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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* 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 <AK/Demangle.h>
#include <AK/TemporaryChange.h>
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/KSyms.h>
#include <Kernel/Process.h>
#include <Kernel/Scheduler.h>
#include <LibELF/ELFLoader.h>
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<KSym*>(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<char*>(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);
}
}
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