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From: Masami Hiramatsu <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Cc: mhiramat@kernel.org, linux-kernel@vger.kernel.org,
	Andy Lutomirski <luto@amacapital.net>,
	Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Changbin Du <changbin.du@gmail.com>, Jann Horn <jannh@google.com>,
	Kees Cook <keescook@chromium.org>,
	Andy Lutomirski <luto@kernel.org>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>,
	Nadav Amit <namit@vmware.com>,
	Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH v3 2/5] uaccess: Use user_access_ok() in user_access_begin()
Date: Wed, 27 Feb 2019 23:43:14 +0900	[thread overview]
Message-ID: <155127859433.32576.17845647712461950214.stgit@devbox> (raw)
In-Reply-To: <155127853496.32576.3705994926675037747.stgit@devbox>

Use user_access_ok() instead of access_ok() in user_access_begin()
to validate the access context is user. This also allow us to
use (generic) strncpy_from_user() and strnlen_user() in atomic
state with setting USER_DS and disable pagefaults.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 arch/x86/include/asm/uaccess.h |    2 +-
 include/linux/uaccess.h        |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 3125d129d3b6..3b7502a34114 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -715,7 +715,7 @@ extern struct movsl_mask {
  */
 static __must_check inline bool user_access_begin(const void __user *ptr, size_t len)
 {
-	if (unlikely(!access_ok(ptr,len)))
+	if (unlikely(!user_access_ok(ptr, len)))
 		return 0;
 	__uaccess_begin_nospec();
 	return 1;
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index bf762689658b..1afd9dfabe67 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -282,7 +282,7 @@ extern long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count);
 	probe_kernel_read(&retval, addr, sizeof(retval))
 
 #ifndef user_access_begin
-#define user_access_begin(ptr,len) access_ok(ptr, len)
+#define user_access_begin(ptr, len) user_access_ok(ptr, len)
 #define user_access_end() do { } while (0)
 #define unsafe_get_user(x, ptr, err) do { if (unlikely(__get_user(x, ptr))) goto err; } while (0)
 #define unsafe_put_user(x, ptr, err) do { if (unlikely(__put_user(x, ptr))) goto err; } while (0)


  parent reply	other threads:[~2019-02-27 14:43 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-27 14:42 [PATCH v3 0/5] tracing/probes: uaccess: Add support user-space access Masami Hiramatsu
2019-02-27 14:42 ` [PATCH v3 1/5] uaccess: Add user_access_ok() Masami Hiramatsu
2019-02-27 14:43 ` Masami Hiramatsu [this message]
2019-02-27 14:43 ` [PATCH v3 3/5] uaccess: Add non-pagefault user-space read functions Masami Hiramatsu
2019-02-27 14:44 ` [PATCH v3 4/5] tracing/probe: Add ustring type for user-space string Masami Hiramatsu
2019-02-28  2:20   ` Steven Rostedt
2019-02-27 14:44 ` [PATCH v3 5/5] tracing/probe: Support user-space dereference Masami Hiramatsu
2019-02-28  2:31   ` Steven Rostedt
2019-02-28  7:00     ` Masami Hiramatsu
2019-02-28 16:20       ` Steven Rostedt
2019-02-28  2:42   ` Steven Rostedt
2019-02-28  6:08     ` Masami Hiramatsu
2019-02-27 22:32 ` [PATCH v3 0/5] tracing/probes: uaccess: Add support user-space access Alexei Starovoitov
2019-02-28  1:54   ` Masami Hiramatsu

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