X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=arch%2Fum%2Fkernel%2Ftrap.c;h=637c6505dc00de1ce482335023bff8227aedaaa1;hb=e576b9ef41c2c1b13e0c123b6e9d0589723c68bf;hp=3850d53f79fdd11afc86319be79e8f96baa12de5;hpb=83c54070ee1a2d05c89793884bea1a03f2851ed4;p=safe%2Fjmp%2Flinux-2.6 diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c index 3850d53..637c650 100644 --- a/arch/um/kernel/trap.c +++ b/arch/um/kernel/trap.c @@ -1,40 +1,25 @@ /* - * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com) + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Licensed under the GPL */ -#include "linux/kernel.h" -#include "asm/errno.h" -#include "linux/sched.h" -#include "linux/mm.h" -#include "linux/spinlock.h" -#include "linux/init.h" -#include "linux/ptrace.h" -#include "asm/semaphore.h" -#include "asm/pgtable.h" -#include "asm/pgalloc.h" -#include "asm/tlbflush.h" -#include "asm/a.out.h" -#include "asm/current.h" -#include "asm/irq.h" -#include "sysdep/sigcontext.h" -#include "kern_util.h" -#include "as-layout.h" +#include +#include +#include +#include +#include +#include #include "arch.h" -#include "kern.h" -#include "chan_kern.h" -#include "mconsole_kern.h" -#include "mem.h" -#include "mem_kern.h" -#include "sysdep/sigcontext.h" -#include "sysdep/ptrace.h" +#include "as-layout.h" +#include "kern_util.h" #include "os.h" -#ifdef CONFIG_MODE_SKAS #include "skas.h" -#endif -#include "os.h" +#include "sysdep/sigcontext.h" -/* Note this is constrained to return 0, -EFAULT, -EACCESS, -ENOMEM by segv(). */ +/* + * Note this is constrained to return 0, -EFAULT, -EACCESS, -ENOMEM by + * segv(). + */ int handle_page_fault(unsigned long address, unsigned long ip, int is_write, int is_user, int *code_out) { @@ -48,40 +33,41 @@ int handle_page_fault(unsigned long address, unsigned long ip, *code_out = SEGV_MAPERR; - /* If the fault was during atomic operation, don't take the fault, just - * fail. */ + /* + * If the fault was during atomic operation, don't take the fault, just + * fail. + */ if (in_atomic()) goto out_nosemaphore; down_read(&mm->mmap_sem); vma = find_vma(mm, address); - if(!vma) + if (!vma) goto out; - else if(vma->vm_start <= address) + else if (vma->vm_start <= address) goto good_area; - else if(!(vma->vm_flags & VM_GROWSDOWN)) + else if (!(vma->vm_flags & VM_GROWSDOWN)) goto out; - else if(is_user && !ARCH_IS_STACKGROW(address)) + else if (is_user && !ARCH_IS_STACKGROW(address)) goto out; - else if(expand_stack(vma, address)) + else if (expand_stack(vma, address)) goto out; good_area: *code_out = SEGV_ACCERR; - if(is_write && !(vma->vm_flags & VM_WRITE)) + if (is_write && !(vma->vm_flags & VM_WRITE)) goto out; /* Don't require VM_READ|VM_EXEC for write faults! */ - if(!is_write && !(vma->vm_flags & (VM_READ | VM_EXEC))) + if (!is_write && !(vma->vm_flags & (VM_READ | VM_EXEC))) goto out; do { int fault; -survive: - fault = handle_mm_fault(mm, vma, address, is_write); + + fault = handle_mm_fault(mm, vma, address, is_write ? FAULT_FLAG_WRITE : 0); if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) { - err = -ENOMEM; goto out_of_memory; } else if (fault & VM_FAULT_SIGBUS) { err = -EACCES; @@ -98,9 +84,10 @@ survive: pud = pud_offset(pgd, address); pmd = pmd_offset(pud, address); pte = pte_offset_kernel(pmd, address); - } while(!pte_present(*pte)); + } while (!pte_present(*pte)); err = 0; - /* The below warning was added in place of + /* + * The below warning was added in place of * pte_mkyoung(); if (is_write) pte_mkdirty(); * If it's triggered, we'd see normally a hang here (a clean pte is * marked read-only to emulate the dirty bit). @@ -114,20 +101,16 @@ survive: out: up_read(&mm->mmap_sem); out_nosemaphore: - return(err); + return err; -/* - * We ran out of memory, or some other thing happened to us that made - * us unable to handle the page fault gracefully. - */ out_of_memory: - if (is_init(current)) { - up_read(&mm->mmap_sem); - yield(); - down_read(&mm->mmap_sem); - goto survive; - } - goto out; + /* + * We ran out of memory, call the OOM killer, and return the userspace + * (which will retry the fault, or kill us if we got oom-killed). + */ + up_read(&mm->mmap_sem); + pagefault_out_of_memory(); + return 0; } static void bad_segv(struct faultinfo fi, unsigned long ip) @@ -141,11 +124,23 @@ static void bad_segv(struct faultinfo fi, unsigned long ip) force_sig_info(SIGSEGV, &si, current); } -static void segv_handler(int sig, union uml_pt_regs *regs) +void fatal_sigsegv(void) +{ + force_sigsegv(SIGSEGV, current); + do_signal(); + /* + * This is to tell gcc that we're not returning - do_signal + * can, in general, return, but in this case, it's not, since + * we just got a fatal SIGSEGV queued. + */ + os_dump_core(); +} + +void segv_handler(int sig, struct uml_pt_regs *regs) { struct faultinfo * fi = UPT_FAULTINFO(regs); - if(UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)){ + if (UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)) { bad_segv(*fi, UPT_IP(regs)); return; } @@ -159,45 +154,49 @@ static void segv_handler(int sig, union uml_pt_regs *regs) * give us bad data! */ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, - union uml_pt_regs *regs) + struct uml_pt_regs *regs) { struct siginfo si; - void *catcher; + 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)){ + if (!is_user && (address >= start_vm) && (address < end_vm)) { flush_tlb_kernel_vm(); return 0; } - else if(current->mm == NULL) { + else if (current->mm == NULL) { show_regs(container_of(regs, struct pt_regs, regs)); - panic("Segfault with no mm"); + 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); + 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. */ + /* + * 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) + if (!err) return 0; - else if(catcher != NULL){ + else if (catcher != NULL) { current->thread.fault_addr = (void *) address; - do_longjmp(catcher, 1); + UML_LONGJMP(catcher, 1); } - else if(current->thread.fault_addr != NULL) + else if (current->thread.fault_addr != NULL) panic("fault_addr set but no fault catcher"); - else if(!is_user && arch_fixup(ip, regs)) + else if (!is_user && arch_fixup(ip, regs)) return 0; - if(!is_user) { + 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); @@ -210,9 +209,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, si.si_addr = (void __user *)address; current->thread.arch.faultinfo = fi; force_sig_info(SIGBUS, &si, current); - } else if (err == -ENOMEM) { - printk("VM: killing process %s\n", current->comm); - do_exit(SIGKILL); } else { BUG_ON(err != -EFAULT); si.si_signo = SIGSEGV; @@ -223,43 +219,33 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, return 0; } -void relay_signal(int sig, union uml_pt_regs *regs) +void relay_signal(int sig, struct uml_pt_regs *regs) { - if(arch_handle_signal(sig, regs)) - return; - - if(!UPT_IS_USER(regs)){ - if(sig == SIGBUS) - printk("Bus error - the host /dev/shm or /tmp mount " - "likely just ran out of space\n"); + if (!UPT_IS_USER(regs)) { + if (sig == SIGBUS) + printk(KERN_ERR "Bus error - the host /dev/shm or /tmp " + "mount likely just ran out of space\n"); panic("Kernel mode signal %d", sig); } + arch_examine_signal(sig, regs); + current->thread.arch.faultinfo = *UPT_FAULTINFO(regs); force_sig(sig, current); } -static void bus_handler(int sig, union uml_pt_regs *regs) +void bus_handler(int sig, struct uml_pt_regs *regs) { - if(current->thread.fault_catcher != NULL) - do_longjmp(current->thread.fault_catcher, 1); + if (current->thread.fault_catcher != NULL) + UML_LONGJMP(current->thread.fault_catcher, 1); else relay_signal(sig, regs); } -static void winch(int sig, union uml_pt_regs *regs) +void winch(int sig, struct uml_pt_regs *regs) { do_IRQ(WINCH_IRQ, regs); } -const struct kern_handlers handlinfo_kern = { - .relay_signal = relay_signal, - .winch = winch, - .bus_handler = bus_handler, - .page_fault = segv_handler, - .sigio_handler = sigio_handler, - .timer_handler = timer_handler -}; - void trap_init(void) { }