Messages in this thread | | | Date | Mon, 2 May 2022 10:16:48 -0300 | From | Wander Lairson Costa <> | Subject | Re: [PATCH v5 3/3] x86/tdx: Add Quote generation support |
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On Sun, May 01, 2022 at 11:35:00AM -0700, Kuppuswamy Sathyanarayanan wrote:
[snip]
> + > +static long tdx_get_quote(void __user *argp) > +{ > + struct tdx_quote_req quote_req; > + long ret = 0; > + int order; > + > + /* Hold lock to serialize GetQuote requests */ > + mutex_lock("e_lock); > + > + reinit_completion(&req_compl); > + > + /* Copy GetQuote request struct from user buffer */ > + if (copy_from_user("e_req, argp, sizeof(struct tdx_quote_req))) { > + ret = -EFAULT; > + goto quote_failed; > + } > + > + /* Make sure the length & timeout is valid */ > + if (!quote_req.len || !quote_req.timeout) { > + ret = -EINVAL; > + goto quote_failed; > + } > + > + /* Get order for Quote buffer page allocation */ > + order = get_order(quote_req.len); > + > + /* > + * Allocate buffer to get TD Quote from the VMM. > + * Size needs to be 4KB aligned (which is already > + * met in page allocation). > + */ > + tdquote = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); > + if (!tdquote) { > + ret = -ENOMEM; > + goto quote_failed; > + } > + > + /* > + * Since this buffer will be shared with the VMM via GetQuote > + * hypercall, decrypt it. > + */ > + ret = set_memory_decrypted((unsigned long)tdquote, 1UL << order); > + if (ret) > + goto quote_failed; > + > + /* Copy TDREPORT from user buffer to kernel Quote buffer */ > + if (copy_from_user(tdquote, (void __user *)quote_req.buf, quote_req.len)) { > + ret = -EFAULT; > + goto quote_failed; > + } > + > + /* Submit GetQuote Request */ > + ret = tdx_get_quote_hypercall(tdquote, (1ULL << order) * PAGE_SIZE); > + if (ret) { > + pr_err("GetQuote hypercall failed, status:%lx\n", ret); > + ret = -EIO; > + goto quote_failed; > + } > + > + /* Wait for attestation completion */ > + ret = wait_for_completion_interruptible(&req_compl); > + if (ret <= 0) { > + ret = -EIO; > + goto quote_failed; > + } > + > + /* Copy output data back to user buffer */ > + if (copy_to_user((void __user *)quote_req.buf, tdquote, quote_req.len)) > + ret = -EFAULT; > +
IIUC, ret has a positive value at this point, due to the call to wait_for_completion_interruptible, so we need add "ret = 0;" here, don't we?
[snip]
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