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/* SPDX-License-Identifier: GPL-2.0-only */
#include <arch/breakpoint.h>
#include <arch/null_breakpoint.h>
#include <bootstate.h>
#include <console/console.h>
#include <types.h>
static struct breakpoint_handle null_deref_bp;
static struct breakpoint_handle null_fetch_bp;
static int handle_fetch_breakpoint(struct breakpoint_handle handle, struct eregs *regs)
{
printk(BIOS_ERR, "Instruction fetch from address zero\n");
return CONFIG(DEBUG_NULL_DEREF_HALT);
}
static int handle_deref_breakpoint(struct breakpoint_handle handle, struct eregs *regs)
{
#if ENV_X86_64
printk(BIOS_ERR, "Null dereference at rip: 0x%llx\n", regs->rip);
#else
printk(BIOS_ERR, "Null dereference at eip: 0x%x\n", regs->eip);
#endif
return CONFIG(DEBUG_NULL_DEREF_HALT);
}
static void create_deref_breakpoint(void)
{
enum breakpoint_result res =
breakpoint_create_data(&null_deref_bp, NULL, sizeof(uintptr_t), false);
if (res != BREAKPOINT_RES_OK) {
printk(BIOS_ERR, "Failed to create NULL dereference breakpoint\n");
return;
}
breakpoint_set_handler(null_deref_bp, &handle_deref_breakpoint);
breakpoint_enable(null_deref_bp, true);
}
static void create_instruction_breakpoint(void)
{
enum breakpoint_result res = breakpoint_create_instruction(&null_fetch_bp, NULL);
if (res != BREAKPOINT_RES_OK) {
printk(BIOS_ERR, "Failed to create address zero instruction fetch breakpoint\n");
return;
}
breakpoint_set_handler(null_fetch_bp, &handle_fetch_breakpoint);
breakpoint_enable(null_fetch_bp, true);
}
void null_breakpoint_init(void)
{
create_deref_breakpoint();
create_instruction_breakpoint();
}
void null_breakpoint_disable(void)
{
breakpoint_remove(null_fetch_bp);
breakpoint_remove(null_deref_bp);
}
static void null_breakpoint_disable_hook(void *unused)
{
null_breakpoint_disable();
}
BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY, null_breakpoint_disable_hook, NULL);
BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_BOOT, BS_ON_ENTRY, null_breakpoint_disable_hook, NULL);
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