diff options
Diffstat (limited to 'arch/mips64/mm/fault.c')
| -rw-r--r-- | arch/mips64/mm/fault.c | 51 |
1 files changed, 44 insertions, 7 deletions
diff --git a/arch/mips64/mm/fault.c b/arch/mips64/mm/fault.c index 42e810176..a070ae50c 100644 --- a/arch/mips64/mm/fault.c +++ b/arch/mips64/mm/fault.c @@ -84,6 +84,18 @@ do_page_fault(struct pt_regs *regs, unsigned long write, unsigned long address) unsigned long fixup; siginfo_t info; + /* + * We fault-in kernel-space virtual memory on-demand. The + * 'reference' page table is init_mm.pgd. + * + * NOTE! We MUST NOT take any locks for this case. We may + * be in an interrupt or a critical region, and should + * only copy the information from the master page table, + * nothing more. + */ + if (address >= TASK_SIZE) + goto vmalloc_fault; + info.si_code = SEGV_MAPERR; /* * If we're in an interrupt or have no user @@ -148,13 +160,7 @@ good_area: bad_area: up_read(&mm->mmap_sem); - /* - * Quickly check for vmalloc range faults. - */ - if ((!vma) && (address >= VMALLOC_START) && (address < VMALLOC_END)) { - printk("Fix vmalloc invalidate fault\n"); - while(1); - } +bad_area_nosemaphore: if (user_mode(regs)) { tsk->thread.cp0_badvaddr = address; tsk->thread.error_code = write; @@ -232,4 +238,35 @@ do_sigbus: /* Kernel mode? Handle exceptions or die */ if (!user_mode(regs)) goto no_context; + + return; + +vmalloc_fault: + { + /* + * Synchronize this task's top level page-table + * with the 'reference' page table. + */ + int offset = pgd_index(address); + pgd_t *pgd, *pgd_k; + pmd_t *pmd, *pmd_k; + + pgd = tsk->active_mm->pgd + offset; + pgd_k = init_mm.pgd + offset; + + if (!pgd_present(*pgd)) { + if (!pgd_present(*pgd_k)) + goto bad_area_nosemaphore; + set_pgd(pgd, *pgd_k); + return; + } + + pmd = pmd_offset(pgd, address); + pmd_k = pmd_offset(pgd_k, address); + + if (pmd_present(*pmd) || !pmd_present(*pmd_k)) + goto bad_area_nosemaphore; + set_pmd(pmd, *pmd_k); + return; + } } |