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#include "KSyms.h"
#include "Process.h"
#include "Scheduler.h"
#include <AK/ELF/ELFLoader.h>
#include <AK/TemporaryChange.h>
#include <Kernel/FileSystem/FileDescription.h>
static KSym* s_ksyms;
dword ksym_lowest_address;
dword ksym_highest_address;
dword ksym_count;
bool ksyms_ready;
static byte parse_hex_digit(char nibble)
{
if (nibble >= '0' && nibble <= '9')
return nibble - '0';
ASSERT(nibble >= 'a' && nibble <= 'f');
return 10 + (nibble - 'a');
}
const KSym* ksymbolicate(dword 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.pointer();
auto* start_of_name = bufptr;
dword 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(dword ebp, bool use_ksyms)
{
if (!current) {
//hang();
return;
}
if (use_ksyms && !ksyms_ready) {
hang();
return;
}
struct RecognizedSymbol {
dword 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 (dword* stack_ptr = (dword*)ebp; current->process().validate_read_from_kernel(VirtualAddress((dword)stack_ptr)); stack_ptr = (dword*)*stack_ptr) {
dword retaddr = stack_ptr[1];
recognized_symbols[recognized_symbol_count++] = { retaddr, ksymbolicate(retaddr) };
}
} else {
for (dword* stack_ptr = (dword*)ebp; current->process().validate_read_from_kernel(VirtualAddress((dword)stack_ptr)); stack_ptr = (dword*)*stack_ptr) {
dword retaddr = stack_ptr[1];
dbgprintf("%x (next: %x)\n", retaddr, stack_ptr ? (dword*)*stack_ptr : 0);
}
return;
}
ASSERT(recognized_symbol_count < max_recognized_symbol_count);
size_t bytes_needed = 0;
for (int i = 0; i < recognized_symbol_count; ++i) {
auto& symbol = recognized_symbols[i];
bytes_needed += (symbol.ksym ? strlen(symbol.ksym->name) : 0) + 8 + 16;
}
for (int i = 0; i < recognized_symbol_count; ++i) {
auto& symbol = recognized_symbols[i];
if (!symbol.address)
break;
if (!symbol.ksym) {
if (current->process().elf_loader() && current->process().elf_loader()->has_symbols()) {
dbgprintf("%p %s\n", symbol.address, current->process().elf_loader()->symbolicate(symbol.address).characters());
} else {
dbgprintf("%p (no ELF symbols for process)\n", symbol.address);
}
continue;
}
unsigned offset = symbol.address - symbol.ksym->address;
if (symbol.ksym->address == ksym_highest_address && offset > 4096)
dbgprintf("%p\n", symbol.address);
else
dbgprintf("%p %s +%u\n", symbol.address, symbol.ksym->name, offset);
}
}
void dump_backtrace()
{
static bool in_dump_backtrace = false;
if (in_dump_backtrace) {
dbgprintf("dump_backtrace() called from within itself, what the hell is going on!\n");
return;
}
TemporaryChange change(in_dump_backtrace, true);
dword ebp;
asm volatile("movl %%ebp, %%eax"
: "=a"(ebp));
dump_backtrace_impl(ebp, ksyms_ready);
}
void init_ksyms()
{
ksyms_ready = false;
ksym_lowest_address = 0xffffffff;
ksym_highest_address = 0;
ksym_count = 0;
}
void load_ksyms()
{
auto result = VFS::the().open("/kernel.map", 0, 0, VFS::the().root_custody());
ASSERT(!result.is_error());
auto descriptor = result.value();
auto buffer = descriptor->read_entire_file();
ASSERT(buffer);
load_ksyms_from_data(buffer);
}
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