[RFC PATCH v3 3/8] x86/cet/ibt: ELF header parsing for IBT
From: Yu-cheng Yu <hidden>
Date: 2018-08-30 14:45:24
Also in:
linux-arch, linux-doc, linux-mm, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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 <redacted> Signed-off-by: Yu-cheng Yu <redacted> --- arch/x86/include/uapi/asm/elf_property.h | 1 + arch/x86/kernel/elf.c | 8 +++++++- 2 files changed, 8 insertions(+), 1 deletion(-)
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 a2c41bf39c58..41957f1bd9d0 100644
--- a/arch/x86/kernel/elf.c
+++ b/arch/x86/kernel/elf.c@@ -298,7 +298,8 @@ int arch_setup_features(void *ehdr_p, void *phdr_p, struct elf64_hdr *ehdr64 = ehdr_p; - if (!cpu_feature_enabled(X86_FEATURE_SHSTK)) + if (!cpu_feature_enabled(X86_FEATURE_SHSTK) && + !cpu_feature_enabled(X86_FEATURE_IBT)) return 0; if (ehdr64->e_ident[EI_CLASS] == ELFCLASS64) {
@@ -333,6 +334,11 @@ 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