[PATCH v26 4/9] x86/cet/ibt: Update ELF header parsing for Indirect Branch Tracking
From: Yu-cheng Yu <hidden>
Date: 2021-04-27 20:48:14
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
An ELF file's .note.gnu.property indicates features the file supports. The property is parsed at loading time and passed to arch_setup_elf_ property(). Update it for Indirect Branch Tracking. Signed-off-by: Yu-cheng Yu <redacted> Cc: Kees Cook <redacted> --- v24: - Update for changes introduced from splitting shadow stack and ibt. arch/x86/Kconfig | 2 ++ arch/x86/kernel/process_64.c | 8 ++++++++ 2 files changed, 10 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6bb69fba0dad..7436e3a608e8 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig@@ -1970,6 +1970,8 @@ config X86_IBT def_bool n depends on X86_SHADOW_STACK depends on $(cc-option,-fcf-protection) + select ARCH_USE_GNU_PROPERTY + select ARCH_BINFMT_ELF_STATE help Indirect Branch Tracking (IBT) provides protection against CALL-/JMP-oriented programming attacks. It is active when
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index d71045b29475..bf8ef10e5b78 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c@@ -864,6 +864,14 @@ int arch_setup_elf_property(struct arch_elf_state *state) r = shstk_setup(); } + if (r < 0) + return r; + + if (cpu_feature_enabled(X86_FEATURE_IBT)) { + if (state->gnu_property & GNU_PROPERTY_X86_FEATURE_1_IBT) + r = ibt_setup(); + } + return r; } #endif
--
2.21.0