Rich Felker
4e8b0938d9
on old kernels, there's no way to detect errors; we must assume negative syscall return values are pgrp ids. but if the F_GETOWN_EX fcntl works, we can get a reliable answer.
27 lines
668 B
C
27 lines
668 B
C
#define _GNU_SOURCE
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#include <fcntl.h>
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#include <unistd.h>
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#include <stdarg.h>
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#include <errno.h>
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#include "syscall.h"
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#include "libc.h"
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int fcntl(int fd, int cmd, ...)
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{
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long arg;
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va_list ap;
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va_start(ap, cmd);
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arg = va_arg(ap, long);
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va_end(ap);
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if (cmd == F_SETFL) arg |= O_LARGEFILE;
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if (cmd == F_SETLKW) return syscall_cp(SYS_fcntl, fd, cmd, arg);
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if (cmd == F_GETOWN) {
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struct f_owner_ex ex;
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int ret = __syscall(SYS_fcntl, fd, F_GETOWN_EX, &ex);
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if (ret == -EINVAL) return __syscall(SYS_fcntl, fd, cmd, arg);
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if (ret) return __syscall_ret(ret);
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return ex.type == F_OWNER_PGRP ? -ex.pid : ex.pid;
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}
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return syscall(SYS_fcntl, fd, cmd, arg);
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}
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