From: Palmer Dabbelt <palmer@sifive.com> To: linux-riscv@lists.infradead.org, Christoph Hellwig <hch@infradead.org> Cc: Palmer Dabbelt <palmer@sifive.com>, aou@eecs.berkeley.edu, Arnd Bergmann <arnd@arndb.de>, tklauser@distanz.ch, linux-kernel@vger.kernel.org, Marcus Comstedt <marcus@mc.pp.se> Subject: [PATCH v2] RISC-V: Don't use a global include guard for uapi/asm/syscalls.h Date: Mon, 6 Aug 2018 13:42:58 -0700 [thread overview] Message-ID: <20180806204258.22280-2-palmer@sifive.com> (raw) In-Reply-To: <20180806204258.22280-1-palmer@sifive.com> 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 + * 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 + * __SYSCALL. + */ /* * Allows the instruction cache to be flushed from userspace. Despite RISC-V @@ -20,7 +23,7 @@ * caller. We don't currently do anything with the address range, that's just * in there for forwards compatibility. */ +#ifndef __NR_riscv_flush_icache #define __NR_riscv_flush_icache (__NR_arch_specific_syscall + 15) -__SYSCALL(__NR_riscv_flush_icache, sys_riscv_flush_icache) - #endif +__SYSCALL(__NR_riscv_flush_icache, sys_riscv_flush_icache) -- 2.16.4
WARNING: multiple messages have this Message-ID (diff)
From: palmer@sifive.com (Palmer Dabbelt) To: linux-riscv@lists.infradead.org Subject: [PATCH v2] RISC-V: Don't use a global include guard for uapi/asm/syscalls.h Date: Mon, 6 Aug 2018 13:42:58 -0700 [thread overview] Message-ID: <20180806204258.22280-2-palmer@sifive.com> (raw) In-Reply-To: <20180806204258.22280-1-palmer@sifive.com> 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 + * 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 + * __SYSCALL. + */ /* * Allows the instruction cache to be flushed from userspace. Despite RISC-V @@ -20,7 +23,7 @@ * caller. We don't currently do anything with the address range, that's just * in there for forwards compatibility. */ +#ifndef __NR_riscv_flush_icache #define __NR_riscv_flush_icache (__NR_arch_specific_syscall + 15) -__SYSCALL(__NR_riscv_flush_icache, sys_riscv_flush_icache) - #endif +__SYSCALL(__NR_riscv_flush_icache, sys_riscv_flush_icache) -- 2.16.4
next prev parent reply other threads:[~2018-08-06 20:58 UTC|newest] Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-08-03 19:53 [PATCH] RISC-V: Don't use a global include guard for uapi/asm/syscalls.h Palmer Dabbelt 2018-08-04 8:54 ` Christoph Hellwig 2018-08-04 8:54 ` Christoph Hellwig 2018-08-06 20:42 ` Palmer Dabbelt 2018-08-06 20:42 ` Palmer Dabbelt 2018-08-06 20:42 ` Palmer Dabbelt [this message] 2018-08-06 20:42 ` [PATCH v2] " Palmer Dabbelt 2018-08-06 21:00 ` Randy Dunlap 2018-08-06 21:00 ` Randy Dunlap 2018-08-07 0:11 ` Palmer Dabbelt 2018-08-07 0:11 ` Palmer Dabbelt 2018-08-07 12:45 ` Christoph Hellwig 2018-08-07 12:45 ` Christoph Hellwig 2018-08-09 5:58 ` Christoph Hellwig 2018-08-09 5:58 ` Christoph Hellwig 2018-08-09 20:58 ` Palmer Dabbelt 2018-08-09 20:58 ` Palmer Dabbelt 2018-08-09 13:26 ` [PATCH] " Guenter Roeck 2018-08-09 13:26 ` Guenter Roeck 2018-08-09 20:58 ` Palmer Dabbelt 2018-08-09 20:58 ` Palmer Dabbelt
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