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Subject: Re: [PATCH] random: fix a compilation error on arm64
To:     Qian Cai <cai@lca.pw>, torvalds@linux-foundation.org
Cc:     daniel.diaz@linaro.org, tytso@mit.edu, catalin.marinas@arm.com,
        will@kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
References: <20200806135836.31736-1-cai@lca.pw>
From:   Guenter Roeck <linux@roeck-us.net>
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Message-ID: <4edcf552-ef82-cdd2-3fda-38d42ebfecc7@roeck-us.net>
Date:   Thu, 6 Aug 2020 07:50:23 -0700
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On 8/6/20 6:58 AM, Qian Cai wrote:
> linux-next failed to compile using this .config,
> https://gitlab.com/cailca/linux-mm/-/blob/master/arm64.config
> 
> 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))
>        ^~~~~~~~~~~~
> cc1: some warnings being treated as errors
> 

This happens because ARCH_RANDOM is disabled. May be I am wrong, but I
would argue that __arm64_rndr() should not be called directly in the
first place. arch_get_random_seed_long_early() should be called instead.

Thanks,
Guenter

> Fixes: 585524081ecd ("random: random.h should include archrandom.h, not the other way around")
> Signed-off-by: Qian Cai <cai@lca.pw>
> ---
>  include/linux/random.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/linux/random.h b/include/linux/random.h
> index f45b8be3e3c4..da782c16c20c 100644
> --- a/include/linux/random.h
> +++ b/include/linux/random.h
> @@ -12,6 +12,8 @@
>  #include <linux/list.h>
>  #include <linux/once.h>
>  
> +#include <asm/archrandom.h>
> +
>  #include <uapi/linux/random.h>
>  
>  struct random_ready_callback {
>