/* * Copyright (c) 2018-2020, Andreas Kling * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include namespace Kernel { static KSym* s_ksyms; u32 ksym_lowest_address = 0xffffffff; u32 ksym_highest_address = 0; u32 ksym_count = 0; bool ksyms_ready = false; static u8 parse_hex_digit(char nibble) { if (nibble >= '0' && nibble <= '9') return nibble - '0'; ASSERT(nibble >= 'a' && nibble <= 'f'); return 10 + (nibble - 'a'); } u32 address_for_kernel_symbol(const StringView& name) { for (unsigned i = 0; i < ksym_count; ++i) { if (!strncmp(name.characters_without_null_termination(), s_ksyms[i].name, name.length())) return s_ksyms[i].address; } return 0; } const KSym* ksymbolicate(u32 address) { if (address < ksym_lowest_address || address > ksym_highest_address) return nullptr; for (unsigned i = 0; i < ksym_count; ++i) { if (address < s_ksyms[i + 1].address) return &s_ksyms[i]; } return nullptr; } static void load_ksyms_from_data(const ByteBuffer& buffer) { ksym_lowest_address = 0xffffffff; ksym_highest_address = 0; auto* bufptr = (const char*)buffer.data(); auto* start_of_name = bufptr; u32 address = 0; for (unsigned i = 0; i < 8; ++i) ksym_count = (ksym_count << 4) | parse_hex_digit(*(bufptr++)); s_ksyms = static_cast(kmalloc_eternal(sizeof(KSym) * ksym_count)); ++bufptr; // skip newline kprintf("Loading ksyms..."); unsigned current_ksym_index = 0; while (bufptr < buffer.end_pointer()) { for (unsigned i = 0; i < 8; ++i) address = (address << 4) | parse_hex_digit(*(bufptr++)); bufptr += 3; start_of_name = bufptr; while (*(++bufptr)) { if (*bufptr == '\n') { break; } } auto& ksym = s_ksyms[current_ksym_index]; ksym.address = address; char* name = static_cast(kmalloc_eternal((bufptr - start_of_name) + 1)); memcpy(name, start_of_name, bufptr - start_of_name); name[bufptr - start_of_name] = '\0'; ksym.name = name; if (ksym.address < ksym_lowest_address) ksym_lowest_address = ksym.address; if (ksym.address > ksym_highest_address) ksym_highest_address = ksym.address; ++bufptr; ++current_ksym_index; } kprintf("ok\n"); ksyms_ready = true; } [[gnu::noinline]] void dump_backtrace_impl(u32 ebp, bool use_ksyms) { SmapDisabler disabler; #if 0 if (!current) { //hang(); return; } #endif if (use_ksyms && !ksyms_ready) { hang(); return; } struct RecognizedSymbol { u32 address; const KSym* ksym; }; int max_recognized_symbol_count = 256; RecognizedSymbol recognized_symbols[max_recognized_symbol_count]; int recognized_symbol_count = 0; if (use_ksyms) { for (u32* stack_ptr = (u32*)ebp; (Process::current ? Process::current->validate_read_from_kernel(VirtualAddress(stack_ptr), sizeof(void*) * 2) : 1) && recognized_symbol_count < max_recognized_symbol_count; stack_ptr = (u32*)*stack_ptr) { u32 retaddr = stack_ptr[1]; recognized_symbols[recognized_symbol_count++] = { retaddr, ksymbolicate(retaddr) }; } } else { for (u32* stack_ptr = (u32*)ebp; (Process::current ? Process::current->validate_read_from_kernel(VirtualAddress(stack_ptr), sizeof(void*) * 2) : 1); stack_ptr = (u32*)*stack_ptr) { u32 retaddr = stack_ptr[1]; dbg() << String::format("%x", retaddr) << " (next: " << String::format("%x", (stack_ptr ? (u32*)*stack_ptr : 0)) << ")"; } return; } ASSERT(recognized_symbol_count <= max_recognized_symbol_count); for (int i = 0; i < recognized_symbol_count; ++i) { auto& symbol = recognized_symbols[i]; if (!symbol.address) break; if (!symbol.ksym) { if (Process::current && Process::current->elf_loader() && Process::current->elf_loader()->has_symbols()) { dbg() << String::format("%p", symbol.address) << " " << Process::current->elf_loader()->symbolicate(symbol.address).characters(); } else { dbg() << String::format("%p", symbol.address) << " (no ELF symbols for process)"; } continue; } unsigned offset = symbol.address - symbol.ksym->address; if (symbol.ksym->address == ksym_highest_address && offset > 4096) dbg() << String::format("%p", symbol.address); else dbg() << String::format("%p", symbol.address) << " " << demangle(symbol.ksym->name).characters() << " +" << offset; } } void dump_backtrace() { static bool in_dump_backtrace = false; if (in_dump_backtrace) return; TemporaryChange change(in_dump_backtrace, true); TemporaryChange disable_kmalloc_stacks(g_dump_kmalloc_stacks, false); u32 ebp; asm volatile("movl %%ebp, %%eax" : "=a"(ebp)); dump_backtrace_impl(ebp, ksyms_ready); } void load_ksyms() { auto result = VFS::the().open("/res/kernel.map", O_RDONLY, 0, VFS::the().root_custody()); ASSERT(!result.is_error()); auto description = result.value(); auto buffer = description->read_entire_file(); ASSERT(buffer); load_ksyms_from_data(buffer); } }