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#include "fs.h"
#include "font.h"
#include "string.h"
#include "halt.h"
#include "debug.h"
static str dbg_disas = NILS;
static str exception[32] = {
S("Division Error"),
S("Debug"),
S("Non-maskable Interrupt"),
S("Breakpoint"),
S("Overflow"),
S("Bound Range Exceeded"),
S("Invalid Opcode"),
S("Device Not Available"),
S("Double Fault"),
S("Coprocessor Segment Overrun"),
S("Invalid TSS"),
S("Segment Not Present"),
S("Stack-Segment Fault"),
S("General Protection Fault"),
S("Page Fault"),
NILS,
S("x87 Floating-Point Exception"),
S("Alignment Check"),
S("Machine Check"),
S("SIMD Floating-Point Exception"),
S("Virtualization Exception"),
S("Control Protection Exception"),
NILS, NILS, NILS, NILS, NILS, NILS,
S("Hypervisor Injection Exception"),
S("VMM Communication Exception"),
S("Security Exception"),
NILS,
};
static bool get_source(u64 code, str *func, str *linep)
{
if (dbg_disas.data == nil)
return false;
*func = (str) NILS;
*linep = (str) NILS;
str iter = dbg_disas;
while (iter.len > 0) {
str line = str_walk(&iter, S("\n"));
u64 func_addr;
usize adv;
if ((adv = str_parse_num(line, 16, &func_addr))) {
line = str_advance(line, adv);
if (line.len < 2 || line.data[0] != ' ' || line.data[1] != '<')
continue;
line = str_advance(line, 2);
usize close = str_find(line, S(">"));
*func = (str) { .len = close, .data = line.data };
} else {
u64 addr;
if (!str_parse_num(str_eat(line, S(" ")), 16, &addr))
continue;
*linep = line;
if (addr == code)
return true;
}
}
return false;
}
static void trace(u64 code, u64 base)
{
if (base == 0)
return;
str func, line;
if (get_source(code, &func, &line)) {
print(S("\t"));
print_hex(code);
print(S(" in "));
print(func);
print(S("\n"));
}
u64 *stack = (u64 *) base;
trace(stack[1], stack[0]);
}
static void dump_frame(interrupt_frame *frame)
{
str func, line;
if (get_source(frame->rip, &func, &line)) {
print(line);
print(S("\n"));
}
print(S("backtrace:\n"));
trace(frame->rip, frame->rbp);
print(S("rip = "));
print_hex(frame->rip);
print(S("\n"));
struct {
u8 bit;
str name;
} flags[] = {
{ 0, S("CF") },
{ 2, S("PF") },
{ 4, S("AF") },
{ 6, S("ZF") },
{ 7, S("SF") },
{ 8, S("TF") },
{ 9, S("IF") },
{ 10, S("DF") },
{ 11, S("OF") },
{ 16, S("RF") },
{ 17, S("VM") },
{ 18, S("AC") },
{ 19, S("VIF") },
{ 20, S("ID") },
};
print(S("rflags = "));
usize f = 0;
for (usize i = 0; i < 63; i++) {
bool has_name = f < LEN(flags) && flags[f].bit == i;
if (frame->rflags & ((u64) 1 << i)) {
if (has_name)
print(flags[f].name);
else
print_dec(i);
print(S(" "));
}
if (has_name)
f++;
}
print(S("\n"));
#define REG(X) print(S(#X)); if (S(#X).len == 2) print(S(" ")); print(S(" = ")); print_num_pad(frame->X, 16, 16, ' ');
#define REGS(A, B) REG(A) print(S(" ")); REG(B) print(S("\n"));
REGS(rax, rbx)
REGS(rcx, rdx)
REGS(rsp, rbp)
REGS(rdi, rsi)
REGS(r8, r9)
REGS(r10, r11)
REGS(r12, r13)
REGS(r14, r15)
REGS(ss, cs)
#undef REG
#undef REGS
}
void debug_exception(interrupt_frame *frame)
{
// TODO: possible race condition due to printing here
// when exception happens in printing code itself
if (exception[frame->which].data == nil) {
print(S("Unknown Exception "));
print_dec(frame->which);
} else {
print(exception[frame->which]);
}
print_char('\n');
if (frame->which == 14) {
str bits[8] = {
S("present"),
S("write"),
S("user"),
S("reserved_write"),
S("instruction_fetch"),
S("protection_key"),
S("shadow_stack"),
S("software_guard_extensions"),
};
u8 err = frame->error_code;
for (int i = 0; i < 8; i++) {
print(bits[i]); print(S(" = ")); print((err & 1) ? S("true\n") : S("false\n"));
err >>= 1;
}
} else {
print(S("error_code = ")); print_dec(frame->error_code); print_char('\n');
}
dump_frame(frame);
freeze();
}
void debug_init()
{
print(S("loading kernel debug info... "));
dbg_disas = fs_read(S("dbg/kernel.dis.asm"));
print(S("done\n"));
}
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