If we are faulting in kernel it is quite possible this will lead to a panic. Save trap number, cr2 (in case of page fault) and error_code in the current thread (these fields already exist for signal delivery but are not used here). This helps later kdump crash analyzing from user-space (a script has been submitted to dig this info out in gdb).
Unified · Split
| @@ -369,6 +369,10 @@ static inline void die_if_kernel(const char * str, struct pt_regs * regs, long e · 368 unmodified lines | |||
| 369 | static void do_trap(int trapnr, int signr, char *str, int vm86, | 369 | static void do_trap(int trapnr, int signr, char *str, int vm86, |
| 370 | struct pt_regs * regs, long error_code, siginfo_t *info) | 370 | struct pt_regs * regs, long error_code, siginfo_t *info) |
| 371 | { | 371 | { |
| 372 | struct task_struct *tsk = current; | ||
| 373 | tsk->thread.error_code = error_code; | ||
| 374 | tsk->thread.trap_no = trapnr; | ||
| 375 | |||
| 372 | if (regs->eflags & VM_MASK) { | 376 | if (regs->eflags & VM_MASK) { |
| 373 | if (vm86) | 377 | if (vm86) |
| 374 | goto vm86_trap; | 378 | goto vm86_trap; |
| @@ -379,9 +383,6 @@ static void do_trap(int trapnr, int signr, char *str, int vm86, · 4 unmodified lines | |||
| 379 | goto kernel_trap; | 383 | goto kernel_trap; |
| 380 | 384 | ||
| 381 | trap_signal: { | 385 | trap_signal: { |
| 382 | struct task_struct *tsk = current; | ||
| 383 | tsk->thread.error_code = error_code; | ||
| 384 | tsk->thread.trap_no = trapnr; | ||
| 385 | if (info) | 386 | if (info) |
| 386 | force_sig_info(signr, info, tsk); | 387 | force_sig_info(signr, info, tsk); |
| 387 | else | 388 | else |
| @@ -494,6 +495,9 @@ fastcall void do_general_protection(struct pt_regs * regs, long error_code) · 106 unmodified lines | |||
| 494 | } | 495 | } |
| 495 | put_cpu(); | 496 | put_cpu(); |
| 496 | 497 | ||
| 498 | current->thread.error_code = error_code; | ||
| 499 | current->thread.trap_no = 13; | ||
| 500 | |||
| 497 | if (regs->eflags & VM_MASK) | 501 | if (regs->eflags & VM_MASK) |
| 498 | goto gp_in_vm86; | 502 | goto gp_in_vm86; |
| 499 | 503 | ||
| @@ -897,9 +901,9 @@ fastcall void do_simd_coprocessor_error(struct pt_regs * regs, · 397 unmodified lines | |||
| 897 | error_code); | 901 | error_code); |
| 898 | return; | 902 | return; |
| 899 | } | 903 | } |
| 900 | die_if_kernel("cache flush denied", regs, error_code); | ||
| 901 | current->thread.trap_no = 19; | 904 | current->thread.trap_no = 19; |
| 902 | current->thread.error_code = error_code; | 905 | current->thread.error_code = error_code; |
| 906 | die_if_kernel("cache flush denied", regs, error_code); | ||
| 903 | force_sig(SIGSEGV, current); | 907 | force_sig(SIGSEGV, current); |
| 904 | } | 908 | } |
| 905 | } | 909 | } |
| @@ -463,6 +463,9 @@ no_context: · 462 unmodified lines | |||
| 463 | printk(KERN_ALERT "*pte = %08lx\n", page); | 463 | printk(KERN_ALERT "*pte = %08lx\n", page); |
| 464 | } | 464 | } |
| 465 | #endif | 465 | #endif |
| 466 | tsk->thread.cr2 = address; | ||
| 467 | tsk->thread.trap_no = 14; | ||
| 468 | tsk->thread.error_code = error_code; | ||
| 466 | die("Oops", regs, error_code); | 469 | die("Oops", regs, error_code); |
| 467 | bust_spinlocks(0); | 470 | bust_spinlocks(0); |
| 468 | do_exit(SIGKILL); | 471 | do_exit(SIGKILL); |