firmware_loader: rework crypto dependencies

The crypto dependencies for the firmwware loader are incomplete,
in particular a built-in FW_LOADER fails to link against a modular
crypto hash driver:

ld.lld: error: undefined symbol: crypto_alloc_shash
ld.lld: error: undefined symbol: crypto_shash_digest
ld.lld: error: undefined symbol: crypto_destroy_tfm
>>> referenced by main.c
>>>               drivers/base/firmware_loader/main.o:(fw_log_firmware_info) in archive vmlinux.a

Rework this to use the usual 'select' from the driver module,
to respect the built-in vs module dependencies, and add a
more verbose crypto dependency to the debug option to prevent
configurations that lead to a link failure.

Fixes: 02fe26f25325 ("firmware_loader: Add debug message with checksum for FW file")
Reviewed-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230414080329.76176-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/firmware_loader/Kconfig b/drivers/base/firmware_loader/Kconfig
index 0cabc78..5ca00e0 100644 (file)
--- a/drivers/base/firmware_loader/Kconfig
+++ b/drivers/base/firmware_loader/Kconfig
@@ -3,6 +3,8 @@ menu "Firmware loader"
 
 config FW_LOADER
        tristate "Firmware loading facility" if EXPERT
+       select CRYPTO_HASH if FW_LOADER_DEBUG
+       select CRYPTO_SHA256 if FW_LOADER_DEBUG
        default y
        help
          This enables the firmware loading facility in the kernel. The kernel
@@ -26,10 +28,9 @@ config FW_LOADER
 
 config FW_LOADER_DEBUG
        bool "Log filenames and checksums for loaded firmware"
+       depends on CRYPTO = FW_LOADER || CRYPTO=y
        depends on DYNAMIC_DEBUG
        depends on FW_LOADER
-       depends on CRYPTO
-       depends on CRYPTO_SHA256
        default FW_LOADER
        help
          Select this option to use dynamic debug to log firmware filenames and