cosmopolitan/libc/runtime/cosmo2.c
Justine Tunney 957c61cbbf
Release Cosmopolitan v3.3
This change upgrades to GCC 12.3 and GNU binutils 2.42. The GNU linker
appears to have changed things so that only a single de-duplicated str
table is present in the binary, and it gets placed wherever the linker
wants, regardless of what the linker script says. To cope with that we
need to stop using .ident to embed licenses. As such, this change does
significant work to revamp how third party licenses are defined in the
codebase, using `.section .notice,"aR",@progbits`.

This new GCC 12.3 toolchain has support for GNU indirect functions. It
lets us support __target_clones__ for the first time. This is used for
optimizing the performance of libc string functions such as strlen and
friends so far on x86, by ensuring AVX systems favor a second codepath
that uses VEX encoding. It shaves some latency off certain operations.
It's a useful feature to have for scientific computing for the reasons
explained by the test/libcxx/openmp_test.cc example which compiles for
fifteen different microarchitectures. Thanks to the upgrades, it's now
also possible to use newer instruction sets, such as AVX512FP16, VNNI.

Cosmo now uses the %gs register on x86 by default for TLS. Doing it is
helpful for any program that links `cosmo_dlopen()`. Such programs had
to recompile their binaries at startup to change the TLS instructions.
That's not great, since it means every page in the executable needs to
be faulted. The work of rewriting TLS-related x86 opcodes, is moved to
fixupobj.com instead. This is great news for MacOS x86 users, since we
previously needed to morph the binary every time for that platform but
now that's no longer necessary. The only platforms where we need fixup
of TLS x86 opcodes at runtime are now Windows, OpenBSD, and NetBSD. On
Windows we morph TLS to point deeper into the TIB, based on a TlsAlloc
assignment, and on OpenBSD/NetBSD we morph %gs back into %fs since the
kernels do not allow us to specify a value for the %gs register.

OpenBSD users are now required to use APE Loader to run Cosmo binaries
and assimilation is no longer possible. OpenBSD kernel needs to change
to allow programs to specify a value for the %gs register, or it needs
to stop marking executable pages loaded by the kernel as mimmutable().

This release fixes __constructor__, .ctor, .init_array, and lastly the
.preinit_array so they behave the exact same way as glibc.

We no longer use hex constants to define math.h symbols like M_PI.
2024-02-20 13:27:59 -08:00

201 lines
6.3 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2023 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/struct/rlimit.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/strace.internal.h"
#include "libc/limits.h"
#include "libc/macros.internal.h"
#include "libc/nexgen32e/rdtsc.h"
#include "libc/runtime/internal.h"
#include "libc/runtime/memtrack.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/stack.h"
#include "libc/runtime/syslib.internal.h"
#include "libc/sysv/consts/auxv.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/nr.h"
#include "libc/sysv/consts/prot.h"
#include "libc/sysv/consts/rlim.h"
#include "libc/sysv/consts/rlimit.h"
#include "libc/sysv/consts/sig.h"
#include "libc/thread/thread.h"
#include "libc/thread/tls.h"
#include "third_party/lua/lunix.h"
#ifndef __x86_64__
/**
* @fileoverview Cosmopolitan C Runtime, Second Edition
*/
int main(int, char **, char **) __attribute__((__weak__));
typedef int init_f(int argc, char **argv, char **envp, unsigned long *auxv);
extern long syscon_start[];
extern long syscon_end[];
extern char syscon_linux[];
extern char syscon_xnu[];
extern char syscon_freebsd[];
extern char syscon_openbsd[];
extern char syscon_netbsd[];
extern char syscon_windows[];
extern init_f __strace_init;
extern init_f *__init_array_start[] __attribute__((__weak__));
extern init_f *__init_array_end[] __attribute__((__weak__));
extern char ape_stack_prot[] __attribute__((__weak__));
extern pthread_mutex_t __mmi_lock_obj;
extern int hostos asm("__hostos");
static const char *DecodeMagnum(const char *p, long *r) {
int k = 0;
unsigned long c, x = 0;
do {
c = *p++;
x |= (c & 127) << k;
k += 7;
} while (c & 128);
return *r = x, p;
}
wontreturn textstartup void cosmo(long *sp, struct Syslib *m1, char *exename,
int os, long *is_freebsd) {
// get startup timestamp as early as possible
// its used by --strace and also kprintf() %T
kStartTsc = rdtsc();
// enable enough tls to survive until it can be allocated properly
struct CosmoTib tib = {
.tib_self = &tib,
.tib_self2 = &tib,
.tib_sigmask = -1,
.tib_sigstack_size = 57344,
.tib_sigstack_addr = (char *)__builtin_frame_address(0) - 57344,
.tib_tid = 1,
};
__set_tls(&tib);
// check for freebsd
if (is_freebsd) {
sp = is_freebsd;
}
// extracts arguments from old sysv stack abi
int argc = *sp;
char **argv = (char **)(sp + 1);
char **envp = (char **)(sp + 1 + argc + 1);
unsigned long *auxv = (unsigned long *)(sp + 1 + argc + 1);
while (*auxv++) donothing;
// set helpful globals
__argc = argc;
__argv = argv;
__envp = envp;
__auxv = auxv;
environ = envp;
__program_executable_name = exename;
program_invocation_name = argv[0];
__oldstack = (intptr_t)sp;
if (!(hostos = os)) {
if (SupportsFreebsd() && is_freebsd) {
hostos = _HOSTFREEBSD;
} else if (SupportsXnu() && m1) {
hostos = _HOSTXNU;
} else if (SupportsLinux()) {
hostos = _HOSTLINUX;
} else {
notpossible;
}
}
const char *magnums;
if (IsFreebsd()) {
magnums = syscon_freebsd;
} else if (IsXnu()) {
if (!(__syslib = m1)) {
notpossible;
}
magnums = syscon_xnu;
} else if (IsLinux()) {
magnums = syscon_linux;
} else {
notpossible;
}
// setup system magic numbers
for (long *mp = syscon_start; mp < syscon_end; ++mp) {
magnums = DecodeMagnum(magnums, mp);
}
// check system call abi compatibility
if (IsXnu() && __syslib->__version < SYSLIB_VERSION_MANDATORY) {
sys_write(2, "need newer ape loader\n", 22);
_Exit(127);
}
// disable enosys trapping
if (IsBsd()) {
void *act[6] = {SIG_IGN};
sys_sigaction(SIGSYS, act, 0, 8, 0);
}
// needed by kisdangerous()
__pid = sys_getpid().ax;
// initialize memory manager
_mmi.i = 0;
_mmi.p = _mmi.s;
_mmi.n = ARRAYLEN(_mmi.s);
__virtualmax = -1;
// initialize file system
__init_fds(argc, argv, envp);
// prepend cwd to executable path
__init_program_executable_name();
__enable_tls();
#if 0
#if IsAsan()
// TODO(jart): Figure out ASAN data model on AARCH64.
__asan_init(argc, argv, envp, auxv);
#endif
#endif
_init();
// initialize program
#if SYSDEBUG
argc = __strace_init(argc, argv, envp, auxv);
#endif
for (init_f **fp = __init_array_start; fp < __init_array_end; ++fp) {
(*fp)(argc, argv, envp, auxv);
}
#ifdef FTRACE
argc = ftrace_init();
#endif
// run program
exit(main(argc, argv, envp));
}
#endif /* __x86_64__ */