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From: Nadav Amit <namit@vmware.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
	x86@kernel.org, Arnd Bergmann <arnd@arndb.de>,
	linux-arch@vger.kernel.org,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Nadav Amit <nadav.amit@gmail.com>, Nadav Amit <namit@vmware.com>,
	Andy Lutomirski <luto@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH v2 6/6] x86/alternatives: remove text_poke() return value
Date: Sun, 2 Sep 2018 10:32:24 -0700	[thread overview]
Message-ID: <20180902173224.30606-7-namit@vmware.com> (raw)
In-Reply-To: <20180902173224.30606-1-namit@vmware.com>

The return value of text_poke() is meaningless - it is one of the
function inputs. One day someone may allow the callers to deal with
text_poke() failures, if those actually happen.

In the meanwhile, remove the return value.

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
---
 arch/x86/include/asm/text-patching.h | 2 +-
 arch/x86/kernel/alternative.c        | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
index ffe7902cc326..1f73f71b4de2 100644
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -34,7 +34,7 @@ extern void *text_poke_early(void *addr, const void *opcode, size_t len);
  * On the local CPU you need to be protected again NMI or MCE handlers seeing an
  * inconsistent instruction while you patch.
  */
-extern void *text_poke(void *addr, const void *opcode, size_t len);
+extern void text_poke(void *addr, const void *opcode, size_t len);
 extern int poke_int3_handler(struct pt_regs *regs);
 extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
 extern int after_bootmem;
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index edca599c4479..7a30c5a3ca37 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -809,7 +809,7 @@ static void text_poke_safe(void *addr, const void *opcode, size_t len,
  *	    holding the mutex and ensures that none of them will acquire the
  *	    mutex while the code runs.
  */
-void *text_poke(void *addr, const void *opcode, size_t len)
+void text_poke(void *addr, const void *opcode, size_t len)
 {
 	bool cross_page_boundary = offset_in_page(addr) + len > PAGE_SIZE;
 	struct page *pages[2] = {0};
@@ -851,7 +851,6 @@ void *text_poke(void *addr, const void *opcode, size_t len)
 	BUG_ON(memcmp(addr, opcode, len));
 
 	local_irq_restore(flags);
-	return addr;
 }
 
 static void do_sync_core(void *info)
-- 
2.17.1

WARNING: multiple messages have this Message-ID (diff)
From: Nadav Amit <namit@vmware.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@redhat.com>,
	<x86@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	<linux-arch@vger.kernel.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Nadav Amit <nadav.amit@gmail.com>, Nadav Amit <namit@vmware.com>,
	Andy Lutomirski <luto@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH v2 6/6] x86/alternatives: remove text_poke() return value
Date: Sun, 2 Sep 2018 10:32:24 -0700	[thread overview]
Message-ID: <20180902173224.30606-7-namit@vmware.com> (raw)
In-Reply-To: <20180902173224.30606-1-namit@vmware.com>

The return value of text_poke() is meaningless - it is one of the
function inputs. One day someone may allow the callers to deal with
text_poke() failures, if those actually happen.

In the meanwhile, remove the return value.

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
---
 arch/x86/include/asm/text-patching.h | 2 +-
 arch/x86/kernel/alternative.c        | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
index ffe7902cc326..1f73f71b4de2 100644
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -34,7 +34,7 @@ extern void *text_poke_early(void *addr, const void *opcode, size_t len);
  * On the local CPU you need to be protected again NMI or MCE handlers seeing an
  * inconsistent instruction while you patch.
  */
-extern void *text_poke(void *addr, const void *opcode, size_t len);
+extern void text_poke(void *addr, const void *opcode, size_t len);
 extern int poke_int3_handler(struct pt_regs *regs);
 extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
 extern int after_bootmem;
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index edca599c4479..7a30c5a3ca37 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -809,7 +809,7 @@ static void text_poke_safe(void *addr, const void *opcode, size_t len,
  *	    holding the mutex and ensures that none of them will acquire the
  *	    mutex while the code runs.
  */
-void *text_poke(void *addr, const void *opcode, size_t len)
+void text_poke(void *addr, const void *opcode, size_t len)
 {
 	bool cross_page_boundary = offset_in_page(addr) + len > PAGE_SIZE;
 	struct page *pages[2] = {0};
@@ -851,7 +851,6 @@ void *text_poke(void *addr, const void *opcode, size_t len)
 	BUG_ON(memcmp(addr, opcode, len));
 
 	local_irq_restore(flags);
-	return addr;
 }
 
 static void do_sync_core(void *info)
-- 
2.17.1


  parent reply	other threads:[~2018-09-02 17:32 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-02 17:32 [PATCH v2 0/6] x86/alternatives: text_poke() fixes Nadav Amit
2018-09-02 17:32 ` Nadav Amit
2018-09-02 17:32 ` [PATCH v2 1/6] Fix "x86/alternatives: Lockdep-enforce text_mutex in text_poke*()" Nadav Amit
2018-09-02 17:32   ` Nadav Amit
2018-09-06 19:40   ` Peter Zijlstra
2018-09-06 19:42     ` Nadav Amit
2018-09-06 19:53       ` Peter Zijlstra
2018-09-06 19:58         ` Nadav Amit
2018-09-06 20:25           ` Peter Zijlstra
2018-09-06 20:57             ` Nadav Amit
2018-09-06 21:41               ` Peter Zijlstra
2018-09-02 17:32 ` [PATCH v2 2/6] x86/mm: temporary mm struct Nadav Amit
2018-09-02 17:32   ` Nadav Amit
2018-09-02 17:32 ` [PATCH v2 3/6] fork: provide a function for copying init_mm Nadav Amit
2018-09-02 17:32   ` Nadav Amit
2018-09-02 17:32 ` [PATCH v2 4/6] x86/alternatives: initializing temporary mm for patching Nadav Amit
2018-09-02 17:32   ` Nadav Amit
2018-09-06  9:01   ` Peter Zijlstra
2018-09-07 20:52     ` Nadav Amit
2018-09-02 17:32 ` [PATCH v2 5/6] x86/alternatives: use temporary mm for text poking Nadav Amit
2018-09-02 17:32   ` Nadav Amit
2018-09-02 17:32 ` Nadav Amit [this message]
2018-09-02 17:32   ` [PATCH v2 6/6] x86/alternatives: remove text_poke() return value Nadav Amit
2018-09-05 18:56 ` [PATCH v2 0/6] x86/alternatives: text_poke() fixes Peter Zijlstra
2018-09-05 19:02   ` Nadav Amit
2018-09-05 19:10     ` Nadav Amit
2018-09-06  8:13       ` Peter Zijlstra
2018-09-06  8:42         ` Peter Zijlstra
2018-09-06  9:18         ` Peter Zijlstra
2018-09-06 10:16         ` Peter Zijlstra
2018-09-06 17:01           ` Nadav Amit
2018-09-06 17:17             ` Peter Zijlstra
2018-09-06 17:58               ` Nadav Amit
2018-09-06 18:09                 ` Andy Lutomirski
2018-09-06 18:31                   ` Peter Zijlstra
2018-09-06 18:38                     ` Nadav Amit
2018-09-06 19:19                       ` Peter Zijlstra
2018-09-06 17:23             ` Peter Zijlstra

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