diff options
Diffstat (limited to 'arch/cris/mm/fault.c')
| -rw-r--r-- | arch/cris/mm/fault.c | 101 |
1 files changed, 86 insertions, 15 deletions
diff --git a/arch/cris/mm/fault.c b/arch/cris/mm/fault.c index 03254b9eded..934c51078cc 100644 --- a/arch/cris/mm/fault.c +++ b/arch/cris/mm/fault.c @@ -6,6 +6,38 @@ * Authors: Bjorn Wesen * * $Log: fault.c,v $ + * Revision 1.20 2005/03/04 08:16:18 starvik + * Merge of Linux 2.6.11. + * + * Revision 1.19 2005/01/14 10:07:59 starvik + * Fixed warning. + * + * Revision 1.18 2005/01/12 08:10:14 starvik + * Readded the change of frametype when handling kernel page fault fixup + * for v10. This is necessary to avoid that the CPU remakes the faulting + * access. + * + * Revision 1.17 2005/01/11 13:53:05 starvik + * Use raw_printk. + * + * Revision 1.16 2004/12/17 11:39:41 starvik + * SMP support. + * + * Revision 1.15 2004/11/23 18:36:18 starvik + * Stack is now non-executable. + * Signal handler trampolines are placed in a reserved page mapped into all + * processes. + * + * Revision 1.14 2004/11/23 07:10:21 starvik + * Moved find_fixup_code to generic code. + * + * Revision 1.13 2004/11/23 07:00:54 starvik + * Actually use the execute permission bit in the MMU. This makes it possible + * to prevent e.g. attacks where executable code is put on the stack. + * + * Revision 1.12 2004/09/29 06:16:04 starvik + * Use instruction_pointer + * * Revision 1.11 2004/05/14 07:58:05 starvik * Merge of changes from 2.4 * @@ -103,6 +135,7 @@ extern int find_fixup_code(struct pt_regs *); extern void die_if_kernel(const char *, struct pt_regs *, long); +extern int raw_printk(const char *fmt, ...); /* debug of low-level TLB reload */ #undef DEBUG @@ -118,7 +151,8 @@ extern void die_if_kernel(const char *, struct pt_regs *, long); /* current active page directory */ -volatile pgd_t *current_pgd; +volatile DEFINE_PER_CPU(pgd_t *,current_pgd); +unsigned long cris_signal_return_page; /* * This routine handles page faults. It determines the address, @@ -146,8 +180,9 @@ do_page_fault(unsigned long address, struct pt_regs *regs, struct vm_area_struct * vma; siginfo_t info; - D(printk("Page fault for %X at %X, prot %d write %d\n", - address, regs->erp, protection, writeaccess)); + D(printk("Page fault for %lX on %X at %lX, prot %d write %d\n", + address, smp_processor_id(), instruction_pointer(regs), + protection, writeaccess)); tsk = current; @@ -175,8 +210,19 @@ do_page_fault(unsigned long address, struct pt_regs *regs, !user_mode(regs)) goto vmalloc_fault; + /* When stack execution is not allowed we store the signal + * trampolines in the reserved cris_signal_return_page. + * Handle this in the exact same way as vmalloc (we know + * that the mapping is there and is valid so no need to + * call handle_mm_fault). + */ + if (cris_signal_return_page && + address == cris_signal_return_page && + !protection && user_mode(regs)) + goto vmalloc_fault; + /* we can and should enable interrupts at this point */ - sti(); + local_irq_enable(); mm = tsk->mm; info.si_code = SEGV_MAPERR; @@ -220,7 +266,10 @@ do_page_fault(unsigned long address, struct pt_regs *regs, /* first do some preliminary protection checks */ - if (writeaccess) { + if (writeaccess == 2){ + if (!(vma->vm_flags & VM_EXEC)) + goto bad_area; + } else if (writeaccess == 1) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; } else { @@ -234,14 +283,14 @@ do_page_fault(unsigned long address, struct pt_regs *regs, * the fault. */ - switch (handle_mm_fault(mm, vma, address, writeaccess)) { - case 1: + switch (handle_mm_fault(mm, vma, address, writeaccess & 1)) { + case VM_FAULT_MINOR: tsk->min_flt++; break; - case 2: + case VM_FAULT_MAJOR: tsk->maj_flt++; break; - case 0: + case VM_FAULT_SIGBUS: goto do_sigbus; default: goto out_of_memory; @@ -292,10 +341,10 @@ do_page_fault(unsigned long address, struct pt_regs *regs, */ if ((unsigned long) (address) < PAGE_SIZE) - printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference"); + raw_printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference"); else - printk(KERN_ALERT "Unable to handle kernel access"); - printk(" at virtual address %08lx\n",address); + raw_printk(KERN_ALERT "Unable to handle kernel access"); + raw_printk(" at virtual address %08lx\n",address); die_if_kernel("Oops", regs, (writeaccess << 1) | protection); @@ -346,10 +395,11 @@ vmalloc_fault: int offset = pgd_index(address); pgd_t *pgd, *pgd_k; + pud_t *pud, *pud_k; pmd_t *pmd, *pmd_k; pte_t *pte_k; - pgd = (pgd_t *)current_pgd + offset; + pgd = (pgd_t *)per_cpu(current_pgd, smp_processor_id()) + offset; pgd_k = init_mm.pgd + offset; /* Since we're two-level, we don't need to do both @@ -364,8 +414,13 @@ vmalloc_fault: * it exists. */ - pmd = pmd_offset(pgd, address); - pmd_k = pmd_offset(pgd_k, address); + pud = pud_offset(pgd, address); + pud_k = pud_offset(pgd_k, address); + if (!pud_present(*pud_k)) + goto no_context; + + pmd = pmd_offset(pud, address); + pmd_k = pmd_offset(pud_k, address); if (!pmd_present(*pmd_k)) goto bad_area_nosemaphore; @@ -385,3 +440,19 @@ vmalloc_fault: return; } } + +/* Find fixup code. */ +int +find_fixup_code(struct pt_regs *regs) +{ + const struct exception_table_entry *fixup; + + if ((fixup = search_exception_tables(instruction_pointer(regs))) != 0) { + /* Adjust the instruction pointer in the stackframe. */ + instruction_pointer(regs) = fixup->fixup; + arch_fixup(regs); + return 1; + } + + return 0; +} |