https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94729
Bug ID: 94729
Summary: aarch64:
__attribute__((target("branch-protection=pac-ret")))
is accepted in ilp32
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: nsz at gcc dot gnu.org
Target Milestone: ---
-mbranch-protection=pac-ret is not supported in ilp32
so i would expect the related attribute to be a compile
time error. (or a warning that it is ignored on ilp32)
gcc generates pac-ret instructions with -mabi=ilp32
which will almost surely fail at runtime on a pac-ret
enabled system:
long bar(void);
__attribute__((target("branch-protection=pac-ret")))
long foo(void)
{
return bar()+1;
}
becomes
foo:
hint 25 // paciasp
stp x29, x30, [sp, -16]!
mov x29, sp
bl bar
add w0, w0, 1
ldp x29, x30, [sp], 16
hint 29 // autiasp
ret
