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From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org
Cc: linux-kernel@vger.kernel.org,
	Dominik Brodowski <linux@dominikbrodowski.net>,
	Andy Lutomirski <luto@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH v2] x86/syscalls: Mark expected switch fall-throughs
Date: Thu, 28 Feb 2019 13:27:46 -0600	[thread overview]
Message-ID: <20190228192746.GA13021@embeddedor> (raw)

In preparation to enable -Wimplicit-fallthrough by default, mark
switch-case statements where fall-through is intentional, explicitly
in order to fix a bunch of -Wimplicit-fallthrough warnings.

In order to get the warnings mentioned above, the following
line was added to the top Makefile:

KBUILD_CFLAGS  += $(call cc-option,-Wimplicit-fallthrough=3,)

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
Changes in v2:
 - Expand commit text as requested by Thomas Gleixner.
 - Add Kees' Reviewed-by.

 arch/x86/include/asm/syscall.h | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index d653139857af..04fc5c120558 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -125,23 +125,30 @@ static inline void syscall_get_arguments(struct task_struct *task,
 		case 0:
 			if (!n--) break;
 			*args++ = regs->bx;
+			/* fall through */
 		case 1:
 			if (!n--) break;
 			*args++ = regs->cx;
+			/* fall through */
 		case 2:
 			if (!n--) break;
 			*args++ = regs->dx;
+			/* fall through */
 		case 3:
 			if (!n--) break;
 			*args++ = regs->si;
+			/* fall through */
 		case 4:
 			if (!n--) break;
 			*args++ = regs->di;
+			/* fall through */
 		case 5:
 			if (!n--) break;
 			*args++ = regs->bp;
+			/* fall through */
 		case 6:
 			if (!n--) break;
+			/* fall through */
 		default:
 			BUG();
 			break;
@@ -152,23 +159,30 @@ static inline void syscall_get_arguments(struct task_struct *task,
 		case 0:
 			if (!n--) break;
 			*args++ = regs->di;
+			/* fall through */
 		case 1:
 			if (!n--) break;
 			*args++ = regs->si;
+			/* fall through */
 		case 2:
 			if (!n--) break;
 			*args++ = regs->dx;
+			/* fall through */
 		case 3:
 			if (!n--) break;
 			*args++ = regs->r10;
+			/* fall through */
 		case 4:
 			if (!n--) break;
 			*args++ = regs->r8;
+			/* fall through */
 		case 5:
 			if (!n--) break;
 			*args++ = regs->r9;
+			/* fall through */
 		case 6:
 			if (!n--) break;
+			/* fall through */
 		default:
 			BUG();
 			break;
@@ -186,23 +200,30 @@ static inline void syscall_set_arguments(struct task_struct *task,
 		case 0:
 			if (!n--) break;
 			regs->bx = *args++;
+			/* fall through */
 		case 1:
 			if (!n--) break;
 			regs->cx = *args++;
+			/* fall through */
 		case 2:
 			if (!n--) break;
 			regs->dx = *args++;
+			/* fall through */
 		case 3:
 			if (!n--) break;
 			regs->si = *args++;
+			/* fall through */
 		case 4:
 			if (!n--) break;
 			regs->di = *args++;
+			/* fall through */
 		case 5:
 			if (!n--) break;
 			regs->bp = *args++;
+			/* fall through */
 		case 6:
 			if (!n--) break;
+			/* fall through */
 		default:
 			BUG();
 			break;
@@ -213,23 +234,30 @@ static inline void syscall_set_arguments(struct task_struct *task,
 		case 0:
 			if (!n--) break;
 			regs->di = *args++;
+			/* fall through */
 		case 1:
 			if (!n--) break;
 			regs->si = *args++;
+			/* fall through */
 		case 2:
 			if (!n--) break;
 			regs->dx = *args++;
+			/* fall through */
 		case 3:
 			if (!n--) break;
 			regs->r10 = *args++;
+			/* fall through */
 		case 4:
 			if (!n--) break;
 			regs->r8 = *args++;
+			/* fall through */
 		case 5:
 			if (!n--) break;
 			regs->r9 = *args++;
+			/* fall through */
 		case 6:
 			if (!n--) break;
+			/* fall through */
 		default:
 			BUG();
 			break;
-- 
2.21.0


             reply	other threads:[~2019-02-28 19:27 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-28 19:27 Gustavo A. R. Silva [this message]
2019-03-23 16:14 ` Thomas Gleixner
2019-03-26 15:12   ` Oleg Nesterov
2019-03-26 16:09     ` Thomas Gleixner
2019-03-26 16:16       ` Steven Rostedt
2019-03-26 16:17         ` Thomas Gleixner
2019-03-27  1:26     ` Dmitry V. Levin
2019-03-27 14:29       ` Thomas Gleixner
2019-03-27 22:20         ` Dmitry V. Levin
2019-03-27 22:52           ` Thomas Gleixner
2019-03-27 23:03             ` Steven Rostedt
2019-03-27 23:12             ` Dmitry V. Levin
2019-03-27 23:15               ` Steven Rostedt

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