ftrace: Synchronize the initialization of ftrace_opsgrafted

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 <rostedt@goodmis.org>

1 files changed, 198 insertions, 0 deletions

diff --git a/lib/tests/siphash_kunit.c b/lib/tests/siphash_kunit.c
new file mode 100644
index 000000000..26bd4e8dc
--- /dev/null
+++ b/lib/tests/siphash_kunit.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+/* Copyright (C) 2016-2022 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * Test cases for siphash.c
+ *
+ * SipHash: a fast short-input PRF
+ * https://131002.net/siphash/
+ *
+ * This implementation is specifically for SipHash2-4 for a secure PRF
+ * and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for
+ * hashtables.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <kunit/test.h>
+#include <linux/siphash.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+
+/* Test vectors taken from reference source available at:
+ *     https://github.com/veorq/SipHash
+ */
+
+static const siphash_key_t test_key_siphash =
+	{{ 0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL }};
+
+static const u64 test_vectors_siphash[64] = {
+	0x726fdb47dd0e0e31ULL, 0x74f839c593dc67fdULL, 0x0d6c8009d9a94f5aULL,
+	0x85676696d7fb7e2dULL, 0xcf2794e0277187b7ULL, 0x18765564cd99a68dULL,
+	0xcbc9466e58fee3ceULL, 0xab0200f58b01d137ULL, 0x93f5f5799a932462ULL,
+	0x9e0082df0ba9e4b0ULL, 0x7a5dbbc594ddb9f3ULL, 0xf4b32f46226bada7ULL,
+	0x751e8fbc860ee5fbULL, 0x14ea5627c0843d90ULL, 0xf723ca908e7af2eeULL,
+	0xa129ca6149be45e5ULL, 0x3f2acc7f57c29bdbULL, 0x699ae9f52cbe4794ULL,
+	0x4bc1b3f0968dd39cULL, 0xbb6dc91da77961bdULL, 0xbed65cf21aa2ee98ULL,
+	0xd0f2cbb02e3b67c7ULL, 0x93536795e3a33e88ULL, 0xa80c038ccd5ccec8ULL,
+	0xb8ad50c6f649af94ULL, 0xbce192de8a85b8eaULL, 0x17d835b85bbb15f3ULL,
+	0x2f2e6163076bcfadULL, 0xde4daaaca71dc9a5ULL, 0xa6a2506687956571ULL,
+	0xad87a3535c49ef28ULL, 0x32d892fad841c342ULL, 0x7127512f72f27cceULL,
+	0xa7f32346f95978e3ULL, 0x12e0b01abb051238ULL, 0x15e034d40fa197aeULL,
+	0x314dffbe0815a3b4ULL, 0x027990f029623981ULL, 0xcadcd4e59ef40c4dULL,
+	0x9abfd8766a33735cULL, 0x0e3ea96b5304a7d0ULL, 0xad0c42d6fc585992ULL,
+	0x187306c89bc215a9ULL, 0xd4a60abcf3792b95ULL, 0xf935451de4f21df2ULL,
+	0xa9538f0419755787ULL, 0xdb9acddff56ca510ULL, 0xd06c98cd5c0975ebULL,
+	0xe612a3cb9ecba951ULL, 0xc766e62cfcadaf96ULL, 0xee64435a9752fe72ULL,
+	0xa192d576b245165aULL, 0x0a8787bf8ecb74b2ULL, 0x81b3e73d20b49b6fULL,
+	0x7fa8220ba3b2eceaULL, 0x245731c13ca42499ULL, 0xb78dbfaf3a8d83bdULL,
+	0xea1ad565322a1a0bULL, 0x60e61c23a3795013ULL, 0x6606d7e446282b93ULL,
+	0x6ca4ecb15c5f91e1ULL, 0x9f626da15c9625f3ULL, 0xe51b38608ef25f57ULL,
+	0x958a324ceb064572ULL
+};
+
+#if BITS_PER_LONG == 64
+static const hsiphash_key_t test_key_hsiphash =
+	{{ 0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL }};
+
+static const u32 test_vectors_hsiphash[64] = {
+	0x050fc4dcU, 0x7d57ca93U, 0x4dc7d44dU,
+	0xe7ddf7fbU, 0x88d38328U, 0x49533b67U,
+	0xc59f22a7U, 0x9bb11140U, 0x8d299a8eU,
+	0x6c063de4U, 0x92ff097fU, 0xf94dc352U,
+	0x57b4d9a2U, 0x1229ffa7U, 0xc0f95d34U,
+	0x2a519956U, 0x7d908b66U, 0x63dbd80cU,
+	0xb473e63eU, 0x8d297d1cU, 0xa6cce040U,
+	0x2b45f844U, 0xa320872eU, 0xdae6c123U,
+	0x67349c8cU, 0x705b0979U, 0xca9913a5U,
+	0x4ade3b35U, 0xef6cd00dU, 0x4ab1e1f4U,
+	0x43c5e663U, 0x8c21d1bcU, 0x16a7b60dU,
+	0x7a8ff9bfU, 0x1f2a753eU, 0xbf186b91U,
+	0xada26206U, 0xa3c33057U, 0xae3a36a1U,
+	0x7b108392U, 0x99e41531U, 0x3f1ad944U,
+	0xc8138825U, 0xc28949a6U, 0xfaf8876bU,
+	0x9f042196U, 0x68b1d623U, 0x8b5114fdU,
+	0xdf074c46U, 0x12cc86b3U, 0x0a52098fU,
+	0x9d292f9aU, 0xa2f41f12U, 0x43a71ed0U,
+	0x73f0bce6U, 0x70a7e980U, 0x243c6d75U,
+	0xfdb71513U, 0xa67d8a08U, 0xb7e8f148U,
+	0xf7a644eeU, 0x0f1837f2U, 0x4b6694e0U,
+	0xb7bbb3a8U
+};
+#else
+static const hsiphash_key_t test_key_hsiphash =
+	{{ 0x03020100U, 0x07060504U }};
+
+static const u32 test_vectors_hsiphash[64] = {
+	0x5814c896U, 0xe7e864caU, 0xbc4b0e30U,
+	0x01539939U, 0x7e059ea6U, 0x88e3d89bU,
+	0xa0080b65U, 0x9d38d9d6U, 0x577999b1U,
+	0xc839caedU, 0xe4fa32cfU, 0x959246eeU,
+	0x6b28096cU, 0x66dd9cd6U, 0x16658a7cU,
+	0xd0257b04U, 0x8b31d501U, 0x2b1cd04bU,
+	0x06712339U, 0x522aca67U, 0x911bb605U,
+	0x90a65f0eU, 0xf826ef7bU, 0x62512debU,
+	0x57150ad7U, 0x5d473507U, 0x1ec47442U,
+	0xab64afd3U, 0x0a4100d0U, 0x6d2ce652U,
+	0x2331b6a3U, 0x08d8791aU, 0xbc6dda8dU,
+	0xe0f6c934U, 0xb0652033U, 0x9b9851ccU,
+	0x7c46fb7fU, 0x732ba8cbU, 0xf142997aU,
+	0xfcc9aa1bU, 0x05327eb2U, 0xe110131cU,
+	0xf9e5e7c0U, 0xa7d708a6U, 0x11795ab1U,
+	0x65671619U, 0x9f5fff91U, 0xd89c5267U,
+	0x007783ebU, 0x95766243U, 0xab639262U,
+	0x9c7e1390U, 0xc368dda6U, 0x38ddc455U,
+	0xfa13d379U, 0x979ea4e8U, 0x53ecd77eU,
+	0x2ee80657U, 0x33dbb66aU, 0xae3f0577U,
+	0x88b4c4ccU, 0x3e7f480bU, 0x74c1ebf8U,
+	0x87178304U
+};
+#endif
+
+#define chk(hash, vector, fmt...)			\
+	KUNIT_EXPECT_EQ_MSG(test, hash, vector, fmt)
+
+static void siphash_test(struct kunit *test)
+{
+	u8 in[64] __aligned(SIPHASH_ALIGNMENT);
+	u8 in_unaligned[65] __aligned(SIPHASH_ALIGNMENT);
+	u8 i;
+
+	for (i = 0; i < 64; ++i) {
+		in[i] = i;
+		in_unaligned[i + 1] = i;
+		chk(siphash(in, i, &test_key_siphash),
+		    test_vectors_siphash[i],
+		    "siphash self-test aligned %u: FAIL", i + 1);
+		chk(siphash(in_unaligned + 1, i, &test_key_siphash),
+		    test_vectors_siphash[i],
+		    "siphash self-test unaligned %u: FAIL", i + 1);
+		chk(hsiphash(in, i, &test_key_hsiphash),
+		    test_vectors_hsiphash[i],
+		    "hsiphash self-test aligned %u: FAIL", i + 1);
+		chk(hsiphash(in_unaligned + 1, i, &test_key_hsiphash),
+		    test_vectors_hsiphash[i],
+		    "hsiphash self-test unaligned %u: FAIL", i + 1);
+	}
+	chk(siphash_1u64(0x0706050403020100ULL, &test_key_siphash),
+	    test_vectors_siphash[8],
+	    "siphash self-test 1u64: FAIL");
+	chk(siphash_2u64(0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL,
+			 &test_key_siphash),
+	    test_vectors_siphash[16],
+	    "siphash self-test 2u64: FAIL");
+	chk(siphash_3u64(0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL,
+			 0x1716151413121110ULL, &test_key_siphash),
+	    test_vectors_siphash[24],
+	    "siphash self-test 3u64: FAIL");
+	chk(siphash_4u64(0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL,
+			 0x1716151413121110ULL, 0x1f1e1d1c1b1a1918ULL,
+			 &test_key_siphash),
+	    test_vectors_siphash[32],
+	    "siphash self-test 4u64: FAIL");
+	chk(siphash_1u32(0x03020100U, &test_key_siphash),
+	    test_vectors_siphash[4],
+	    "siphash self-test 1u32: FAIL");
+	chk(siphash_2u32(0x03020100U, 0x07060504U, &test_key_siphash),
+	    test_vectors_siphash[8],
+	    "siphash self-test 2u32: FAIL");
+	chk(siphash_3u32(0x03020100U, 0x07060504U,
+			 0x0b0a0908U, &test_key_siphash),
+	    test_vectors_siphash[12],
+	    "siphash self-test 3u32: FAIL");
+	chk(siphash_4u32(0x03020100U, 0x07060504U,
+			 0x0b0a0908U, 0x0f0e0d0cU, &test_key_siphash),
+	    test_vectors_siphash[16],
+	    "siphash self-test 4u32: FAIL");
+	chk(hsiphash_1u32(0x03020100U, &test_key_hsiphash),
+	    test_vectors_hsiphash[4],
+	    "hsiphash self-test 1u32: FAIL");
+	chk(hsiphash_2u32(0x03020100U, 0x07060504U, &test_key_hsiphash),
+	    test_vectors_hsiphash[8],
+	    "hsiphash self-test 2u32: FAIL");
+	chk(hsiphash_3u32(0x03020100U, 0x07060504U,
+			  0x0b0a0908U, &test_key_hsiphash),
+	    test_vectors_hsiphash[12],
+	    "hsiphash self-test 3u32: FAIL");
+	chk(hsiphash_4u32(0x03020100U, 0x07060504U,
+			  0x0b0a0908U, 0x0f0e0d0cU, &test_key_hsiphash),
+	    test_vectors_hsiphash[16],
+	    "hsiphash self-test 4u32: FAIL");
+}
+
+static struct kunit_case siphash_test_cases[] = {
+	KUNIT_CASE(siphash_test),
+	{}
+};
+
+static struct kunit_suite siphash_test_suite = {
+	.name = "siphash",
+	.test_cases = siphash_test_cases,
+};
+
+kunit_test_suite(siphash_test_suite);
+
+MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
+MODULE_DESCRIPTION("Test cases for siphash.c");
+MODULE_LICENSE("Dual BSD/GPL");