Commit 585524081ecd ("random: random.h should include archrandom.h, not
the other way around") tries to fix a problem with recursive inclusion
of linux/random.h and arch/archrandom.h for arm64. Unfortunately, this
results in the following compile error if ARCH_RANDOM is disabled.
arch/arm64/kernel/kaslr.c: In function 'kaslr_early_init':
arch/arm64/kernel/kaslr.c:128:6: error: implicit declaration of function
'__early_cpu_has_rndr'; did you mean '__early_pfn_to_nid'?
[-Werror=implicit-function-declaration]
if (__early_cpu_has_rndr()) {
^~~~~~~~~~~~~~~~~~~~
__early_pfn_to_nid
arch/arm64/kernel/kaslr.c:131:7: error: implicit declaration of function
'__arm64_rndr' [-Werror=implicit-function-declaration]
if (__arm64_rndr(&raw))
^~~~~~~~~~~~
Problem is that arch/archrandom.h is only included from linux/random.h if
ARCH_RANDOM is enabled. If not, __arm64_rndr() and __early_cpu_has_rndr()
are undeclared, causing the problem.
Use arch_get_random_seed_long_early() instead of arm64 specific functions
to solve the problem. As a side effect of this change, the code no longer
bypasses ARCH_RANDOM, which I consider desirable (after all, ARCH_RANDOM
was disabled for a reason).
Reported-by: Qian Cai <[email protected]>
Fixes: 585524081ecd ("random: random.h should include archrandom.h, not the
other way around")
Fixes: 2e8e1ea88cbc ("arm64: Use v8.5-RNG entropy for KASLR seed")
Cc: Qian Cai <[email protected]>
Cc: Mark Brown <[email protected]>
Signed-off-by: Guenter Roeck <[email protected]>
---
arch/arm64/kernel/kaslr.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
index 9ded4237e1c1..b181e0544b79 100644
--- a/arch/arm64/kernel/kaslr.c
+++ b/arch/arm64/kernel/kaslr.c
@@ -84,6 +84,7 @@ u64 __init kaslr_early_init(u64 dt_phys)
void *fdt;
u64 seed, offset, mask, module_range;
const u8 *cmdline, *str;
+ unsigned long raw;
int size;
/*
@@ -122,15 +123,12 @@ u64 __init kaslr_early_init(u64 dt_phys)
}
/*
- * Mix in any entropy obtainable architecturally, open coded
- * since this runs extremely early.
+ * Mix in any entropy obtainable architecturally if enabled
+ * and supported.
*/
- if (__early_cpu_has_rndr()) {
- unsigned long raw;
- if (__arm64_rndr(&raw))
- seed ^= raw;
- }
+ if (arch_get_random_seed_long_early(&raw))
+ seed ^= raw;
if (!seed) {
kaslr_status = KASLR_DISABLED_NO_SEED;
--
2.17.1
