diff options
| -rw-r--r-- | arch/alpha/mm/fault.c | 36 |
1 files changed, 30 insertions, 6 deletions
diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c index 5eecab1a84e..0c4132dd350 100644 --- a/arch/alpha/mm/fault.c +++ b/arch/alpha/mm/fault.c @@ -89,6 +89,8 @@ do_page_fault(unsigned long address, unsigned long mmcsr, const struct exception_table_entry *fixup; int fault, si_code = SEGV_MAPERR; siginfo_t info; + unsigned int flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | + (cause > 0 ? FAULT_FLAG_WRITE : 0)); /* As of EV6, a load into $31/$f31 is a prefetch, and never faults (or is suppressed by the PALcode). Support that for older CPUs @@ -114,6 +116,7 @@ do_page_fault(unsigned long address, unsigned long mmcsr, goto vmalloc_fault; #endif +retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); if (!vma) @@ -144,8 +147,11 @@ do_page_fault(unsigned long address, unsigned long mmcsr, /* If for any reason at all we couldn't handle the fault, make sure we exit gracefully rather than endlessly redo the fault. */ - fault = handle_mm_fault(mm, vma, address, cause > 0 ? FAULT_FLAG_WRITE : 0); - up_read(&mm->mmap_sem); + fault = handle_mm_fault(mm, vma, address, flags); + + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) + return; + if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; @@ -153,10 +159,26 @@ do_page_fault(unsigned long address, unsigned long mmcsr, goto do_sigbus; BUG(); } - if (fault & VM_FAULT_MAJOR) - current->maj_flt++; - else - current->min_flt++; + + if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (fault & VM_FAULT_MAJOR) + current->maj_flt++; + else + current->min_flt++; + if (fault & VM_FAULT_RETRY) { + flags &= ~FAULT_FLAG_ALLOW_RETRY; + + /* No need to up_read(&mm->mmap_sem) as we would + * have already released it in __lock_page_or_retry + * in mm/filemap.c. + */ + + goto retry; + } + } + + up_read(&mm->mmap_sem); + return; /* Something tried to access memory that isn't in our memory map. @@ -186,12 +208,14 @@ do_page_fault(unsigned long address, unsigned long mmcsr, /* 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: + up_read(&mm->mmap_sem); if (!user_mode(regs)) goto no_context; pagefault_out_of_memory(); return; do_sigbus: + up_read(&mm->mmap_sem); /* Send a sigbus, regardless of whether we were in kernel or user mode. */ info.si_signo = SIGBUS; |