linux-kernel - [PATCH v4 10/39] x86/uaccess: Add unsafe_copy_from

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <a87d41fe9b258cfede10727081fefdb1fd4f894b.1737511963.git.jpoimboe@kernel.org>
Date: Tue, 21 Jan 2025 18:31:02 -0800
From: Josh Poimboeuf <jpoimboe@...nel.org>
To: x86@...nel.org
Cc: Peter Zijlstra <peterz@...radead.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Ingo Molnar <mingo@...nel.org>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	linux-kernel@...r.kernel.org,
	Indu Bhagat <indu.bhagat@...cle.com>,
	Mark Rutland <mark.rutland@....com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Ian Rogers <irogers@...gle.com>,
	Adrian Hunter <adrian.hunter@...el.com>,
	linux-perf-users@...r.kernel.org,
	Mark Brown <broonie@...nel.org>,
	linux-toolchains@...r.kernel.org,
	Jordan Rome <jordalgo@...a.com>,
	Sam James <sam@...too.org>,
	linux-trace-kernel@...r.kernel.org,
	Andrii Nakryiko <andrii.nakryiko@...il.com>,
	Jens Remus <jremus@...ux.ibm.com>,
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	Florian Weimer <fweimer@...hat.com>,
	Andy Lutomirski <luto@...nel.org>,
	Masami Hiramatsu <mhiramat@...nel.org>,
	Weinan Liu <wnliu@...gle.com>
Subject: [PATCH v4 10/39] x86/uaccess: Add unsafe_copy_from_user() implementation

Add an x86 implementation of unsafe_copy_from_user() similar to the
existing unsafe_copy_to_user().

Signed-off-by: Josh Poimboeuf <jpoimboe@...nel.org>
---
 arch/x86/include/asm/uaccess.h | 39 +++++++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 3a7755c1a441..a3148865bc57 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -599,23 +599,42 @@ _label:									\
  * We want the unsafe accessors to always be inlined and use
  * the error labels - thus the macro games.
  */
-#define unsafe_copy_loop(dst, src, len, type, label)				\
+#define unsafe_copy_to_user_loop(dst, src, len, type, label)			\
 	while (len >= sizeof(type)) {						\
-		unsafe_put_user(*(type *)(src),(type __user *)(dst),label);	\
+		unsafe_put_user(*(type *)(src), (type __user *)(dst), label);	\
 		dst += sizeof(type);						\
 		src += sizeof(type);						\
 		len -= sizeof(type);						\
 	}
 
-#define unsafe_copy_to_user(_dst,_src,_len,label)			\
+#define unsafe_copy_to_user(_dst, _src, _len, label)			\
 do {									\
-	char __user *__ucu_dst = (_dst);				\
-	const char *__ucu_src = (_src);					\
-	size_t __ucu_len = (_len);					\
-	unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u64, label);	\
-	unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u32, label);	\
-	unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u16, label);	\
-	unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u8, label);	\
+	void __user *__dst = (_dst);					\
+	const void *__src = (_src);					\
+	size_t __len = (_len);						\
+	unsafe_copy_to_user_loop(__dst, __src, __len, u64, label);	\
+	unsafe_copy_to_user_loop(__dst, __src, __len, u32, label);	\
+	unsafe_copy_to_user_loop(__dst, __src, __len, u16, label);	\
+	unsafe_copy_to_user_loop(__dst, __src, __len, u8,  label);	\
+} while (0)
+
+#define unsafe_copy_from_user_loop(dst, src, len, type, label)			\
+	while (len >= sizeof(type)) {						\
+		unsafe_get_user(*(type *)(dst),(type __user *)(src),label);	\
+		dst += sizeof(type);						\
+		src += sizeof(type);						\
+		len -= sizeof(type);						\
+	}
+
+#define unsafe_copy_from_user(_dst, _src, _len, label)			\
+do {									\
+	void *__dst = (_dst);						\
+	void __user *__src = (_src);					\
+	size_t __len = (_len);						\
+	unsafe_copy_from_user_loop(__dst, __src, __len, u64, label);	\
+	unsafe_copy_from_user_loop(__dst, __src, __len, u32, label);	\
+	unsafe_copy_from_user_loop(__dst, __src, __len, u16, label);	\
+	unsafe_copy_from_user_loop(__dst, __src, __len, u8,  label);	\
 } while (0)
 
 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
-- 
2.48.1