| /* 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); |