+++ /dev/null
-/* Copyright (c) 2015-2023. The SimGrid Team. All rights reserved. */
-
-/* This program is free software; you can redistribute it and/or modify it
- * under the terms of the license (GNU LGPL) which comes with this package. */
-
-/** \file
- * Libunwind support for mc_address_space objects.
- */
-
-// We need this for the register indices:
-// #define _GNU_SOURCE
-
-#include "src/mc/inspect/mc_unw.hpp"
-#include "src/mc/inspect/Frame.hpp"
-#include "src/mc/remote/RemoteProcess.hpp"
-
-#include <cstring>
-
-// On x86_64, libunwind unw_context_t has the same layout as ucontext_t:
-#include <sys/types.h>
-#include <sys/ucontext.h>
-#ifdef __FreeBSD__
-typedef register_t greg_t;
-#endif
-
-#include <libunwind.h>
-
-namespace simgrid::mc {
-
-// ***** Implementation
-
-/** Get frame unwind information (libunwind method)
- *
- * Delegates to the local/ptrace implementation.
- */
-int UnwindContext::find_proc_info(unw_addr_space_t /*as*/, unw_word_t ip, unw_proc_info_t* pip, int need_unwind_info,
- void* arg) noexcept
-{
- const simgrid::mc::UnwindContext* context = (simgrid::mc::UnwindContext*)arg;
- return unw_get_accessors(context->process_->unw_underlying_addr_space)
- ->find_proc_info(context->process_->unw_underlying_addr_space, ip, pip, need_unwind_info,
- context->process_->unw_underlying_context);
-}
-
-/** Release frame unwind information (libunwind method)
- *
- * Delegates to the local/ptrace implementation.
- */
-void UnwindContext::put_unwind_info(unw_addr_space_t /*as*/, unw_proc_info_t* pip, void* arg) noexcept
-{
- const simgrid::mc::UnwindContext* context = (simgrid::mc::UnwindContext*)arg;
- return unw_get_accessors(context->process_->unw_underlying_addr_space)
- ->put_unwind_info(context->process_->unw_underlying_addr_space, pip, context->process_->unw_underlying_context);
-}
-
-/** (libunwind method)
- *
- * Not implemented.
- */
-int UnwindContext::get_dyn_info_list_addr(unw_addr_space_t /*as*/, unw_word_t* dilap, void* arg) noexcept
-{
- const simgrid::mc::UnwindContext* context = (simgrid::mc::UnwindContext*)arg;
- return unw_get_accessors(context->process_->unw_underlying_addr_space)
- ->get_dyn_info_list_addr(context->process_->unw_underlying_addr_space, dilap,
- context->process_->unw_underlying_context);
-}
-
-/** Read from the target address space memory (libunwind method)
- *
- * Delegates to the `simgrid::mc::Process*`.
- */
-int UnwindContext::access_mem(unw_addr_space_t /*as*/, unw_word_t addr, unw_word_t* valp, int write, void* arg) noexcept
-{
- const simgrid::mc::UnwindContext* context = (simgrid::mc::UnwindContext*)arg;
- if (write)
- return -UNW_EREADONLYREG;
- context->address_space_->read_bytes(valp, sizeof(unw_word_t), remote(addr));
- return 0;
-}
-
-void* UnwindContext::get_reg(unw_context_t* context, unw_regnum_t regnum) noexcept
-{
-#ifdef __x86_64
- mcontext_t* mcontext = &context->uc_mcontext;
- switch (regnum) {
-#ifdef __linux__
- case UNW_X86_64_RAX:
- return &mcontext->gregs[REG_RAX];
- case UNW_X86_64_RDX:
- return &mcontext->gregs[REG_RDX];
- case UNW_X86_64_RCX:
- return &mcontext->gregs[REG_RCX];
- case UNW_X86_64_RBX:
- return &mcontext->gregs[REG_RBX];
- case UNW_X86_64_RSI:
- return &mcontext->gregs[REG_RSI];
- case UNW_X86_64_RDI:
- return &mcontext->gregs[REG_RDI];
- case UNW_X86_64_RBP:
- return &mcontext->gregs[REG_RBP];
- case UNW_X86_64_RSP:
- return &mcontext->gregs[REG_RSP];
- case UNW_X86_64_R8:
- return &mcontext->gregs[REG_R8];
- case UNW_X86_64_R9:
- return &mcontext->gregs[REG_R9];
- case UNW_X86_64_R10:
- return &mcontext->gregs[REG_R10];
- case UNW_X86_64_R11:
- return &mcontext->gregs[REG_R11];
- case UNW_X86_64_R12:
- return &mcontext->gregs[REG_R12];
- case UNW_X86_64_R13:
- return &mcontext->gregs[REG_R13];
- case UNW_X86_64_R14:
- return &mcontext->gregs[REG_R14];
- case UNW_X86_64_R15:
- return &mcontext->gregs[REG_R15];
- case UNW_X86_64_RIP:
- return &mcontext->gregs[REG_RIP];
-#elif defined __FreeBSD__
- case UNW_X86_64_RAX:
- return &mcontext->mc_rax;
- case UNW_X86_64_RDX:
- return &mcontext->mc_rdx;
- case UNW_X86_64_RCX:
- return &mcontext->mc_rcx;
- case UNW_X86_64_RBX:
- return &mcontext->mc_rbx;
- case UNW_X86_64_RSI:
- return &mcontext->mc_rsi;
- case UNW_X86_64_RDI:
- return &mcontext->mc_rdi;
- case UNW_X86_64_RBP:
- return &mcontext->mc_rbp;
- case UNW_X86_64_RSP:
- return &mcontext->mc_rsp;
- case UNW_X86_64_R8:
- return &mcontext->mc_r8;
- case UNW_X86_64_R9:
- return &mcontext->mc_r9;
- case UNW_X86_64_R10:
- return &mcontext->mc_r10;
- case UNW_X86_64_R11:
- return &mcontext->mc_r11;
- case UNW_X86_64_R12:
- return &mcontext->mc_r12;
- case UNW_X86_64_R13:
- return &mcontext->mc_r13;
- case UNW_X86_64_R14:
- return &mcontext->mc_r14;
- case UNW_X86_64_R15:
- return &mcontext->mc_r15;
- case UNW_X86_64_RIP:
- return &mcontext->mc_rip;
-#else
-#error "Unable to get register from ucontext, please add your case"
-#endif
- default:
- return nullptr;
- }
-#else
- return nullptr;
-#endif
-}
-
-/** Read a standard register (libunwind method)
- */
-int UnwindContext::access_reg(unw_addr_space_t /*as*/, unw_regnum_t regnum, unw_word_t* valp, int write,
- void* arg) noexcept
-{
- auto* as_context = static_cast<simgrid::mc::UnwindContext*>(arg);
- unw_context_t* context = &as_context->unwind_context_;
- if (write)
- return -UNW_EREADONLYREG;
- const greg_t* preg = (greg_t*)get_reg(context, regnum);
- if (not preg)
- return -UNW_EBADREG;
- *valp = *preg;
- return 0;
-}
-
-/** Find information about a function (libunwind method)
- */
-int UnwindContext::get_proc_name(unw_addr_space_t /*as*/, unw_word_t addr, char* bufp, size_t buf_len, unw_word_t* offp,
- void* arg) noexcept
-{
- const simgrid::mc::UnwindContext* context = (simgrid::mc::UnwindContext*)arg;
- const simgrid::mc::Frame* frame = context->process_->find_function(remote(addr));
- if (not frame)
- return -UNW_ENOINFO;
- *offp = (unw_word_t)frame->range.begin() - addr;
-
- strncpy(bufp, frame->name.c_str(), buf_len);
- if (bufp[buf_len - 1]) {
- bufp[buf_len - 1] = 0;
- return -UNW_ENOMEM;
- }
-
- return 0;
-}
-
-// ***** Init
-
-unw_addr_space_t UnwindContext::createUnwindAddressSpace()
-{
- /** Virtual table for our `libunwind` implementation
- *
- * Stack unwinding on a `simgrid::mc::Process*` (for memory, unwinding information)
- * and `ucontext_t` (for processor registers).
- *
- * It works with the `simgrid::mc::UnwindContext` context.
- *
- * Use nullptr as access_fpreg and resume, as we don't need them.
- */
- unw_accessors_t accessors = {&find_proc_info, &put_unwind_info, &get_dyn_info_list_addr, &access_mem, &access_reg,
- nullptr, nullptr, &get_proc_name};
- return unw_create_addr_space(&accessors, BYTE_ORDER);
-}
-
-void UnwindContext::initialize(simgrid::mc::RemoteProcess* process, unw_context_t* c)
-{
- this->address_space_ = process;
- this->process_ = process;
-
- // Take a copy of the context for our own purpose:
- this->unwind_context_ = *c;
-#if SIMGRID_PROCESSOR_x86_64 || SIMGRID_PROCESSOR_i686
-#ifdef __linux__
- // On x86_64, ucontext_t contains a pointer to itself for FP registers.
- // We don't really need support for FR registers as they are caller saved
- // and probably never use those fields as libunwind-x86_64 does not read
- // FP registers from the unw_context_t
- // Let's ignore this and see what happens:
- this->unwind_context_.uc_mcontext.fpregs = nullptr;
-#endif
-#elif SIMGRID_PROCESSOR_arm64
-#ifdef __linux__
- // On ARM64, ucontext_t doesn't contain `fpregs` and the FP registers
- // are instead held in the `__reserved` field of the struct. It doesn't
- // appear anything needs to be done here, although this should be verified
-#endif
-#else
- // Do we need to do any fixup like this?
-#error Target CPU type is not handled.
-#endif
-}
-
-unw_cursor_t UnwindContext::cursor()
-{
- unw_cursor_t cursor;
- xbt_assert(process_ != nullptr && address_space_ != nullptr &&
- unw_init_remote(&cursor, process_->unw_addr_space, this) == 0,
- "UnwindContext not initialized");
- return cursor;
-}
-
-} // namespace simgrid::mc
