lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Sat, 3 Oct 2020 07:50:44 +0300 From: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com> To: x86@...nel.org, linux-sgx@...r.kernel.org Cc: linux-kernel@...r.kernel.org, Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>, Jethro Beekman <jethro@...tanix.com>, Darren Kenny <darren.kenny@...cle.com>, Sean Christopherson <sean.j.christopherson@...el.com>, akpm@...ux-foundation.org, andriy.shevchenko@...ux.intel.com, asapek@...gle.com, bp@...en8.de, cedric.xing@...el.com, chenalexchen@...gle.com, conradparker@...gle.com, cyhanish@...gle.com, dave.hansen@...el.com, haitao.huang@...el.com, kai.huang@...el.com, kai.svahn@...el.com, kmoy@...gle.com, ludloff@...gle.com, luto@...nel.org, nhorman@...hat.com, npmccallum@...hat.com, puiterwijk@...hat.com, rientjes@...gle.com, tglx@...utronix.de, yaozhangx@...gle.com, mikko.ylinen@...el.com Subject: [PATCH v39 09/24] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page() Add __sgx_alloc_epc_page(), which iterates through EPC sections and borrows a page structure that is not used by anyone else. When a page is no longer needed it must be released with sgx_free_epc_page(). This function implicitly calls ENCLS[EREMOVE], which will return the page to the uninitialized state (i.e. not required from caller part). Acked-by: Jethro Beekman <jethro@...tanix.com> Reviewed-by: Darren Kenny <darren.kenny@...cle.com> Co-developed-by: Sean Christopherson <sean.j.christopherson@...el.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com> --- arch/x86/kernel/cpu/sgx/main.c | 62 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 3 ++ 2 files changed, 65 insertions(+) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index c5831e3db14a..97c6895fb6c9 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -83,6 +83,68 @@ static bool __init sgx_page_reclaimer_init(void) return true; } +static struct sgx_epc_page *__sgx_alloc_epc_page_from_section(struct sgx_epc_section *section) +{ + struct sgx_epc_page *page; + + if (list_empty(§ion->page_list)) + return NULL; + + page = list_first_entry(§ion->page_list, struct sgx_epc_page, list); + list_del_init(&page->list); + + return page; +} + +/** + * __sgx_alloc_epc_page() - Allocate an EPC page + * + * Iterate through EPC sections and borrow a free EPC page to the caller. When a + * page is no longer needed it must be released with sgx_free_epc_page(). + * + * Return: + * an EPC page, + * -errno on error + */ +struct sgx_epc_page *__sgx_alloc_epc_page(void) +{ + struct sgx_epc_section *section; + struct sgx_epc_page *page; + int i; + + for (i = 0; i < sgx_nr_epc_sections; i++) { + section = &sgx_epc_sections[i]; + spin_lock(§ion->lock); + page = __sgx_alloc_epc_page_from_section(section); + spin_unlock(§ion->lock); + + if (page) + return page; + } + + return ERR_PTR(-ENOMEM); +} + +/** + * 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. + */ +void sgx_free_epc_page(struct sgx_epc_page *page) +{ + struct sgx_epc_section *section = sgx_get_epc_section(page); + int ret; + + ret = __eremove(sgx_get_epc_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); + spin_unlock(§ion->lock); +} + static void __init sgx_free_epc_section(struct sgx_epc_section *section) { struct sgx_epc_page *page; diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index dff4f5f16d09..fce756c3434b 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -49,4 +49,7 @@ static inline void *sgx_get_epc_addr(struct sgx_epc_page *page) return section->va + (page->desc & PAGE_MASK) - section->pa; } +struct sgx_epc_page *__sgx_alloc_epc_page(void); +void sgx_free_epc_page(struct sgx_epc_page *page); + #endif /* _X86_SGX_H */ -- 2.25.1
Powered by blists - more mailing lists