riscv: convert to generic syscall table

The uapi/asm/unistd_{32,64}.h and asm/syscall_table_{32,64}.h headers can now be generated from scripts/syscall.tbl, which makes this consistent with the other architectures that have their own syscall.tbl. riscv has two extra system call that gets added to scripts/syscall.tbl. The newstat and rlimit entries in the syscall_abis_64 line are for system calls that were part of the generic ABI when riscv64 got added but are no longer enabled by default for new architectures. Both riscv32 and riscv64 also implement memfd_secret, which is optional for all architectures. Unlike all the other 32-bit architectures, the time32 and stat64 sets of syscalls are not enabled on riscv32. Both the user visible side of asm/unistd.h and the internal syscall table in the kernel should have the same effective contents after this.

Arnd Bergmann committed 2 years ago

Commit 3db80c91 parent 77122bf9 files · +40 −44Browse files

Unified · Split

9 files

arch/riscv/include/asm/Kbuild +3 −0
arch/riscv/include/asm/syscall_table.h +7 −0
arch/riscv/include/asm/unistd.h +8 −5
arch/riscv/include/uapi/asm/Kbuild +2 −0
arch/riscv/include/uapi/asm/unistd.h +5 −35
arch/riscv/kernel/Makefile.syscalls +4 −0
arch/riscv/kernel/compat_syscall_table.c +4 −2
arch/riscv/kernel/syscall_table.c +4 −2
scripts/syscall.tbl +3 −0

arch/riscv/include/asm/Kbuild+3−0

@@ -1,4 +1,7 @@
1	1	# SPDX-License-Identifier: GPL-2.0
	2	+syscall-y += syscall_table_32.h
	3	+syscall-y += syscall_table_64.h
	4	+
2	5	generic-y += early_ioremap.h
3	6	generic-y += flat.h
4	7	generic-y += kvm_para.h

arch/riscv/include/asm/syscall_table.h+7−0

@@ -0,0 +1,7 @@
	1	+#include <asm/bitsperlong.h>
	2	+
	3	+#if __BITS_PER_LONG == 64
	4	+#include <asm/syscall_table_64.h>
	5	+#else
	6	+#include <asm/syscall_table_32.h>
	7	+#endif

arch/riscv/include/asm/unistd.h+8−5

@@ -3,11 +3,6 @@ · 2 unmodified lines
3	3	* Copyright (C) 2012 Regents of the University of California
4	4	*/
5	5
6		−/*
7		− * There is explicitly no include guard here because this file is expected to
8		− * be included multiple times.
9		− */
10		−
11	6	#define __ARCH_WANT_SYS_CLONE
12	7
13	8	#ifdef CONFIG_COMPAT
@@ -21,6 +16,14 @@ · 7 unmodified lines
21	16	#define __ARCH_WANT_COMPAT_FADVISE64_64
22	17	#endif
23	18
	19	+#if defined(__LP64__) && !defined(__SYSCALL_COMPAT)
	20	+#define __ARCH_WANT_NEW_STAT
	21	+#define __ARCH_WANT_SET_GET_RLIMIT
	22	+#endif /* __LP64__ */
	23	+
	24	+#define __ARCH_WANT_MEMFD_SECRET
	25	+
	26	+
24	27	#include <uapi/asm/unistd.h>
25	28
26	29	#define NR_syscalls (__NR_syscalls)

arch/riscv/include/uapi/asm/Kbuild+2−0

@@ -1 +1,3 @@
1	1	# SPDX-License-Identifier: GPL-2.0
	2	+syscall-y += unistd_32.h
	3	+syscall-y += unistd_64.h

arch/riscv/include/uapi/asm/unistd.h+5−35

@@ -14,40 +14,10 @@ · 13 unmodified lines
14	14	* You should have received a copy of the GNU General Public License
15	15	* along with this program. If not, see <https://www.gnu.org/licenses/>.
16	16	*/
	17	+#include <asm/bitsperlong.h>
17	18
18		−#if defined(__LP64__) && !defined(__SYSCALL_COMPAT)
19		−#define __ARCH_WANT_NEW_STAT
20		−#define __ARCH_WANT_SET_GET_RLIMIT
21		−#endif /* __LP64__ */
22		−
23		−#define __ARCH_WANT_MEMFD_SECRET
24		−
25		−#include <asm-generic/unistd.h>
26		−
27		−/*
28		− * Allows the instruction cache to be flushed from userspace. Despite RISC-V
29		− * having a direct 'fence.i' instruction available to userspace (which we
30		− * can't trap!), that's not actually viable when running on Linux because the
31		− * kernel might schedule a process on another hart. There is no way for
32		− * userspace to handle this without invoking the kernel (as it doesn't know the
33		− * thread->hart mappings), so we've defined a RISC-V specific system call to
34		− * flush the instruction cache.
35		− *
36		− * __NR_riscv_flush_icache is defined to flush the instruction cache over an
37		− * address range, with the flush applying to either all threads or just the
38		− * caller. We don't currently do anything with the address range, that's just
39		− * in there for forwards compatibility.
40		− */
41		−#ifndef __NR_riscv_flush_icache
42		−#define __NR_riscv_flush_icache (__NR_arch_specific_syscall + 15)
43		−#endif
44		−__SYSCALL(__NR_riscv_flush_icache, sys_riscv_flush_icache)
45		−
46		−/*
47		− * Allows userspace to query the kernel for CPU architecture and
48		− * microarchitecture details across a given set of CPUs.
49		− */
50		−#ifndef __NR_riscv_hwprobe
51		−#define __NR_riscv_hwprobe (__NR_arch_specific_syscall + 14)
	19	+#if __BITS_PER_LONG == 64
	20	+#include <asm/unistd_64.h>
	21	+#else
	22	+#include <asm/unistd_32.h>
52	23	#endif
53		−__SYSCALL(__NR_riscv_hwprobe, sys_riscv_hwprobe)

arch/riscv/kernel/Makefile.syscalls+4−0

@@ -0,0 +1,4 @@
	1	+# SPDX-License-Identifier: GPL-2.0
	2	+
	3	+syscall_abis_32 += riscv memfd_secret
	4	+syscall_abis_64 += riscv newstat rlimit memfd_secret

arch/riscv/kernel/compat_syscall_table.c+4−2

@@ -8,9 +8,11 @@ · 7 unmodified lines
8	8	#include <asm-generic/syscalls.h>
9	9	#include <asm/syscall.h>
10	10
	11	+#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, compat)
	12	+
11	13	#undef __SYSCALL
12	14	#define __SYSCALL(nr, call) asmlinkage long __riscv_##call(const struct pt_regs *);
13		−#include <asm/unistd.h>
	15	+#include <asm/syscall_table_32.h>
14	16
15	17	#undef __SYSCALL
16	18	#define __SYSCALL(nr, call) [nr] = __riscv_##call,
@@ -19,5 +21,5 @@ asmlinkage long compat_sys_rt_sigreturn(void); · 2 unmodified lines
19	21
20	22	void * const compat_sys_call_table[__NR_syscalls] = {
21	23	[0 ... __NR_syscalls - 1] = __riscv_sys_ni_syscall,
22		−#include <asm/unistd.h>
	24	+#include <asm/syscall_table_32.h>
23	25	};

arch/riscv/kernel/syscall_table.c+4−2

@@ -9,14 +9,16 @@ · 8 unmodified lines
9	9	#include <asm-generic/syscalls.h>
10	10	#include <asm/syscall.h>
11	11
	12	+#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
	13	+
12	14	#undef __SYSCALL
13	15	#define __SYSCALL(nr, call) asmlinkage long __riscv_##call(const struct pt_regs *);
14		−#include <asm/unistd.h>
	16	+#include <asm/syscall_table.h>
15	17
16	18	#undef __SYSCALL
17	19	#define __SYSCALL(nr, call) [nr] = __riscv_##call,
18	20
19	21	void * const sys_call_table[__NR_syscalls] = {
20	22	[0 ... __NR_syscalls - 1] = __riscv_sys_ni_syscall,
21		−#include <asm/unistd.h>
	23	+#include <asm/syscall_table.h>
22	24	};

scripts/syscall.tbl+3−0

@@ -301,6 +301,9 @@ · 300 unmodified lines
301	301
302	302	244 or1k or1k_atomic sys_or1k_atomic
303	303
	304	+258 riscv riscv_hwprobe sys_riscv_hwprobe
	305	+259 riscv riscv_flush_icache sys_riscv_flush_icache
	306	+
304	307	260 time32 wait4 sys_wait4 compat_sys_wait4
305	308	260 64 wait4 sys_wait4
306	309	261 common prlimit64 sys_prlimit64