From: Mark Rutland mark.rutland@arm.com
mainline inclusion from mainline-v5.6-rc3 commit ead5084cdf5af51445d219800c2ac8b01eb85f2f category:bugfix bugzilla:NA CVE:NA
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Currently arm64 doesn't initialize the primary CRNG in a (potentially) trusted manner as we only detect the presence of the RNG once secondary CPUs are up.
Now that the core RNG code distinguishes the early initialization of the primary CRNG, we can implement arch_get_random_seed_long_early() to support this.
This patch does so.
Signed-off-by: Mark Rutland mark.rutland@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Mark Brown broonie@kernel.org Cc: Theodore Ts'o tytso@mit.edu Cc: Will Deacon will@kernel.org Link: https://lore.kernel.org/r/20200210130015.17664-4-mark.rutland@arm.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Chen Jun chenjun102@huawei.com Reviewed-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- arch/arm64/include/asm/archrandom.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/arch/arm64/include/asm/archrandom.h b/arch/arm64/include/asm/archrandom.h index 3fe02da70004..fc1594a0710e 100644 --- a/arch/arm64/include/asm/archrandom.h +++ b/arch/arm64/include/asm/archrandom.h @@ -4,6 +4,8 @@
#ifdef CONFIG_ARCH_RANDOM
+#include <linux/bug.h> +#include <linux/kernel.h> #include <linux/random.h> #include <asm/cpufeature.h>
@@ -66,6 +68,18 @@ static inline bool __init __early_cpu_has_rndr(void) return (ftr >> ID_AA64ISAR0_RNDR_SHIFT) & 0xf; }
+static inline bool __init __must_check +arch_get_random_seed_long_early(unsigned long *v) +{ + WARN_ON(system_state != SYSTEM_BOOTING); + + if (!__early_cpu_has_rndr()) + return false; + + return __arm64_rndr(v); +} +#define arch_get_random_seed_long_early arch_get_random_seed_long_early + #else
static inline bool __arm64_rndr(unsigned long *v) { return false; }