From patchwork Sun Dec 29 15:54:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Samuel Thibault X-Patchwork-Id: 1216118 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=sourceware.org (client-ip=209.132.180.131; helo=sourceware.org; envelope-from=libc-alpha-return-108345-incoming=patchwork.ozlabs.org@sourceware.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ens-lyon.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.b="a1FuP/m5"; dkim-atps=neutral Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 47m4rr31hZz9sPK for ; Mon, 30 Dec 2019 02:55:08 +1100 (AEDT) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; q=dns; s=default; b=Mrm 703mfnRAiv/AC5m8BP5Fpn+4agir20bD7tQwRC9K788rdeb1SDVJd5KMhUOPPfb6 yD3plPP/qvXvWqWg03SVRz6AVXRaOxw/Y+VdKQ6QmXBe6f6XmEFrZIgCxAJj3pL5 +7ZAf4wC3Y96/opM8KugWjxayOUCnGETVZd/o6+g= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; s=default; bh=CV+9t4G7a ze/ZexLvEgSxwhwxkE=; b=a1FuP/m5qQiuQyUyjFudUvjhc20COyGjkIZ8dIDtK i+AMHdu6owH/IlrnhXLR3vqlWsgbWFfj0CJtLraTnbuh5IJfnWgfG59UXesdWub3 +833UCNMRRqDWKwTMaKSgK9irqddh1TPhaMk/EaWTS9xo/4nQ9GLpfow0+itcVm/ AI= Received: (qmail 61663 invoked by alias); 29 Dec 2019 15:55:01 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 61653 invoked by uid 89); 29 Dec 2019 15:55:00 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-25.1 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_SHORT, RCVD_IN_DNSWL_NONE, SCC_5_SHORT_WORD_LINES, SPF_HELO_PASS, SPF_NEUTRAL autolearn=ham version=3.3.1 spammy=thoroughly, fetch X-HELO: hera.aquilenet.fr From: Samuel Thibault To: libc-alpha@sourceware.org Cc: Thomas Schwinge , commit-hurd@gnu.org Subject: [hurd, commited] hurd: Add getcontext, makecontext, setcontext, swapcontext Date: Sun, 29 Dec 2019 16:54:52 +0100 Message-Id: <20191229155452.2749344-1-samuel.thibault@ens-lyon.org> MIME-Version: 1.0 From: Thomas Schwinge Adapted from the Linux x86 functions. Not thoroughly tested, but manual testing as well as glibc tests look fine, and manual -lpthread testing also looks fine (within the given bounds for a new stack to be used with makecontext). This has also been in use in Debian since 2013. --- sysdeps/mach/hurd/i386/Makefile | 4 + sysdeps/mach/hurd/i386/getcontext.S | 74 +++++++++++++++ sysdeps/mach/hurd/i386/makecontext.S | 130 ++++++++++++++++++++++++++ sysdeps/mach/hurd/i386/setcontext.S | 93 ++++++++++++++++++ sysdeps/mach/hurd/i386/swapcontext.S | 110 ++++++++++++++++++++++ sysdeps/mach/hurd/i386/ucontext_i.sym | 29 ++++++ 6 files changed, 440 insertions(+) create mode 100644 sysdeps/mach/hurd/i386/getcontext.S create mode 100644 sysdeps/mach/hurd/i386/makecontext.S create mode 100644 sysdeps/mach/hurd/i386/setcontext.S create mode 100644 sysdeps/mach/hurd/i386/swapcontext.S create mode 100644 sysdeps/mach/hurd/i386/ucontext_i.sym diff --git a/sysdeps/mach/hurd/i386/Makefile b/sysdeps/mach/hurd/i386/Makefile index 8404eb086c..2a7d138fff 100644 --- a/sysdeps/mach/hurd/i386/Makefile +++ b/sysdeps/mach/hurd/i386/Makefile @@ -106,3 +106,7 @@ ifeq ($(subdir),elf) # callbacks whose parameters don't permit to get the context parameters. check-execstack-xfail += ld.so libc.so libpthread.so endif + +ifeq ($(subdir),stdlib) +gen-as-const-headers += ucontext_i.sym +endif diff --git a/sysdeps/mach/hurd/i386/getcontext.S b/sysdeps/mach/hurd/i386/getcontext.S new file mode 100644 index 0000000000..cad6762db2 --- /dev/null +++ b/sysdeps/mach/hurd/i386/getcontext.S @@ -0,0 +1,74 @@ +/* Save current context. + Copyright (C) 2001-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 2001. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include + +#include "ucontext_i.h" + + +ENTRY(__getcontext) + /* Load address of the context data structure. */ + movl 4(%esp), %eax + + /* Return value of getcontext. EAX is the only register whose + value is not preserved. */ + movl $0, oEAX(%eax) + + /* Save the 32-bit register values and the return address. */ + movl %ecx, oECX(%eax) + movl %edx, oEDX(%eax) + movl %edi, oEDI(%eax) + movl %esi, oESI(%eax) + movl %ebp, oEBP(%eax) + movl (%esp), %ecx + movl %ecx, oEIP(%eax) + leal 4(%esp), %ecx /* Exclude the return address. */ + movl %ecx, oESP(%eax) + movl %ebx, oEBX(%eax) + + /* Save the FS segment register. We don't touch the GS register + since it is used for threads. */ + xorl %edx, %edx + movw %fs, %dx + movl %edx, oFS(%eax) + + leal oFPREGS(%eax), %ecx + /* Save the floating-point context. */ + fnstenv (%ecx) + /* And load it right back since the processor changes the mask. + Intel thought this opcode to be used in interrupt handlers which + would block all exceptions. */ + fldenv (%ecx) + + /* Save the current signal mask. */ + subl $12, %esp + cfi_adjust_cfa_offset (12) + leal oSIGMASK(%eax), %eax + movl %eax, 8(%esp) + movl $0, 4(%esp) + movl $SIG_BLOCK, (%esp) + call HIDDEN_JUMPTARGET (__sigprocmask) + addl $12, %esp + cfi_adjust_cfa_offset (-12) + /* Propagate %eax (and errno, in case). */ + + ret +PSEUDO_END(__getcontext) + +weak_alias (__getcontext, getcontext) diff --git a/sysdeps/mach/hurd/i386/makecontext.S b/sysdeps/mach/hurd/i386/makecontext.S new file mode 100644 index 0000000000..e2f8afc895 --- /dev/null +++ b/sysdeps/mach/hurd/i386/makecontext.S @@ -0,0 +1,130 @@ +/* Create new context. + Copyright (C) 2001-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 2001. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include + +#include "ucontext_i.h" + + +ENTRY(__makecontext) + movl 4(%esp), %eax + + /* Load the address of the function we are supposed to run. */ + movl 8(%esp), %ecx + + /* Compute the address of the stack. The information comes from + to us_stack element. */ + movl oSS_SP(%eax), %edx + movl %ecx, oEIP(%eax) + addl oSS_SIZE(%eax), %edx + + /* Remember the number of parameters for the exit handler since + it has to remove them. We store the number in the EBX register + which the function we will call must preserve. */ + movl 12(%esp), %ecx + movl %ecx, oEBX(%eax) + + /* Make room on the new stack for the parameters. + Room for the arguments, return address (== L(exitcode)) and + oLINK pointer is needed. One of the pointer sizes is subtracted + after aligning the stack. */ + negl %ecx + leal -4(%edx,%ecx,4), %edx + negl %ecx + + /* Align the stack. */ + andl $0xfffffff0, %edx + subl $4, %edx + + /* Store the future stack pointer. */ + movl %edx, oESP(%eax) + + /* Put the next context on the new stack (from the uc_link + element). */ + movl oLINK(%eax), %eax + movl %eax, 4(%edx,%ecx,4) + + /* Copy all the parameters. */ + jecxz 2f +1: movl 12(%esp,%ecx,4), %eax + movl %eax, (%edx,%ecx,4) + decl %ecx + jnz 1b +2: + + /* If the function we call returns we must continue with the + context which is given in the uc_link element. To do this + set the return address for the function the user provides + to a little bit of helper code which does the magic (see + below). */ +#ifdef PIC + call 1f + cfi_adjust_cfa_offset (4) +1: popl %ecx + cfi_adjust_cfa_offset (-4) + addl $L(exitcode)-1b, %ecx + movl %ecx, (%edx) +#else + movl $L(exitcode), (%edx) +#endif + /* We need to terminate the FDE here instead of after ret because + the unwinder looks at ra-1 for unwind information. */ + cfi_endproc + + /* 'makecontext' returns no value. */ + ret + + /* This is the helper code which gets called if a function which + is registered with 'makecontext' returns. In this case we + have to install the context listed in the uc_link element of + the context 'makecontext' manipulated at the time of the + 'makecontext' call. If the pointer is NULL the process must + terminate. */ +L(exitcode): + /* This removes the parameters passed to the function given to + 'makecontext' from the stack. EBX contains the number of + parameters (see above). */ + leal (%esp,%ebx,4), %esp + + cmpl $0, (%esp) /* Check the next context. */ + je 2f /* If it is zero exit. */ + + call HIDDEN_JUMPTARGET(__setcontext) + /* If this returns (which can happen if the syscall fails) we'll + exit the program with the return error value (-1). */ + jmp L(call_exit) + +2: + /* Exit with status 0. */ + xorl %eax, %eax + +L(call_exit): + /* Align the stack and pass the exit code (from %eax). */ + andl $0xfffffff0, %esp + subl $12, %esp + pushl %eax + + call HIDDEN_JUMPTARGET(exit) + /* The 'exit' call should never return. In case it does cause + the process to terminate. */ + hlt + cfi_startproc +END(__makecontext) + +weak_alias (__makecontext, makecontext) diff --git a/sysdeps/mach/hurd/i386/setcontext.S b/sysdeps/mach/hurd/i386/setcontext.S new file mode 100644 index 0000000000..ce6da9c47d --- /dev/null +++ b/sysdeps/mach/hurd/i386/setcontext.S @@ -0,0 +1,93 @@ +/* Install given context. + Copyright (C) 2001-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 2001. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include + +#include "ucontext_i.h" + + +ENTRY(__setcontext) + /* Load address of the context data structure. */ + movl 4(%esp), %eax + + /* Get the current signal mask. */ + subl $12, %esp + cfi_adjust_cfa_offset (12) + movl $0, 8(%esp) + leal oSIGMASK(%eax), %eax + movl %eax, 4(%esp) + movl $SIG_SETMASK, (%esp) + call HIDDEN_JUMPTARGET (__sigprocmask) + addl $12, %esp + cfi_adjust_cfa_offset (-12) + testl %eax, %eax + jne L(pseudo_end) + + /* EAX was modified, reload it. */ + movl 4(%esp), %eax + + /* Restore the floating-point context. Not the registers, only the + rest. */ + leal oFPREGS(%eax), %ecx + fldenv (%ecx) + + /* Restore the FS segment register. We don't touch the GS register + since it is used for threads. */ + movl oFS(%eax), %ecx + movw %cx, %fs + + /* Fetch the address to return to. */ + movl oEIP(%eax), %ecx + + /* Load the new stack pointer. */ + cfi_def_cfa (eax, 0) + cfi_offset (edi, oEDI) + cfi_offset (esi, oESI) + cfi_offset (ebp, oEBP) + cfi_offset (ebx, oEBX) + cfi_offset (edx, oEDX) + cfi_offset (ecx, oECX) + movl oESP(%eax), %esp + + /* Push the return address on the new stack so we can return there. */ + pushl %ecx + + /* Load the values of all the 32-bit registers (except ESP). + Since we are loading from EAX, it must be last. */ + movl oEDI(%eax), %edi + movl oESI(%eax), %esi + movl oEBP(%eax), %ebp + movl oEBX(%eax), %ebx + movl oEDX(%eax), %edx + movl oECX(%eax), %ecx + movl oEAX(%eax), %eax + + /* End FDE here, we fall into another context. */ + cfi_endproc + cfi_startproc + + /* The following 'ret' will pop the address of the code and jump + to it. */ + +L(pseudo_end): + ret +PSEUDO_END(__setcontext) +libc_hidden_def (__setcontext) + +weak_alias (__setcontext, setcontext) diff --git a/sysdeps/mach/hurd/i386/swapcontext.S b/sysdeps/mach/hurd/i386/swapcontext.S new file mode 100644 index 0000000000..45d1e2cb2b --- /dev/null +++ b/sysdeps/mach/hurd/i386/swapcontext.S @@ -0,0 +1,110 @@ +/* Save current context and install the given one. + Copyright (C) 2001-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 2001. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include + +#include "ucontext_i.h" + + +ENTRY(__swapcontext) + /* Load address of the context data structure we save in. */ + movl 4(%esp), %eax + + /* Return value of swapcontext. EAX is the only register whose + value is not preserved. */ + movl $0, oEAX(%eax) + + /* Save the 32-bit register values and the return address. */ + movl %ecx, oECX(%eax) + movl %edx, oEDX(%eax) + movl %edi, oEDI(%eax) + movl %esi, oESI(%eax) + movl %ebp, oEBP(%eax) + movl (%esp), %ecx + movl %ecx, oEIP(%eax) + leal 4(%esp), %ecx + movl %ecx, oESP(%eax) + movl %ebx, oEBX(%eax) + + /* Save the FS segment register. */ + xorl %edx, %edx + movw %fs, %dx + movl %edx, oFS(%eax) + + leal oFPREGS(%eax), %ecx + /* Save the floating-point context. */ + fnstenv (%ecx) + + /* Load address of the context data structure we have to load. */ + movl 8(%esp), %ecx + + /* Save the current signal mask and install the new one. */ + subl $12, %esp + cfi_adjust_cfa_offset (12) + leal oSIGMASK(%eax), %eax + movl %eax, 8(%esp) + leal oSIGMASK(%ecx), %eax + movl %eax, 4(%esp) + movl $SIG_SETMASK, (%esp) + call HIDDEN_JUMPTARGET (__sigprocmask) + addl $12, %esp + cfi_adjust_cfa_offset (-12) + testl %eax, %eax + jne L(pseudo_end) + + /* EAX was modified, reload it. */ + movl 8(%esp), %eax + + /* Restore the floating-point context. Not the registers, only the + rest. */ + leal oFPREGS(%eax), %ecx + fldenv (%ecx) + + /* Restore the FS segment register. We don't touch the GS register + since it is used for threads. */ + movl oFS(%eax), %edx + movw %dx, %fs + + /* Fetch the address to return to. */ + movl oEIP(%eax), %ecx + + /* Load the new stack pointer. */ + movl oESP(%eax), %esp + + /* Push the return address on the new stack so we can return there. */ + pushl %ecx + + /* Load the values of all the 32-bit registers (except ESP). + Since we are loading from EAX, it must be last. */ + movl oEDI(%eax), %edi + movl oESI(%eax), %esi + movl oEBP(%eax), %ebp + movl oEBX(%eax), %ebx + movl oEDX(%eax), %edx + movl oECX(%eax), %ecx + movl oEAX(%eax), %eax + + /* The following 'ret' will pop the address of the code and jump + to it. */ + +L(pseudo_end): + ret +PSEUDO_END(__swapcontext) + +weak_alias (__swapcontext, swapcontext) diff --git a/sysdeps/mach/hurd/i386/ucontext_i.sym b/sysdeps/mach/hurd/i386/ucontext_i.sym new file mode 100644 index 0000000000..cc1cfd578d --- /dev/null +++ b/sysdeps/mach/hurd/i386/ucontext_i.sym @@ -0,0 +1,29 @@ +#include +#include +#include + +-- + +SIG_BLOCK +SIG_SETMASK + +#define ucontext(member) offsetof (ucontext_t, member) +#define mcontext(member) ucontext (uc_mcontext.member) +#define mreg(reg) mcontext (gregs[REG_##reg]) + +oLINK ucontext (uc_link) +oSS_SP ucontext (uc_stack.ss_sp) +oSS_SIZE ucontext (uc_stack.ss_size) +oGS mreg (GS) +oFS mreg (FS) +oEDI mreg (EDI) +oESI mreg (ESI) +oEBP mreg (EBP) +oESP mreg (ESP) +oEBX mreg (EBX) +oEDX mreg (EDX) +oECX mreg (ECX) +oEAX mreg (EAX) +oEIP mreg (EIP) +oFPREGS mcontext (fpregs) +oSIGMASK ucontext (uc_sigmask)