diff options
Diffstat (limited to 'arch/mips/mm/fault.c')
| -rw-r--r-- | arch/mips/mm/fault.c | 101 |
1 files changed, 89 insertions, 12 deletions
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c index e97a7a2fb2c..becc42bb184 100644 --- a/arch/mips/mm/fault.c +++ b/arch/mips/mm/fault.c @@ -5,6 +5,7 @@ * * Copyright (C) 1995 - 2000 by Ralf Baechle */ +#include <linux/context_tracking.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/interrupt.h> @@ -16,23 +17,24 @@ #include <linux/mman.h> #include <linux/mm.h> #include <linux/smp.h> -#include <linux/vt_kern.h> /* For unblank_screen() */ #include <linux/module.h> +#include <linux/kprobes.h> +#include <linux/perf_event.h> #include <asm/branch.h> #include <asm/mmu_context.h> -#include <asm/system.h> #include <asm/uaccess.h> #include <asm/ptrace.h> #include <asm/highmem.h> /* For VMALLOC_END */ +#include <linux/kdebug.h> /* * This routine handles page faults. It determines the address, * and the problem, and then passes it off to one of the appropriate * routines. */ -asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, - unsigned long address) +static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write, + unsigned long address) { struct vm_area_struct * vma = NULL; struct task_struct *tsk = current; @@ -40,6 +42,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, const int field = sizeof(unsigned long) * 2; siginfo_t info; int fault; + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; #if 0 printk("Cpu%d[%s:%d:%0*lx:%ld:%0*lx]\n", raw_smp_processor_id(), @@ -47,6 +50,17 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, field, regs->cp0_epc); #endif +#ifdef CONFIG_KPROBES + /* + * This is to notify the fault handler of the kprobes. The + * exception code is redundant as it is also carried in REGS, + * but we pass it anyhow. + */ + if (notify_die(DIE_PAGE_FAULT, "page fault", regs, -1, + (regs->cp0_cause >> 2) & 0x1f, SIGSEGV) == NOTIFY_STOP) + return; +#endif + info.si_code = SEGV_MAPERR; /* @@ -78,6 +92,9 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, if (in_atomic() || !mm) goto bad_area_nosemaphore; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; +retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); if (!vma) @@ -98,9 +115,33 @@ good_area: if (write) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } else { - if (!(vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC))) - goto bad_area; + if (cpu_has_rixi) { + if (address == regs->cp0_epc && !(vma->vm_flags & VM_EXEC)) { +#if 0 + pr_notice("Cpu%d[%s:%d:%0*lx:%ld:%0*lx] XI violation\n", + raw_smp_processor_id(), + current->comm, current->pid, + field, address, write, + field, regs->cp0_epc); +#endif + goto bad_area; + } + if (!(vma->vm_flags & VM_READ)) { +#if 0 + pr_notice("Cpu%d[%s:%d:%0*lx:%ld:%0*lx] RI violation\n", + raw_smp_processor_id(), + current->comm, current->pid, + field, address, write, + field, regs->cp0_epc); +#endif + goto bad_area; + } + } else { + if (!(vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC))) + goto bad_area; + } } /* @@ -108,7 +149,12 @@ good_area: * make sure we exit gracefully rather than endlessly redo * the fault. */ - fault = handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0); + fault = handle_mm_fault(mm, vma, address, flags); + + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) + return; + + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; @@ -116,10 +162,29 @@ good_area: goto do_sigbus; BUG(); } - if (fault & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; + if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (fault & VM_FAULT_MAJOR) { + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, + regs, address); + tsk->maj_flt++; + } else { + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, + regs, address); + tsk->min_flt++; + } + if (fault & VM_FAULT_RETRY) { + flags &= ~FAULT_FLAG_ALLOW_RETRY; + flags |= FAULT_FLAG_TRIED; + + /* + * 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; @@ -154,7 +219,7 @@ bad_area_nosemaphore: } no_context: - /* Are we prepared to handle this kernel fault? */ + /* Are we prepared to handle this kernel fault? */ if (fixup_exception(regs)) { current->thread.cp0_baduaddr = address; return; @@ -178,6 +243,8 @@ out_of_memory: * (which will retry the fault, or kill us if we got oom-killed). */ up_read(&mm->mmap_sem); + if (!user_mode(regs)) + goto no_context; pagefault_out_of_memory(); return; @@ -250,3 +317,13 @@ vmalloc_fault: } #endif } + +asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, + unsigned long write, unsigned long address) +{ + enum ctx_state prev_state; + + prev_state = exception_enter(); + __do_page_fault(regs, write, address); + exception_exit(prev_state); +} |