[Bug target/85044] ENDBR is missing in ix86_trampoline_init

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85044

--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> ---
[hjl@gnu-cfl-1 tmp]$ cat y.c
extern void foo (void);
extern void bar (void);
extern void callme (void *);
void
tryme (void)
{
  int ok = 0;
  void callback (void) { ok = 1; }

  callme (&callback);

  if (ok)
    foo ();
  else
    bar ();
}
[hjl@gnu-cfl-1 tmp]$  /usr/gcc-8.0.1-x32/bin/gcc -O2 -fPIC -S -fcf-protection
-mcet y.c
[hjl@gnu-cfl-1 tmp]$ cat y.s
        .file   "y.c"
        .text
        .p2align 4,,15
        .type   callback.1980, @function
callback.1980:
.LFB1:
        .cfi_startproc
        endbr64
        movl    $1, (%r10)
        ret
        .cfi_endproc
.LFE1:
        .size   callback.1980, .-callback.1980
        .p2align 4,,15
        .globl  tryme
        .type   tryme, @function
tryme:
.LFB0:
        .cfi_startproc
        endbr64
        subq    $56, %rsp
        .cfi_def_cfa_offset 64
        movl    $-17591, %edx
        movl    $-17847, %ecx
        leaq    64(%rsp), %rax
        movw    %dx, 4(%rsp)
        leaq    callback.1980(%rip), %rdx
        movq    %rax, 32(%rsp)
        movq    %rsp, %rax
        leaq    4(%rax), %rdi
        movq    %rdx, 2(%rdi)
        movw    %cx, 10(%rdi)
        movq    %rax, 12(%rdi)
        movl    $-1864106167, 20(%rdi)
        movl    $0, (%rsp)
        call    callme@PLT
        movl    (%rsp), %esi
        testl   %esi, %esi
        je      .L4
        call    foo@PLT
        addq    $56, %rsp
        .cfi_remember_state
        .cfi_def_cfa_offset 8
        ret
        .p2align 4,,10
        .p2align 3
.L4:
        .cfi_restore_state
        call    bar@PLT
        addq    $56, %rsp
        .cfi_def_cfa_offset 8
        ret
        .cfi_endproc
.LFE0:
        .size   tryme, .-tryme
        .ident  "GCC: (GNU) 8.0.1 20180322 (experimental)"
        .section        .note.GNU-stack,"x",@progbits
        .section        .note.gnu.property,"a"
        .align 8
        .long    1f - 0f
        .long    4f - 1f
        .long    5
0:
        .string  "GNU"
1:
        .align 8
        .long    0xc0000002
        .long    3f - 2f
2:
        .long    0x3
3:
        .align 8
4:
[hjl@gnu-cfl-1 tmp]$ 

It generates trampoline on stack like

Dump of assembler code from 0x7fffffffddc1 to 0x7fffffffdddf:
=> 0x00007fffffffddc1:  49 bb 80 81 ce f7 fe 7f 00 00   movabs
$0x7ffef7ce8180,%r11
   0x00007fffffffddcb:  49 ba c0 dd ff ff ff 7f 00 00   movabs
$0x7fffffffddc0,%r10
   0x00007fffffffddd5:  49 ff e3        rex.WB jmpq *%r11