[Bug middle-end/85620] Missing ENDBR after swapcontext

["hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85620

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-05-02
                 CC|                            |igor.v.tsimbalist at intel dot com
             Blocks|                            |81652
            Summary|swapcontext isn't marked    |Missing ENDBR after
                   |return twice                |swapcontext
     Ever confirmed|0                           |1

--- Comment #5 from H.J. Lu <hjl.tools at gmail dot com> ---
[hjl@gnu-skx-1 ucontext-1]$ cat y.i
struct ucontext;
typedef struct ucontext ucontext_t;

extern int swapcontext (ucontext_t *__restrict __oucp,
                        const ucontext_t *__restrict __ucp);

extern int res;

void
foo (ucontext_t *oucp, ucontext_t *ucp)
{
  res = swapcontext (oucp, ucp);
}
[hjl@gnu-skx-1 ucontext-1]$ make y.s
/export/build/gnu/gcc-8-test/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc-8-test/build-x86_64-linux/gcc/ -O2  -fcf-protection -S
y.i
[hjl@gnu-skx-1 ucontext-1]$ cat y.s
        .file   "y.i"
        .text
        .p2align 4,,15
        .globl  foo
        .type   foo, @function
foo:
.LFB0:
        .cfi_startproc
        endbr64
        subq    $8, %rsp
        .cfi_def_cfa_offset 16
        call    swapcontext  <<<<<<< This may return via indirect branch.
<<<<<<<<<<< Need ENDBR here.
        movl    %eax, res(%rip)
        addq    $8, %rsp
        .cfi_def_cfa_offset 8
        ret
        .cfi_endproc
.LFE0:
        .size   foo, .-foo
        .ident  "GCC: (GNU) 8.1.1 20180502"
        .section        .note.GNU-stack,"",@progbits
        .section        .note.gnu.property,"a"
        .align 8
        .long    1f - 0f
        .long    4f - 1f
        .long    5
0:
        .string  "GNU"
1:
        .align 8
        .long    0xc0000002
        .long    3f - 2f
2:
        .long    0x3
3:
        .align 8
4:
[hjl@gnu-skx-1 ucontext-1]$


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81652
[Bug 81652] [meta-bug] -fcf-protection=full bugs