X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fpowerpc%2Fmm%2Ffault.c;h=2d9e651b9bc311aa1ef841f2caa648d9bd0c5aa0;hb=refs%2Fheads%2Fvserver;hp=a4815d316722cddcf9c614b4524f57238f7a4c9f;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index a4815d316..2d9e651b9 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -1,6 +1,4 @@ /* - * arch/ppc/mm/fault.c - * * PowerPC version * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * @@ -17,7 +15,6 @@ * 2 of the License, or (at your option) any later version. */ -#include #include #include #include @@ -42,6 +39,40 @@ #include #include +#ifdef CONFIG_KPROBES +ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain); + +/* Hook to register for page fault notifications */ +int register_page_fault_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_register(¬ify_page_fault_chain, nb); +} + +int unregister_page_fault_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb); +} + +static inline int notify_page_fault(enum die_val val, const char *str, + struct pt_regs *regs, long err, int trap, int sig) +{ + struct die_args args = { + .regs = regs, + .str = str, + .err = err, + .trapnr = trap, + .signr = sig + }; + return atomic_notifier_call_chain(¬ify_page_fault_chain, val, &args); +} +#else +static inline int notify_page_fault(enum die_val val, const char *str, + struct pt_regs *regs, long err, int trap, int sig) +{ + return NOTIFY_DONE; +} +#endif + /* * Check whether the instruction at regs->nip is a store using * an update addressing form which will update r1. @@ -144,7 +175,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address, is_write = error_code & ESR_DST; #endif /* CONFIG_4xx || CONFIG_BOOKE */ - if (notify_die(DIE_PAGE_FAULT, "page_fault", regs, error_code, + if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs, error_code, 11, SIGSEGV) == NOTIFY_STOP) return 0; @@ -179,15 +210,15 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address, /* When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in the - * kernel and should generate an OOPS. Unfortunatly, in the case of an - * erroneous fault occuring in a code path which already holds mmap_sem + * kernel and should generate an OOPS. Unfortunately, in the case of an + * erroneous fault occurring in a code path which already holds mmap_sem * we will deadlock attempting to validate the fault against the * address space. Luckily the kernel only validly references user * space from well defined areas of code, which are listed in the * exceptions table. * * As the vast majority of faults will be valid we will only perform - * the source reference check when there is a possibilty of a deadlock. + * the source reference check when there is a possibility of a deadlock. * Attempt to lock the address space, if we cannot we then validate the * source. If this is invalid we can skip the address space check, * thus avoiding the deadlock. @@ -269,25 +300,29 @@ good_area: #endif #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) pte_t *ptep; + pmd_t *pmdp; /* Since 4xx/Book-E supports per-page execute permission, * we lazily flush dcache to icache. */ ptep = NULL; - if (get_pteptr(mm, address, &ptep) && pte_present(*ptep)) { - struct page *page = pte_page(*ptep); - - if (! test_bit(PG_arch_1, &page->flags)) { - flush_dcache_icache_page(page); - set_bit(PG_arch_1, &page->flags); + if (get_pteptr(mm, address, &ptep, &pmdp)) { + spinlock_t *ptl = pte_lockptr(mm, pmdp); + spin_lock(ptl); + if (pte_present(*ptep)) { + struct page *page = pte_page(*ptep); + + if (!test_bit(PG_arch_1, &page->flags)) { + flush_dcache_icache_page(page); + set_bit(PG_arch_1, &page->flags); + } + pte_update(ptep, 0, _PAGE_HWEXEC); + _tlbie(address); + pte_unmap_unlock(ptep, ptl); + up_read(&mm->mmap_sem); + return 0; } - pte_update(ptep, 0, _PAGE_HWEXEC); - _tlbie(address); - pte_unmap(ptep); - up_read(&mm->mmap_sem); - return 0; + pte_unmap_unlock(ptep, ptl); } - if (ptep != NULL) - pte_unmap(ptep); #endif /* a write */ } else if (is_write) { @@ -298,7 +333,7 @@ good_area: /* protection fault */ if (error_code & 0x08000000) goto bad_area; - if (!(vma->vm_flags & (VM_READ | VM_EXEC))) + if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) goto bad_area; } @@ -351,12 +386,13 @@ bad_area_nosemaphore: */ out_of_memory: up_read(&mm->mmap_sem); - if (current->pid == 1) { + if (is_init(current)) { yield(); down_read(&mm->mmap_sem); goto survive; } - printk("VM: killing process %s\n", current->comm); + printk("VM: killing process %s(%d:#%u)\n", + current->comm, current->pid, current->xid); if (user_mode(regs)) do_exit(SIGKILL); return SIGKILL; @@ -391,18 +427,21 @@ void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig) /* kernel has accessed a bad area */ - printk(KERN_ALERT "Unable to handle kernel paging request for "); switch (regs->trap) { - case 0x300: - case 0x380: - printk("data at address 0x%08lx\n", regs->dar); - break; - case 0x400: - case 0x480: - printk("instruction fetch\n"); - break; - default: - printk("unknown fault\n"); + case 0x300: + case 0x380: + printk(KERN_ALERT "Unable to handle kernel paging request for " + "data at address 0x%08lx\n", regs->dar); + break; + case 0x400: + case 0x480: + printk(KERN_ALERT "Unable to handle kernel paging request for " + "instruction fetch\n"); + break; + default: + printk(KERN_ALERT "Unable to handle kernel paging request for " + "unknown fault\n"); + break; } printk(KERN_ALERT "Faulting instruction address: 0x%08lx\n", regs->nip);