void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs) { if (current->thread.fault_catcher != NULL) UML_LONGJMP(current->thread.fault_catcher, 1); else relay_signal(sig, si, regs); }
/* * We give a *copy* of the faultinfo in the regs to segv. * This must be done, since nesting SEGVs could overwrite * the info in the regs. A pointer to the info then would * give us bad data! */ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, struct uml_pt_regs *regs) { struct siginfo si; jmp_buf *catcher; int err; int is_write = FAULT_WRITE(fi); unsigned long address = FAULT_ADDRESS(fi); if (!is_user && (address >= start_vm) && (address < end_vm)) { flush_tlb_kernel_vm(); return 0; } else if (current->mm == NULL) { show_regs(container_of(regs, struct pt_regs, regs)); panic("Segfault with no mm"); } if (SEGV_IS_FIXABLE(&fi) || SEGV_MAYBE_FIXABLE(&fi)) err = handle_page_fault(address, ip, is_write, is_user, &si.si_code); else { err = -EFAULT; /* * A thread accessed NULL, we get a fault, but CR2 is invalid. * This code is used in __do_copy_from_user() of TT mode. * XXX tt mode is gone, so maybe this isn't needed any more */ address = 0; } catcher = current->thread.fault_catcher; if (!err) return 0; else if (catcher != NULL) { current->thread.fault_addr = (void *) address; UML_LONGJMP(catcher, 1); } else if (current->thread.fault_addr != NULL) panic("fault_addr set but no fault catcher"); else if (!is_user && arch_fixup(ip, regs)) return 0; if (!is_user) { show_regs(container_of(regs, struct pt_regs, regs)); panic("Kernel mode fault at addr 0x%lx, ip 0x%lx", address, ip); } if (err == -EACCES) { si.si_signo = SIGBUS; si.si_errno = 0; si.si_code = BUS_ADRERR; si.si_addr = (void __user *)address; current->thread.arch.faultinfo = fi; force_sig_info(SIGBUS, &si, current); } else if (err == -ENOMEM) { printk(KERN_INFO "VM: killing process %s\n", current->comm); do_exit(SIGKILL); } else { BUG_ON(err != -EFAULT); si.si_signo = SIGSEGV; si.si_addr = (void __user *) address; current->thread.arch.faultinfo = fi; force_sig_info(SIGSEGV, &si, current); } return 0; }
void do_longjmp(void *b, int val) { jmp_buf *buf = b; UML_LONGJMP(buf, val); }