Commit e4a9af79 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

crypto: ccp: Use the stack for small SEV command buffers 



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: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210406224952.4177376-6-seanjc@google.com>
Reviewed-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
Acked-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 8347b994

drivers/crypto/ccp/sev-dev.c

+44 −73
Original line number Diff line number Diff line
@@ -397,7 +397,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable) 
{

	struct sev_device *sev = psp_master->sev_data;

	struct sev_user_data_pek_csr input;

	struct sev_data_pek_csr *data;

	struct sev_data_pek_csr data;

	void __user *input_address;

	void *blob = NULL;

	int ret;
@@ -408,9 +408,7 @@ 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;



	data = kzalloc(sizeof(*data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;

	memset(&data, 0, sizeof(data));



	/* userspace wants to query CSR length */

	if (!input.address || !input.length)
@@ -418,19 +416,15 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable) 


	/* allocate a physically contiguous buffer to store the CSR blob */

	input_address = (void __user *)input.address;

	if (input.length > SEV_FW_BLOB_MAX_SIZE) {

		ret = -EFAULT;

		goto e_free;

	}

	if (input.length > SEV_FW_BLOB_MAX_SIZE)

		return -EFAULT;



	blob = kmalloc(input.length, GFP_KERNEL);

	if (!blob) {

		ret = -ENOMEM;

		goto e_free;

	}

	if (!blob)

		return -ENOMEM;



	data->address = __psp_pa(blob);

	data->len = input.length;

	data.address = __psp_pa(blob);

	data.len = input.length;



cmd:

	if (sev->state == SEV_STATE_UNINIT) {
@@ -439,10 +433,10 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable) 
			goto e_free_blob;

	}



	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, data, &argp->error);

	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);



	 /* If we query the CSR length, FW responded with expected data. */

	input.length = data->len;

	input.length = data.len;



	if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {

		ret = -EFAULT;
@@ -456,8 +450,6 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable) 


e_free_blob:

	kfree(blob);

e_free:

	kfree(data);

	return ret;

}
@@ -589,7 +581,7 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable) 
{

	struct sev_device *sev = psp_master->sev_data;

	struct sev_user_data_pek_cert_import input;

	struct sev_data_pek_cert_import *data;

	struct sev_data_pek_cert_import data;

	void *pek_blob, *oca_blob;

	int ret;
@@ -599,19 +591,14 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable) 
	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))

		return -EFAULT;



	data = kzalloc(sizeof(*data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	/* copy PEK certificate blobs from userspace */

	pek_blob = psp_copy_user_blob(input.pek_cert_address, input.pek_cert_len);

	if (IS_ERR(pek_blob)) {

		ret = PTR_ERR(pek_blob);

		goto e_free;

	}

	if (IS_ERR(pek_blob))

		return PTR_ERR(pek_blob);



	data->pek_cert_address = __psp_pa(pek_blob);

	data->pek_cert_len = input.pek_cert_len;

	data.reserved = 0;

	data.pek_cert_address = __psp_pa(pek_blob);

	data.pek_cert_len = input.pek_cert_len;



	/* copy PEK certificate blobs from userspace */

	oca_blob = psp_copy_user_blob(input.oca_cert_address, input.oca_cert_len);
@@ -620,8 +607,8 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable) 
		goto e_free_pek;

	}



	data->oca_cert_address = __psp_pa(oca_blob);

	data->oca_cert_len = input.oca_cert_len;

	data.oca_cert_address = __psp_pa(oca_blob);

	data.oca_cert_len = input.oca_cert_len;



	/* If platform is not in INIT state then transition it to INIT */

	if (sev->state != SEV_STATE_INIT) {
@@ -630,21 +617,19 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable) 
			goto e_free_oca;

	}



	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, data, &argp->error);

	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);



e_free_oca:

	kfree(oca_blob);

e_free_pek:

	kfree(pek_blob);

e_free:

	kfree(data);

	return ret;

}



static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)

{

	struct sev_user_data_get_id2 input;

	struct sev_data_get_id *data;

	struct sev_data_get_id data;

	void __user *input_address;

	void *id_blob = NULL;

	int ret;
@@ -658,28 +643,25 @@ static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp) 


	input_address = (void __user *)input.address;



	data = kzalloc(sizeof(*data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	if (input.address && input.length) {

		id_blob = kmalloc(input.length, GFP_KERNEL);

		if (!id_blob) {

			kfree(data);

		if (!id_blob)

			return -ENOMEM;

		}



		data->address = __psp_pa(id_blob);

		data->len = input.length;

		data.address = __psp_pa(id_blob);

		data.len = input.length;

	} else {

		data.address = 0;

		data.len = 0;

	}



	ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, data, &argp->error);

	ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, &data, &argp->error);



	/*

	 * Firmware will return the length of the ID value (either the minimum

	 * required length or the actual length written), return it to the user.

	 */

	input.length = data->len;

	input.length = data.len;



	if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {

		ret = -EFAULT;
@@ -687,7 +669,7 @@ static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp) 
	}



	if (id_blob) {

		if (copy_to_user(input_address, id_blob, data->len)) {

		if (copy_to_user(input_address, id_blob, data.len)) {

			ret = -EFAULT;

			goto e_free;

		}
@@ -695,7 +677,6 @@ static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp) 


e_free:

	kfree(id_blob);

	kfree(data);



	return ret;

}
@@ -745,7 +726,7 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) 
	struct sev_device *sev = psp_master->sev_data;

	struct sev_user_data_pdh_cert_export input;

	void *pdh_blob = NULL, *cert_blob = NULL;

	struct sev_data_pdh_cert_export *data;

	struct sev_data_pdh_cert_export data;

	void __user *input_cert_chain_address;

	void __user *input_pdh_cert_address;

	int ret;
@@ -763,9 +744,7 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) 
	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))

		return -EFAULT;



	data = kzalloc(sizeof(*data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;

	memset(&data, 0, sizeof(data));



	/* Userspace wants to query the certificate length. */

	if (!input.pdh_cert_address ||
@@ -777,25 +756,19 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) 
	input_cert_chain_address = (void __user *)input.cert_chain_address;



	/* Allocate a physically contiguous buffer to store the PDH blob. */

	if (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE) {

		ret = -EFAULT;

		goto e_free;

	}

	if (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE)

		return -EFAULT;



	/* Allocate a physically contiguous buffer to store the cert chain blob. */

	if (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE) {

		ret = -EFAULT;

		goto e_free;

	}

	if (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE)

		return -EFAULT;



	pdh_blob = kmalloc(input.pdh_cert_len, GFP_KERNEL);

	if (!pdh_blob) {

		ret = -ENOMEM;

		goto e_free;

	}

	if (!pdh_blob)

		return -ENOMEM;



	data->pdh_cert_address = __psp_pa(pdh_blob);

	data->pdh_cert_len = input.pdh_cert_len;

	data.pdh_cert_address = __psp_pa(pdh_blob);

	data.pdh_cert_len = input.pdh_cert_len;



	cert_blob = kmalloc(input.cert_chain_len, GFP_KERNEL);

	if (!cert_blob) {
@@ -803,15 +776,15 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) 
		goto e_free_pdh;

	}



	data->cert_chain_address = __psp_pa(cert_blob);

	data->cert_chain_len = input.cert_chain_len;

	data.cert_chain_address = __psp_pa(cert_blob);

	data.cert_chain_len = input.cert_chain_len;



cmd:

	ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, data, &argp->error);

	ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, &data, &argp->error);



	/* If we query the length, FW responded with expected data. */

	input.cert_chain_len = data->cert_chain_len;

	input.pdh_cert_len = data->pdh_cert_len;

	input.cert_chain_len = data.cert_chain_len;

	input.pdh_cert_len = data.pdh_cert_len;



	if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {

		ret = -EFAULT;
@@ -836,8 +809,6 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) 
	kfree(cert_blob);

e_free_pdh:

	kfree(pdh_blob);

e_free:

	kfree(data);

	return ret;

}