diff options
Diffstat (limited to 'arch/s390/lib')
-rw-r--r-- | arch/s390/lib/uaccess_mvcos.c | 53 | ||||
-rw-r--r-- | arch/s390/lib/uaccess_pt.c | 320 |
2 files changed, 372 insertions, 1 deletions
diff --git a/arch/s390/lib/uaccess_mvcos.c b/arch/s390/lib/uaccess_mvcos.c index 78c48f88f5f7..6d8772339d76 100644 --- a/arch/s390/lib/uaccess_mvcos.c +++ b/arch/s390/lib/uaccess_mvcos.c @@ -162,6 +162,44 @@ static size_t clear_user_mvcos(size_t size, void __user *to) return size; } +static size_t strnlen_user_mvcos(size_t count, const char __user *src) +{ + char buf[256]; + int rc; + size_t done, len, len_str; + + done = 0; + do { + len = min(count - done, (size_t) 256); + rc = uaccess.copy_from_user(len, src + done, buf); + if (unlikely(rc == len)) + return 0; + len -= rc; + len_str = strnlen(buf, len); + done += len_str; + } while ((len_str == len) && (done < count)); + return done + 1; +} + +static size_t strncpy_from_user_mvcos(size_t count, const char __user *src, + char *dst) +{ + int rc; + size_t done, len, len_str; + + done = 0; + do { + len = min(count - done, (size_t) 4096); + rc = uaccess.copy_from_user(len, src + done, dst); + if (unlikely(rc == len)) + return -EFAULT; + len -= rc; + len_str = strnlen(dst, len); + done += len_str; + } while ((len_str == len) && (done < count)); + return done; +} + struct uaccess_ops uaccess_mvcos = { .copy_from_user = copy_from_user_mvcos_check, .copy_from_user_small = copy_from_user_std, @@ -174,3 +212,18 @@ struct uaccess_ops uaccess_mvcos = { .futex_atomic_op = futex_atomic_op_std, .futex_atomic_cmpxchg = futex_atomic_cmpxchg_std, }; + +#ifdef CONFIG_S390_SWITCH_AMODE +struct uaccess_ops uaccess_mvcos_switch = { + .copy_from_user = copy_from_user_mvcos, + .copy_from_user_small = copy_from_user_mvcos, + .copy_to_user = copy_to_user_mvcos, + .copy_to_user_small = copy_to_user_mvcos, + .copy_in_user = copy_in_user_mvcos, + .clear_user = clear_user_mvcos, + .strnlen_user = strnlen_user_mvcos, + .strncpy_from_user = strncpy_from_user_mvcos, + .futex_atomic_op = futex_atomic_op_pt, + .futex_atomic_cmpxchg = futex_atomic_cmpxchg_pt, +}; +#endif diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c index 24ead559c7bb..637192fa7c9a 100644 --- a/arch/s390/lib/uaccess_pt.c +++ b/arch/s390/lib/uaccess_pt.c @@ -1,7 +1,8 @@ /* * arch/s390/lib/uaccess_pt.c * - * User access functions based on page table walks. + * User access functions based on page table walks for enhanced + * system layout without hardware support. * * Copyright IBM Corp. 2006 * Author(s): Gerald Schaefer (gerald.schaefer@de.ibm.com) @@ -134,6 +135,49 @@ fault: goto retry; } +/* + * Do DAT for user address by page table walk, return kernel address. + * This function needs to be called with current->mm->page_table_lock held. + */ +static inline unsigned long __dat_user_addr(unsigned long uaddr) +{ + struct mm_struct *mm = current->mm; + unsigned long pfn, ret; + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + int rc; + + ret = 0; +retry: + pgd = pgd_offset(mm, uaddr); + if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) + goto fault; + + pmd = pmd_offset(pgd, uaddr); + if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) + goto fault; + + pte = pte_offset_map(pmd, uaddr); + if (!pte || !pte_present(*pte)) + goto fault; + + pfn = pte_pfn(*pte); + if (!pfn_valid(pfn)) + goto out; + + ret = (pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE - 1)); +out: + return ret; +fault: + spin_unlock(&mm->page_table_lock); + rc = __handle_fault(mm, uaddr, 0); + spin_lock(&mm->page_table_lock); + if (rc) + goto out; + goto retry; +} + size_t copy_from_user_pt(size_t n, const void __user *from, void *to) { size_t rc; @@ -156,3 +200,277 @@ size_t copy_to_user_pt(size_t n, void __user *to, const void *from) } return __user_copy_pt((unsigned long) to, (void *) from, n, 1); } + +static size_t clear_user_pt(size_t n, void __user *to) +{ + long done, size, ret; + + if (segment_eq(get_fs(), KERNEL_DS)) { + memset((void __kernel __force *) to, 0, n); + return 0; + } + done = 0; + do { + if (n - done > PAGE_SIZE) + size = PAGE_SIZE; + else + size = n - done; + ret = __user_copy_pt((unsigned long) to + done, + &empty_zero_page, size, 1); + done += size; + if (ret) + return ret + n - done; + } while (done < n); + return 0; +} + +static size_t strnlen_user_pt(size_t count, const char __user *src) +{ + char *addr; + unsigned long uaddr = (unsigned long) src; + struct mm_struct *mm = current->mm; + unsigned long offset, pfn, done, len; + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + size_t len_str; + + if (segment_eq(get_fs(), KERNEL_DS)) + return strnlen((const char __kernel __force *) src, count) + 1; + done = 0; +retry: + spin_lock(&mm->page_table_lock); + do { + pgd = pgd_offset(mm, uaddr); + if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) + goto fault; + + pmd = pmd_offset(pgd, uaddr); + if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) + goto fault; + + pte = pte_offset_map(pmd, uaddr); + if (!pte || !pte_present(*pte)) + goto fault; + + pfn = pte_pfn(*pte); + if (!pfn_valid(pfn)) { + done = -1; + goto out; + } + + offset = uaddr & (PAGE_SIZE-1); + addr = (char *)(pfn << PAGE_SHIFT) + offset; + len = min(count - done, PAGE_SIZE - offset); + len_str = strnlen(addr, len); + done += len_str; + uaddr += len_str; + } while ((len_str == len) && (done < count)); +out: + spin_unlock(&mm->page_table_lock); + return done + 1; +fault: + spin_unlock(&mm->page_table_lock); + if (__handle_fault(mm, uaddr, 0)) { + return 0; + } + goto retry; +} + +static size_t strncpy_from_user_pt(size_t count, const char __user *src, + char *dst) +{ + size_t n = strnlen_user_pt(count, src); + + if (!n) + return -EFAULT; + if (n > count) + n = count; + if (segment_eq(get_fs(), KERNEL_DS)) { + memcpy(dst, (const char __kernel __force *) src, n); + if (dst[n-1] == '\0') + return n-1; + else + return n; + } + if (__user_copy_pt((unsigned long) src, dst, n, 0)) + return -EFAULT; + if (dst[n-1] == '\0') + return n-1; + else + return n; +} + +static size_t copy_in_user_pt(size_t n, void __user *to, + const void __user *from) +{ + struct mm_struct *mm = current->mm; + unsigned long offset_from, offset_to, offset_max, pfn_from, pfn_to, + uaddr, done, size; + unsigned long uaddr_from = (unsigned long) from; + unsigned long uaddr_to = (unsigned long) to; + pgd_t *pgd_from, *pgd_to; + pmd_t *pmd_from, *pmd_to; + pte_t *pte_from, *pte_to; + int write_user; + + done = 0; +retry: + spin_lock(&mm->page_table_lock); + do { + pgd_from = pgd_offset(mm, uaddr_from); + if (pgd_none(*pgd_from) || unlikely(pgd_bad(*pgd_from))) { + uaddr = uaddr_from; + write_user = 0; + goto fault; + } + pgd_to = pgd_offset(mm, uaddr_to); + if (pgd_none(*pgd_to) || unlikely(pgd_bad(*pgd_to))) { + uaddr = uaddr_to; + write_user = 1; + goto fault; + } + + pmd_from = pmd_offset(pgd_from, uaddr_from); + if (pmd_none(*pmd_from) || unlikely(pmd_bad(*pmd_from))) { + uaddr = uaddr_from; + write_user = 0; + goto fault; + } + pmd_to = pmd_offset(pgd_to, uaddr_to); + if (pmd_none(*pmd_to) || unlikely(pmd_bad(*pmd_to))) { + uaddr = uaddr_to; + write_user = 1; + goto fault; + } + + pte_from = pte_offset_map(pmd_from, uaddr_from); + if (!pte_from || !pte_present(*pte_from)) { + uaddr = uaddr_from; + write_user = 0; + goto fault; + } + pte_to = pte_offset_map(pmd_to, uaddr_to); + if (!pte_to || !pte_present(*pte_to) || !pte_write(*pte_to)) { + uaddr = uaddr_to; + write_user = 1; + goto fault; + } + + pfn_from = pte_pfn(*pte_from); + if (!pfn_valid(pfn_from)) + goto out; + pfn_to = pte_pfn(*pte_to); + if (!pfn_valid(pfn_to)) + goto out; + + offset_from = uaddr_from & (PAGE_SIZE-1); + offset_to = uaddr_from & (PAGE_SIZE-1); + offset_max = max(offset_from, offset_to); + size = min(n - done, PAGE_SIZE - offset_max); + + memcpy((void *)(pfn_to << PAGE_SHIFT) + offset_to, + (void *)(pfn_from << PAGE_SHIFT) + offset_from, size); + done += size; + uaddr_from += size; + uaddr_to += size; + } while (done < n); +out: + spin_unlock(&mm->page_table_lock); + return n - done; +fault: + spin_unlock(&mm->page_table_lock); + if (__handle_fault(mm, uaddr, write_user)) + return n - done; + goto retry; +} + +#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \ + asm volatile("0: l %1,0(%6)\n" \ + "1: " insn \ + "2: cs %1,%2,0(%6)\n" \ + "3: jl 1b\n" \ + " lhi %0,0\n" \ + "4:\n" \ + EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b) \ + : "=d" (ret), "=&d" (oldval), "=&d" (newval), \ + "=m" (*uaddr) \ + : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \ + "m" (*uaddr) : "cc" ); + +int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old) +{ + int oldval = 0, newval, ret; + + spin_lock(¤t->mm->page_table_lock); + uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr); + if (!uaddr) { + spin_unlock(¤t->mm->page_table_lock); + return -EFAULT; + } + get_page(virt_to_page(uaddr)); + spin_unlock(¤t->mm->page_table_lock); + switch (op) { + case FUTEX_OP_SET: + __futex_atomic_op("lr %2,%5\n", + ret, oldval, newval, uaddr, oparg); + break; + case FUTEX_OP_ADD: + __futex_atomic_op("lr %2,%1\nar %2,%5\n", + ret, oldval, newval, uaddr, oparg); + break; + case FUTEX_OP_OR: + __futex_atomic_op("lr %2,%1\nor %2,%5\n", + ret, oldval, newval, uaddr, oparg); + break; + case FUTEX_OP_ANDN: + __futex_atomic_op("lr %2,%1\nnr %2,%5\n", + ret, oldval, newval, uaddr, oparg); + break; + case FUTEX_OP_XOR: + __futex_atomic_op("lr %2,%1\nxr %2,%5\n", + ret, oldval, newval, uaddr, oparg); + break; + default: + ret = -ENOSYS; + } + put_page(virt_to_page(uaddr)); + *old = oldval; + return ret; +} + +int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval) +{ + int ret; + + spin_lock(¤t->mm->page_table_lock); + uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr); + if (!uaddr) { + spin_unlock(¤t->mm->page_table_lock); + return -EFAULT; + } + get_page(virt_to_page(uaddr)); + spin_unlock(¤t->mm->page_table_lock); + asm volatile(" cs %1,%4,0(%5)\n" + "0: lr %0,%1\n" + "1:\n" + EX_TABLE(0b,1b) + : "=d" (ret), "+d" (oldval), "=m" (*uaddr) + : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr) + : "cc", "memory" ); + put_page(virt_to_page(uaddr)); + return ret; +} + +struct uaccess_ops uaccess_pt = { + .copy_from_user = copy_from_user_pt, + .copy_from_user_small = copy_from_user_pt, + .copy_to_user = copy_to_user_pt, + .copy_to_user_small = copy_to_user_pt, + .copy_in_user = copy_in_user_pt, + .clear_user = clear_user_pt, + .strnlen_user = strnlen_user_pt, + .strncpy_from_user = strncpy_from_user_pt, + .futex_atomic_op = futex_atomic_op_pt, + .futex_atomic_cmpxchg = futex_atomic_cmpxchg_pt, +}; |