• No .cfi_sections .eh_frame for ia32_exception.S, apic_vector.S, and atpic_vector.S
• Restore TDP_KTHREAD
• fork_trampoline and fork_trampoline_kthread share post fork_exit code. Jump from fork_trampoline_kthread to .fork_trampoline_return after returning from fork_exit

ping @jhb @olce for mentor approval

In D59838#1373575, @kib wrote:

In D59838#1373406, @mchoo wrote:

clang 18 and 19 worked but clang15 cannot recognize any of cs, ss, rflags, es, ds, fs, and gs:

00000014 00000040 00000018 FDE cie=00000000 pc=00000000...00000001
  Format:       DWARF32
  DW_CFA_def_cfa: RSP +72
  DW_CFA_offset_extended: reg4294967295 -64
  DW_CFA_offset: RFLAGS -56
  DW_CFA_offset_extended: reg4294967295 -48
  DW_CFA_offset_extended: reg4294967295 -40
  DW_CFA_offset_extended: reg4294967295 -32
  DW_CFA_offset_extended: reg4294967295 -24
  DW_CFA_offset_extended: reg4294967295 -16

I tested llvm 16 and 17 as well and only 17 compiles correctly, so I think we still need a if guard but replace it with #if !defined(__clang__) || (__clang_major__ >= 17)

This is unfortunate. But do we need to care about so old llvms? llvm15 sounds esp. odd, I suspect that the web page is quite outdated.

• Move .cfi_sections to assembly files
• Rename trap_cfi_full to trap_cfi_trapframe
• Rename trap_cfi_entry's full state to trapframe
• Add missing CFI directives (e.g. amd64_syscall invalidating r10, r11)
• Add CFI directives to FRED handlers described in trap.c.
• fork_trampoline_kthread should run for P_KPROC, not TDP_KTHREAD
• Place nop after returning from fork_exit so return address sees terminal not trapframe

I tested

.text
      .globl  cfi_segments
      .type   cfi_segments, @function
cfi_segments:
      .cfi_startproc simple
      .cfi_def_cfa    %rsp, 72
      .cfi_offset     %cs, -64
      .cfi_offset     49,  -56 /* rflags */
      .cfi_offset     %ss, -48
      .cfi_offset     %es, -40
      .cfi_offset     %ds, -32
      .cfi_offset     %fs, -24
      .cfi_offset     %gs, -16
      ret
      .cfi_endproc
      .size   cfi_segments, . - cfi_segments

ping @olce for mentor approval

ping @olce for mentor approval

ping @olce for mentor approval

In D59649#1371990, @kib wrote:

How do you validate the correctness of the .cfi annotations?

ping @jhb for mentor approval

ping @jhb for mentor approval

In D59651#1370103, @mchoo wrote:

I could not open HPT mmu minidump through libkvm, so this hasn't been tested yet similar to armv7 (D59650)

In D59650#1370098, @mchoo wrote:

I wanted to test this through QEMU, but it seems like armv7 minidump is broken (it cannot locate allproc, stoppcbs, etc)

Remove trap_cfi_end and use raw .cfi_endproc
Remove name from trap_cfi_entry
Remove .cfi_startproc from trap_cfi_entry. ENTRY() used in this patch doesn't have .cfi_startproc (the one in machine/asm.h does) but most architectures have only one ENTRY() which has the directive. For consistency between different architectures, omit it from trap_cfi_entry
.cfi_sections .eh_frame should only be emitted once (the original compiled and ran fine, but there's no need to have it under macro)
Added cfi directives to FRED code paths
kthread can return from fork_exit back to trampoline, so handle AST

cleanup

reflect code cleanup

cleanup

style and format

cleanup

cleanup

Restore ENTRY() and END() changes

In D59647#1370108, @jrtc27 wrote:

Is this necessary? Do you not want LLDB to print trapframes as special, like KGDB does, and like GDB does for signal frames?

I could not open HPT mmu minidump through libkvm, so this hasn't been tested yet similar to armv7 (D59650)

• trap_cfi(9): add assembly interface for powerpc
• trap_cfi(9): add exception handler CFI for powerpc

I wanted to test this through QEMU, but it seems like armv7 minidump is broken (it cannot locate allproc, stoppcbs, etc)

Add second part

Add second part

Tested on lldb

ping @jhb for mentor approval

ping @jhb for mentor approval

Post first part as well

@kib, I was going to create revisions for actual changes once the macros are accepted, but since I tested this on amd64 with lldb, I'm posting second part of the change here.

ping @jhb for mentor approval

In D59651#1368829, @adrian wrote:

ooo whats this do!

Add MFC info