[PATCH 0/5] crypto: Drop stale usages in various help texts

[PATCH 0/5] crypto: Drop stale usages in various help texts

[Geert Uytterhoeven]

	Hi all,

This patch series drops stale references to subsystems that are using
various crypto algoritms.  It was triggered by "make oldconfig" in
v7.0-rc1 showing new prompts about BLAKE2b, SHA-256, xxHash, and CRC32c
algorithms.  When querying these symbols, the corresponding help texts
incorrectly claim they are used by btrfs.

Notw that even if correct, there is no need for such references, as all
users should select the needed symbols anyway.

Geert Uytterhoeven (5):
  crypto: Drop stale CRYPTO_BLAKE2B usage
  crypto: Drop stale CRYPTO_SHA256 usage
  crypto: Drop stale CRYPTO_XXHASH usage
  crypto: Drop stale CRYPTO_CRC32C usage
  crypto: Drop stale CRYPTO_CRC32 usage

 crypto/Kconfig | 9 ---------
 1 file changed, 9 deletions(-)

-- 
2.43.0

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

[PATCH 1/5] crypto: Clean up CRYPTO_BLAKE2B usage

[Geert Uytterhoeven]

Btrfs stopped using this BLAKE2b implementations in commit
fe11ac191ce0ad91 ("btrfs: switch to library APIs for checksums").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 crypto/Kconfig | 2 --
 1 file changed, 2 deletions(-)

diff --git a/crypto/Kconfig b/crypto/Kconfig
index e2b4106ac961eb52..8bc95e69faa5557a 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -876,8 +876,6 @@ config CRYPTO_BLAKE2B
 	  - blake2b-384
 	  - blake2b-512
 
-	  Used by the btrfs filesystem.
-
 	  See https://blake2.net for further information.
 
 config CRYPTO_CMAC
-- 
2.43.0

[PATCH 2/5] crypto: Clean up CRYPTO_SHA256 usage

[Geert Uytterhoeven]

NFS, Ceph, SMB, and Btrfs stopped using this SHA-256 implementation in
commits c2c90a8b2620626c ("nfsd: use SHA-256 library API instead of
crypto_shash API"), 27c0a7b05d13a0dc ("libceph: Use HMAC-SHA256 library
instead of crypto_shash"), 924067ef183bd17f ("ksmbd: Use HMAC-SHA256
library for message signing and key generation"), and fe11ac191ce0ad91
("btrfs: switch to library APIs for checksums").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 crypto/Kconfig | 1 -
 1 file changed, 1 deletion(-)

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 8bc95e69faa5557a..c84fda3acdbda57c 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -963,7 +963,6 @@ config CRYPTO_SHA256
 	  10118-3), including HMAC support.
 
 	  This is required for IPsec AH (XFRM_AH) and IPsec ESP (XFRM_ESP).
-	  Used by the btrfs filesystem, Ceph, NFS, and SMB.
 
 config CRYPTO_SHA512
 	tristate "SHA-384 and SHA-512"
-- 
2.43.0

[PATCH 3/5] crypto: Clean up CRYPTO_XXHASH usage

[Geert Uytterhoeven]

Btrfs stopped using this xxHash implementation in commit
fe11ac191ce0ad91 ("btrfs: switch to library APIs for checksums").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 crypto/Kconfig | 2 --
 1 file changed, 2 deletions(-)

diff --git a/crypto/Kconfig b/crypto/Kconfig
index c84fda3acdbda57c..49293b656aff6f52 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1036,8 +1036,6 @@ config CRYPTO_XXHASH
 
 	  Extremely fast, working at speeds close to RAM limits.
 
-	  Used by the btrfs filesystem.
-
 endmenu
 
 menu "CRCs (cyclic redundancy checks)"
-- 
2.43.0

[PATCH 4/5] crypto: Clean up CRYPTO_CRC32C usage

[Geert Uytterhoeven]

Ext4, jbd2, iSCSI, NVMeoF/TCP, and Btrfs stopped using this CRC32c
implementation in commits f2b4fa19647e18a2 ("ext4: switch to using the
crc32c library"), dd348f054b24a3f5 ("jbd2: switch to using the crc32c
library"), 92186c1455a2d356 ("scsi: iscsi_tcp: Switch to using the
crc32c library"), 427fff9aff295e2c ("nvme-tcp: use crc32c() and
skb_copy_and_crc32c_datagram_iter()"), and fe11ac191ce0ad91 ("btrfs:
switch to library APIs for checksums").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 crypto/Kconfig | 2 --
 1 file changed, 2 deletions(-)

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 49293b656aff6f52..5e66de2948ed02f9 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1053,8 +1053,6 @@ config CRYPTO_CRC32C
 	  on Communications, Vol. 41, No. 6, June 1993, selected for use with
 	  iSCSI.
 
-	  Used by btrfs, ext4, jbd2, NVMeoF/TCP, and iSCSI.
-
 config CRYPTO_CRC32
 	tristate "CRC32"
 	select CRYPTO_HASH
-- 
2.43.0

[PATCH 5/5] crypto: Clean up CRYPTO_CRC32 usage

[Geert Uytterhoeven]

F2fs and RoCEv2 stopped using this CRC32 implementation in commits
3ca4bec40ee211cd ("f2fs: switch to using the crc32 library") and
ccca5e8aa1457231 ("RDMA/rxe: switch to using the crc32 library").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 crypto/Kconfig | 2 --
 1 file changed, 2 deletions(-)

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 5e66de2948ed02f9..b4bb85e8e2261209 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1060,8 +1060,6 @@ config CRYPTO_CRC32
 	help
 	  CRC32 CRC algorithm (IEEE 802.3)
 
-	  Used by RoCEv2 and f2fs.
-
 endmenu
 
 menu "Compression"
-- 
2.43.0

Re: [PATCH 0/5] crypto: Drop stale usages in various help texts

[Eric Biggers]

On Thu, Feb 26, 2026 at 03:46:04PM +0100, Geert Uytterhoeven wrote:
> 	Hi all,
> 
> This patch series drops stale references to subsystems that are using
> various crypto algoritms.  It was triggered by "make oldconfig" in
> v7.0-rc1 showing new prompts about BLAKE2b, SHA-256, xxHash, and CRC32c
> algorithms.  When querying these symbols, the corresponding help texts
> incorrectly claim they are used by btrfs.
> 
> Notw that even if correct, there is no need for such references, as all
> users should select the needed symbols anyway.
> 
> Geert Uytterhoeven (5):
>   crypto: Drop stale CRYPTO_BLAKE2B usage
>   crypto: Drop stale CRYPTO_SHA256 usage
>   crypto: Drop stale CRYPTO_XXHASH usage
>   crypto: Drop stale CRYPTO_CRC32C usage
>   crypto: Drop stale CRYPTO_CRC32 usage
> 
>  crypto/Kconfig | 9 ---------
>  1 file changed, 9 deletions(-)

Thanks for cleaning this up!

If there are no objections I'd like take these through libcrypto-fixes,
given that they are related to the library conversions.

- Eric

Re: [PATCH 0/5] crypto: Drop stale usages in various help texts

[Eric Biggers]

On Thu, Feb 26, 2026 at 11:54:40AM -0800, Eric Biggers wrote:
> On Thu, Feb 26, 2026 at 03:46:04PM +0100, Geert Uytterhoeven wrote:
> > 	Hi all,
> > 
> > This patch series drops stale references to subsystems that are using
> > various crypto algoritms.  It was triggered by "make oldconfig" in
> > v7.0-rc1 showing new prompts about BLAKE2b, SHA-256, xxHash, and CRC32c
> > algorithms.  When querying these symbols, the corresponding help texts
> > incorrectly claim they are used by btrfs.
> > 
> > Notw that even if correct, there is no need for such references, as all
> > users should select the needed symbols anyway.
> > 
> > Geert Uytterhoeven (5):
> >   crypto: Drop stale CRYPTO_BLAKE2B usage
> >   crypto: Drop stale CRYPTO_SHA256 usage
> >   crypto: Drop stale CRYPTO_XXHASH usage
> >   crypto: Drop stale CRYPTO_CRC32C usage
> >   crypto: Drop stale CRYPTO_CRC32 usage
> > 
> >  crypto/Kconfig | 9 ---------
> >  1 file changed, 9 deletions(-)
> 
> Thanks for cleaning this up!
> 
> If there are no objections I'd like take these through libcrypto-fixes,
> given that they are related to the library conversions.

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git/log/?h=libcrypto-fixes

I adjusted the commit titles to make it clear that the changes are to
the help text, not e.g. to selections of the symbols.

    crypto: Clean up help text for CRYPTO_CRC32

- Eric

Re: [PATCH 0/5] crypto: Drop stale usages in various help texts

[Geert Uytterhoeven]

Hi Eric,

On Tue, 3 Mar 2026 at 00:42, Eric Biggers <ebiggers@kernel.org> wrote:
> On Thu, Feb 26, 2026 at 11:54:40AM -0800, Eric Biggers wrote:
> > On Thu, Feb 26, 2026 at 03:46:04PM +0100, Geert Uytterhoeven wrote:
> > > This patch series drops stale references to subsystems that are using
> > > various crypto algoritms.  It was triggered by "make oldconfig" in
> > > v7.0-rc1 showing new prompts about BLAKE2b, SHA-256, xxHash, and CRC32c
> > > algorithms.  When querying these symbols, the corresponding help texts
> > > incorrectly claim they are used by btrfs.
> > >
> > > Notw that even if correct, there is no need for such references, as all
> > > users should select the needed symbols anyway.
> > >
> > > Geert Uytterhoeven (5):
> > >   crypto: Drop stale CRYPTO_BLAKE2B usage
> > >   crypto: Drop stale CRYPTO_SHA256 usage
> > >   crypto: Drop stale CRYPTO_XXHASH usage
> > >   crypto: Drop stale CRYPTO_CRC32C usage
> > >   crypto: Drop stale CRYPTO_CRC32 usage
> > >
> > >  crypto/Kconfig | 9 ---------
> > >  1 file changed, 9 deletions(-)
> >
> > Thanks for cleaning this up!
> >
> > If there are no objections I'd like take these through libcrypto-fixes,
> > given that they are related to the library conversions.
>
> Applied to https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git/log/?h=libcrypto-fixes
>
> I adjusted the commit titles to make it clear that the changes are to
> the help text, not e.g. to selections of the symbols.
>
>     crypto: Clean up help text for CRYPTO_CRC32

Thank you!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds