Rich Felker
efd4d87aa4
this mirrors the stdio_impl.h cleanup. one header which is not strictly needed, errno.h, is left in pthread_impl.h, because since pthread functions return their error codes rather than using errno, nearly every single pthread function needs the errno constants. in a few places, rather than bringing in string.h to use memset, the memset was replaced by direct assignment. this seems to generate much better code anyway, and makes many functions which were previously non-leaf functions into leaf functions (possibly eliminating a great deal of bloat on some platforms where non-leaf functions require ugly prologue and/or epilogue).
74 lines
1.4 KiB
C
74 lines
1.4 KiB
C
#include <fcntl.h>
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#include <unistd.h>
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#include <errno.h>
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#include <string.h>
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#include "stdio_impl.h"
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#include "pthread_impl.h"
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#include "syscall.h"
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static void dummy_0()
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{
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}
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weak_alias(dummy_0, __acquire_ptc);
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weak_alias(dummy_0, __release_ptc);
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pid_t __vfork(void);
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FILE *popen(const char *cmd, const char *mode)
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{
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int p[2], op, i;
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pid_t pid;
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FILE *f;
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sigset_t old;
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const char *modes = "rw", *mi = strchr(modes, *mode);
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if (mi) {
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op = mi-modes;
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} else {
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errno = EINVAL;
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return 0;
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}
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if (pipe2(p, O_CLOEXEC)) return NULL;
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f = fdopen(p[op], mode);
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if (!f) {
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__syscall(SYS_close, p[0]);
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__syscall(SYS_close, p[1]);
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return NULL;
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}
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sigprocmask(SIG_BLOCK, SIGALL_SET, &old);
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__acquire_ptc();
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pid = __vfork();
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if (pid) {
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__release_ptc();
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__syscall(SYS_close, p[1-op]);
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sigprocmask(SIG_SETMASK, &old, 0);
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if (pid < 0) {
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fclose(f);
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return 0;
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}
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f->pipe_pid = pid;
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return f;
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}
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/* See notes in system.c for why this is needed. */
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for (i=1; i<=8*__SYSCALL_SSLEN; i++) {
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struct sigaction sa;
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__libc_sigaction(i, 0, &sa);
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if (sa.sa_handler!=SIG_IGN && sa.sa_handler!=SIG_DFL) {
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sa.sa_handler = SIG_DFL;
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__libc_sigaction(i, &sa, 0);
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}
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}
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if (dup2(p[1-op], 1-op) < 0) _exit(127);
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fcntl(1-op, F_SETFD, 0);
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if (p[0] != 1-op) __syscall(SYS_close, p[0]);
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if (p[1] != 1-op) __syscall(SYS_close, p[1]);
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sigprocmask(SIG_SETMASK, &old, 0);
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execl("/bin/sh", "sh", "-c", cmd, (char *)0);
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_exit(127);
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}
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