mirror of
https://github.com/jart/cosmopolitan.git
synced 2024-05-17 02:52:40 +00:00
69f4152f38
We had previously not enabled TLS in MODE=tiny in order to keep the smallest example programs (e.g. life.com) just 16kb in size. But it was error prone doing that, so now we just always enable it because this change uses hacks to ensure it won't increase life.com's size. This change also fixes a bug on NetBSD, where signal handlers would break thread local storage if SA_SIGINFO was being used. This looks like it might be a bug in NetBSD, but it's got a simple workaround.
637 lines
24 KiB
C
637 lines
24 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 2021 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/calls/strace.internal.h"
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#include "libc/calls/struct/ucontext-netbsd.internal.h"
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#include "libc/calls/syscall-sysv.internal.h"
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#include "libc/dce.h"
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#include "libc/errno.h"
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#include "libc/intrin/asan.internal.h"
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#include "libc/intrin/spinlock.h"
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#include "libc/limits.h"
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#include "libc/macros.internal.h"
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#include "libc/nexgen32e/gettls.h"
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#include "libc/nexgen32e/threaded.h"
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#include "libc/nt/runtime.h"
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#include "libc/nt/thread.h"
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#include "libc/nt/thunk/msabi.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/str/str.h"
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#include "libc/sysv/consts/clone.h"
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#include "libc/sysv/consts/futex.h"
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#include "libc/sysv/consts/nr.h"
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#include "libc/sysv/consts/nrlinux.h"
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#include "libc/sysv/errfuns.h"
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#include "libc/thread/freebsd.internal.h"
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#include "libc/thread/openbsd.internal.h"
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#include "libc/thread/xnu.internal.h"
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#define __NR_thr_new 455
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#define __NR_clone_linux 56
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#define __NR__lwp_create 309
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#define __NR_getcontext_netbsd 307
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#define __NR_bsdthread_create 0x02000168
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#define __NR_thread_fast_set_cthread_self 0x03000003
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#define PTHREAD_START_CUSTOM_XNU 0x01000000
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#define LWP_DETACHED 0x00000040
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#define LWP_SUSPENDED 0x00000080
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__msabi extern typeof(TlsSetValue) *const __imp_TlsSetValue;
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__msabi extern typeof(ExitThread) *const __imp_ExitThread;
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struct CloneArgs {
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union {
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int tid;
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uint32_t utid;
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int64_t tid64;
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};
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char lock;
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int *ptid;
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int *ctid;
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int *ztid;
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char *tls;
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int (*func)(void *, int);
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void *arg;
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};
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////////////////////////////////////////////////////////////////////////////////
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// THE NEW TECHNOLOGY
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int WinThreadLaunch(void *arg, // rdi
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int tid, // rsi
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int (*func)(void *, int), // rdx
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intptr_t rsp); // rcx
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// we can't log this function because:
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// 1. windows owns the backtrace pointer right now
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// 2. ftrace unwinds rbp to determine depth
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// 3. tid in tls for ftrace isn't set yet
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// we can't use address sanitizer because:
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// 1. __asan_handle_no_return wipes stack
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// 2. windows owns the stack memory right now
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// we need win32 raw imports because:
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// 1. generated thunks are function logged
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noasan noinstrument static textwindows wontreturn void //
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WinThreadEntry(int rdi, // rcx
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int rsi, // rdx
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int rdx, // r8
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struct CloneArgs *wt) { // r9
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int rc;
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if (wt->tls) {
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asm("mov\t%1,%%gs:%0"
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: "=m"(*((long *)0x1480 + __tls_index))
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: "r"(wt->tls));
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}
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*wt->ptid = wt->tid;
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*wt->ctid = wt->tid;
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rc = WinThreadLaunch(wt->arg, wt->tid, wt->func, (intptr_t)wt & -16);
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// we can now clear ctid directly since we're no longer using our own
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// stack memory, which can now be safely free'd by the parent thread.
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*wt->ztid = 0;
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// since we didn't indirect this function through NT2SYSV() it's not
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// safe to simply return, and as such, we just call ExitThread().
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__imp_ExitThread(rc);
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unreachable;
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}
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static textwindows int CloneWindows(int (*func)(void *, int), char *stk,
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size_t stksz, int flags, void *arg,
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void *tls, int *ptid, int *ctid) {
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int64_t h;
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struct CloneArgs *wt;
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wt = (struct CloneArgs *)(((intptr_t)(stk + stksz) -
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sizeof(struct CloneArgs)) &
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-alignof(struct CloneArgs));
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wt->ptid = flags & CLONE_PARENT_SETTID ? ptid : &wt->tid;
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wt->ctid = flags & CLONE_CHILD_SETTID ? ctid : &wt->tid;
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wt->ztid = flags & CLONE_CHILD_CLEARTID ? ctid : &wt->tid;
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wt->func = func;
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wt->arg = arg;
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wt->tls = flags & CLONE_SETTLS ? tls : 0;
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if ((h = CreateThread(0, 4096, (void *)WinThreadEntry, wt, 0, &wt->utid))) {
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CloseHandle(h);
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return wt->tid;
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} else {
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return -1;
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}
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}
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////////////////////////////////////////////////////////////////////////////////
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// XNU'S NOT UNIX
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void XnuThreadThunk(void *pthread, // rdi
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int machport, // rsi
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void *(*func)(void *), // rdx
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void *arg, // rcx
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intptr_t *stack, // r8
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unsigned xnuflags); // r9
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asm("XnuThreadThunk:\n\t"
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"xor\t%ebp,%ebp\n\t"
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"mov\t%r8,%rsp\n\t"
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"and\t$-16,%rsp\n\t"
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"push\t%rax\n\t"
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"jmp\tXnuThreadMain\n\t"
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".size\tXnuThreadThunk,.-XnuThreadThunk");
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__attribute__((__used__, __no_reorder__))
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static wontreturn void
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XnuThreadMain(void *pthread, // rdi
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int tid, // rsi
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int (*func)(void *arg, int tid), // rdx
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void *arg, // rcx
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struct CloneArgs *wt, // r8
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unsigned xnuflags) { // r9
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int ax;
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wt->tid = tid;
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*wt->ptid = tid;
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*wt->ctid = tid;
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_spunlock(&wt->lock);
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if (wt->tls) {
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// XNU uses the same 0x30 offset as the WIN32 TIB x64. They told the
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// Go team at Google that they Apply stands by our ability to use it
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// https://github.com/golang/go/issues/23617#issuecomment-376662373
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asm volatile("syscall"
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: "=a"(ax)
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: "0"(__NR_thread_fast_set_cthread_self), "D"(wt->tls - 0x30)
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: "rcx", "r11", "memory", "cc");
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}
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func(arg, tid);
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// we no longer use the stack after this point
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// %rax = int bsdthread_terminate(%rdi = void *stackaddr,
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// %rsi = size_t freesize,
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// %rdx = uint32_t port,
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// %r10 = uint32_t sem);
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asm volatile("movl\t$0,%0\n\t" // *wt->ztid = 0
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"xor\t%%r10d,%%r10d\n\t" // sem = 0
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"syscall\n\t" // __bsdthread_terminate()
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"ud2"
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: "=m"(*wt->ztid)
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: "a"(0x2000000 | 361), "D"(0), "S"(0), "d"(0)
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: "rcx", "r10", "r11", "memory");
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unreachable;
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}
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static int CloneXnu(int (*fn)(void *), char *stk, size_t stksz, int flags,
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void *arg, void *tls, int *ptid, int *ctid) {
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int rc;
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bool failed;
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static bool once;
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static int broken;
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struct CloneArgs *wt;
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if (!once) {
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if (bsdthread_register(XnuThreadThunk, 0, 0, 0, 0, 0, 0) == -1) {
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broken = errno;
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}
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once = true;
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}
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if (broken) {
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errno = broken;
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return -1;
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}
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wt = (struct CloneArgs *)(((intptr_t)(stk + stksz) -
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sizeof(struct CloneArgs)) &
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-alignof(struct CloneArgs));
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wt->ptid = flags & CLONE_PARENT_SETTID ? ptid : &wt->tid;
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wt->ctid = flags & CLONE_CHILD_SETTID ? ctid : &wt->tid;
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wt->ztid = flags & CLONE_CHILD_CLEARTID ? ctid : &wt->tid;
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wt->tls = flags & CLONE_SETTLS ? tls : 0;
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wt->lock = 1;
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if ((rc = bsdthread_create(fn, arg, wt, 0, PTHREAD_START_CUSTOM_XNU)) != -1) {
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_spinlock(&wt->lock);
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rc = wt->tid;
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_spunlock(&wt->lock);
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}
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return rc;
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}
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////////////////////////////////////////////////////////////////////////////////
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// FREE BESIYATA DISHMAYA
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static wontreturn void FreebsdThreadMain(void *p) {
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struct CloneArgs *wt = p;
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*wt->ptid = wt->tid;
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*wt->ctid = wt->tid;
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wt->func(wt->arg, wt->tid);
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// we no longer use the stack after this point
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// void thr_exit(%rdi = long *state);
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asm volatile("movl\t$0,%0\n\t" // *wt->ztid = 0
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"syscall" // thr_exit()
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: "=m"(*wt->ztid)
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: "a"(431), "D"(0)
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: "rcx", "r11", "memory");
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unreachable;
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}
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static int CloneFreebsd(int (*func)(void *, int), char *stk, size_t stksz,
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int flags, void *arg, void *tls, int *ptid, int *ctid) {
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int ax;
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bool failed;
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int64_t tid;
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struct CloneArgs *wt;
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wt = (struct CloneArgs *)(((intptr_t)(stk + stksz) -
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sizeof(struct CloneArgs)) &
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-alignof(struct CloneArgs));
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wt->ptid = flags & CLONE_PARENT_SETTID ? ptid : &wt->tid;
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wt->ctid = flags & CLONE_CHILD_SETTID ? ctid : &wt->tid;
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wt->ztid = flags & CLONE_CHILD_CLEARTID ? ctid : &wt->tid;
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wt->tls = tls;
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wt->func = func;
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wt->arg = arg;
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struct thr_param params = {
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.start_func = FreebsdThreadMain,
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.arg = wt,
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.stack_base = stk,
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.stack_size = (((intptr_t)wt - (intptr_t)stk) & -16) - 8,
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.tls_base = flags & CLONE_SETTLS ? tls : 0,
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.tls_size = 64,
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.child_tid = &wt->tid64,
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.parent_tid = &tid,
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};
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asm volatile(CFLAG_ASM("syscall")
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: CFLAG_CONSTRAINT(failed), "=a"(ax)
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: "1"(__NR_thr_new), "D"(¶ms), "S"(sizeof(params))
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: "rcx", "rdx", "r8", "r9", "r10", "r11", "memory");
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if (failed) {
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errno = ax;
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tid = -1;
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}
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return tid;
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}
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////////////////////////////////////////////////////////////////////////////////
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// OPEN BESIYATA DISHMAYA
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static void *oldrsp;
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__attribute__((__constructor__)) static void OpenbsdGetSafeRsp(void) {
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// main thread stack should never be freed during process lifetime. we
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// won't actually change this stack below. we just need need a place
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// where threads can park RSP for a few instructions while dying.
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oldrsp = __builtin_frame_address(0);
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}
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// we can't use address sanitizer because:
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// 1. __asan_handle_no_return wipes stack [todo?]
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noasan static wontreturn void OpenbsdThreadMain(void *p) {
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struct CloneArgs *wt = p;
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*wt->ptid = wt->tid;
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*wt->ctid = wt->tid;
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wt->func(wt->arg, wt->tid);
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// we no longer use the stack after this point. however openbsd
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// validates the rsp register too so a race condition can still
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// happen if the parent tries to free the stack. we'll solve it
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// by simply changing rsp back to the old value before exiting!
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// although ideally there should be a better solution.
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//
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// void __threxit(%rdi = int32_t *notdead);
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asm volatile("mov\t%2,%%rsp\n\t"
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"movl\t$0,(%%rdi)\n\t" // *wt->ztid = 0
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"syscall\n\t" // futex()
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"mov\t$302,%%eax\n\t" // threxit()
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"syscall"
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: "=m"(*wt->ztid)
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: "a"(83), "m"(oldrsp), "D"(wt->ztid), "S"(FUTEX_WAKE),
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"d"(INT_MAX)
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: "rcx", "r11", "memory");
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unreachable;
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}
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static int CloneOpenbsd(int (*func)(void *, int), char *stk, size_t stksz,
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int flags, void *arg, void *tls, int *ptid, int *ctid) {
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int tid;
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intptr_t sp;
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struct __tfork *tf;
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struct CloneArgs *wt;
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sp = (intptr_t)stk + stksz;
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sp -= sizeof(struct __tfork);
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sp &= -alignof(struct __tfork);
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tf = (struct __tfork *)sp;
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sp -= sizeof(struct CloneArgs);
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sp &= -MAX(16, alignof(struct CloneArgs));
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wt = (struct CloneArgs *)sp;
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wt->ptid = flags & CLONE_PARENT_SETTID ? ptid : &wt->tid;
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wt->ctid = flags & CLONE_CHILD_SETTID ? ctid : &wt->tid;
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wt->ztid = flags & CLONE_CHILD_CLEARTID ? ctid : &wt->tid;
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wt->arg = arg;
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wt->func = func;
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tf->tf_stack = (char *)wt - 8;
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tf->tf_tcb = flags & CLONE_SETTLS ? tls : 0;
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tf->tf_tid = &wt->tid;
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if ((tid = __tfork_thread(tf, sizeof(*tf), OpenbsdThreadMain, wt)) < 0) {
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errno = -tid;
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tid = -1;
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}
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return tid;
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}
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////////////////////////////////////////////////////////////////////////////////
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// NET BESIYATA DISHMAYA
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static wontreturn void NetbsdThreadMain(void *arg, // rdi
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int (*func)(void *, int), // rsi
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int *tid, // rdx
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int *ctid, // rcx
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int *ztid, // r8
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int *ptid) { // r9
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int ax, dx;
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ax = *tid;
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*ptid = ax;
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*ctid = ax;
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func(arg, ax);
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// we no longer use the stack after this point
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// %eax = int __lwp_exit(void);
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asm volatile("movl\t$0,%2\n\t" // *wt->ztid = 0
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"syscall\n\t" // __lwp_exit()
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"ud2"
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: "=a"(ax), "=d"(dx), "=m"(*ztid)
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: "0"(310)
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: "rcx", "r11", "memory");
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unreachable;
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}
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static int CloneNetbsd(int (*func)(void *, int), char *stk, size_t stksz,
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int flags, void *arg, void *tls, int *ptid, int *ctid) {
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// NetBSD has its own clone() and it works, but it's technically a
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// second-class API, intended to help Linux folks migrate to this.
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bool failed;
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int ax, *tid;
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intptr_t dx, sp;
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static bool once;
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static int broken;
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struct ucontext_netbsd *ctx;
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static struct ucontext_netbsd netbsd_clone_template;
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// memoize arbitrary valid processor state structure
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if (!once) {
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asm volatile(CFLAG_ASM("syscall")
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: CFLAG_CONSTRAINT(failed), "=a"(ax)
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: "1"(__NR_getcontext_netbsd), "D"(&netbsd_clone_template)
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: "rcx", "rdx", "r11", "memory");
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if (failed) {
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broken = ax;
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}
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once = true;
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}
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if (broken) {
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errno = broken;
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return -1;
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}
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sp = (intptr_t)(stk + stksz);
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// allocate memory for tid
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sp -= sizeof(int);
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sp = sp & -alignof(int);
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tid = (int *)sp;
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// align the stack
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sp = sp & -16;
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// simulate call to misalign stack and ensure backtrace looks good
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sp -= 8;
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*(intptr_t *)sp = (intptr_t)CloneNetbsd + 1;
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// place the giant 784 byte ucontext structure in the red zone!
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// it only has to live long enough for the thread to come alive
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ctx = (struct ucontext_netbsd *)((sp - sizeof(struct ucontext_netbsd)) &
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-alignof(struct ucontext_netbsd));
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// pass parameters in process state
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memcpy(ctx, &netbsd_clone_template, sizeof(*ctx));
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ctx->uc_link = 0;
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ctx->uc_mcontext.rbp = 0;
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ctx->uc_mcontext.rsp = sp;
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ctx->uc_mcontext.rip = (intptr_t)NetbsdThreadMain;
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ctx->uc_mcontext.rdi = (intptr_t)arg;
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ctx->uc_mcontext.rsi = (intptr_t)func;
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ctx->uc_mcontext.rdx = (intptr_t)tid;
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ctx->uc_mcontext.rcx = (intptr_t)(flags & CLONE_CHILD_SETTID ? ctid : tid);
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ctx->uc_mcontext.r8 = (intptr_t)(flags & CLONE_CHILD_CLEARTID ? ctid : tid);
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ctx->uc_mcontext.r9 = (intptr_t)(flags & CLONE_PARENT_SETTID ? ptid : tid);
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ctx->uc_flags |= _UC_STACK;
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ctx->uc_stack.ss_sp = stk;
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ctx->uc_stack.ss_size = stksz;
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ctx->uc_stack.ss_flags = 0;
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|
if (flags & CLONE_SETTLS) {
|
|
ctx->uc_flags |= _UC_TLSBASE;
|
|
ctx->uc_mcontext._mc_tlsbase = (intptr_t)tls;
|
|
}
|
|
|
|
// perform the system call
|
|
asm volatile(CFLAG_ASM("syscall")
|
|
: CFLAG_CONSTRAINT(failed), "=a"(ax), "=d"(dx)
|
|
: "1"(__NR__lwp_create), "D"(ctx), "S"(LWP_DETACHED), "2"(tid)
|
|
: "rcx", "r11", "memory");
|
|
if (!failed) {
|
|
return *tid;
|
|
} else {
|
|
errno = ax;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// GNU/SYSTEMD
|
|
|
|
int sys_clone_linux(int flags, // rdi
|
|
long sp, // rsi
|
|
int *ptid, // rdx
|
|
int *ctid, // rcx
|
|
void *tls, // r8
|
|
void *func, // r9
|
|
void *arg); // 8(rsp)
|
|
|
|
static int CloneLinux(int (*func)(void *arg, int tid), char *stk, size_t stksz,
|
|
int flags, void *arg, void *tls, int *ptid, int *ctid) {
|
|
long sp;
|
|
sp = (intptr_t)(stk + stksz);
|
|
if (~flags & CLONE_CHILD_SETTID) {
|
|
flags |= CLONE_CHILD_SETTID;
|
|
sp -= sizeof(int);
|
|
sp = sp & -alignof(int);
|
|
ctid = (int *)sp;
|
|
}
|
|
sp = sp & -16; // align the stack
|
|
return sys_clone_linux(flags, sp, ptid, ctid, tls, func, arg);
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// COSMOPOLITAN
|
|
|
|
/**
|
|
* Creates thread.
|
|
*
|
|
* Threads are created in a detached manner. They currently can't be
|
|
* synchronized using wait() or posix signals. Threads created by this
|
|
* function should be synchronized using shared memory operations.
|
|
*
|
|
* Any memory that's required by this system call wrapper is allocated
|
|
* to the top of your stack. This shouldn't be more than 128 bytes.
|
|
*
|
|
* Your function is called from within the stack you specify. A return
|
|
* address is pushed onto your stack, that causes returning to jump to
|
|
* _Exit1() which terminates the thread. Even though the callback says
|
|
* it supports a return code, that'll only work on Linux and Windows.
|
|
*
|
|
* The `tls` parameter is for thread-local storage. If you specify this
|
|
* then clone() will implicitly rewire libc (e.g. errno) to use TLS:
|
|
*
|
|
* static char tib[64];
|
|
* __initialize_tls(tib);
|
|
* __install_tls(tib);
|
|
*
|
|
* If you want a main process TLS size that's larger call it manually.
|
|
* Once you've done the above and/or started creating your own threads
|
|
* you'll be able to access your `tls` thread information block, using
|
|
*
|
|
* char *p = __get_tls();
|
|
* printf("errno is %d\n", *(int *)(p + 0x3c));
|
|
*
|
|
* This function follows the same ABI convention as the Linux userspace
|
|
* libraries, with a few small changes. The varargs has been removed to
|
|
* help prevent broken code, and the stack size and tls size parameters
|
|
* are introduced for compatibility with FreeBSD.
|
|
*
|
|
* To keep this system call lightweight, only the thread creation use
|
|
* case is polyfilled across platforms. For example, if you want fork
|
|
* that works on OpenBSD for example, don't do it with clone(SIGCHLD)
|
|
* and please just call fork(). Even if you do that on Linux, it will
|
|
* effectively work around libc features like atfork(), so that means
|
|
* other calls like getpid() may return incorrect values.
|
|
*
|
|
* @param func is your callback function, which this wrapper requires
|
|
* not be null, otherwise EINVAL is raised. It is passed two args
|
|
* within the child thread: (1) the caller-supplied `arg` and (2)
|
|
* the new tid is always passed in the second arg for convenience
|
|
*
|
|
* @param stk points to the bottom of a caller allocated stack, which
|
|
* must be allocated via mmap() using the MAP_STACK flag, or else
|
|
* you won't get optimal performance and it won't work on OpenBSD
|
|
*
|
|
* @param stksz is the size of that stack in bytes, we recommend that
|
|
* that this be set to GetStackSize() or else memory safety tools
|
|
* like kprintf() can't do as good and quick of a job; this value
|
|
* must be 16-aligned plus it must be at least 4192 bytes in size
|
|
* and it's advised to have the bottom-most page, be a guard page
|
|
*
|
|
* @param flags which SHOULD always have all of these flags:
|
|
*
|
|
* - `CLONE_THREAD`
|
|
* - `CLONE_VM`
|
|
* - `CLONE_FS`
|
|
* - `CLONE_FILES`
|
|
* - `CLONE_SIGHAND`
|
|
*
|
|
* This system call wrapper is intended for threads, and as such, we
|
|
* won't polyfill Linux's ability to simulate unrelated calls (e.g.
|
|
* fork, vfork) via clone() on other platforms. Please just call
|
|
* fork() and vfork() when that's what you want.
|
|
*
|
|
* Your `flags` may also optionally also additionally bitwise-OR any
|
|
* combination of the following additional flags:
|
|
*
|
|
* - `CLONE_PARENT_SETTID` must be specified if you intend to set
|
|
* the `ptid` argument, which is guaranteed to be updated with the
|
|
* child tid BEFORE BOTH clone() returns and `func` is invoked
|
|
*
|
|
* - `CLONE_CHILD_SETTID` must be specified if you intend to set the
|
|
* `ctid` argument, which is guaranteed to be updated with the
|
|
* child tid before `func` is called, however we CAN NOT guarantee
|
|
* this will happen BEFORE clone() returns
|
|
*
|
|
* - `CLONE_CHILD_CLEARTID` causes `*ctid = 0` upon child thread
|
|
* termination. This is used to implement join so that the parent
|
|
* may know when it's safe to free the child's stack memory, and
|
|
* as such, is guaranteed to happen AFTER the child thread has
|
|
* either terminated or has finished using its stack memory
|
|
*
|
|
* - `CLONE_SETTLS` is needed if you intend to specify the `tls`
|
|
* argument, which after thread creation may be accessed using
|
|
* __get_tls(). Doing this means that `errno`, gettid(), etc.
|
|
* correctly work. Caveat emptor if you choose not to do this.
|
|
*
|
|
* @param arg is passed as an argument to `func` in the child thread
|
|
* @param tls may be used to set the thread local storage segment;
|
|
* this parameter is ignored if `CLONE_SETTLS` is not set
|
|
* @param ctid lets the child receive its thread id without having to
|
|
* call gettid() and is ignored if `CLONE_CHILD_SETTID` isn't set
|
|
* @return tid of child on success, or -1 w/ errno
|
|
* @threadsafe
|
|
*/
|
|
int clone(void *func, void *stk, size_t stksz, int flags, void *arg, int *ptid,
|
|
void *tls, int *ctid) {
|
|
int rc;
|
|
struct CloneArgs *wt;
|
|
|
|
if (flags & CLONE_THREAD) {
|
|
__enable_threads();
|
|
}
|
|
|
|
if (!func) {
|
|
rc = einval();
|
|
} else if (!IsTiny() &&
|
|
((flags & CLONE_VM) && (stksz < PAGESIZE || (stksz & 15)))) {
|
|
rc = einval();
|
|
} else if (IsAsan() &&
|
|
((stksz > PAGESIZE &&
|
|
!__asan_is_valid((char *)stk + PAGESIZE, stksz - PAGESIZE)) ||
|
|
((flags & CLONE_SETTLS) && !__asan_is_valid(tls, 64)) ||
|
|
((flags & CLONE_SETTLS) && !__asan_is_valid(tls, sizeof(long))) ||
|
|
((flags & CLONE_PARENT_SETTID) &&
|
|
!__asan_is_valid(ptid, sizeof(*ptid))) ||
|
|
((flags & CLONE_CHILD_SETTID) &&
|
|
!__asan_is_valid(ctid, sizeof(*ctid))))) {
|
|
rc = efault();
|
|
} else if (IsLinux()) {
|
|
rc = CloneLinux(func, stk, stksz, flags, arg, tls, ptid, ctid);
|
|
} else if (!IsTiny() &&
|
|
(flags & ~(CLONE_SETTLS | CLONE_PARENT_SETTID |
|
|
CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) !=
|
|
(CLONE_THREAD | CLONE_VM | CLONE_FS | CLONE_FILES |
|
|
CLONE_SIGHAND)) {
|
|
STRACE("clone flag unsupported on this platform");
|
|
rc = einval();
|
|
} else if (IsXnu()) {
|
|
rc = CloneXnu(func, stk, stksz, flags, arg, tls, ptid, ctid);
|
|
} else if (IsFreebsd()) {
|
|
rc = CloneFreebsd(func, stk, stksz, flags, arg, tls, ptid, ctid);
|
|
} else if (IsNetbsd()) {
|
|
rc = CloneNetbsd(func, stk, stksz, flags, arg, tls, ptid, ctid);
|
|
} else if (IsOpenbsd()) {
|
|
rc = CloneOpenbsd(func, stk, stksz, flags, arg, tls, ptid, ctid);
|
|
} else if (IsWindows()) {
|
|
rc = CloneWindows(func, stk, stksz, flags, arg, tls, ptid, ctid);
|
|
} else {
|
|
rc = enosys();
|
|
}
|
|
|
|
// TODO(jart): do we need it?
|
|
if (rc != -1 && (flags & CLONE_PARENT_SETTID)) {
|
|
*ptid = rc;
|
|
}
|
|
|
|
STRACE("clone(%t, %p, %'zu, %#x, %p, %p, %p, %p) → %d% m", func, stk, stksz,
|
|
flags, arg, ptid, tls, ctid, rc);
|
|
|
|
return rc;
|
|
}
|