_kernel_read);
 
@@ -91,11 +72,16 @@ long probe_user_read(void *dst, const void __user *src, size_t size)
 	mm_segment_t old_fs = get_fs();
 
 	set_fs(USER_DS);
-	if (access_ok(src, size))
-		ret = probe_read_common(dst, src, size);
+	if (access_ok(src, size)) {
+		pagefault_disable();
+		ret = __copy_from_user_inatomic(dst, src, size);
+		pagefault_enable();
+	}
 	set_fs(old_fs);
 
-	return ret;
+	if (ret)
+		return -EFAULT;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(probe_user_read);
 
@@ -114,10 +100,14 @@ long probe_kernel_write(void *dst, const void *src, size_t size)
 	mm_segment_t old_fs = get_fs();
 
 	set_fs(KERNEL_DS);
-	ret = probe_write_common((__force void __user *)dst, src, size);
+	pagefault_disable();
+	ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
+	pagefault_enable();
 	set_fs(old_fs);
 
-	return ret;
+	if (ret)
+		return -EFAULT;
+	return 0;
 }
 
 /**
@@ -135,11 +125,16 @@ long probe_user_write(void __user *dst, const void *src, size_t size)
 	mm_segment_t old_fs = get_fs();
 
 	set_fs(USER_DS);
-	if (access_ok(dst, size))
-		ret = probe_write_common(dst, src, size);
+	if (access_ok(dst, size)) {
+		pagefault_disable();
+		ret = __copy_to_user_inatomic(dst, src, size);
+		pagefault_enable();
+	}
 	set_fs(old_fs);
 
-	return ret;
+	if (ret)
+		return -EFAULT;
+	return 0;
 }
 
 /**
-- 
2.26.2


  parent reply	other threads:[~2020-05-19 13:45 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-19 13:44 clean up and streamline probe_kernel_* and friends v3 Christoph Hellwig
2020-05-19 13:44 ` [PATCH 01/20] maccess: unexport probe_kernel_write and probe_user_write Christoph Hellwig
2020-05-19 13:44 ` [PATCH 02/20] maccess: remove various unused weak aliases Christoph Hellwig
2020-05-19 13:44 ` [PATCH 03/20] maccess: remove duplicate kerneldoc comments Christoph Hellwig
2020-05-19 13:44 ` [PATCH 04/20] maccess: clarify " Christoph Hellwig
2020-05-19 13:44 ` [PATCH 05/20] maccess: update the top of file comment Christoph Hellwig
2020-05-19 13:44 ` [PATCH 06/20] maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault Christoph Hellwig
2020-05-19 13:44 ` [PATCH 07/20] maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault Christoph Hellwig
2020-05-19 13:44 ` [PATCH 08/20] maccess: rename strnlen_unsafe_user to strnlen_user_nofault Christoph Hellwig
2020-05-19 13:44 ` Christoph Hellwig [this message]
2020-05-19 13:44 ` [PATCH 10/20] maccess: unify the probe kernel arch hooks Christoph Hellwig
2020-05-19 13:44 ` [PATCH 11/20] bpf: factor out a bpf_trace_copy_string helper Christoph Hellwig
2020-05-19 16:07   ` Linus Torvalds
2020-05-19 16:14     ` Christoph Hellwig
2020-05-19 16:36       ` Linus Torvalds
2020-05-19 13:44 ` [PATCH 12/20] maccess: remove strncpy_from_unsafe Christoph Hellwig
2020-05-19 16:25   ` Linus Torvalds
2020-05-19 16:41     ` Christoph Hellwig
2020-05-19 16:46       ` Linus Torvalds
2020-05-19 13:44 ` [PATCH 13/20] maccess: always use strict semantics for probe_kernel_read Christoph Hellwig
2020-05-19 16:33   ` Linus Torvalds
2020-05-20 11:11   ` Masami Hiramatsu
2020-05-20 11:13     ` Christoph Hellwig
2020-05-19 13:44 ` [PATCH 14/20] maccess: move user access routines together Christoph Hellwig
2020-05-19 13:44 ` [PATCH 15/20] maccess: allow architectures to provide kernel probing directly Christoph Hellwig
2020-05-19 13:44 ` [PATCH 16/20] x86: use non-set_fs based maccess routines Christoph Hellwig
2020-05-19 13:44 ` [PATCH 17/20] maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault Christoph Hellwig
2020-05-19 13:44 ` [PATCH 18/20] maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault Christoph Hellwig
2020-05-19 13:44 ` [PATCH 19/20] maccess: rename probe_kernel_address to get_kernel_nofault Christoph Hellwig
2020-05-19 13:44 ` [PATCH 20/20] maccess: return -ERANGE when copy_from_kernel_nofault_allowed fails Christoph Hellwig
2020-05-20 11:02   ` Masami Hiramatsu
2020-05-20 16:16     ` Christoph Hellwig
2020-05-19 16:34 ` clean up and streamline probe_kernel_* and friends v3 Linus Torvalds

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