[PATCH] x86/sgx: Always deregister /dev/sgx_provision on failure

From: Jarkko Sakkinen
Date: Tue Aug 10 2021 - 18:56:43 EST


When /dev/sgx_vepc for KVM was added, the initialization was relaxed so
that this file can be accessed even when the driver is disabled.

Deregister /dev/sgx_provision when the driver is disabled, because it is
only useful for the driver.

Fixes: faa7d3e6f3b9 ("x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled")
Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
---
arch/x86/kernel/cpu/sgx/driver.c | 17 +++++++++++++++++
arch/x86/kernel/cpu/sgx/main.c | 20 +-------------------
2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c
index aa9b8b868867..b7698f7628d4 100644
--- a/arch/x86/kernel/cpu/sgx/driver.c
+++ b/arch/x86/kernel/cpu/sgx/driver.c
@@ -143,6 +143,17 @@ static struct miscdevice sgx_dev_enclave = {
.fops = &sgx_encl_fops,
};

+const struct file_operations sgx_provision_fops = {
+ .owner = THIS_MODULE,
+};
+
+static struct miscdevice sgx_dev_provision = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "sgx_provision",
+ .nodename = "sgx_provision",
+ .fops = &sgx_provision_fops,
+};
+
int __init sgx_drv_init(void)
{
unsigned int eax, ebx, ecx, edx;
@@ -176,5 +187,11 @@ int __init sgx_drv_init(void)
if (ret)
return ret;

+ ret = misc_register(&sgx_dev_provision);
+ if (ret) {
+ misc_deregister(&sgx_dev_enclave);
+ return ret;
+ }
+
return 0;
}
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 63d3de02bbcc..b8f210f15b62 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -745,17 +745,6 @@ void sgx_update_lepubkeyhash(u64 *lepubkeyhash)
wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]);
}

-const struct file_operations sgx_provision_fops = {
- .owner = THIS_MODULE,
-};
-
-static struct miscdevice sgx_dev_provision = {
- .minor = MISC_DYNAMIC_MINOR,
- .name = "sgx_provision",
- .nodename = "sgx_provision",
- .fops = &sgx_provision_fops,
-};
-
/**
* sgx_set_attribute() - Update allowed attributes given file descriptor
* @allowed_attributes: Pointer to allowed enclave attributes
@@ -806,10 +795,6 @@ static int __init sgx_init(void)
goto err_page_cache;
}

- ret = misc_register(&sgx_dev_provision);
- if (ret)
- goto err_kthread;
-
/*
* Always try to initialize the native *and* KVM drivers.
* The KVM driver is less picky than the native one and
@@ -821,13 +806,10 @@ static int __init sgx_init(void)
ret = sgx_drv_init();

if (sgx_vepc_init() && ret)
- goto err_provision;
+ goto err_kthread;

return 0;

-err_provision:
- misc_deregister(&sgx_dev_provision);
-
err_kthread:
kthread_stop(ksgxd_tsk);

--
2.32.0