mango/arch/x86_64/panic.c

#include "socks/machine/panic.h"
#include "socks/vm.h"
#include <socks/printk.h>
#include <socks/libc/stdio.h>
#include <arch/irq.h>

#define R_CF 0
#define R_PF 2
#define R_AF 4
#define R_ZF 6
#define R_SF 7
#define R_TF 8
#define R_IF 9
#define R_DF 10
#define R_OF 11
#define R_NT 14
#define R_VM 17
#define R_AC 18
#define R_VIF 19
#define R_VIP 20
#define R_ID 21
#define R_MAX 21

struct stack_frame {
	uintptr_t rbp;
	uintptr_t rip;
} __attribute__((packed));

const char *pf_rfl_name(int bit)
{
	switch (bit) {
	case R_CF:
		return "CF";
	case R_PF:
		return "PF";
	case R_AF:
		return "AF";
	case R_ZF:
		return "ZF";
	case R_SF:
		return "SF";
	case R_TF:
		return "TF";
	case R_IF:
		return "IF";
	case R_DF:
		return "DF";
	case R_OF:
		return "OF";
	case R_NT:
		return "NT";
	case R_VM:
		return "VM";
	case R_AC:
		return "AC";
	case R_VIF:
		return "VIF";
	case R_VIP:
		return "VIP";
	case R_ID:
		return "ID";
	default:
		return NULL;
	}
}

int pf_rfl_iopl(uint64_t flags)
{
	int mask = 0x3000;
	int val = flags & mask;
	return val >> 12;
}

static void print_rflags(uintptr_t rflags)
{
	char buf[128];
	size_t buf_i = 0;

	buf_i += snprintf(buf, sizeof(buf), "  rfl %08lx [", rflags);

	for (int i = 0; i < R_MAX; i++) {
		if (rflags & (1 << i)) {
			const char *name = pf_rfl_name(i);
			if (name) {
				buf_i += snprintf(buf + buf_i, sizeof(buf) - buf_i, " %s", name);
			}
		}
	}

	snprintf(buf + buf_i, sizeof(buf) - buf_i, " ]");
	printk(buf);
}

void ml_print_cpu_state(struct cpu_context *ctx)
{
	printk("cpu state:");
	if (ctx) {
		printk("  rax %016llx rbx %016llx rcx %016llx",
		       ctx->rax, ctx->rbx, ctx->rcx);
		printk("  rdx %016llx rsi %016llx rdi %016llx",
		       ctx->rdx, ctx->rsi, ctx->rdi);
		printk("  rsp %016llx rbp %016llx r8  %016llx",
		       ctx->rsp, ctx->rbp, ctx->r8);
		printk("  r9  %016llx r10 %016llx r11 %016llx",
		       ctx->r9, ctx->r10, ctx->r11);
		printk("  r12 %016llx r13 %016llx r14 %016llx",
		       ctx->r12, ctx->r13, ctx->r14);
		printk("  r15 %016llx rip %016llx cs  %04x ss %04x",
		       ctx->r15, ctx->rip, ctx->cs, ctx->ss);
		print_rflags(ctx->rflags);
	}

	uintptr_t cr0 = 0, cr2 = 0, cr3 = 0, cr4 = 0;
	asm volatile("mov %%cr0, %%rax" : "=a" (cr0));
	asm volatile("mov %%cr2, %%rax" : "=a" (cr2));
	asm volatile("mov %%cr3, %%rax" : "=a" (cr3));
	asm volatile("mov %%cr4, %%rax" : "=a" (cr4));
	printk("  cr0 %016llx cr2 %016llx", cr0, cr2);
	printk("  cr3 %016llx cr4 %016llx", cr3, cr4);
}

static void print_stack_item(uintptr_t addr)
{
	if (!addr) {
		return;
	}
	
	char buf[64];
	size_t i = 0;
	
	i += snprintf(buf, sizeof(buf), "  [<%p>] ", addr);
	
	size_t offset = 0;
	char name[128];
	int found = -1;
	
	if (found == 0 && name[0] != '\0') {
		i += snprintf(buf + i, sizeof(buf) - i, "%s+0x%lx", name, offset);
	} else {
		i += snprintf(buf + i, sizeof(buf) - i, "?");
	}
	
	printk("%s", buf);
}

static void print_stack_trace(uintptr_t ip, uintptr_t *bp)
{
	struct stack_frame *stk = (struct stack_frame *)bp;
	printk("call trace:");
	
	print_stack_item(ip);

	int max_frames = 10, current_frame = 0;
	while (1) {
		if (!vm_virt_to_phys(stk) ||
		    bp == NULL ||
		    current_frame > max_frames) {
			break;
		}
		
		uintptr_t addr = stk->rip;
		print_stack_item(addr);
		
		stk = (struct stack_frame *)stk->rbp;
		current_frame++;
	}
}

void ml_print_stack_trace(uintptr_t ip)
{
	uintptr_t *bp;
	asm volatile("mov %%rbp, %0" : "=r" (bp));
	print_stack_trace(ip, bp);
}

void ml_print_stack_trace_irq(struct cpu_context *ctx)
{
	print_stack_trace(ctx->rip, (uintptr_t *)ctx->rbp);
}