mirror of
https://github.com/jart/cosmopolitan.git
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5f4f6b0e69
We now rewrite the binary image at runtime on Windows and XNU to change mov %fs:0,%reg instructions to use %gs instead. There's also simpler threading API introduced by this change and it's called _spawn() and _join(), which has replaced most clone() usage.
113 lines
4.5 KiB
C
113 lines
4.5 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 2022 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/calls/calls.h"
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#include "libc/intrin/kprintf.h"
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#include "libc/intrin/wait0.internal.h"
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#include "libc/macros.internal.h"
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#include "libc/mem/mem.h"
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#include "libc/nexgen32e/threaded.h"
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#include "libc/runtime/internal.h"
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#include "libc/runtime/runtime.h"
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#include "libc/runtime/stack.h"
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#include "libc/str/str.h"
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#include "libc/sysv/consts/clone.h"
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#include "libc/sysv/consts/map.h"
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#include "libc/sysv/consts/prot.h"
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#include "libc/thread/spawn.h"
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#include "libc/thread/thread.h"
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STATIC_YOINK("_main_thread_ctor");
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/**
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* @fileoverview Simple System Threads API
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*/
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#define _TLSZ ((intptr_t)_tls_size)
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#define _TLDZ ((intptr_t)_tdata_size)
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#define _TIBZ sizeof(struct cthread_descriptor_t)
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#define _MEMZ ROUNDUP(_TLSZ + _TIBZ, alignof(struct cthread_descriptor_t))
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/**
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* Spawns thread.
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*
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* @param fun is thread worker callback, which receives `arg` and `ctid`
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* @param arg shall be passed to `fun`
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* @param opt_out_thread needn't be initialiized and is always clobbered
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* except when it isn't specified, in which case, the thread is kind
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* of detached and will leak in stack / tls memory
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* @return 0 on success, or -1 w/ errno
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*/
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int _spawn(int fun(void *, int), void *arg, struct spawn *opt_out_thread) {
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struct spawn *th, ths;
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// we need to to clobber the output memory before calling clone, since
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// there's no guarantee clone() won't suspend the parent, and focus on
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// running the child instead; in that case child might want to read it
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if (opt_out_thread) {
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th = opt_out_thread;
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} else {
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th = &ths;
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}
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// Allocate enough TLS memory for all the GNU Linuker (_tls_size)
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// organized _Thread_local data, as well as Cosmpolitan Libc (64)
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if (!(th->tls = _mktls(&th->tib))) {
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return -1;
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}
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th->ctid = (int *)(th->tib + 0x38);
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// We must use _mapstack() to allocate the stack because OpenBSD has
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// very strict requirements for what's allowed to be used for stacks
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if (!(th->stk = _mapstack())) {
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free(th->tls);
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return -1;
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}
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if (clone(fun, th->stk, GetStackSize(),
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CLONE_VM | CLONE_THREAD | CLONE_FS | CLONE_FILES | CLONE_SIGHAND |
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CLONE_SETTLS | CLONE_PARENT_SETTID | CLONE_CHILD_SETTID |
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CLONE_CHILD_CLEARTID,
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arg, &th->ptid, th->tib, _TIBZ, th->ctid) == -1) {
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_freestack(th->stk);
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free(th->tls);
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return -1;
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}
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return 0;
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}
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/**
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* Waits for thread created by _spawn() to terminate.
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*
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* This will free your thread's stack and tls memory too.
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*/
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int _join(struct spawn *th) {
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int rc;
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if (th->ctid) {
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// wait for ctid to become zero
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_wait0(th->ctid);
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// free thread memory
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free(th->tls);
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rc = munmap(th->stk, GetStackSize());
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} else {
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rc = 0;
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}
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bzero(th, sizeof(*th));
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return rc;
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}
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