Description

Intel Control Flow Enforcement Technology (CET) is enabled since gcc v8.1. Gcc emits following processor-specific program property types in .note.gnu.property section if we compile with "gcc -fcf-protection foo.c":

• Indirect Branch Tracking (IBT)
• Shadow Stack (SHSTK)

Furthermore, CET (-fcf-protection) becomes default since gcc 11.

Such properties are there before PHP-8.1.0.

$ sudo readelf -n sapi/cli/php
Displaying notes found in: .note.gnu.property
  Owner                Data size        Description
  GNU                  0x00000020       NT_GNU_PROPERTY_TYPE_0
        Properties: x86 feature: IBT, SHSTK
        x86 ISA needed: x86-64-baseline

However, the properties are missing since PHP-8.1.0.

$ sudo readelf -n sapi/cli/php
Displaying notes found in: .note.gnu.property
  Owner                Data size        Description
  GNU                  0x00000010       NT_GNU_PROPERTY_TYPE_0
      Properties: x86 ISA needed: x86-64-baseline

This is caused by commit c276c16 "Implement Fibers" which introduces some assembly file such as jump_x86_64_sysv_elf_gas.S and make_x86_64_sysv_elf_gas.S. The object files of such assembly miss .note.gnu.property section and thus the final output files miss it too.

I want to submit a patch to fix this.

PHP Version

PHP-8.1.0

Operating System

Ubuntu 22.04