https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89839
Bug ID: 89839
Summary: section not reset to text for top level asm
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: inline-asm
Assignee: unassigned at gcc dot gnu.org
Reporter: andi-gcc at firstfloor dot org
Target Milestone: ---
The ELF section from the previous function doesn't get reset before top level
asm statements:
e.g.
__attribute__((section("foo"))) void func(void)
{
}
asm("foo:\n");
gcc -S gives
.section foo,"ax",@progbits <----------------- sets the section
.globl func
.type func, @function
func:
.LFB0:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
nop
popq %rbp
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE0:
.size func, .-func
<--------------------------- no section reset before the asm
#APP
foo:
The problem is if foo is some section with special behavior (for example
initcall sections in the Linux kernel) this can cause crashes. I've seen such
problems with LTO on the Linux kernel.
gcc should always reset the section to .text before emitting top level asm.
See with 8.x, but also trunk.
