[PATCH v30 05/10] x86/cet/ibt: Update ELF header parsing for Indirect Branch Tracking

From: Yu-cheng Yu
Date: Mon Aug 30 2021 - 14:24:00 EST


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 <yu-cheng.yu@xxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
---
v27:
- Remove selecting of ARCH_USE_GNU_PROPERTY and ARCH_BINFMT_ELF_STATE,
since they are already selected by X86_64.
---
arch/x86/kernel/process_64.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 4271963fdd8c..4ab751a5146e 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -884,6 +884,12 @@ int arch_setup_elf_property(struct arch_elf_state *state)

if (state->gnu_property & GNU_PROPERTY_X86_FEATURE_1_SHSTK)
r = shstk_setup();
+
+ if (r < 0)
+ return r;
+
+ if (state->gnu_property & GNU_PROPERTY_X86_FEATURE_1_IBT)
+ r = ibt_setup();
#endif

return r;
--
2.21.0