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https://github.com/jart/cosmopolitan.git
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50d8d953ce
As of now, the syscall function is implemented as alike to how the linux kernel sycall ABI works, returning -errno upon errors without setting the value of errno. However, this does not conform to the expectations of most software, which expect it to return -1 and set errno, which is how it works on other libcs, which document it accordingly: > The return value is defined by the system call being invoked. In > general, a 0 return value indicates success. A -1 return value > indicates an error, and an error number is stored in errno. - Linux man-pages, syscall(2) > The return value is the return value from the system call, unless > the system call failed. In that case, ‘syscall’ returns ‘-1’ and > sets ‘errno’ to an error code that the system call returned. - glibc manual, (libc)System Calls > When the C-bit is set, syscall returns -1 and sets the external > variable errno (see intro(2)). - 4BSD manual, syscall(2) > A -1 return value indicates an error, and an error code is stored in > errno. - 4.4BSD, FreeBSD, OpenBSD and NetBSD manuals (same quote is found in all of them), syscall(2) This patch corrects the syscall function to work in the same way as in other libcs.
50 lines
2.5 KiB
C
50 lines
2.5 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2023 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/stdio/syscall.h"
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#include "libc/calls/calls.h"
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#include "libc/errno.h"
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#include "libc/stdio/rand.h"
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/**
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* Translation layer for some Linux system calls:
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*
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* - `SYS_gettid`
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* - `SYS_getrandom`
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*
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* @return negative errno on error
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*/
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long syscall(long number, ...) {
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switch (number) {
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default:
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errno = ENOSYS;
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return -1;
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case SYS_gettid:
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return gettid();
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case SYS_getrandom: {
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va_list va;
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va_start(va, number);
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void *buf = va_arg(va, void *);
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size_t buflen = va_arg(va, size_t);
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unsigned flags = va_arg(va, unsigned);
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va_end(va);
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ssize_t rc = getrandom(buf, buflen, flags);
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return rc;
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}
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}
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}
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