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From: Nadav Amit <namit@vmware.com>
To: Ingo Molnar <mingo@redhat.com>
Cc: <linux-kernel@vger.kernel.org>, <x86@kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Nadav Amit <namit@vmware.com>, Andy Lutomirski <luto@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH v3 7/7] x86/alternatives: remove text_poke() return value
Date: Fri, 2 Nov 2018 16:29:46 -0700	[thread overview]
Message-ID: <20181102232946.98461-8-namit@vmware.com> (raw)
In-Reply-To: <20181102232946.98461-1-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 1a40df4db450..6d64d7f8c2ed 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -698,7 +698,7 @@ __ro_after_init unsigned long poking_addr;
  *	    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;
 	temporary_mm_state_t prev;
@@ -805,7 +805,6 @@ 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:[~2018-11-02 23:31 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-02 23:29 [PATCH v3 0/7] x86/alternatives: text_poke() fixes Nadav Amit
2018-11-02 23:29 ` [PATCH v3 1/7] Fix "x86/alternatives: Lockdep-enforce text_mutex in text_poke*()" Nadav Amit
2018-11-03 10:11   ` Jiri Kosina
2018-11-04 20:58   ` Thomas Gleixner
2018-11-05 18:14     ` Nadav Amit
2018-11-02 23:29 ` [PATCH v3 2/7] x86/jump_label: Use text_poke_early() during early_init Nadav Amit
2018-11-05 12:39   ` Peter Zijlstra
2018-11-05 13:33     ` Peter Zijlstra
2018-11-05 14:09   ` Peter Zijlstra
2018-11-05 17:22     ` Andy Lutomirski
2018-11-05 17:49       ` Nadav Amit
2018-11-05 19:03         ` Andy Lutomirski
2018-11-05 19:25           ` Nadav Amit
2018-11-05 20:05             ` Andy Lutomirski
2018-11-05 20:28               ` Thomas Gleixner
2018-11-05 21:31                 ` Nadav Amit
2018-11-07 19:13     ` Nadav Amit
2018-11-08 10:41       ` Peter Zijlstra
2018-11-02 23:29 ` [PATCH v3 3/7] x86/mm: temporary mm struct Nadav Amit
2018-11-02 23:29 ` [PATCH v3 4/7] fork: provide a function for copying init_mm Nadav Amit
2018-11-02 23:29 ` [PATCH v3 5/7] x86/alternatives: initializing temporary mm for patching Nadav Amit
2018-11-02 23:29 ` [PATCH v3 6/7] x86/alternatives: use temporary mm for text poking Nadav Amit
2018-11-05 13:19   ` Peter Zijlstra
2018-11-05 13:30   ` Peter Zijlstra
2018-11-05 18:04     ` Nadav Amit
2018-11-06  8:20       ` Peter Zijlstra
2018-11-06 13:11         ` Peter Zijlstra
2018-11-06 18:11           ` Nadav Amit
2018-11-06 19:08             ` Peter Zijlstra
2018-11-02 23:29 ` Nadav Amit [this message]

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