Re: [PATCH] pstore: fix crypto dependencies

[Kees Cook]

On Thu, Mar 15, 2018 at 8:34 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> The new crypto API use causes some problems with Kconfig dependencies,
> including this link error:
>
> fs/pstore/platform.o: In function `pstore_register':
> platform.c:(.text+0x248): undefined reference to `crypto_has_alg'
> platform.c:(.text+0x2a0): undefined reference to `crypto_alloc_base'
> fs/pstore/platform.o: In function `pstore_unregister':
> platform.c:(.text+0x498): undefined reference to `crypto_destroy_tfm'
> crypto/lz4hc.o: In function `lz4hc_sdecompress':
> lz4hc.c:(.text+0x1a): undefined reference to `LZ4_decompress_safe'
> crypto/lz4hc.o: In function `lz4hc_decompress_crypto':
> lz4hc.c:(.text+0x5a): undefined reference to `LZ4_decompress_safe'
> crypto/lz4hc.o: In function `lz4hc_scompress':
> lz4hc.c:(.text+0xaa): undefined reference to `LZ4_compress_HC'
> crypto/lz4hc.o: In function `lz4hc_mod_init':
> lz4hc.c:(.init.text+0xf): undefined reference to `crypto_register_alg'
> lz4hc.c:(.init.text+0x1f): undefined reference to `crypto_register_scomp'
> lz4hc.c:(.init.text+0x2f): undefined reference to `crypto_unregister_alg'
>
> The problem is that with CONFIG_CRYPTO=m, we must not 'select CRYPTO_LZ4'
> from a bool symbol, or call crypto API functions from a built-in
> module.
>
> This turns the sub-options into 'tristate' ones so the dependencies
> are honored, and makes the pstore itself select the crypto core
> if necessary.
>
> Fixes: cb3bee0369bc ("pstore: Use crypto compress API")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Ah, thanks for this! I'm running it through tests now and should be in
-next shortly.

-Kees

-- 
Kees Cook
Pixel Security