https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116962
Bug ID: 116962
Summary: Bad interaction between __attribute__((naked)) and
-fstack-protector-all
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: nicolas.savoire at datadoghq dot com
Target Milestone: ---
The following C code:
__attribute__((naked)) void foo() { asm("ret"); }
compiled with -O0 -fstack-protector-all -S on x86_64 results in:
foo:
movq %fs:40, %rax
movq %rax, -8(%rbp)
xorl %eax, %eax
ret
nop
movq -8(%rbp), %rax
subq %fs:40, %rax
je .L2
call __stack_chk_fail
.L2:
ud2
Generated code seems wrong since "movq %rax, -8(%rbp)" will overwrite a value
in the previous frame.
