From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> To: <x86@kernel.org>, <platform-driver-x86@vger.kernel.org>, <linux-sgx@vger.kernel.org> Cc: <dave.hansen@intel.com>, <sean.j.christopherson@intel.com>, <nhorman@redhat.com>, <npmccallum@redhat.com>, <serge.ayoun@intel.com>, <shay.katz-zamir@intel.com>, <haitao.huang@intel.com>, <andriy.shevchenko@linux.intel.com>, <tglx@linutronix.de>, <kai.svahn@intel.com>, Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>, Suresh Siddha <suresh.b.siddha@intel.com>, "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <linux-kernel@vger.kernel.org> Subject: [PATCH v16 16/22] x86/sgx: Add functions to allocate and free EPC pages Date: Tue, 6 Nov 2018 15:45:55 +0200 [thread overview] Message-ID: <20181106134758.10572-17-jarkko.sakkinen@linux.intel.com> (raw) In-Reply-To: <20181106134758.10572-1-jarkko.sakkinen@linux.intel.com> At this time there is no support for reclaiming pages prior to the owner explicitly freeing the page. As for freeing pages, because freeing a page is expected to succeed in the vast majority of cases and because most call sites will not be equipped to handle failure, provide a variant for freeing a page that warns on failure, e.g. due to ENCLS[EREMOVE] failing. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/include/asm/sgx.h | 4 ++ arch/x86/kernel/cpu/intel_sgx.c | 77 +++++++++++++++++++++++++++++++++ 2 files changed, 81 insertions(+) diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h index efe3e213e582..372fc378018b 100644 --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -307,4 +307,8 @@ static inline int __emodt(struct sgx_secinfo *secinfo, void *addr) return __encls_ret_2(SGX_EMODT, secinfo, addr); } +struct sgx_epc_page *sgx_alloc_page(void); +int __sgx_free_page(struct sgx_epc_page *page); +void sgx_free_page(struct sgx_epc_page *page); + #endif /* _ASM_X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/intel_sgx.c b/arch/x86/kernel/cpu/intel_sgx.c index 7587fc7ef9ef..e9a225fa14b7 100644 --- a/arch/x86/kernel/cpu/intel_sgx.c +++ b/arch/x86/kernel/cpu/intel_sgx.c @@ -15,6 +15,83 @@ EXPORT_SYMBOL_GPL(sgx_epc_sections); static int sgx_nr_epc_sections; +/** + * sgx_alloc_page - Allocate an EPC page + * + * Try to grab a page from the free EPC page list. + * + * Return: + * a pointer to a &struct sgx_epc_page instance, + * -errno on error + */ +struct sgx_epc_page *sgx_alloc_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); + if (section->free_cnt) { + page = section->pages[section->free_cnt - 1]; + section->free_cnt--; + } + spin_unlock(§ion->lock); + + if (page) + return page; + } + + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(sgx_alloc_page); + +/** + * __sgx_free_page - Free an EPC page + * @page: pointer a previously allocated EPC page + * + * EREMOVE an EPC page and insert it back to the list of free pages. + * + * Return: + * 0 on success + * SGX error code if EREMOVE fails + */ +int __sgx_free_page(struct sgx_epc_page *page) +{ + struct sgx_epc_section *section = sgx_epc_section(page); + int ret; + + ret = __eremove(sgx_epc_addr(page)); + if (ret) + return ret; + + spin_lock(§ion->lock); + section->pages[section->free_cnt++] = page; + spin_unlock(§ion->lock); + + return 0; +} +EXPORT_SYMBOL_GPL(__sgx_free_page); + +/** + * sgx_free_page - Free an EPC page and WARN on failure + * @page: pointer to a previously allocated EPC page + * + * EREMOVE an EPC page and insert it back to the list of free pages, and WARN + * if EREMOVE fails. For use when the call site cannot (or chooses not to) + * handle failure, i.e. the page is leaked on failure. + */ +void sgx_free_page(struct sgx_epc_page *page) +{ + int ret; + + ret = __sgx_free_page(page); + WARN(ret > 0, "sgx: EREMOVE returned %d (0x%x)", ret, ret); +} +EXPORT_SYMBOL_GPL(sgx_free_page); + + static __init void sgx_free_epc_section(struct sgx_epc_section *section) { int i; -- 2.19.1
WARNING: multiple messages have this Message-ID (diff)
From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> To: x86@kernel.org, platform-driver-x86@vger.kernel.org, linux-sgx@vger.kernel.org Cc: dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, serge.ayoun@intel.com, shay.katz-zamir@intel.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>, Suresh Siddha <suresh.b.siddha@intel.com>, linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)) Subject: [PATCH v16 16/22] x86/sgx: Add functions to allocate and free EPC pages Date: Tue, 6 Nov 2018 15:45:55 +0200 [thread overview] Message-ID: <20181106134758.10572-17-jarkko.sakkinen@linux.intel.com> (raw) Message-ID: <20181106134555.M06eEqvi9WiKLIFTdLlPkaIe2I6wGlhBQ6grw4H1nH0@z> (raw) In-Reply-To: <20181106134758.10572-1-jarkko.sakkinen@linux.intel.com> At this time there is no support for reclaiming pages prior to the owner explicitly freeing the page. As for freeing pages, because freeing a page is expected to succeed in the vast majority of cases and because most call sites will not be equipped to handle failure, provide a variant for freeing a page that warns on failure, e.g. due to ENCLS[EREMOVE] failing. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/include/asm/sgx.h | 4 ++ arch/x86/kernel/cpu/intel_sgx.c | 77 +++++++++++++++++++++++++++++++++ 2 files changed, 81 insertions(+) diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h index efe3e213e582..372fc378018b 100644 --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -307,4 +307,8 @@ static inline int __emodt(struct sgx_secinfo *secinfo, void *addr) return __encls_ret_2(SGX_EMODT, secinfo, addr); } +struct sgx_epc_page *sgx_alloc_page(void); +int __sgx_free_page(struct sgx_epc_page *page); +void sgx_free_page(struct sgx_epc_page *page); + #endif /* _ASM_X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/intel_sgx.c b/arch/x86/kernel/cpu/intel_sgx.c index 7587fc7ef9ef..e9a225fa14b7 100644 --- a/arch/x86/kernel/cpu/intel_sgx.c +++ b/arch/x86/kernel/cpu/intel_sgx.c @@ -15,6 +15,83 @@ EXPORT_SYMBOL_GPL(sgx_epc_sections); static int sgx_nr_epc_sections; +/** + * sgx_alloc_page - Allocate an EPC page + * + * Try to grab a page from the free EPC page list. + * + * Return: + * a pointer to a &struct sgx_epc_page instance, + * -errno on error + */ +struct sgx_epc_page *sgx_alloc_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); + if (section->free_cnt) { + page = section->pages[section->free_cnt - 1]; + section->free_cnt--; + } + spin_unlock(§ion->lock); + + if (page) + return page; + } + + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(sgx_alloc_page); + +/** + * __sgx_free_page - Free an EPC page + * @page: pointer a previously allocated EPC page + * + * EREMOVE an EPC page and insert it back to the list of free pages. + * + * Return: + * 0 on success + * SGX error code if EREMOVE fails + */ +int __sgx_free_page(struct sgx_epc_page *page) +{ + struct sgx_epc_section *section = sgx_epc_section(page); + int ret; + + ret = __eremove(sgx_epc_addr(page)); + if (ret) + return ret; + + spin_lock(§ion->lock); + section->pages[section->free_cnt++] = page; + spin_unlock(§ion->lock); + + return 0; +} +EXPORT_SYMBOL_GPL(__sgx_free_page); + +/** + * sgx_free_page - Free an EPC page and WARN on failure + * @page: pointer to a previously allocated EPC page + * + * EREMOVE an EPC page and insert it back to the list of free pages, and WARN + * if EREMOVE fails. For use when the call site cannot (or chooses not to) + * handle failure, i.e. the page is leaked on failure. + */ +void sgx_free_page(struct sgx_epc_page *page) +{ + int ret; + + ret = __sgx_free_page(page); + WARN(ret > 0, "sgx: EREMOVE returned %d (0x%x)", ret, ret); +} +EXPORT_SYMBOL_GPL(sgx_free_page); + + static __init void sgx_free_epc_section(struct sgx_epc_section *section) { int i; -- 2.19.1
next prev parent reply other threads:[~2018-11-06 13:45 UTC|newest] Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-11-06 13:45 [PATCH v16 00/22] Intel SGX1 support Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 01/22] x86/sgx: Update MAINTAINERS Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 02/22] x86/cpufeatures: Add Intel-defined SGX feature bit Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 03/22] x86/cpufeatures: Add SGX sub-features (as Linux-defined bits) Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 04/22] x86/msr: Add IA32_FEATURE_CONTROL.SGX_ENABLE definition Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 05/22] x86/cpufeatures: Add Intel-defined SGX_LC feature bit Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 06/22] x86/cpu/intel: Detect SGX support and update caps appropriately Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:58 ` Sean Christopherson 2018-11-06 13:58 ` Sean Christopherson 2018-11-07 15:58 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 07/22] x86/mm: x86/sgx: Add new 'PF_SGX' page fault error code bit Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 08/22] x86/mm: x86/sgx: Signal SIGSEGV for userspace #PFs w/ PF_SGX Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 09/22] x86/sgx: Define SGX1 and SGX2 ENCLS leafs Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 10/22] x86/sgx: Add ENCLS architectural error codes Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 11/22] x86/sgx: Add SGX1 and SGX2 architectural data structures Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 12/22] x86/sgx: Add definitions for SGX's CPUID leaf and variable sub-leafs Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 13/22] x86/msr: Add SGX Launch Control MSR definitions Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 14/22] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 15/22] x86/sgx: Enumerate and track EPC sections Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen [this message] 2018-11-06 13:45 ` [PATCH v16 16/22] x86/sgx: Add functions to allocate and free EPC pages Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 17/22] x86/sgx: Add sgx_einit() for initializing enclaves Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 18/22] platform/x86: Intel SGX driver Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 16:40 ` Sean Christopherson 2018-11-06 16:57 ` Dave Hansen 2018-11-07 16:37 ` Jarkko Sakkinen 2018-11-07 18:00 ` Sean Christopherson 2018-11-07 18:00 ` Sean Christopherson 2018-11-08 14:46 ` Jarkko Sakkinen 2018-11-15 20:00 ` Jarkko Sakkinen 2018-11-15 20:04 ` Jarkko Sakkinen 2018-11-15 20:16 ` Jarkko Sakkinen 2018-11-21 11:46 ` Jarkko Sakkinen 2018-11-07 10:29 ` David Laight 2018-11-06 13:45 ` [PATCH v16 19/22] platform/x86: sgx: Add swapping functionality to the " Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:45 ` [PATCH v16 20/22] x86/sgx: Add a simple swapper for the EPC memory manager Jarkko Sakkinen 2018-11-06 13:45 ` Jarkko Sakkinen 2018-11-06 13:46 ` [PATCH v16 21/22] platform/x86: ptrace() support for the SGX driver Jarkko Sakkinen 2018-11-06 13:46 ` Jarkko Sakkinen 2018-11-06 13:46 ` [PATCH v16 22/22] x86/sgx: SGX documentation Jarkko Sakkinen 2018-11-06 13:46 ` Jarkko Sakkinen 2018-11-27 20:13 ` Pavel Machek
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