On Tue, Sep 16, 2025 at 10:41:50AM +0200, Emanuele Rocca wrote:
> On arm64, ELF files supporting what in Debian we call the "branch"
> hardening features (PAC, BTI, GCS) are marked with a special ELF note.
>
> $ readelf -n a.out | grep Properties
> Properties: AArch64 feature: BTI, PAC, GCS
GCC 15 got code to emit related information on x86-64:
| void
| file_end_indicate_exec_stack_and_gnu_property (void)
| {
| file_end_indicate_exec_stack ();
|
| if (flag_cf_protection == CF_NONE
| && !ix86_needed
| && !ix86_has_no_direct_extern_access)
| return;
|
| unsigned int feature_1 = 0;
|
| if (flag_cf_protection & CF_BRANCH)
| /* GNU_PROPERTY_X86_FEATURE_1_IBT. */
| feature_1 |= 0x1;
|
| if (flag_cf_protection & CF_RETURN)
| /* GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
| feature_1 |= 0x2;
|
| /* Generate GNU_PROPERTY_X86_FEATURE_1_AND. */
| if (feature_1)
| emit_gnu_property (0xc0000002, feature_1);
I have not seen this in binaries however.
Bastian
--
Prepare for tomorrow -- get ready.
-- Edith Keeler, "The City On the Edge of Forever",
stardate unknown
