[RFC,18/23] hurd: Implement longjmp for AArch64

Message ID	20240103171502.1358371-19-bugaevc@gmail.com
State	New
Headers	show Return-Path: <libc-alpha-bounces+incoming=patchwork.ozlabs.org@sourceware.org> DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 8B0283857C4B From: Sergey Bugaev <bugaevc@gmail.com> To: libc-alpha@sourceware.org, bug-hurd@gnu.org Subject: [RFC PATCH 18/23] hurd: Implement longjmp for AArch64 Date: Wed, 3 Jan 2024 20:14:51 +0300 Message-ID: <20240103171502.1358371-19-bugaevc@gmail.com> In-Reply-To: <20240103171502.1358371-1-bugaevc@gmail.com> References: <20240103171502.1358371-1-bugaevc@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: list Errors-To: libc-alpha-bounces+incoming=patchwork.ozlabs.org@sourceware.org
Series	aarch64-gnu port \| expand [RFC,00/23] aarch64-gnu port [01/23] hurd: Add some missing includes [02/23] hurd: Declare _hurd_intr_rpc_msg* with protected visibility [RFC,03/23] Allow glibc to be compiled without EXEC_PAGESIZE [04/23] mach: Drop some unnecessary vm_param.h includes [RFC,05/23] hurd: Disable Prefer_MAP_32BIT_EXEC on non-x86_64 for now [06/23] mach: Drop SNARF_ARGS macro [RFC,07/23] hurd: Pass the data pointer to _hurd_stack_setup explicitly [RFC,08/23] hurd: Drop x86-specific assembly from init-first.c [RFC,09/23] hurd: Make init-first.c no longer x86-specific [RFC,10/23] hurd: Only init early static TLS if it's used to store stack or pointer guards [RFC,11/23] hurd: Initializy _dl_pagesize early in static builds [RFC,12/23] aarch64: Make cpu-features definitions not Linux-specific [RFC,13/23] aarch64: Add dl-procinfo [RFC,14/23] aarch64: Allow building without kernel support for BTI [RFC,15/23] mach: Add a basic AArch64 port [RFC,16/23] hurd: Add a basic AArch64 port [RFC,17/23] hurd: Implement TLS on AArch64 [RFC,18/23] hurd: Implement longjmp for AArch64 [RFC,19/23] Add FPE_FLTIDO [RFC,20/23] hurd: Add an AArch64 signal implementation [RFC,21/23] htl: Implement some support for TLS_DTV_AT_TP [RFC,22/23] htl: Add an AArch64 implementation [RFC,23/23] hurd: Add expected aarch64-gnu abistlists

diff --git a/sysdeps/aarch64/htl/tcb-offsets.sym b/sysdeps/aarch64/htl/tcb-offsets.sym new file mode 100644 index 00000000..56140780 --- /dev/null +++ b/sysdeps/aarch64/htl/tcb-offsets.sym @@ -0,0 +1,5 @@ +#include <sysdep.h> +#include <tls.h> +#include <kernel-features.h> + +SIGSTATE_OFFSET offsetof (tcbprehead_t, _hurd_sigstate) - sizeof (tcbprehead_t) diff --git a/sysdeps/mach/hurd/aarch64/Makefile b/sysdeps/mach/hurd/aarch64/Makefile new file mode 100644 index 00000000..9210d436 --- /dev/null +++ b/sysdeps/mach/hurd/aarch64/Makefile @@ -0,0 +1,24 @@ +# Copyright (C) 2020-2024 Free Software Foundation, Inc. +# This file is part of the GNU C Library. + +# 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 +# <https://www.gnu.org/licenses/>. + +ifeq ($(subdir),debug) +gen-as-const-headers += signal-defines.sym +endif + +ifeq ($(subdir),setjmp) +gen-as-const-headers += signal-defines.sym +endif diff --git a/sysdeps/mach/hurd/aarch64/____longjmp_chk.S b/sysdeps/mach/hurd/aarch64/____longjmp_chk.S new file mode 100644 index 00000000..90f062df --- /dev/null +++ b/sysdeps/mach/hurd/aarch64/____longjmp_chk.S @@ -0,0 +1,173 @@ +/* Copyright (C) 1997-2024 Free Software Foundation, Inc. + + This file is part of the GNU C Library. + + 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 + <https://www.gnu.org/licenses/>. */ + +#include <asm-syntax.h> +#include <jmpbuf-offsets.h> +#include <pointer_guard.h> +#include <tcb-offsets.h> +#include <signal-defines.h> +#include <stap-probe.h> +#include <sysdep.h> + +#define SS_ONSTACK 1 +#define SS_ONSTACK_BIT 0 + + .section .rodata.str1.1,"aMS",%progbits,1 + .type longjmp_msg,%object +longjmp_msg: + .string "longjmp causes uninitialized stack frame" + .size longjmp_msg, .-longjmp_msg + .text + +# define CALL_FAIL \ + adrp x0, longjmp_msg; \ + add x0, x0, :lo12:longjmp_msg; \ + b HIDDEN_JUMPTARGET(__fortify_fail) \ + +/* Jump to the position specified by ENV, causing the + setjmp call there to return VAL, or 1 if VAL is 0. + void __longjmp (__jmp_buf env, int val). */ + .text +ENTRY(____longjmp_chk) + cfi_def_cfa(x0, 0) + cfi_offset(x19, JB_X19<<3) + cfi_offset(x20, JB_X20<<3) + cfi_offset(x21, JB_X21<<3) + cfi_offset(x22, JB_X22<<3) + cfi_offset(x23, JB_X23<<3) + cfi_offset(x24, JB_X24<<3) + cfi_offset(x25, JB_X25<<3) + cfi_offset(x26, JB_X26<<3) + cfi_offset(x27, JB_X27<<3) + cfi_offset(x28, JB_X28<<3) + cfi_offset(x29, JB_X29<<3) + cfi_offset(x30, JB_LR<<3) + + cfi_offset( d8, JB_D8<<3) + cfi_offset( d9, JB_D9<<3) + cfi_offset(d10, JB_D10<<3) + cfi_offset(d11, JB_D11<<3) + cfi_offset(d12, JB_D12<<3) + cfi_offset(d13, JB_D13<<3) + cfi_offset(d14, JB_D14<<3) + cfi_offset(d15, JB_D15<<3) + + PTR_ARG (0) + + ldp x19, x20, [x0, #JB_X19<<3] + ldp x21, x22, [x0, #JB_X21<<3] + ldp x23, x24, [x0, #JB_X23<<3] + ldp x25, x26, [x0, #JB_X25<<3] + ldp x27, x28, [x0, #JB_X27<<3] +#ifdef PTR_DEMANGLE + ldp x29, x4, [x0, #JB_X29<<3] + PTR_DEMANGLE (30, 4, 3, 2) +#else + ldp x29, x30, [x0, #JB_X29<<3] +#endif + /* longjmp probe takes 3 arguments, address of jump buffer as + first argument (8@x0), return value as second argument (-4@x1), + and target address (8@x30), respectively. */ + LIBC_PROBE (longjmp, 3, 8@x0, -4@x1, 8@x30) + ldp d8, d9, [x0, #JB_D8<<3] + ldp d10, d11, [x0, #JB_D10<<3] + ldp d12, d13, [x0, #JB_D12<<3] + ldp d14, d15, [x0, #JB_D14<<3] + + /* Originally this was implemented with a series of + .cfi_restore() directives. + + The theory was that cfi_restore should revert to previous + frame value is the same as the current value. In practice + this doesn't work, even after cfi_restore() gdb continues + to try to recover a previous frame value offset from x0, + which gets stuffed after a few more instructions. The + cfi_same_value() mechanism appears to work fine. */ + + cfi_same_value(x19) + cfi_same_value(x20) + cfi_same_value(x21) + cfi_same_value(x22) + cfi_same_value(x23) + cfi_same_value(x24) + cfi_same_value(x25) + cfi_same_value(x26) + cfi_same_value(x27) + cfi_same_value(x28) + cfi_same_value(x29) + cfi_same_value(x30) + cfi_same_value(d8) + cfi_same_value(d9) + cfi_same_value(d10) + cfi_same_value(d11) + cfi_same_value(d12) + cfi_same_value(d13) + cfi_same_value(d14) + cfi_same_value(d15) +#ifdef PTR_DEMANGLE + ldr x4, [x0, #JB_SP<<3] + PTR_DEMANGLE (5, 4, 3, 2) +#else + ldr x5, [x0, #JB_SP<<3] +#endif + + mrs x3, tpidr_el0 +#if !defined (SHARED) || IS_IN (rtld) + cbz x3, L(ok) /* TLS not initialized yet */ +#endif + ldr x3, [x3, #SIGSTATE_OFFSET] + cbz x3, L(ok) /* sigstate not initialized yet */ + + ldrb w4, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)] + tbnz w4, #SS_ONSTACK_BIT, L(onstack) + /* We haven't been using an altstack. Jumping to a higher-address + frame is always allowed, otherwise it's not allowed. */ + mov x6, sp + cmp x5, x6 + b.lt L(ok) + +L(fail): + CALL_FAIL + +L(onstack): + /* We have been using an altstack. Was it above or below ours? */ + ldr x2, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)] + cmp x2, x5 + b.lt L(oks) /* Jumping below the altstack, switch */ + ldr x6, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)] + add x2, x2, x6 + cmp x2, x5 + b.lt L(ok) /* Jumping inside the altstack, do not switch */ + + /* Jumping above the altstack, switch */ +L(oks): + and w4, w4, #~(SS_ONSTACK) + str w4, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)] +L(ok): + mov sp, x5 + + /* longjmp_target probe takes 3 arguments, address of jump buffer + as first argument (8@x0), return value as second argument (-4@x1), + and target address (8@x30), respectively. */ + LIBC_PROBE (longjmp_target, 3, 8@x0, -4@x1, 8@x30) + cmp x1, #0 + mov x0, #1 + csel x0, x1, x0, ne + /* Use br instead of ret because ret is guaranteed to mispredict */ + br x30 +END (____longjmp_chk) diff --git a/sysdeps/mach/hurd/aarch64/__longjmp.S b/sysdeps/mach/hurd/aarch64/__longjmp.S new file mode 100644 index 00000000..c9f2e1ce --- /dev/null +++ b/sysdeps/mach/hurd/aarch64/__longjmp.S @@ -0,0 +1,150 @@ +/* Copyright (C) 1997-2024 Free Software Foundation, Inc. + + This file is part of the GNU C Library. + + 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 + <https://www.gnu.org/licenses/>. */ + +#include <asm-syntax.h> +#include <jmpbuf-offsets.h> +#include <pointer_guard.h> +#include <tcb-offsets.h> +#include <signal-defines.h> +#include <stap-probe.h> +#include <sysdep.h> + +#define SS_ONSTACK 1 +#define SS_ONSTACK_BIT 0 + +/* __longjmp(jmpbuf, val) */ + +ENTRY (__longjmp) + cfi_def_cfa(x0, 0) + cfi_offset(x19, JB_X19<<3) + cfi_offset(x20, JB_X20<<3) + cfi_offset(x21, JB_X21<<3) + cfi_offset(x22, JB_X22<<3) + cfi_offset(x23, JB_X23<<3) + cfi_offset(x24, JB_X24<<3) + cfi_offset(x25, JB_X25<<3) + cfi_offset(x26, JB_X26<<3) + cfi_offset(x27, JB_X27<<3) + cfi_offset(x28, JB_X28<<3) + cfi_offset(x29, JB_X29<<3) + cfi_offset(x30, JB_LR<<3) + + cfi_offset( d8, JB_D8<<3) + cfi_offset( d9, JB_D9<<3) + cfi_offset(d10, JB_D10<<3) + cfi_offset(d11, JB_D11<<3) + cfi_offset(d12, JB_D12<<3) + cfi_offset(d13, JB_D13<<3) + cfi_offset(d14, JB_D14<<3) + cfi_offset(d15, JB_D15<<3) + + PTR_ARG (0) + + ldp x19, x20, [x0, #JB_X19<<3] + ldp x21, x22, [x0, #JB_X21<<3] + ldp x23, x24, [x0, #JB_X23<<3] + ldp x25, x26, [x0, #JB_X25<<3] + ldp x27, x28, [x0, #JB_X27<<3] +#ifdef PTR_DEMANGLE + ldp x29, x4, [x0, #JB_X29<<3] + PTR_DEMANGLE (30, 4, 3, 2) +#else + ldp x29, x30, [x0, #JB_X29<<3] +#endif + /* longjmp probe takes 3 arguments, address of jump buffer as + first argument (8@x0), return value as second argument (-4@x1), + and target address (8@x30), respectively. */ + LIBC_PROBE (longjmp, 3, 8@x0, -4@x1, 8@x30) + ldp d8, d9, [x0, #JB_D8<<3] + ldp d10, d11, [x0, #JB_D10<<3] + ldp d12, d13, [x0, #JB_D12<<3] + ldp d14, d15, [x0, #JB_D14<<3] + + /* Originally this was implemented with a series of + .cfi_restore() directives. + + The theory was that cfi_restore should revert to previous + frame value is the same as the current value. In practice + this doesn't work, even after cfi_restore() gdb continues + to try to recover a previous frame value offset from x0, + which gets stuffed after a few more instructions. The + cfi_same_value() mechanism appears to work fine. */ + + cfi_same_value(x19) + cfi_same_value(x20) + cfi_same_value(x21) + cfi_same_value(x22) + cfi_same_value(x23) + cfi_same_value(x24) + cfi_same_value(x25) + cfi_same_value(x26) + cfi_same_value(x27) + cfi_same_value(x28) + cfi_same_value(x29) + cfi_same_value(x30) + cfi_same_value(d8) + cfi_same_value(d9) + cfi_same_value(d10) + cfi_same_value(d11) + cfi_same_value(d12) + cfi_same_value(d13) + cfi_same_value(d14) + cfi_same_value(d15) +#ifdef PTR_DEMANGLE + ldr x4, [x0, #JB_SP<<3] + PTR_DEMANGLE (5, 4, 3, 2) +#else + ldr x5, [x0, #JB_SP<<3] +#endif + + mrs x3, tpidr_el0 +#if !defined (SHARED) || IS_IN (rtld) + cbz x3, L(ok) /* TLS not initialized yet */ +#endif + ldr x3, [x3, #SIGSTATE_OFFSET] + cbz x3, L(ok) /* sigstate not initialized yet */ + /* If we haven't been using an altstack, don't switch */ + ldrb w4, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)] + tbz w4, #SS_ONSTACK_BIT, L(ok) + + /* We have been using an altstack. Was it above or below ours? */ + ldr x2, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)] + cmp x2, x5 + b.lt L(oks) /* Jumping below the altstack, switch */ + ldr x6, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)] + add x2, x2, x6 + cmp x2, x5 + b.lt L(ok) /* Jumping inside the altstack, do not switch */ + + /* Jumping above the altstack, switch */ +L(oks): + and w4, w4, #~(SS_ONSTACK) + str w4, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)] +L(ok): + mov sp, x5 + + /* longjmp_target probe takes 3 arguments, address of jump buffer + as first argument (8@x0), return value as second argument (-4@x1), + and target address (8@x30), respectively. */ + LIBC_PROBE (longjmp_target, 3, 8@x0, -4@x1, 8@x30) + cmp x1, #0 + mov x0, #1 + csel x0, x1, x0, ne + /* Use br instead of ret because ret is guaranteed to mispredict */ + br x30 +END (__longjmp) diff --git a/sysdeps/mach/hurd/aarch64/signal-defines.sym b/sysdeps/mach/hurd/aarch64/signal-defines.sym new file mode 100644 index 00000000..e42bbbe0 --- /dev/null +++ b/sysdeps/mach/hurd/aarch64/signal-defines.sym @@ -0,0 +1,10 @@ +#include <hurd/signal.h> +#include <signal.h> + +-- + +HURD_SIGSTATE__SIGALTSTACK__OFFSET offsetof(struct hurd_sigstate, sigaltstack) + +SIGALTSTACK__SS_SP__OFFSET offsetof(stack_t, ss_sp) +SIGALTSTACK__SS_SIZE__OFFSET offsetof(stack_t, ss_size) +SIGALTSTACK__SS_FLAGS__OFFSET offsetof(stack_t, ss_flags)

[RFC,18/23] hurd: Implement longjmp for AArch64

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