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

Jason A. Donenfeld Jason at zx2c4.com
Fri Jun 3 05:15:43 PDT 2022


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 at chromium.org>
Suggested-by: Ard Biesheuvel <ardb at kernel.org>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: stable at vger.kernel.org
Fixes: f5bda35fba61 ("random: use static branch for crng_ready()")
Signed-off-by: Jason A. Donenfeld <Jason at zx2c4.com>
---
 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




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