[PATCH v4 2/5] x86/sgx: Reduce the locking range in sgx_sanitize_section()

The spin lock of sgx_epc_section only locks the page_list. The EREMOVE operation and init_laundry_list is not necessary in the protection range of the spin lock. This patch reduces the lock range of the spin lock in the function sgx_sanitize_section() and only protects the operation of the page_list.

Suggested-by: Sean Christopherson seanjc@google.com Signed-off-by: Tianjia Zhang tianjia.zhang@linux.alibaba.com --- arch/x86/kernel/cpu/sgx/main.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index c519fc5f6948..4465912174fd 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -41,20 +41,17 @@ static void sgx_sanitize_section(struct sgx_epc_section *section) if (kthread_should_stop()) return;

- /* needed for access to ->page_list: */ - spin_lock(&section->lock); - page = list_first_entry(&section->init_laundry_list, struct sgx_epc_page, list);

ret = __eremove(sgx_get_epc_virt_addr(page)); - if (!ret) + if (!ret) { + spin_lock(&section->lock); list_move(&page->list, &section->page_list); - else + spin_unlock(&section->lock); + } else list_move_tail(&page->list, &dirty);

- spin_unlock(&section->lock); - cond_resched(); }