From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu-cheng Yu Subject: [RFC PATCH v6 05/11] x86/cet/ibt: ELF header parsing for IBT Date: Mon, 19 Nov 2018 13:49:28 -0800 Message-ID: <20181119214934.6174-6-yu-cheng.yu@intel.com> References: <20181119214934.6174-1-yu-cheng.yu@intel.com> Return-path: In-Reply-To: <20181119214934.6174-1-yu-cheng.yu@intel.com> Sender: linux-kernel-owner@vger.kernel.org To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pa Cc: Yu-cheng Yu List-Id: linux-api@vger.kernel.org Look in .note.gnu.property of an ELF file and check if Indirect Branch Tracking needs to be enabled for the task. Signed-off-by: H.J. Lu Signed-off-by: Yu-cheng Yu --- arch/x86/include/uapi/asm/elf_property.h | 1 + arch/x86/kernel/elf.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/arch/x86/include/uapi/asm/elf_property.h b/arch/x86/include/uapi/asm/elf_property.h index af361207718c..343a871b8fc1 100644 --- a/arch/x86/include/uapi/asm/elf_property.h +++ b/arch/x86/include/uapi/asm/elf_property.h @@ -11,5 +11,6 @@ * Bits for GNU_PROPERTY_X86_FEATURE_1_AND */ #define GNU_PROPERTY_X86_FEATURE_1_SHSTK (0x00000002) +#define GNU_PROPERTY_X86_FEATURE_1_IBT (0x00000001) #endif /* _UAPI_ASM_X86_ELF_PROPERTY_H */ diff --git a/arch/x86/kernel/elf.c b/arch/x86/kernel/elf.c index 60e396e2abe9..7727b9332097 100644 --- a/arch/x86/kernel/elf.c +++ b/arch/x86/kernel/elf.c @@ -353,6 +353,11 @@ int arch_setup_features(void *ehdr_p, void *phdr_p, } } + if (cpu_feature_enabled(X86_FEATURE_IBT)) { + if (feature & GNU_PROPERTY_X86_FEATURE_1_IBT) + err = cet_setup_ibt(); + } + out: return err; } -- 2.17.1