From 53fcfafa8c5c848d4ef1712053f6ea23b263a0de Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= Date: Sat, 20 May 2023 09:58:57 +0200 Subject: [PATCH] tools/nolibc/unistd: add syscall() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit syscall() is used by "normal" libcs to allow users to directly call syscalls. By having the same syntax inside nolibc users can more easily write code that works with different libcs. The macro logic is adapted from systemtaps STAP_PROBEV() macro that is released in the public domain / CC0. Signed-off-by: Thomas Weißschuh Signed-off-by: Willy Tarreau Signed-off-by: Paul E. McKenney --- tools/include/nolibc/unistd.h | 15 +++++++++++++++ tools/testing/selftests/nolibc/nolibc-test.c | 2 ++ 2 files changed, 17 insertions(+) diff --git a/tools/include/nolibc/unistd.h b/tools/include/nolibc/unistd.h index ac7d53d986cd..0e832e10a0b2 100644 --- a/tools/include/nolibc/unistd.h +++ b/tools/include/nolibc/unistd.h @@ -56,6 +56,21 @@ int tcsetpgrp(int fd, pid_t pid) return ioctl(fd, TIOCSPGRP, &pid); } +#define _syscall(N, ...) \ +({ \ + long _ret = my_syscall##N(__VA_ARGS__); \ + if (_ret < 0) { \ + SET_ERRNO(-_ret); \ + _ret = -1; \ + } \ + _ret; \ +}) + +#define _syscall_narg(...) __syscall_narg(__VA_ARGS__, 6, 5, 4, 3, 2, 1, 0) +#define __syscall_narg(_0, _1, _2, _3, _4, _5, _6, N, ...) N +#define _syscall_n(N, ...) _syscall(N, __VA_ARGS__) +#define syscall(...) _syscall_n(_syscall_narg(__VA_ARGS__), ##__VA_ARGS__) + /* make sure to include all global symbols */ #include "nolibc.h" diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index f042a6436b6b..54bf91847af3 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -588,6 +588,8 @@ int run_syscall(int min, int max) CASE_TEST(waitpid_child); EXPECT_SYSER(1, waitpid(getpid(), &tmp, WNOHANG), -1, ECHILD); break; CASE_TEST(write_badf); EXPECT_SYSER(1, write(-1, &tmp, 1), -1, EBADF); break; CASE_TEST(write_zero); EXPECT_SYSZR(1, write(1, &tmp, 0)); break; + CASE_TEST(syscall_noargs); EXPECT_SYSEQ(1, syscall(__NR_getpid), getpid()); break; + CASE_TEST(syscall_args); EXPECT_SYSER(1, syscall(__NR_fstat, 0, NULL), -1, EFAULT); break; case __LINE__: return ret; /* must be last */ /* note: do not set any defaults so as to permit holes above */