From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- .../crypto/libcrypto-unauth-encryption.rst | 49 ++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 Documentation/crypto/libcrypto-unauth-encryption.rst (limited to 'Documentation/crypto/libcrypto-unauth-encryption.rst') diff --git a/Documentation/crypto/libcrypto-unauth-encryption.rst b/Documentation/crypto/libcrypto-unauth-encryption.rst new file mode 100644 index 000000000..b4639b892 --- /dev/null +++ b/Documentation/crypto/libcrypto-unauth-encryption.rst @@ -0,0 +1,49 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +Unauthenticated encryption +========================== + +These APIs provide support for unauthenticated encryption and decryption, +including bare stream ciphers and other length-preserving algorithms such as +block ciphers in XTS mode. The legitimate use cases for these algorithms are: + +- Support for legacy protocols that really should have chosen an authenticated + mode (or even another primitive entirely) but didn't. + +- Internal components of authenticated modes. For example, AES-CTR is used by + AES-GCM and AES-CCM internally. + +- Storage encryption that cannot accommodate ciphertext expansion. Usually + AES-XTS is used for this. + +- Stream ciphers for key derivation and random number generation. + +Besides the above, these shouldn't be used. + +AES-CBC and AES-CBC-CTS +----------------------- + +This API provides support for AES in the CBC and CBC-CTS modes of operation. + +.. kernel-doc:: include/crypto/aes-cbc.h + +AES-CTR and AES-XCTR +-------------------- + +This API provides support for AES in the CTR and XCTR modes of operation. + +.. kernel-doc:: include/crypto/aes-ctr.h + +AES-ECB +------- + +This API provides support for AES in the ECB mode of operation. + +.. kernel-doc:: include/crypto/aes-ecb.h + +AES-XTS +------- + +This API provides support for AES in the XTS mode of operation. + +.. kernel-doc:: include/crypto/aes-xts.h -- cgit v1.3.1