vm_prot_bits is very bad and misleading name for the field in struct
sgx_encl_page. What the field contains exactly is not @prot of
mprotect() but the *maximum* VM flags for the VMA that contains the
given enclave page.
Thus, the only viable name for the field is max_vm_flags. In functions
that also pass VM flags the parameter name is renamed from vm_prot_bits
to vm_flags.
To summarize, this commit makes two improvements to clarify the
permission handling:
1. Changes the name to match better the contents.
2. Uses naming to differentiate the field inside the struct and
the parameter passed to functions.
Cc: Sean Christopherson <sean.j.christpherson@xxxxxxxxx>
Cc: Shay Katz-zamir <shay.katz-zamir@xxxxxxxxx>
Cc: Serge Ayoun <serge.ayoun@xxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/sgx/driver/ioctl.c | 2 +-
arch/x86/kernel/cpu/sgx/encl.c | 14 +++++++-------
arch/x86/kernel/cpu/sgx/encl.h | 4 ++--
3 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/driver/ioctl.c b/arch/x86/kernel/cpu/sgx/driver/ioctl.c
index 2415dcb20a6e..b61e06daad6e 100644
--- a/arch/x86/kernel/cpu/sgx/driver/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/driver/ioctl.c
@@ -261,7 +261,7 @@ static struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
encl_page->encl = encl;
/* Calculate maximum of the VM flags for the page. */
- encl_page->vm_prot_bits = calc_vm_prot_bits(prot, 0);
+ encl_page->max_vm_flags = calc_vm_prot_bits(prot, 0);
ret = radix_tree_insert(&encl->page_tree, PFN_DOWN(encl_page->desc),
encl_page);
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index a20d498e9dcd..890eacb45a80 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -292,25 +292,25 @@ static unsigned int sgx_vma_fault(struct vm_fault *vmf)
* @encl: an enclave
* @start: lower bound of the address range, inclusive
* @end: upper bound of the address range, exclusive
- * @vm_prot_bits: requested protections of the address range
+ * @vm_flags: requested VM flags for the address range
*
* Iterate through the enclave pages contained within [@start, @end) to verify
- * the permissions requested by @vm_prot_bits do not exceed that of any enclave
- * page to be mapped. Page addresses that do not have an associated enclave
- * page are interpreted to zero permissions.
+ * the the VM flags do not exceed that of any enclave page to be mapped. Page
+ * addresses that do not have an associated enclave page are interpreted to zero
+ * permissions.
*
* Return:
* 0 on success,
* -EACCES if VMA permissions exceed enclave page permissions
*/
int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
- unsigned long end, unsigned long vm_prot_bits)
+ unsigned long end, unsigned long vm_flags)
{
unsigned long idx, idx_start, idx_end;
struct sgx_encl_page *page;
/* PROT_NONE always succeeds. */
- if (!vm_prot_bits)
+ if (!vm_flags)
return 0;
idx_start = PFN_DOWN(start);
@@ -321,7 +321,7 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
page = radix_tree_lookup(&encl->page_tree, idx);
mutex_unlock(&encl->lock);
- if (!page || (~page->vm_prot_bits & vm_prot_bits))
+ if (!page || (~page->max_vm_flags & vm_flags))
return -EACCES;
}
diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h
index d3a1687ed84c..0e28b784a8c5 100644
--- a/arch/x86/kernel/cpu/sgx/encl.h
+++ b/arch/x86/kernel/cpu/sgx/encl.h
@@ -44,7 +44,7 @@ enum sgx_encl_page_desc {
struct sgx_encl_page {
unsigned long desc;
- unsigned long vm_prot_bits;
+ unsigned long max_vm_flags;
struct sgx_epc_page *epc_page;
struct sgx_va_page *va_page;
struct sgx_encl *encl;
@@ -134,6 +134,6 @@ 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);
int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
- unsigned long end, unsigned long vm_prot_bits);
+ unsigned long end, unsigned long vm_flags);
#endif /* _X86_ENCL_H */
--
2.20.1
