diff options
Diffstat (limited to 'arch/powerpc/mm/fault.c')
| -rw-r--r-- | arch/powerpc/mm/fault.c | 71 |
1 files changed, 61 insertions, 10 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index a8d0ce85d39a..2bef19cc1b98 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -270,7 +270,11 @@ static bool access_error(bool is_write, bool is_exec, struct vm_area_struct *vma return false; } - if (unlikely(!vma_is_accessible(vma))) + /* + * Check for a read fault. This could be caused by a read on an + * inaccessible page (i.e. PROT_NONE), or a Radix MMU execute-only page. + */ + if (unlikely(!(vma->vm_flags & VM_READ))) return true; /* * We should ideally do the vma pkey access check here. But in the @@ -367,7 +371,22 @@ static void sanity_check_fault(bool is_write, bool is_user, #elif defined(CONFIG_PPC_8xx) #define page_fault_is_bad(__err) ((__err) & DSISR_NOEXEC_OR_G) #elif defined(CONFIG_PPC64) -#define page_fault_is_bad(__err) ((__err) & DSISR_BAD_FAULT_64S) +static int page_fault_is_bad(unsigned long err) +{ + unsigned long flag = DSISR_BAD_FAULT_64S; + + /* + * PAPR+ v2.11 ยง 14.15.3.4.1 (unreleased) + * If byte 0, bit 3 of pi-attribute-specifier-type in + * ibm,pi-features property is defined, ignore the DSI error + * which is caused by the paste instruction on the + * suspended NX window. + */ + if (mmu_has_feature(MMU_FTR_NX_DSI)) + flag &= ~DSISR_BAD_COPYPASTE; + + return err & flag; +} #else #define page_fault_is_bad(__err) ((__err) & DSISR_BAD_FAULT_32S) #endif @@ -511,15 +530,17 @@ retry: if (fault_signal_pending(fault, regs)) return user_mode(regs) ? 0 : SIGBUS; + /* The fault is fully completed (including releasing mmap lock) */ + if (fault & VM_FAULT_COMPLETED) + goto out; + /* * Handle the retry right now, the mmap_lock has been released in that * case. */ if (unlikely(fault & VM_FAULT_RETRY)) { - if (flags & FAULT_FLAG_ALLOW_RETRY) { - flags |= FAULT_FLAG_TRIED; - goto retry; - } + flags |= FAULT_FLAG_TRIED; + goto retry; } mmap_read_unlock(current->mm); @@ -527,6 +548,7 @@ retry: if (unlikely(fault & VM_FAULT_ERROR)) return mm_fault_error(regs, address, fault); +out: /* * Major/minor page fault accounting. */ @@ -568,18 +590,24 @@ NOKPROBE_SYMBOL(hash__do_page_fault); static void __bad_page_fault(struct pt_regs *regs, int sig) { int is_write = page_fault_is_write(regs->dsisr); + const char *msg; /* kernel has accessed a bad area */ + if (regs->dar < PAGE_SIZE) + msg = "Kernel NULL pointer dereference"; + else + msg = "Unable to handle kernel data access"; + switch (TRAP(regs)) { case INTERRUPT_DATA_STORAGE: - case INTERRUPT_DATA_SEGMENT: case INTERRUPT_H_DATA_STORAGE: - pr_alert("BUG: %s on %s at 0x%08lx\n", - regs->dar < PAGE_SIZE ? "Kernel NULL pointer dereference" : - "Unable to handle kernel data access", + pr_alert("BUG: %s on %s at 0x%08lx\n", msg, is_write ? "write" : "read", regs->dar); break; + case INTERRUPT_DATA_SEGMENT: + pr_alert("BUG: %s at 0x%08lx\n", msg, regs->dar); + break; case INTERRUPT_INST_STORAGE: case INTERRUPT_INST_SEGMENT: pr_alert("BUG: Unable to handle kernel instruction fetch%s", @@ -620,4 +648,27 @@ DEFINE_INTERRUPT_HANDLER(do_bad_page_fault_segv) { bad_page_fault(regs, SIGSEGV); } + +/* + * In radix, segment interrupts indicate the EA is not addressable by the + * page table geometry, so they are always sent here. + * + * In hash, this is called if do_slb_fault returns error. Typically it is + * because the EA was outside the region allowed by software. + */ +DEFINE_INTERRUPT_HANDLER(do_bad_segment_interrupt) +{ + int err = regs->result; + + if (err == -EFAULT) { + if (user_mode(regs)) + _exception(SIGSEGV, regs, SEGV_BNDERR, regs->dar); + else + bad_page_fault(regs, SIGSEGV); + } else if (err == -EINVAL) { + unrecoverable_exception(regs); + } else { + BUG(); + } +} #endif |