huntedbytheirsandSisyphus
b9f8d9bf19
Real string core and process teardown; thin read/write/close/getpid/_exit syscall wrappers; the rest follows the stub convention (documented error return, errno = ENOSYS, TODO). syscall.c is the only kernel ABI surface; crt0.S is the static entry point, kept out of libc.a. Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <[email protected]>
48 lines
993 B
C
48 lines
993 B
C
/*
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* unistd.c — thin wrappers around raw syscalls.
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*
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* Each function here is a one-liner on purpose: the kernel is the API
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* (project guideline #6), and a wrapper that does more than translate
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* arguments is a wrapper that can lie. Error translation (kernel -errno
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* -> errno) happens inside syscall() itself.
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*/
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#include <errno.h>
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#include <sys/syscall.h>
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#include <unistd.h>
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ssize_t read(int fd, void *buf, size_t count)
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{
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return (ssize_t)syscall(SYS_read, fd, buf, count);
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}
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ssize_t write(int fd, const void *buf, size_t count)
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{
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return (ssize_t)syscall(SYS_write, fd, buf, count);
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}
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int close(int fd)
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{
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return (int)syscall(SYS_close, fd);
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}
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pid_t getpid(void)
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{
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return (pid_t)syscall(SYS_getpid);
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}
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void _exit(int status)
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{
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syscall(SYS_exit, status);
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for (;;)
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; /* unreachable */
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}
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/* Stub: trivially a one-liner once wanted (SYS_unlink = 87 on x86_64). */
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int unlink(const char *path)
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{
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(void)path;
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errno = ENOSYS;
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return -1;
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}
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