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
