mirror of
https://github.com/fluencelabs/musl
synced 2025-06-02 01:21:34 +00:00
594c827a22
open is handled specially because it is used from so many places, in so many variants (2 or 3 arguments, setting errno or not, and cancellable or not). trying to do it as a function would not only increase bloat, but would also risk subtle breakage. this is the first step towards supporting "new" archs where linux lacks "old" syscalls.
46 lines
877 B
C
46 lines
877 B
C
#include <stdlib.h>
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#include <limits.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <unistd.h>
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#include <string.h>
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#include "syscall.h"
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void __procfdname(char *, unsigned);
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char *realpath(const char *restrict filename, char *restrict resolved)
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{
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int fd;
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ssize_t r;
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struct stat st1, st2;
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char buf[15+3*sizeof(int)];
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char tmp[PATH_MAX];
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if (!filename) {
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errno = EINVAL;
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return 0;
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}
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fd = sys_open(filename, O_PATH|O_NONBLOCK|O_CLOEXEC);
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if (fd < 0) return 0;
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__procfdname(buf, fd);
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r = readlink(buf, tmp, sizeof tmp - 1);
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if (r < 0) goto err;
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tmp[r] = 0;
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fstat(fd, &st1);
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r = stat(tmp, &st2);
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if (r<0 || st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino) {
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if (!r) errno = ELOOP;
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goto err;
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}
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__syscall(SYS_close, fd);
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return resolved ? strcpy(resolved, tmp) : strdup(tmp);
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err:
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__syscall(SYS_close, fd);
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return 0;
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}
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