Description of problem:

  It appears that compiling with -flto enabled disables CET support.

Version-Release number of selected component (if applicable):


How reproducible:

  100% using current RHEL-8.3 latest nightly compose.

Steps to Reproduce:

1. cat delme.c

  int main (void) { return 0; }

2. gcc -fcf-protection delme.c -o delme.exe

3. readelf --wide --notes delme.exe | grep IBT

     GNU    0x00000010	NT_GNU_PROPERTY_TYPE_0	      
     Properties: x86 feature: IBT, SHSTK

4. gcc -fcf-protection -flto delme.c -o delme.lto.exe

5. readelf --wide --notes delme.lto.exe | grep IBT

     GNU    0x00000010	NT_GNU_PROPERTY_TYPE_0	      
     Properties: x86 feature: IBT, SHSTK

6. gcc -fcf-protection -g delme.c -o delme.g.exe

7. readelf --wide --notes delme.g.exe | grep IBT

    GNU    0x00000010	NT_GNU_PROPERTY_TYPE_0	      
     Properties: x86 feature: IBT, SHSTK

8. gcc -fcf-protection -flto -g delme.c -o delme.g.lto.exe

9. readelf --wide --notes delme.g.lto.exe | grep IBT

  <no output>


Expected results:


Additional info:

  Adding -Wl,-Map,delme.g.lto.map to the gcc command line and then looking
  in the map file shows:

    Removed property 0xc0000000 to merge 0x55edf35fc4f0B (not found) and 0x55edf3650e10B (0x0)
    Removed property 0xc0000001 to merge 0x55edf35fc4f0B (not found) and 0x55edf3650e10B (0x0)
    Removed property 0xc0000002 to merge 0x55edf35fc4f0B (0x3) and 0x55edf3822920B (not found)
    Removed property 0xc0000002 to merge 0x55edf35fc4f0B (not found) and 0x55edf3822d30B (0x3)

  For the failing case (-g -flto) but for other cases:

    Removed property 0xc0000000 to merge 0x5640400bf4f0B (not found) and 
0x56404013ff10B (0x0)
    Removed property 0xc0000001 to merge 0x5640400bf4f0B (not found) and 0x56404013ff10B (0x0)

The versions of the tools involved:

  gcc-8.3.1-5.1.el8.x86_64
  binutils-2.30-75.el8.x86_64

Note - This may well be a linker bug, but the fact that it is triggered by adding -g to the gcc command line makes me suspect that gcc, or the LTO plugin, is having problems, rather than ld.