[PATCH v2] ARM: initialize jump labels before setup_machine_fdt()

From: Jason A. Donenfeld
Date: Fri Jun 03 2022 - 08:16:11 EST


Stephen reported that a static key warning splat appears during early
boot on arm64 systems that credit randomness from device trees that
contain an "rng-seed" property, because setup_machine_fdt() is called
before jump_label_init() during setup_arch(), which was fixed by
73e2d827a501 ("arm64: Initialize jump labels before
setup_machine_fdt()").

Upon cursory inspection, the same basic issue appears to apply to arm32
as well. So this commit adds a call to jump_label_init() just before
setup_machine_fdt().

Reported-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Suggested-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: f5bda35fba61 ("random: use static branch for crng_ready()")
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
arch/arm/kernel/setup.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 1e8a50a97edf..3ff80b1ee0b5 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1101,6 +1101,7 @@ void __init setup_arch(char **cmdline_p)
atags_vaddr = FDT_VIRT_BASE(__atags_pointer);

setup_processor();
+ jump_label_init();
if (atags_vaddr) {
mdesc = setup_machine_fdt(atags_vaddr);
if (mdesc)
--
2.35.1