Messages in this thread Patch in this message | | | Subject | Re: [PATCH v2 5/8] crypto: ccp: Use the stack for small SEV command buffers | From | Paolo Bonzini <> | Date | Sat, 17 Apr 2021 14:40:39 +0200 |
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On 07/04/21 00:49, Sean Christopherson wrote: > For commands with small input/output buffers, use the local stack to > "allocate" the structures used to communicate with the PSP. Now that > __sev_do_cmd_locked() gracefully handles vmalloc'd buffers, there's no > reason to avoid using the stack, e.g. CONFIG_VMAP_STACK=y will just work. > > Signed-off-by: Sean Christopherson <seanjc@google.com>
Squashing this in (inspired by Christophe's review, though not quite matching his suggestion).
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 0f5644a3b138..246b281b6376 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -408,12 +408,11 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable) if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) return -EFAULT; + memset(&data, 0, sizeof(data)); + /* userspace wants to query CSR length */ - if (!input.address || !input.length) { - data.address = 0; - data.len = 0; + if (!input.address || !input.length) goto cmd; - } /* allocate a physically contiguous buffer to store the CSR blob */ input_address = (void __user *)input.address;
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