On Mon, 06 Aug 2018 14:00:53 PDT (-0700), rdun...@infradead.org wrote:
On 08/06/2018 01:42 PM, Palmer Dabbelt wrote:
This file is expected to be included multiple times in the same file in
order to allow the __SYSCALL macro to generate system call tables. With
a global include guard we end up missing __NR_riscv_flush_icache in the
syscall table, which results in icache flushes that escape the vDSO call
to not actually do anything.
The fix is to move to per-#define include guards, which allows the
system call tables to actually be populated. Thanks to Macrus Comstedt
for finding and fixing the bug!
I also went ahead and fixed the SPDX header to use a //-style comment,
which I've been told is the canonical way to do it.
Cc: Marcus Comstedt <mar...@mc.pp.se>
Signed-off-by: Palmer Dabbelt <pal...@sifive.com>
---
arch/riscv/include/asm/unistd.h | 5 +++++
arch/riscv/include/uapi/asm/syscalls.h | 15 +++++++++------
2 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/arch/riscv/include/asm/unistd.h b/arch/riscv/include/asm/unistd.h
index 080fb28061de..508be1780323 100644
--- a/arch/riscv/include/asm/unistd.h
+++ b/arch/riscv/include/asm/unistd.h
@@ -11,6 +11,11 @@
* GNU General Public License for more details.
*/
+/*
+ * There is explicitly no include guard here because this file is expected to
to .. be .. included
Thanks. I'm not going to spin a v3 unless there's more feedback, but I'll
include it in the PR.
+ * included multiple times. See uapi/asm/syscalls.h for more info.
+ */
+
#define __ARCH_WANT_SYS_CLONE
#include <uapi/asm/unistd.h>
#include <uapi/asm/syscalls.h>
diff --git a/arch/riscv/include/uapi/asm/syscalls.h
b/arch/riscv/include/uapi/asm/syscalls.h
index 818655b0d535..690beb002d1d 100644
--- a/arch/riscv/include/uapi/asm/syscalls.h
+++ b/arch/riscv/include/uapi/asm/syscalls.h
@@ -1,10 +1,13 @@
-/* SPDX-License-Identifier: GPL-2.0 */
+// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (C) 2017 SiFive
+ * Copyright (C) 2017-2018 SiFive
*/
-#ifndef _ASM__UAPI__SYSCALLS_H
-#define _ASM__UAPI__SYSCALLS_H
+/*
+ * There is explicitly no include guard here because this file is expected to
+ * be included multiple times in order to define the syscall macros via
like that one :)
+ * __SYSCALL.
+ */
/*
* Allows the instruction cache to be flushed from userspace. Despite RISC-V
