Messages in this thread | | | Date | Mon, 06 Aug 2018 17:11:10 -0700 (PDT) | Subject | Re: [PATCH v2] RISC-V: Don't use a global include guard for uapi/asm/syscalls.h | From | Palmer Dabbelt <> |
| |
On Mon, 06 Aug 2018 14:00:53 PDT (-0700), rdunlap@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 <marcus@mc.pp.se> >> Signed-off-by: Palmer Dabbelt <palmer@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
| |