Build a local laundry list in sgx_init(), and transfer its ownsership to ksgxd for sanitization, thus getting rid of useless member in struct sgx_epc_section.
Signed-off-by: Jarkko Sakkinen <[email protected]> --- arch/x86/kernel/cpu/sgx/main.c | 64 ++++++++++++++++++---------------- arch/x86/kernel/cpu/sgx/sgx.h | 7 ---- 2 files changed, 34 insertions(+), 37 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 52d070fb4c9a..f4633a2b7685 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -30,35 +30,33 @@ static DEFINE_SPINLOCK(sgx_reclaimer_lock); * Reset dirty EPC pages to uninitialized state. Laundry can be left with SECS * pages whose child pages blocked EREMOVE. */ -static void sgx_sanitize_section(struct sgx_epc_section *section) +static void sgx_sanitize_section(struct list_head *laundry) { struct sgx_epc_page *page; LIST_HEAD(dirty); int ret; /* init_laundry_list is thread-local, no need for a lock: */ - while (!list_empty(§ion->init_laundry_list)) { + while (!list_empty(laundry)) { if (kthread_should_stop()) return; - /* needed for access to ->page_list: */ - spin_lock(§ion->lock); - - page = list_first_entry(§ion->init_laundry_list, - struct sgx_epc_page, list); + page = list_first_entry(laundry, struct sgx_epc_page, list); ret = __eremove(sgx_get_epc_virt_addr(page)); - if (!ret) - list_move(&page->list, §ion->page_list); - else + if (!ret) { + /* The page is clean - move to the free list. */ + list_del(&page->list); + sgx_free_epc_page(page); + } else { + /* The page is not yet clean - move to the dirty list. */ list_move_tail(&page->list, &dirty); - - spin_unlock(§ion->lock); + } cond_resched(); } - list_splice(&dirty, §ion->init_laundry_list); + list_splice(&dirty, laundry); } static bool sgx_reclaimer_age(struct sgx_epc_page *epc_page) @@ -405,6 +403,7 @@ static bool sgx_should_reclaim(unsigned long watermark) static int ksgxd(void *p) { + struct list_head *laundry = p; int i; set_freezable(); @@ -413,16 +412,13 @@ static int ksgxd(void *p) * Sanitize pages in order to recover from kexec(). The 2nd pass is * required for SECS pages, whose child pages blocked EREMOVE. */ - for (i = 0; i < sgx_nr_epc_sections; i++) - sgx_sanitize_section(&sgx_epc_sections[i]); + sgx_sanitize_section(laundry); + sgx_sanitize_section(laundry); - for (i = 0; i < sgx_nr_epc_sections; i++) { - sgx_sanitize_section(&sgx_epc_sections[i]); + if (!list_empty(laundry)) + WARN(1, "EPC section %d has unsanitized pages.\n", i); - /* Should never happen. */ - if (!list_empty(&sgx_epc_sections[i].init_laundry_list)) - WARN(1, "EPC section %d has unsanitized pages.\n", i); - } + kfree(laundry); while (!kthread_should_stop()) { if (try_to_freeze()) @@ -441,11 +437,11 @@ static int ksgxd(void *p) return 0; } -static bool __init sgx_page_reclaimer_init(void) +static bool __init sgx_page_reclaimer_init(struct list_head *laundry) { struct task_struct *tsk; - tsk = kthread_run(ksgxd, NULL, "ksgxd"); + tsk = kthread_run(ksgxd, laundry, "ksgxd"); if (IS_ERR(tsk)) return false; @@ -619,7 +615,8 @@ void sgx_free_epc_page(struct sgx_epc_page *page) static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size, unsigned long index, - struct sgx_epc_section *section) + struct sgx_epc_section *section, + struct list_head *laundry) { unsigned long nr_pages = size >> PAGE_SHIFT; unsigned long i; @@ -637,13 +634,12 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size, section->phys_addr = phys_addr; spin_lock_init(§ion->lock); INIT_LIST_HEAD(§ion->page_list); - INIT_LIST_HEAD(§ion->init_laundry_list); for (i = 0; i < nr_pages; i++) { section->pages[i].section = index; section->pages[i].flags = 0; section->pages[i].owner = NULL; - list_add_tail(§ion->pages[i].list, §ion->init_laundry_list); + list_add_tail(§ion->pages[i].list, laundry); } section->free_cnt = nr_pages; @@ -661,7 +657,7 @@ static inline u64 __init sgx_calc_section_metric(u64 low, u64 high) ((high & GENMASK_ULL(19, 0)) << 32); } -static bool __init sgx_page_cache_init(void) +static bool __init sgx_page_cache_init(struct list_head *laundry) { u32 eax, ebx, ecx, edx, type; u64 pa, size; @@ -684,7 +680,7 @@ static bool __init sgx_page_cache_init(void) pr_info("EPC section 0x%llx-0x%llx\n", pa, pa + size - 1); - if (!sgx_setup_epc_section(pa, size, i, &sgx_epc_sections[i])) { + if (!sgx_setup_epc_section(pa, size, i, &sgx_epc_sections[i], laundry)) { pr_err("No free memory for an EPC section\n"); break; } @@ -702,18 +698,25 @@ static bool __init sgx_page_cache_init(void) static int __init sgx_init(void) { + struct list_head *laundry; int ret; int i; if (!cpu_feature_enabled(X86_FEATURE_SGX)) return -ENODEV; - if (!sgx_page_cache_init()) { + laundry = kzalloc(sizeof(*laundry), GFP_KERNEL); + if (!laundry) + return -ENOMEM; + + INIT_LIST_HEAD(laundry); + + if (!sgx_page_cache_init(laundry)) { ret = -ENOMEM; goto err_page_cache; } - if (!sgx_page_reclaimer_init()) { + if (!sgx_page_reclaimer_init(laundry)) { ret = -ENOMEM; goto err_page_cache; } @@ -733,6 +736,7 @@ static int __init sgx_init(void) memunmap(sgx_epc_sections[i].virt_addr); } + kfree(laundry); return ret; } diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 5fa42d143feb..bc8af0428640 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -45,13 +45,6 @@ struct sgx_epc_section { spinlock_t lock; struct list_head page_list; unsigned long free_cnt; - - /* - * Pages which need EREMOVE run on them before they can be - * used. Only safe to be accessed in ksgxd and init code. - * Not protected by locks. - */ - struct list_head init_laundry_list; }; extern struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS]; -- 2.30.1
