* [PATCH v4 0/2] Take away EREMOVE from sgx_free_epc_page()
@ 2021-01-13 23:35 jarkko
2021-01-13 23:35 ` [PATCH v4 1/2] x86/sgx: Remove a warn " jarkko
2021-01-13 23:35 ` [PATCH v4 2/2] x86/sgx: Wipe out EREMOVE " jarkko
0 siblings, 2 replies; 3+ messages in thread
From: jarkko @ 2021-01-13 23:35 UTC (permalink / raw)
To: linux-sgx; +Cc: dave.hansen, kai.huang, haitao.huang, seanjc, jarkko
From: "jarkko@kernel.org" <jarkko@kernel.org>
Refactor EREMOVE out of sgx_free_epc_page() since it is only used in
one function.
v4:
- No code changes to v4. Re-send because of
"-to linux@sgx.vger.kernel.org"
jarkko@kernel.org (2):
x86/sgx: Remove a warn from sgx_free_epc_page()
x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()
arch/x86/kernel/cpu/sgx/encl.c | 13 +++++++++++++
arch/x86/kernel/cpu/sgx/main.c | 12 ++++--------
2 files changed, 17 insertions(+), 8 deletions(-)
--
2.29.2
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v4 1/2] x86/sgx: Remove a warn from sgx_free_epc_page()
2021-01-13 23:35 [PATCH v4 0/2] Take away EREMOVE from sgx_free_epc_page() jarkko
@ 2021-01-13 23:35 ` jarkko
2021-01-13 23:35 ` [PATCH v4 2/2] x86/sgx: Wipe out EREMOVE " jarkko
1 sibling, 0 replies; 3+ messages in thread
From: jarkko @ 2021-01-13 23:35 UTC (permalink / raw)
To: linux-sgx
Cc: dave.hansen, kai.huang, haitao.huang, seanjc, jarkko,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
H. Peter Anvin
From: "jarkko@kernel.org" <jarkko@kernel.org>
Remove SGX_EPC_PAGE_RECLAIMER_TRACKED check and warning. This cannot
happen, as enclave pages are freed only at the time when encl->refcount
triggers, i.e. when both VFS and the page reclaimer have given up on
their references.
Signed-off-by: jarkko@kernel.org <jarkko@kernel.org>
---
arch/x86/kernel/cpu/sgx/main.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index c519fc5f6948..ebbd3b97b3d0 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -605,8 +605,6 @@ void sgx_free_epc_page(struct sgx_epc_page *page)
struct sgx_epc_section *section = &sgx_epc_sections[page->section];
int ret;
- WARN_ON_ONCE(page->flags & SGX_EPC_PAGE_RECLAIMER_TRACKED);
-
ret = __eremove(sgx_get_epc_virt_addr(page));
if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret))
return;
--
2.29.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v4 2/2] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()
2021-01-13 23:35 [PATCH v4 0/2] Take away EREMOVE from sgx_free_epc_page() jarkko
2021-01-13 23:35 ` [PATCH v4 1/2] x86/sgx: Remove a warn " jarkko
@ 2021-01-13 23:35 ` jarkko
1 sibling, 0 replies; 3+ messages in thread
From: jarkko @ 2021-01-13 23:35 UTC (permalink / raw)
To: linux-sgx
Cc: dave.hansen, kai.huang, haitao.huang, seanjc, jarkko,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
H. Peter Anvin
From: "jarkko@kernel.org" <jarkko@kernel.org>
Encapsulate the snippet in sgx_free_epc_page() concerning EREMOVE to
sgx_reset_epc_page(), which is a static helper function for
sgx_encl_release(). It's the only function existing, which deals with
initialized pages.
Signed-off-by: jarkko@kernel.org <jarkko@kernel.org>
---
v3: Fixed va_page desctruction.
v2: Fixed a compilation error s/page/epc_page/ change not amended
to the patches.
arch/x86/kernel/cpu/sgx/encl.c | 13 +++++++++++++
arch/x86/kernel/cpu/sgx/main.c | 10 ++++------
2 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index ee50a5010277..a78b71447771 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -389,6 +389,16 @@ const struct vm_operations_struct sgx_vm_ops = {
.access = sgx_vma_access,
};
+
+static void sgx_reset_epc_page(struct sgx_epc_page *epc_page)
+{
+ int ret;
+
+ ret = __eremove(sgx_get_epc_virt_addr(epc_page));
+ if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret))
+ return;
+}
+
/**
* sgx_encl_release - Destroy an enclave instance
* @kref: address of a kref inside &sgx_encl
@@ -412,6 +422,7 @@ void sgx_encl_release(struct kref *ref)
if (sgx_unmark_page_reclaimable(entry->epc_page))
continue;
+ sgx_reset_epc_page(entry->epc_page);
sgx_free_epc_page(entry->epc_page);
encl->secs_child_cnt--;
entry->epc_page = NULL;
@@ -423,6 +434,7 @@ void sgx_encl_release(struct kref *ref)
xa_destroy(&encl->page_array);
if (!encl->secs_child_cnt && encl->secs.epc_page) {
+ sgx_reset_epc_page(encl->secs.epc_page);
sgx_free_epc_page(encl->secs.epc_page);
encl->secs.epc_page = NULL;
}
@@ -431,6 +443,7 @@ void sgx_encl_release(struct kref *ref)
va_page = list_first_entry(&encl->va_pages, struct sgx_va_page,
list);
list_del(&va_page->list);
+ sgx_reset_epc_page(va_page->epc_page);
sgx_free_epc_page(va_page->epc_page);
kfree(va_page);
}
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index ebbd3b97b3d0..5e20b42f2639 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -598,16 +598,14 @@ struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim)
* sgx_free_epc_page() - Free an EPC page
* @page: an EPC page
*
- * Call EREMOVE for an EPC page and insert it back to the list of free pages.
+ * Put the EPC page back to the list of free pages. It's the callers
+ * responsibility to make sure that the page is in uninitialized state In other
+ * words, do EREMOVE, EWB or whatever operation is necessary before calling
+ * this function.
*/
void sgx_free_epc_page(struct sgx_epc_page *page)
{
struct sgx_epc_section *section = &sgx_epc_sections[page->section];
- int ret;
-
- ret = __eremove(sgx_get_epc_virt_addr(page));
- if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret))
- return;
spin_lock(§ion->lock);
list_add_tail(&page->list, §ion->page_list);
--
2.29.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-01-14 1:57 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-01-13 23:35 [PATCH v4 0/2] Take away EREMOVE from sgx_free_epc_page() jarkko
2021-01-13 23:35 ` [PATCH v4 1/2] x86/sgx: Remove a warn " jarkko
2021-01-13 23:35 ` [PATCH v4 2/2] x86/sgx: Wipe out EREMOVE " jarkko
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).