[PATCH 1/3] x86/sgx: Move struct sgx_va_page creation to sgx_alloc_va_page()

From: Jarkko Sakkinen
Date: Wed Feb 24 2021 - 17:22:16 EST


The VA page creation is illogically split in-between sgx_encl_grow() and
sgx_alloc_va_page(). Move it fully to sgx_alloc_va_page().

Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
---
arch/x86/kernel/cpu/sgx/encl.c | 36 +++++++++++++++++++++++----------
arch/x86/kernel/cpu/sgx/encl.h | 2 +-
arch/x86/kernel/cpu/sgx/ioctl.c | 20 ++++--------------
3 files changed, 30 insertions(+), 28 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index 7449ef33f081..42eb879c167a 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -671,26 +671,40 @@ int sgx_encl_test_and_clear_young(struct mm_struct *mm,
* Allocate a free EPC page and convert it to a Version Array (VA) page.
*
* Return:
- * a VA page,
- * -errno otherwise
+ * - A VA page: On success.
+ * - ERR_PTR(-errno): Otherwise.
*/
-struct sgx_epc_page *sgx_alloc_va_page(void)
+struct sgx_va_page *sgx_alloc_va_page(void)
{
- struct sgx_epc_page *epc_page;
+ struct sgx_va_page *va_page;
int ret;

- epc_page = sgx_alloc_epc_page(NULL, true);
- if (IS_ERR(epc_page))
- return ERR_CAST(epc_page);
+ va_page = kzalloc(sizeof(*va_page), GFP_KERNEL);
+ if (!va_page)
+ return ERR_PTR(-ENOMEM);

- ret = __epa(sgx_get_epc_virt_addr(epc_page));
+ va_page->epc_page = sgx_alloc_epc_page(NULL, true);
+ if (IS_ERR(va_page->epc_page)) {
+ ret = PTR_ERR(va_page->epc_page);
+ goto err_va_page;
+ }
+
+ ret = __epa(sgx_get_epc_virt_addr(va_page->epc_page));
if (ret) {
WARN_ONCE(1, "EPA returned %d (0x%x)", ret, ret);
- sgx_free_epc_page(epc_page);
- return ERR_PTR(-EFAULT);
+ ret = -EFAULT;
+ goto err_epc_page;
}

- return epc_page;
+ return va_page;
+
+err_epc_page:
+ sgx_free_epc_page(va_page->epc_page);
+
+err_va_page:
+ kfree(va_page);
+
+ return ERR_PTR(ret);
}

/**
diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h
index d8d30ccbef4c..315e87fcc142 100644
--- a/arch/x86/kernel/cpu/sgx/encl.h
+++ b/arch/x86/kernel/cpu/sgx/encl.h
@@ -111,7 +111,7 @@ void sgx_encl_put_backing(struct sgx_backing *backing, bool do_write);
int sgx_encl_test_and_clear_young(struct mm_struct *mm,
struct sgx_encl_page *page);

-struct sgx_epc_page *sgx_alloc_va_page(void);
+struct sgx_va_page *sgx_alloc_va_page(void);
unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page);
void sgx_free_va_slot(struct sgx_va_page *va_page, unsigned int offset);
bool sgx_va_page_full(struct sgx_va_page *va_page);
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 90a5caf76939..db6e2c6ad42d 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -19,26 +19,14 @@
static struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl)
{
struct sgx_va_page *va_page = NULL;
- void *err;

- BUILD_BUG_ON(SGX_VA_SLOT_COUNT !=
- (SGX_ENCL_PAGE_VA_OFFSET_MASK >> 3) + 1);
+ BUILD_BUG_ON(SGX_VA_SLOT_COUNT != (SGX_ENCL_PAGE_VA_OFFSET_MASK >> 3) + 1);

- if (!(encl->page_cnt % SGX_VA_SLOT_COUNT)) {
- va_page = kzalloc(sizeof(*va_page), GFP_KERNEL);
- if (!va_page)
- return ERR_PTR(-ENOMEM);
+ if (!(encl->page_cnt % SGX_VA_SLOT_COUNT))
+ va_page = sgx_alloc_va_page();

- va_page->epc_page = sgx_alloc_va_page();
- if (IS_ERR(va_page->epc_page)) {
- err = ERR_CAST(va_page->epc_page);
- kfree(va_page);
- return err;
- }
-
- WARN_ON_ONCE(encl->page_cnt % SGX_VA_SLOT_COUNT);
- }
encl->page_cnt++;
+
return va_page;
}

--
2.30.1