Paul Mundt | 5a4f7c6 | 2007-11-20 18:08:06 +0900 | [diff] [blame] | 1 | #include <linux/bug.h> |
| 2 | #include <linux/io.h> |
| 3 | #include <linux/types.h> |
| 4 | #include <linux/kdebug.h> |
Paul Mundt | 47a3eb9 | 2007-11-26 18:17:51 +0900 | [diff] [blame] | 5 | #include <linux/signal.h> |
| 6 | #include <linux/sched.h> |
Paul Mundt | 9a33fc2 | 2008-05-19 19:32:07 +0900 | [diff] [blame] | 7 | #include <linux/uaccess.h> |
Paul Mundt | 1e1030d | 2009-09-01 17:38:32 +0900 | [diff] [blame] | 8 | #include <linux/hardirq.h> |
Paul Mundt | e115f2c | 2009-08-22 05:28:25 +0900 | [diff] [blame] | 9 | #include <asm/unwinder.h> |
Paul Mundt | 5a4f7c6 | 2007-11-20 18:08:06 +0900 | [diff] [blame] | 10 | #include <asm/system.h> |
| 11 | |
| 12 | #ifdef CONFIG_BUG |
Matt Fleming | b344e24a | 2009-08-16 21:54:48 +0100 | [diff] [blame] | 13 | void handle_BUG(struct pt_regs *regs) |
Paul Mundt | 5a4f7c6 | 2007-11-20 18:08:06 +0900 | [diff] [blame] | 14 | { |
Paul Mundt | e115f2c | 2009-08-22 05:28:25 +0900 | [diff] [blame] | 15 | const struct bug_entry *bug; |
| 16 | unsigned long bugaddr = regs->pc; |
Paul Mundt | 5a4f7c6 | 2007-11-20 18:08:06 +0900 | [diff] [blame] | 17 | enum bug_trap_type tt; |
Paul Mundt | e115f2c | 2009-08-22 05:28:25 +0900 | [diff] [blame] | 18 | |
| 19 | if (!is_valid_bugaddr(bugaddr)) |
| 20 | goto invalid; |
| 21 | |
| 22 | bug = find_bug(bugaddr); |
| 23 | |
| 24 | /* Switch unwinders when unwind_stack() is called */ |
| 25 | if (bug->flags & BUGFLAG_UNWINDER) |
| 26 | unwinder_faulted = 1; |
| 27 | |
| 28 | tt = report_bug(bugaddr, regs); |
Paul Mundt | 5a4f7c6 | 2007-11-20 18:08:06 +0900 | [diff] [blame] | 29 | if (tt == BUG_TRAP_TYPE_WARN) { |
Paul Mundt | e115f2c | 2009-08-22 05:28:25 +0900 | [diff] [blame] | 30 | regs->pc += instruction_size(bugaddr); |
Paul Mundt | 5a4f7c6 | 2007-11-20 18:08:06 +0900 | [diff] [blame] | 31 | return; |
| 32 | } |
| 33 | |
Paul Mundt | e115f2c | 2009-08-22 05:28:25 +0900 | [diff] [blame] | 34 | invalid: |
Paul Mundt | 5a4f7c6 | 2007-11-20 18:08:06 +0900 | [diff] [blame] | 35 | die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); |
| 36 | } |
| 37 | |
| 38 | int is_valid_bugaddr(unsigned long addr) |
| 39 | { |
Paul Mundt | 2bcfffa | 2009-05-09 16:02:08 +0900 | [diff] [blame] | 40 | insn_size_t opcode; |
Paul Mundt | 9a33fc2 | 2008-05-19 19:32:07 +0900 | [diff] [blame] | 41 | |
| 42 | if (addr < PAGE_OFFSET) |
| 43 | return 0; |
Paul Mundt | 2bcfffa | 2009-05-09 16:02:08 +0900 | [diff] [blame] | 44 | if (probe_kernel_address((insn_size_t *)addr, opcode)) |
Paul Mundt | 9a33fc2 | 2008-05-19 19:32:07 +0900 | [diff] [blame] | 45 | return 0; |
Paul Mundt | e115f2c | 2009-08-22 05:28:25 +0900 | [diff] [blame] | 46 | if (opcode == TRAPA_BUG_OPCODE) |
Matt Fleming | b344e24a | 2009-08-16 21:54:48 +0100 | [diff] [blame] | 47 | return 1; |
| 48 | |
| 49 | return 0; |
Paul Mundt | 5a4f7c6 | 2007-11-20 18:08:06 +0900 | [diff] [blame] | 50 | } |
| 51 | #endif |
| 52 | |
| 53 | /* |
| 54 | * Generic trap handler. |
| 55 | */ |
| 56 | BUILD_TRAP_HANDLER(debug) |
| 57 | { |
| 58 | TRAP_HANDLER_DECL; |
| 59 | |
| 60 | /* Rewind */ |
| 61 | regs->pc -= instruction_size(ctrl_inw(regs->pc - 4)); |
| 62 | |
| 63 | if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff, |
| 64 | SIGTRAP) == NOTIFY_STOP) |
| 65 | return; |
| 66 | |
| 67 | force_sig(SIGTRAP, current); |
| 68 | } |
| 69 | |
| 70 | /* |
| 71 | * Special handler for BUG() traps. |
| 72 | */ |
| 73 | BUILD_TRAP_HANDLER(bug) |
| 74 | { |
| 75 | TRAP_HANDLER_DECL; |
| 76 | |
| 77 | /* Rewind */ |
| 78 | regs->pc -= instruction_size(ctrl_inw(regs->pc - 4)); |
| 79 | |
| 80 | if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff, |
| 81 | SIGTRAP) == NOTIFY_STOP) |
| 82 | return; |
| 83 | |
| 84 | #ifdef CONFIG_BUG |
| 85 | if (__kernel_text_address(instruction_pointer(regs))) { |
Paul Mundt | 2bcfffa | 2009-05-09 16:02:08 +0900 | [diff] [blame] | 86 | insn_size_t insn = *(insn_size_t *)instruction_pointer(regs); |
Paul Mundt | 5a4f7c6 | 2007-11-20 18:08:06 +0900 | [diff] [blame] | 87 | if (insn == TRAPA_BUG_OPCODE) |
| 88 | handle_BUG(regs); |
Magnus Damm | 0ec3988 | 2009-06-17 04:48:20 +0000 | [diff] [blame] | 89 | return; |
Paul Mundt | 5a4f7c6 | 2007-11-20 18:08:06 +0900 | [diff] [blame] | 90 | } |
| 91 | #endif |
| 92 | |
| 93 | force_sig(SIGTRAP, current); |
| 94 | } |
Paul Mundt | 1e1030d | 2009-09-01 17:38:32 +0900 | [diff] [blame] | 95 | |
| 96 | BUILD_TRAP_HANDLER(nmi) |
| 97 | { |
| 98 | TRAP_HANDLER_DECL; |
| 99 | |
| 100 | nmi_enter(); |
| 101 | |
| 102 | switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) { |
| 103 | case NOTIFY_OK: |
| 104 | case NOTIFY_STOP: |
| 105 | break; |
| 106 | case NOTIFY_BAD: |
| 107 | die("Fatal Non-Maskable Interrupt", regs, SIGINT); |
| 108 | default: |
| 109 | printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n"); |
| 110 | break; |
| 111 | } |
| 112 | |
| 113 | nmi_exit(); |
| 114 | } |