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arm64: kaslr: Use standard early random function

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Commit 585524081e ("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))
         ^~~~~~~~~~~~

The 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.

Reported-by: Qian Cai <cai@lca.pw>
Fixes: 585524081e ("random: random.h should include archrandom.h, not the other way around")
Cc: Qian Cai <cai@lca.pw>
Cc: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Guenter Roeck 2020-08-07 07:45:21 -07:00 committed by Linus Torvalds
parent 0f5d0a4c01
commit 9bceb80b3c
1 changed files with 5 additions and 7 deletions
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12
arch/arm64/kernel/kaslr.c
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@ -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;