[Bug target/103925] New: Missing int3 in ix86_output_indirect_function_return

[Bug target/103925] New: Missing int3 in ix86_output_indirect_function_return

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103925

            Bug ID: 103925
           Summary: Missing int3 in ix86_output_indirect_function_return
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
                CC: andrew.cooper3 at citrix dot com, ubizjak at gmail dot com
  Target Milestone: ---

[hjl@gnu-tgl-2 tmp]$ cat foo.c
struct _Unwind_Context _Unwind_Resume_or_Rethrow_this_context;

void offset (int);

struct _Unwind_Context {
  void *reg[7];
} _Unwind_Resume_or_Rethrow() {
  struct _Unwind_Context cur_contextcur_context =
      _Unwind_Resume_or_Rethrow_this_context;
  offset(0);
  __builtin_eh_return ((long) offset, 0);
}
[hjl@gnu-tgl-2 tmp]$ /usr/gcc-12.0.0-x32/bin/gcc -S -O2 -fcf-protection
-mharden-sls=all foo.c 
[hjl@gnu-tgl-2 tmp]$ cat foo.s
        .file   "foo.c"
        .text
        .p2align 4
        .globl  _Unwind_Resume_or_Rethrow
        .type   _Unwind_Resume_or_Rethrow, @function
_Unwind_Resume_or_Rethrow:
.LFB0:
        .cfi_startproc
        endbr64
        pushq   %rdx
        .cfi_def_cfa_offset 16
        .cfi_offset 1, -16
        xorl    %edi, %edi
        pushq   %rax
        .cfi_def_cfa_offset 24
        .cfi_offset 0, -24
        subq    $8, %rsp
        .cfi_def_cfa_offset 32
        call    offset
        movl    $offset, %ecx
        movq    $0, 24(%rsp,%rcx)
        movq    8(%rsp), %rax
        movq    16(%rsp), %rdx
        leaq    24(%rsp,%rcx), %rsp
        .cfi_def_cfa_offset 8
        popq    %rcx
        .cfi_register 16, 2
        .cfi_def_cfa_offset 0
        jmp     *%rcx <<<< Missing int3
        .cfi_endproc
.LFE0:
        .size   _Unwind_Resume_or_Rethrow, .-_Unwind_Resume_or_Rethrow
        .globl  _Unwind_Resume_or_Rethrow_this_context
        .bss
        .align 32
        .type   _Unwind_Resume_or_Rethrow_this_context, @object
        .size   _Unwind_Resume_or_Rethrow_this_context, 56
_Unwind_Resume_or_Rethrow_this_context:
        .zero   56
        .ident  "GCC: (GNU) 12.0.0 20211225 (experimental)"
        .section        .note.GNU-stack,"",@progbits
        .section        .note.gnu.property,"a"
        .align 8
        .long   1f - 0f
        .long   4f - 1f
        .long   5
0:
        .string "GNU"
1:
        .align 8
        .long   0xc0000002
        .long   3f - 2f
2:
        .long   0x3
3:
        .align 8
4:
[hjl@gnu-tgl-2 tmp]$

[Bug target/103925] Missing int3 in ix86_output_indirect_function_return

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103925

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |WAITING
   Last reconfirmed|                            |2022-01-06

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
>	jmp	*%rcx <<<< Missing int3


Can you expand on why you think int3 is missing here?

[Bug target/103925] Missing int3 in ix86_output_indirect_function_return

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103925

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Andrew Pinski from comment #1)
> >	jmp	*%rcx <<<< Missing int3
> 
> 
> Can you expand on why you think int3 is missing here?

-mharden-sls=all should generate INT3 after indirect jmp.

[Bug target/103925] Missing int3 in ix86_output_indirect_function_return

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103925

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The bug is in ix86_output_indirect_function_return.

[Bug target/103925] Missing int3 in ix86_output_indirect_function_return

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103925

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by H.J. Lu <hjl@gcc.gnu.org>:

https://gcc.gnu.org/g:c2e5c4feed32c808591b5278f680bbabe63eb225

commit r12-6321-gc2e5c4feed32c808591b5278f680bbabe63eb225
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Wed Jan 5 18:04:21 2022 -0800

    x86: Generate INT3 for __builtin_eh_return

    Generate INT3 after indirect jmp in exception return for -fcf-protection
    with -mharden-sls=indirect-jmp.

    gcc/

            PR target/103925
            * config/i386/i386.c (ix86_output_indirect_function_return):
            Generate INT3 after indirect jmp for -mharden-sls=indirect-jmp.

    gcc/testsuite/

            PR target/103925
            * gcc.target/i386/harden-sls-6.c: New test.

[Bug target/103925] Missing int3 in ix86_output_indirect_function_return

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103925

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED
   Target Milestone|---                         |12.0

--- Comment #5 from H.J. Lu <hjl.tools at gmail dot com> ---
Fixed.

[Bug target/103925] Missing int3 in ix86_output_indirect_function_return

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103925

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by H.J. Lu <hjl@gcc.gnu.org>:

https://gcc.gnu.org/g:978956485a663493130b02f787095095d163290e

commit r11-9578-g978956485a663493130b02f787095095d163290e
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Wed Jan 5 18:04:21 2022 -0800

    x86: Generate INT3 for __builtin_eh_return

    Generate INT3 after indirect jmp in exception return for -fcf-protection
    with -mharden-sls=indirect-jmp.

    gcc/

            PR target/103925
            * config/i386/i386.c (ix86_output_indirect_function_return):
            Generate INT3 after indirect jmp for -mharden-sls=indirect-jmp.

    gcc/testsuite/

            PR target/103925
            * gcc.target/i386/harden-sls-6.c: New test.

    (cherry picked from commit c2e5c4feed32c808591b5278f680bbabe63eb225)