diff options
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/encl.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index b74dadf85989..ee50a5010277 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -272,10 +272,121 @@ static int sgx_vma_mprotect(struct vm_area_struct *vma, unsigned long start, return sgx_encl_may_map(vma->vm_private_data, start, end, newflags); } +static int sgx_encl_debug_read(struct sgx_encl *encl, struct sgx_encl_page *page, + unsigned long addr, void *data) +{ + unsigned long offset = addr & ~PAGE_MASK; + int ret; + + + ret = __edbgrd(sgx_get_epc_virt_addr(page->epc_page) + offset, data); + if (ret) + return -EIO; + + return 0; +} + +static int sgx_encl_debug_write(struct sgx_encl *encl, struct sgx_encl_page *page, + unsigned long addr, void *data) +{ + unsigned long offset = addr & ~PAGE_MASK; + int ret; + + ret = __edbgwr(sgx_get_epc_virt_addr(page->epc_page) + offset, data); + if (ret) + return -EIO; + + return 0; +} + +/* + * Load an enclave page to EPC if required, and take encl->lock. + */ +static struct sgx_encl_page *sgx_encl_reserve_page(struct sgx_encl *encl, + unsigned long addr, + unsigned long vm_flags) +{ + struct sgx_encl_page *entry; + + for ( ; ; ) { + mutex_lock(&encl->lock); + + entry = sgx_encl_load_page(encl, addr, vm_flags); + if (PTR_ERR(entry) != -EBUSY) + break; + + mutex_unlock(&encl->lock); + } + + if (IS_ERR(entry)) + mutex_unlock(&encl->lock); + + return entry; +} + +static int sgx_vma_access(struct vm_area_struct *vma, unsigned long addr, + void *buf, int len, int write) +{ + struct sgx_encl *encl = vma->vm_private_data; + struct sgx_encl_page *entry = NULL; + char data[sizeof(unsigned long)]; + unsigned long align; + int offset; + int cnt; + int ret = 0; + int i; + + /* + * If process was forked, VMA is still there but vm_private_data is set + * to NULL. + */ + if (!encl) + return -EFAULT; + + if (!test_bit(SGX_ENCL_DEBUG, &encl->flags)) + return -EFAULT; + + for (i = 0; i < len; i += cnt) { + entry = sgx_encl_reserve_page(encl, (addr + i) & PAGE_MASK, + vma->vm_flags); + if (IS_ERR(entry)) { + ret = PTR_ERR(entry); + break; + } + + align = ALIGN_DOWN(addr + i, sizeof(unsigned long)); + offset = (addr + i) & (sizeof(unsigned long) - 1); + cnt = sizeof(unsigned long) - offset; + cnt = min(cnt, len - i); + + ret = sgx_encl_debug_read(encl, entry, align, data); + if (ret) + goto out; + + if (write) { + memcpy(data + offset, buf + i, cnt); + ret = sgx_encl_debug_write(encl, entry, align, data); + if (ret) + goto out; + } else { + memcpy(buf + i, data + offset, cnt); + } + +out: + mutex_unlock(&encl->lock); + + if (ret) + break; + } + + return ret < 0 ? ret : i; +} + const struct vm_operations_struct sgx_vm_ops = { .fault = sgx_vma_fault, .mprotect = sgx_vma_mprotect, .open = sgx_vma_open, + .access = sgx_vma_access, }; /** |