diff options
| -rw-r--r-- | src/process/posix_spawn.c | 13 | ||||
| -rw-r--r-- | src/process/system.c | 65 | ||||
| -rw-r--r-- | src/stdio/popen.c | 68 | ||||
| -rw-r--r-- | src/unistd/pipe2.c | 20 |
4 files changed, 110 insertions, 56 deletions
diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c index 8a6ff6db..e8557487 100644 --- a/src/process/posix_spawn.c +++ b/src/process/posix_spawn.c @@ -4,6 +4,7 @@ #include <stdint.h> #include <fcntl.h> #include "syscall.h" +#include "pthread_impl.h" #include "fdop.h" #include "libc.h" @@ -30,7 +31,7 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path, if (!attr) attr = &dummy_attr; - sigprocmask(SIG_BLOCK, (void *)(uint64_t []){-1}, &oldmask); + sigprocmask(SIG_BLOCK, SIGALL_SET, &oldmask); __acquire_ptc(); pid = __vfork(); @@ -43,14 +44,14 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path, return 0; } - for (i=1; i<=64; i++) { + for (i=1; i<=8*__SYSCALL_SSLEN; i++) { struct sigaction sa; - sigaction(i, 0, &sa); - if (sa.sa_handler!=SIG_IGN || + __libc_sigaction(i, 0, &sa); + if (sa.sa_handler!=SIG_DFL && (sa.sa_handler!=SIG_IGN || ((attr->__flags & POSIX_SPAWN_SETSIGDEF) - && sigismember(&attr->__def, i) )) { + && sigismember(&attr->__def, i) ))) { sa.sa_handler = SIG_DFL; - sigaction(i, &sa, 0); + __libc_sigaction(i, &sa, 0); } } diff --git a/src/process/system.c b/src/process/system.c index 0f1c07b5..c8f26008 100644 --- a/src/process/system.c +++ b/src/process/system.c @@ -3,43 +3,62 @@ #include <signal.h> #include <sys/wait.h> #include <errno.h> +#include "pthread_impl.h" +#include "libc.h" + +static void dummy_0() +{ +} +weak_alias(dummy_0, __acquire_ptc); +weak_alias(dummy_0, __release_ptc); + +pid_t __vfork(void); int system(const char *cmd) { pid_t pid; - sigset_t old, new; - struct sigaction sa, oldint, oldquit; - int status; + sigset_t old; + struct sigaction sa = { .sa_handler = SIG_IGN }, oldint, oldquit; + int status = -1, i; if (!cmd) return 1; - sa.sa_handler = SIG_IGN; - sigemptyset(&sa.sa_mask); - sa.sa_flags = 0; - sigaction(SIGINT, &sa, &oldint); sigaction(SIGQUIT, &sa, &oldquit); - sigaddset(&sa.sa_mask, SIGCHLD); - sigprocmask(SIG_BLOCK, &new, &old); + sigprocmask(SIG_BLOCK, SIGALL_SET, &old); + + __acquire_ptc(); + pid = __vfork(); + __release_ptc(); - pid = fork(); - if (pid <= 0) { + if (pid > 0) { + sigset_t new = old; + sigaddset(&new, SIGCHLD); + sigprocmask(SIG_BLOCK, &new, 0); + while (waitpid(pid, &status, 0) && errno == EINTR); + } + + if (pid) { sigaction(SIGINT, &oldint, NULL); sigaction(SIGQUIT, &oldquit, NULL); sigprocmask(SIG_SETMASK, &old, NULL); - if (pid == 0) { - execl("/bin/sh", "sh", "-c", cmd, (char *)0); - _exit(127); - } - return -1; + return status; } - while (waitpid(pid, &status, 0) == -1) - if (errno != EINTR) { - status = -1; - break; + + /* Before we can unblock signals in the child, all signal + * handlers must be eliminated -- even implementation-internal + * ones. Otherwise, a signal handler could run in the child + * and clobber the parent's memory (due to vfork). */ + for (i=1; i<=8*__SYSCALL_SSLEN; i++) { + struct sigaction sa; + __libc_sigaction(i, 0, &sa); + if (sa.sa_handler!=SIG_IGN && sa.sa_handler!=SIG_DFL) { + sa.sa_handler = SIG_DFL; + __libc_sigaction(i, &sa, 0); } - sigaction(SIGINT, &oldint, NULL); - sigaction(SIGQUIT, &oldquit, NULL); + } + sigprocmask(SIG_SETMASK, &old, NULL); - return status; + execl("/bin/sh", "sh", "-c", cmd, (char *)0); + _exit(127); } diff --git a/src/stdio/popen.c b/src/stdio/popen.c index 4f9d6e9e..0c9f24e3 100644 --- a/src/stdio/popen.c +++ b/src/stdio/popen.c @@ -1,18 +1,22 @@ +#include <fcntl.h> #include "stdio_impl.h" +#include "pthread_impl.h" #include "syscall.h" -static inline void nc_close(int fd) +static void dummy_0() { - __syscall(SYS_close, fd); } -#define close(x) nc_close(x) +weak_alias(dummy_0, __acquire_ptc); +weak_alias(dummy_0, __release_ptc); + +pid_t __vfork(void); FILE *popen(const char *cmd, const char *mode) { - int p[2]; - int op; + int p[2], op, i; pid_t pid; FILE *f; + sigset_t old; const char *modes = "rw", *mi = strchr(modes, *mode); if (mi) { @@ -22,29 +26,45 @@ FILE *popen(const char *cmd, const char *mode) return 0; } - if (pipe(p)) return NULL; + if (pipe2(p, O_CLOEXEC)) return NULL; f = fdopen(p[op], mode); if (!f) { - close(p[0]); - close(p[1]); + __syscall(SYS_close, p[0]); + __syscall(SYS_close, p[1]); return NULL; } + + sigprocmask(SIG_BLOCK, SIGALL_SET, &old); - pid = fork(); - switch (pid) { - case -1: - fclose(f); - close(p[0]); - close(p[1]); - return NULL; - case 0: - if (dup2(p[1-op], 1-op) < 0) _exit(127); - if (p[0] != 1-op) close(p[0]); - if (p[1] != 1-op) close(p[1]); - execl("/bin/sh", "sh", "-c", cmd, (char *)0); - _exit(127); + __acquire_ptc(); + pid = __vfork(); + __release_ptc(); + + if (pid) { + __syscall(SYS_close, p[1-op]); + sigprocmask(SIG_BLOCK, SIGALL_SET, &old); + if (pid < 0) { + fclose(f); + return 0; + } + f->pipe_pid = pid; + return f; + } + + /* See notes in system.c for why this is needed. */ + for (i=1; i<=8*__SYSCALL_SSLEN; i++) { + struct sigaction sa; + __libc_sigaction(i, 0, &sa); + if (sa.sa_handler!=SIG_IGN && sa.sa_handler!=SIG_DFL) { + sa.sa_handler = SIG_DFL; + __libc_sigaction(i, &sa, 0); + } } - close(p[1-op]); - f->pipe_pid = pid; - return f; + if (dup2(p[1-op], 1-op) < 0) _exit(127); + fcntl(1-op, F_SETFD, 0); + if (p[0] != 1-op) __syscall(SYS_close, p[0]); + if (p[1] != 1-op) __syscall(SYS_close, p[1]); + sigprocmask(SIG_SETMASK, &old, 0); + execl("/bin/sh", "sh", "-c", cmd, (char *)0); + _exit(127); } diff --git a/src/unistd/pipe2.c b/src/unistd/pipe2.c index 83282bb9..04e0c128 100644 --- a/src/unistd/pipe2.c +++ b/src/unistd/pipe2.c @@ -1,8 +1,22 @@ -#define _GNU_SOURCE #include <unistd.h> +#include <errno.h> +#include <fcntl.h> #include "syscall.h" -int pipe2(int fd[2], int flg) +int pipe2(int fd[2], int flag) { - return syscall(SYS_pipe2, fd, flg); + if (!flag) return syscall(SYS_pipe, fd); + int ret = __syscall(SYS_pipe2, fd, flag); + if (ret != -ENOSYS) return __syscall_ret(ret); + ret = syscall(SYS_pipe, fd); + if (ret) return __syscall_ret(ret); + if (flag & O_CLOEXEC) { + fcntl(fd[0], F_SETFD, FD_CLOEXEC); + fcntl(fd[1], F_SETFD, FD_CLOEXEC); + } + if (flag & O_NONBLOCK) { + fcntl(fd[0], F_SETFL, fcntl(fd[0], F_GETFL) | O_NONBLOCK); + fcntl(fd[1], F_SETFL, fcntl(fd[1], F_GETFL) | O_NONBLOCK); + } + return 0; } |