diff options
Diffstat (limited to 'arch/parisc/mm/fault.c')
| -rw-r--r-- | arch/parisc/mm/fault.c | 138 |
1 files changed, 117 insertions, 21 deletions
diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c index 4a6221b869fd..869204e97ec9 100644 --- a/arch/parisc/mm/fault.c +++ b/arch/parisc/mm/fault.c @@ -22,6 +22,8 @@ #include <asm/traps.h> +#define DEBUG_NATLB 0 + /* Various important other fields */ #define bit22set(x) (x & 0x00000200) #define bits23_25set(x) (x & 0x000001c0) @@ -36,7 +38,7 @@ int show_unhandled_signals = 1; /* * parisc_acctyp(unsigned int inst) -- * Given a PA-RISC memory access instruction, determine if the - * the instruction would perform a memory read or memory write + * instruction would perform a memory read or memory write * operation. * * This function assumes that the given instruction is a memory access @@ -148,11 +150,11 @@ int fixup_exception(struct pt_regs *regs) * Fix up get_user() and put_user(). * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() sets the least-significant * bit in the relative address of the fixup routine to indicate - * that %r8 should be loaded with -EFAULT to report a userspace - * access error. + * that gr[ASM_EXCEPTIONTABLE_REG] should be loaded with + * -EFAULT to report a userspace access error. */ if (fix->fixup & 1) { - regs->gr[8] = -EFAULT; + regs->gr[ASM_EXCEPTIONTABLE_REG] = -EFAULT; /* zero target register for get_user() */ if (parisc_acctyp(0, regs->iir) == VM_READ) { @@ -266,14 +268,14 @@ void do_page_fault(struct pt_regs *regs, unsigned long code, unsigned long acc_type; vm_fault_t fault = 0; unsigned int flags; - - if (faulthandler_disabled()) - goto no_context; + char *msg; tsk = current; mm = tsk->mm; - if (!mm) + if (!mm) { + msg = "Page fault: no context"; goto no_context; + } flags = FAULT_FLAG_DEFAULT; if (user_mode(regs)) @@ -309,6 +311,10 @@ good_area: if (fault_signal_pending(fault, regs)) return; + /* The fault is fully completed (including releasing mmap lock) */ + if (fault & VM_FAULT_COMPLETED) + return; + if (unlikely(fault & VM_FAULT_ERROR)) { /* * We hit a shared mapping outside of the file, or some @@ -324,16 +330,14 @@ good_area: goto bad_area; BUG(); } - if (flags & FAULT_FLAG_ALLOW_RETRY) { - if (fault & VM_FAULT_RETRY) { - /* - * No need to mmap_read_unlock(mm) as we would - * have already released it in __lock_page_or_retry - * in mm/filemap.c. - */ - flags |= FAULT_FLAG_TRIED; - goto retry; - } + if (fault & VM_FAULT_RETRY) { + /* + * No need to mmap_read_unlock(mm) as we would + * have already released it in __lock_page_or_retry + * in mm/filemap.c. + */ + flags |= FAULT_FLAG_TRIED; + goto retry; } mmap_read_unlock(mm); return; @@ -409,6 +413,7 @@ bad_area: force_sig_fault(signo, si_code, (void __user *) address); return; } + msg = "Page fault: bad address"; no_context: @@ -416,11 +421,102 @@ no_context: return; } - parisc_terminate("Bad Address (null pointer deref?)", regs, code, address); + parisc_terminate(msg, regs, code, address); - out_of_memory: +out_of_memory: mmap_read_unlock(mm); - if (!user_mode(regs)) + if (!user_mode(regs)) { + msg = "Page fault: out of memory"; goto no_context; + } pagefault_out_of_memory(); } + +/* Handle non-access data TLB miss faults. + * + * For probe instructions, accesses to userspace are considered allowed + * if they lie in a valid VMA and the access type matches. We are not + * allowed to handle MM faults here so there may be situations where an + * actual access would fail even though a probe was successful. + */ +int +handle_nadtlb_fault(struct pt_regs *regs) +{ + unsigned long insn = regs->iir; + int breg, treg, xreg, val = 0; + struct vm_area_struct *vma, *prev_vma; + struct task_struct *tsk; + struct mm_struct *mm; + unsigned long address; + unsigned long acc_type; + + switch (insn & 0x380) { + case 0x280: + /* FDC instruction */ + fallthrough; + case 0x380: + /* PDC and FIC instructions */ + if (DEBUG_NATLB && printk_ratelimit()) { + pr_warn("WARNING: nullifying cache flush/purge instruction\n"); + show_regs(regs); + } + if (insn & 0x20) { + /* Base modification */ + breg = (insn >> 21) & 0x1f; + xreg = (insn >> 16) & 0x1f; + if (breg && xreg) + regs->gr[breg] += regs->gr[xreg]; + } + regs->gr[0] |= PSW_N; + return 1; + + case 0x180: + /* PROBE instruction */ + treg = insn & 0x1f; + if (regs->isr) { + tsk = current; + mm = tsk->mm; + if (mm) { + /* Search for VMA */ + address = regs->ior; + mmap_read_lock(mm); + vma = find_vma_prev(mm, address, &prev_vma); + mmap_read_unlock(mm); + + /* + * Check if access to the VMA is okay. + * We don't allow for stack expansion. + */ + acc_type = (insn & 0x40) ? VM_WRITE : VM_READ; + if (vma + && address >= vma->vm_start + && (vma->vm_flags & acc_type) == acc_type) + val = 1; + } + } + if (treg) + regs->gr[treg] = val; + regs->gr[0] |= PSW_N; + return 1; + + case 0x300: + /* LPA instruction */ + if (insn & 0x20) { + /* Base modification */ + breg = (insn >> 21) & 0x1f; + xreg = (insn >> 16) & 0x1f; + if (breg && xreg) + regs->gr[breg] += regs->gr[xreg]; + } + treg = insn & 0x1f; + if (treg) + regs->gr[treg] = 0; + regs->gr[0] |= PSW_N; + return 1; + + default: + break; + } + + return 0; +} |