[PATCH 26/46] x86/apic, lto: Mark apic_driver*() as __noreorder

Jiri Slaby (SUSE)
2022-11-14T11:46:53Z

From: Jiri Slaby <jslaby@suse.cz>

The apic code assumes that the apic drivers are in a particular order in
memory. gcc LTO can violate this. So add __noreorder to apic_driver()
and apic_drivers() to avoid a boot BUG().

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Martin Liska <mliska@suse.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
arch/x86/include/asm/apic.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 3415321c8240..9c5c69482ab0 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -363,12 +363,12 @@ extern struct apic *apic;
* to enforce the order with in them.
*/
#define apic_driver(sym) \
- static const struct apic *__apicdrivers_##sym __used \
+ static const struct apic *__apicdrivers_##sym __used __noreorder \
__aligned(sizeof(struct apic *)) \
__section(".apicdrivers") = { &sym }

#define apic_drivers(sym1, sym2) \
- static struct apic *__apicdrivers_##sym1##sym2[2] __used \
+ static struct apic *__apicdrivers_##sym1##sym2[2] __used __noreorder \
__aligned(sizeof(struct apic *)) \
__section(".apicdrivers") = { &sym1, &sym2 }

--
2.38.1