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https://github.com/jart/cosmopolitan.git
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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.
166 lines
5 KiB
ArmAsm
166 lines
5 KiB
ArmAsm
/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
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│ vi: set noet ft=asm ts=8 sw=8 fenc=utf-8 :vi │
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 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/dce.h"
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#include "libc/macros.internal.h"
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.section .start,"ax",@progbits
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#if SupportsXnu() && defined(__x86_64__)
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// XNU AMD64 Entrypoint
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//
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// @note Rosetta barely implements MAC_LC_UNIXTHREAD
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// @note Rosetta sets many registers to weird values
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_apple: mov $_HOSTXNU,%cl
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jmp 1f
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.endfn _apple,weak,hidden
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#endif
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#if SupportsWindows() && defined(__x86_64__) && !IsTiny()
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// implements all win32 apis on non-windows hosts
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// it is just enough code to get a good backtrace
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__oops_win32:
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ud2
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nop
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.endfn __oops_win32
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#endif
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// System Five userspace program entrypoint.
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//
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// @param rsp is [n,argv₀..argvₙ₋₁,0,envp₀..,0,auxv₀..,0,..]
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// @note FreeBSD is special (see freebsd/lib/csu/amd64/...)
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// @note NetBSD will only zero the call-clobbered registers
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// @note ape.S and ape-loader both set RCX to XNU on Darwin
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// @noreturn
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_start:
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#ifdef __x86_64__
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#if SupportsFreebsd()
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// detect free besiyata dishmaya
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test %rdi,%rdi
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cmovnz %rdi,%rsp
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jz 0f
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movb $_HOSTFREEBSD,%cl
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0:
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#endif
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// set operating system when already detected
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1: mov %cl,__hostos(%rip)
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mov %rdx,__program_executable_name(%rip)
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// get startup timestamp as early as possible
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// its used by --strace flag and kprintf() %T
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rdtsc
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ezlea kStartTsc,bx
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mov %eax,(%rbx)
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mov %edx,4(%rbx)
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// translates arguments from old stack abi
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mov (%rsp),%ebx // argc
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lea 8(%rsp),%rsi // argv
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lea 16(%rsp,%rbx,8),%rdx // envp
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mov %rsp,__oldstack(%rip)
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mov %rdx,__envp(%rip)
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// setup stack
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xor %ebp,%ebp
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and $ape_stack_round,%rsp
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#if SupportsWindows() && !IsTiny()
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// make win32 imps crash
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.weak ape_idata_iat
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.weak ape_idata_iatend
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ezlea __oops_win32,ax
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ezlea ape_idata_iat,di
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ezlea ape_idata_iatend,cx
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sub %rdi,%rcx
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shr $3,%ecx
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rep stosq
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#endif
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// scan through environment varis
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// find start of auxiliary values
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xor %eax,%eax
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or $-1,%ecx
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mov %rdx,%rdi
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repnz scasq
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mov %rdi,%rcx // auxv
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#if SupportsXnu()
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// xnu doesn't have auxiliary values
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testb IsXnu()
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jz 1f // polyfill xnu auxv
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push $0 // auxv[1][1]=0
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push $0 // auxv[1][0]=0
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mov %rsp,%rcx // auxv
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#endif
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// enter cosmopolitan runtime
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1: mov %ebx,%edi
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call cosmo
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9: .unreachable
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// strongly link main() function (discarded by linker)
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// libc_runtime had to weakly link, due to package.com
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.section .yoink
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call main
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.previous
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////////////////////////////////////////////////////////////////////////////////
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#elif defined(__aarch64__)
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#if SupportsFreebsd()
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// save first arg
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mov x4,x0
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#endif
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// save original stack pointer
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// this is the first argument to cosmo() below
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mov x0,sp
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// setup the stack
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mov x28,#0
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mov x29,#0
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mov x30,#0
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ldr x1,=ape_stack_round
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and x1,x0,x1
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mov sp,x1
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// second arg shall be struct Syslib passed by ape-m1.c
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// used to talk to apple's authoritarian libraries
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// should be set to zero on other platforms
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mov x1,x15
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// third arg is program path passed by loader
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// fourth arg is detected os passed by loader
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// switch to c code
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bl cosmo
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.unreachable
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// strongly link main() function (discarded by linker)
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// libc_runtime had to weakly link, due to package.com
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.section .yoink
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bl main
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.previous
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////////////////////////////////////////////////////////////////////////////////
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#else
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#error "architecture unsupported"
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#endif /* __x86_64__ */
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.endfn _start,weak,hidden
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