* [PATCH 1/3] kunit, lib/crypto: Move run_irq_test() to common header
2025-08-11 18:26 [PATCH 0/3] Test CRC computation in interrupt contexts Eric Biggers
@ 2025-08-11 18:26 ` Eric Biggers
2025-08-11 18:26 ` [PATCH 2/3] lib/crc: crc_kunit: Test CRC computation in interrupt contexts Eric Biggers
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Eric Biggers @ 2025-08-11 18:26 UTC (permalink / raw)
To: linux-kernel
Cc: linux-crypto, Ard Biesheuvel, linux-kselftest, kunit-dev,
Eric Biggers
Rename run_irq_test() to kunit_run_irq_test() and move it to a public
header so that it can be reused by crc_kunit.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
include/kunit/run-in-irq-context.h | 129 ++++++++++++++++++++++++++
lib/crypto/tests/hash-test-template.h | 123 +-----------------------
2 files changed, 133 insertions(+), 119 deletions(-)
create mode 100644 include/kunit/run-in-irq-context.h
diff --git a/include/kunit/run-in-irq-context.h b/include/kunit/run-in-irq-context.h
new file mode 100644
index 0000000000000..108e96433ea45
--- /dev/null
+++ b/include/kunit/run-in-irq-context.h
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Helper function for testing code in interrupt contexts
+ *
+ * Copyright 2025 Google LLC
+ */
+#ifndef _KUNIT_RUN_IN_IRQ_CONTEXT_H
+#define _KUNIT_RUN_IN_IRQ_CONTEXT_H
+
+#include <kunit/test.h>
+#include <linux/timekeeping.h>
+#include <linux/hrtimer.h>
+#include <linux/workqueue.h>
+
+#define KUNIT_IRQ_TEST_HRTIMER_INTERVAL us_to_ktime(5)
+
+struct kunit_irq_test_state {
+ bool (*func)(void *test_specific_state);
+ void *test_specific_state;
+ bool task_func_reported_failure;
+ bool hardirq_func_reported_failure;
+ bool softirq_func_reported_failure;
+ unsigned long hardirq_func_calls;
+ unsigned long softirq_func_calls;
+ struct hrtimer timer;
+ struct work_struct bh_work;
+};
+
+static enum hrtimer_restart kunit_irq_test_timer_func(struct hrtimer *timer)
+{
+ struct kunit_irq_test_state *state =
+ container_of(timer, typeof(*state), timer);
+
+ WARN_ON_ONCE(!in_hardirq());
+ state->hardirq_func_calls++;
+
+ if (!state->func(state->test_specific_state))
+ state->hardirq_func_reported_failure = true;
+
+ hrtimer_forward_now(&state->timer, KUNIT_IRQ_TEST_HRTIMER_INTERVAL);
+ queue_work(system_bh_wq, &state->bh_work);
+ return HRTIMER_RESTART;
+}
+
+static void kunit_irq_test_bh_work_func(struct work_struct *work)
+{
+ struct kunit_irq_test_state *state =
+ container_of(work, typeof(*state), bh_work);
+
+ WARN_ON_ONCE(!in_serving_softirq());
+ state->softirq_func_calls++;
+
+ if (!state->func(state->test_specific_state))
+ state->softirq_func_reported_failure = true;
+}
+
+/*
+ * Helper function which repeatedly runs the given @func in task, softirq, and
+ * hardirq context concurrently, and reports a failure to KUnit if any
+ * invocation of @func in any context returns false. @func is passed
+ * @test_specific_state as its argument. At most 3 invocations of @func will
+ * run concurrently: one in each of task, softirq, and hardirq context.
+ *
+ * The main purpose of this interrupt context testing is to validate fallback
+ * code paths that run in contexts where the normal code path cannot be used,
+ * typically due to the FPU or vector registers already being in-use in kernel
+ * mode. These code paths aren't covered when the test code is executed only by
+ * the KUnit test runner thread in task context. The reason for the concurrency
+ * is because merely using hardirq context is not sufficient to reach a fallback
+ * code path on some architectures; the hardirq actually has to occur while the
+ * FPU or vector unit was already in-use in kernel mode.
+ *
+ * Another purpose of this testing is to detect issues with the architecture's
+ * irq_fpu_usable() and kernel_fpu_begin/end() or equivalent functions,
+ * especially in softirq context when the softirq may have interrupted a task
+ * already using kernel-mode FPU or vector (if the arch didn't prevent that).
+ * Crypto functions are often executed in softirqs, so this is important.
+ */
+static inline void kunit_run_irq_test(struct kunit *test, bool (*func)(void *),
+ int max_iterations,
+ void *test_specific_state)
+{
+ struct kunit_irq_test_state state = {
+ .func = func,
+ .test_specific_state = test_specific_state,
+ };
+ unsigned long end_jiffies;
+
+ /*
+ * Set up a hrtimer (the way we access hardirq context) and a work
+ * struct for the BH workqueue (the way we access softirq context).
+ */
+ hrtimer_setup_on_stack(&state.timer, kunit_irq_test_timer_func,
+ CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
+ INIT_WORK_ONSTACK(&state.bh_work, kunit_irq_test_bh_work_func);
+
+ /* Run for up to max_iterations or 1 second, whichever comes first. */
+ end_jiffies = jiffies + HZ;
+ hrtimer_start(&state.timer, KUNIT_IRQ_TEST_HRTIMER_INTERVAL,
+ HRTIMER_MODE_REL_HARD);
+ for (int i = 0; i < max_iterations && !time_after(jiffies, end_jiffies);
+ i++) {
+ if (!func(test_specific_state))
+ state.task_func_reported_failure = true;
+ }
+
+ /* Cancel the timer and work. */
+ hrtimer_cancel(&state.timer);
+ flush_work(&state.bh_work);
+
+ /* Sanity check: the timer and BH functions should have been run. */
+ KUNIT_EXPECT_GT_MSG(test, state.hardirq_func_calls, 0,
+ "Timer function was not called");
+ KUNIT_EXPECT_GT_MSG(test, state.softirq_func_calls, 0,
+ "BH work function was not called");
+
+ /* Check for incorrect hash values reported from any context. */
+ KUNIT_EXPECT_FALSE_MSG(
+ test, state.task_func_reported_failure,
+ "Incorrect hash values reported from task context");
+ KUNIT_EXPECT_FALSE_MSG(
+ test, state.hardirq_func_reported_failure,
+ "Incorrect hash values reported from hardirq context");
+ KUNIT_EXPECT_FALSE_MSG(
+ test, state.softirq_func_reported_failure,
+ "Incorrect hash values reported from softirq context");
+}
+
+#endif /* _KUNIT_RUN_IN_IRQ_CONTEXT_H */
diff --git a/lib/crypto/tests/hash-test-template.h b/lib/crypto/tests/hash-test-template.h
index f437a0a9ac6cd..61b43e62779fb 100644
--- a/lib/crypto/tests/hash-test-template.h
+++ b/lib/crypto/tests/hash-test-template.h
@@ -3,15 +3,13 @@
* Test cases for hash functions, including a benchmark. This is included by
* KUnit test suites that want to use it. See sha512_kunit.c for an example.
*
* Copyright 2025 Google LLC
*/
+#include <kunit/run-in-irq-context.h>
#include <kunit/test.h>
-#include <linux/hrtimer.h>
-#include <linux/timekeeping.h>
#include <linux/vmalloc.h>
-#include <linux/workqueue.h>
/* test_buf is a guarded buffer, i.e. &test_buf[TEST_BUF_LEN] is not mapped. */
#define TEST_BUF_LEN 16384
static u8 *test_buf;
@@ -317,123 +315,10 @@ static void test_hash_ctx_zeroization(struct kunit *test)
HASH_FINAL(&ctx, test_buf);
KUNIT_ASSERT_MEMEQ_MSG(test, &ctx, zeroes, sizeof(ctx),
"Hash context was not zeroized by finalization");
}
-#define IRQ_TEST_HRTIMER_INTERVAL us_to_ktime(5)
-
-struct hash_irq_test_state {
- bool (*func)(void *test_specific_state);
- void *test_specific_state;
- bool task_func_reported_failure;
- bool hardirq_func_reported_failure;
- bool softirq_func_reported_failure;
- unsigned long hardirq_func_calls;
- unsigned long softirq_func_calls;
- struct hrtimer timer;
- struct work_struct bh_work;
-};
-
-static enum hrtimer_restart hash_irq_test_timer_func(struct hrtimer *timer)
-{
- struct hash_irq_test_state *state =
- container_of(timer, typeof(*state), timer);
-
- WARN_ON_ONCE(!in_hardirq());
- state->hardirq_func_calls++;
-
- if (!state->func(state->test_specific_state))
- state->hardirq_func_reported_failure = true;
-
- hrtimer_forward_now(&state->timer, IRQ_TEST_HRTIMER_INTERVAL);
- queue_work(system_bh_wq, &state->bh_work);
- return HRTIMER_RESTART;
-}
-
-static void hash_irq_test_bh_work_func(struct work_struct *work)
-{
- struct hash_irq_test_state *state =
- container_of(work, typeof(*state), bh_work);
-
- WARN_ON_ONCE(!in_serving_softirq());
- state->softirq_func_calls++;
-
- if (!state->func(state->test_specific_state))
- state->softirq_func_reported_failure = true;
-}
-
-/*
- * Helper function which repeatedly runs the given @func in task, softirq, and
- * hardirq context concurrently, and reports a failure to KUnit if any
- * invocation of @func in any context returns false. @func is passed
- * @test_specific_state as its argument. At most 3 invocations of @func will
- * run concurrently: one in each of task, softirq, and hardirq context.
- *
- * The main purpose of this interrupt context testing is to validate fallback
- * code paths that run in contexts where the normal code path cannot be used,
- * typically due to the FPU or vector registers already being in-use in kernel
- * mode. These code paths aren't covered when the test code is executed only by
- * the KUnit test runner thread in task context. The reason for the concurrency
- * is because merely using hardirq context is not sufficient to reach a fallback
- * code path on some architectures; the hardirq actually has to occur while the
- * FPU or vector unit was already in-use in kernel mode.
- *
- * Another purpose of this testing is to detect issues with the architecture's
- * irq_fpu_usable() and kernel_fpu_begin/end() or equivalent functions,
- * especially in softirq context when the softirq may have interrupted a task
- * already using kernel-mode FPU or vector (if the arch didn't prevent that).
- * Crypto functions are often executed in softirqs, so this is important.
- */
-static void run_irq_test(struct kunit *test, bool (*func)(void *),
- int max_iterations, void *test_specific_state)
-{
- struct hash_irq_test_state state = {
- .func = func,
- .test_specific_state = test_specific_state,
- };
- unsigned long end_jiffies;
-
- /*
- * Set up a hrtimer (the way we access hardirq context) and a work
- * struct for the BH workqueue (the way we access softirq context).
- */
- hrtimer_setup_on_stack(&state.timer, hash_irq_test_timer_func,
- CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
- INIT_WORK_ONSTACK(&state.bh_work, hash_irq_test_bh_work_func);
-
- /* Run for up to max_iterations or 1 second, whichever comes first. */
- end_jiffies = jiffies + HZ;
- hrtimer_start(&state.timer, IRQ_TEST_HRTIMER_INTERVAL,
- HRTIMER_MODE_REL_HARD);
- for (int i = 0; i < max_iterations && !time_after(jiffies, end_jiffies);
- i++) {
- if (!func(test_specific_state))
- state.task_func_reported_failure = true;
- }
-
- /* Cancel the timer and work. */
- hrtimer_cancel(&state.timer);
- flush_work(&state.bh_work);
-
- /* Sanity check: the timer and BH functions should have been run. */
- KUNIT_EXPECT_GT_MSG(test, state.hardirq_func_calls, 0,
- "Timer function was not called");
- KUNIT_EXPECT_GT_MSG(test, state.softirq_func_calls, 0,
- "BH work function was not called");
-
- /* Check for incorrect hash values reported from any context. */
- KUNIT_EXPECT_FALSE_MSG(
- test, state.task_func_reported_failure,
- "Incorrect hash values reported from task context");
- KUNIT_EXPECT_FALSE_MSG(
- test, state.hardirq_func_reported_failure,
- "Incorrect hash values reported from hardirq context");
- KUNIT_EXPECT_FALSE_MSG(
- test, state.softirq_func_reported_failure,
- "Incorrect hash values reported from softirq context");
-}
-
#define IRQ_TEST_DATA_LEN 256
#define IRQ_TEST_NUM_BUFFERS 3 /* matches max concurrency level */
struct hash_irq_test1_state {
u8 expected_hashes[IRQ_TEST_NUM_BUFFERS][HASH_SIZE];
@@ -467,11 +352,11 @@ static void test_hash_interrupt_context_1(struct kunit *test)
rand_bytes(test_buf, IRQ_TEST_NUM_BUFFERS * IRQ_TEST_DATA_LEN);
for (int i = 0; i < IRQ_TEST_NUM_BUFFERS; i++)
HASH(&test_buf[i * IRQ_TEST_DATA_LEN], IRQ_TEST_DATA_LEN,
state.expected_hashes[i]);
- run_irq_test(test, hash_irq_test1_func, 100000, &state);
+ kunit_run_irq_test(test, hash_irq_test1_func, 100000, &state);
}
struct hash_irq_test2_hash_ctx {
struct HASH_CTX hash_ctx;
atomic_t in_use;
@@ -498,11 +383,11 @@ static bool hash_irq_test2_func(void *state_)
break;
}
if (WARN_ON_ONCE(ctx == &state->ctxs[ARRAY_SIZE(state->ctxs)])) {
/*
* This should never happen, as the number of contexts is equal
- * to the maximum concurrency level of run_irq_test().
+ * to the maximum concurrency level of kunit_run_irq_test().
*/
return false;
}
if (ctx->step == 0) {
@@ -564,11 +449,11 @@ static void test_hash_interrupt_context_2(struct kunit *test)
}
if (remaining)
state->update_lens[state->num_steps++] = remaining;
state->num_steps += 2; /* for init and final */
- run_irq_test(test, hash_irq_test2_func, 250000, state);
+ kunit_run_irq_test(test, hash_irq_test2_func, 250000, state);
}
#define UNKEYED_HASH_KUNIT_CASES \
KUNIT_CASE(test_hash_test_vectors), \
KUNIT_CASE(test_hash_all_lens_up_to_4096), \
--
2.50.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/3] lib/crc: crc_kunit: Test CRC computation in interrupt contexts
2025-08-11 18:26 [PATCH 0/3] Test CRC computation in interrupt contexts Eric Biggers
2025-08-11 18:26 ` [PATCH 1/3] kunit, lib/crypto: Move run_irq_test() to common header Eric Biggers
@ 2025-08-11 18:26 ` Eric Biggers
2025-08-11 18:26 ` [PATCH 3/3] lib/crc: Use underlying functions instead of crypto_simd_usable() Eric Biggers
2025-08-21 3:37 ` [PATCH 0/3] Test CRC computation in interrupt contexts Eric Biggers
3 siblings, 0 replies; 5+ messages in thread
From: Eric Biggers @ 2025-08-11 18:26 UTC (permalink / raw)
To: linux-kernel
Cc: linux-crypto, Ard Biesheuvel, linux-kselftest, kunit-dev,
Eric Biggers
Test that if CRCs are computed in task, softirq, and hardirq context
concurrently, then all results are as expected. Implement this using
kunit_run_irq_test() which is also used by the lib/crypto/ tests.
As with the corresponding lib/crypto/ tests, the purpose of this is to
test fallback code paths and to exercise edge cases in the
architecture's support for in-kernel FPU/SIMD/vector.
Remove the code from crc_test() that sometimes disabled interrupts, as
that was just an incomplete attempt to achieve similar test coverage.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
lib/crc/tests/crc_kunit.c | 62 +++++++++++++++++++++++++++++++++------
1 file changed, 53 insertions(+), 9 deletions(-)
diff --git a/lib/crc/tests/crc_kunit.c b/lib/crc/tests/crc_kunit.c
index f08d985d8860e..9a450e25ac811 100644
--- a/lib/crc/tests/crc_kunit.c
+++ b/lib/crc/tests/crc_kunit.c
@@ -4,10 +4,11 @@
*
* Copyright 2024 Google LLC
*
* Author: Eric Biggers <ebiggers@google.com>
*/
+#include <kunit/run-in-irq-context.h>
#include <kunit/test.h>
#include <linux/crc7.h>
#include <linux/crc16.h>
#include <linux/crc-t10dif.h>
#include <linux/crc32.h>
@@ -139,19 +140,66 @@ static size_t generate_random_length(size_t max_length)
break;
}
return len % (max_length + 1);
}
+#define IRQ_TEST_DATA_LEN 512
+#define IRQ_TEST_NUM_BUFFERS 3 /* matches max concurrency level */
+
+struct crc_irq_test_state {
+ const struct crc_variant *v;
+ u64 initial_crc;
+ u64 expected_crcs[IRQ_TEST_NUM_BUFFERS];
+ atomic_t seqno;
+};
+
+/*
+ * Compute the CRC of one of the test messages and verify that it matches the
+ * expected CRC from @state->expected_crcs. To increase the chance of detecting
+ * problems, cycle through multiple messages.
+ */
+static bool crc_irq_test_func(void *state_)
+{
+ struct crc_irq_test_state *state = state_;
+ const struct crc_variant *v = state->v;
+ u32 i = (u32)atomic_inc_return(&state->seqno) % IRQ_TEST_NUM_BUFFERS;
+ u64 actual_crc = v->func(state->initial_crc,
+ &test_buffer[i * IRQ_TEST_DATA_LEN],
+ IRQ_TEST_DATA_LEN);
+
+ return actual_crc == state->expected_crcs[i];
+}
+
+/*
+ * Test that if CRCs are computed in task, softirq, and hardirq context
+ * concurrently, then all results are as expected.
+ */
+static void crc_interrupt_context_test(struct kunit *test,
+ const struct crc_variant *v)
+{
+ struct crc_irq_test_state state = {
+ .v = v,
+ .initial_crc = generate_random_initial_crc(v),
+ };
+
+ for (int i = 0; i < IRQ_TEST_NUM_BUFFERS; i++) {
+ state.expected_crcs[i] = crc_ref(
+ v, state.initial_crc,
+ &test_buffer[i * IRQ_TEST_DATA_LEN], IRQ_TEST_DATA_LEN);
+ }
+
+ kunit_run_irq_test(test, crc_irq_test_func, 100000, &state);
+}
+
/* Test that v->func gives the same CRCs as a reference implementation. */
static void crc_test(struct kunit *test, const struct crc_variant *v)
{
size_t i;
for (i = 0; i < CRC_KUNIT_NUM_TEST_ITERS; i++) {
u64 init_crc, expected_crc, actual_crc;
size_t len, offset;
- bool nosimd;
init_crc = generate_random_initial_crc(v);
len = generate_random_length(CRC_KUNIT_MAX_LEN);
/* Generate a random offset. */
@@ -166,26 +214,22 @@ static void crc_test(struct kunit *test, const struct crc_variant *v)
if (rand32() % 8 == 0)
/* Refresh the data occasionally. */
prandom_bytes_state(&rng, &test_buffer[offset], len);
- nosimd = rand32() % 8 == 0;
-
/*
* Compute the CRC, and verify that it equals the CRC computed
* by a simple bit-at-a-time reference implementation.
*/
expected_crc = crc_ref(v, init_crc, &test_buffer[offset], len);
- if (nosimd)
- local_irq_disable();
actual_crc = v->func(init_crc, &test_buffer[offset], len);
- if (nosimd)
- local_irq_enable();
KUNIT_EXPECT_EQ_MSG(test, expected_crc, actual_crc,
- "Wrong result with len=%zu offset=%zu nosimd=%d",
- len, offset, nosimd);
+ "Wrong result with len=%zu offset=%zu",
+ len, offset);
}
+
+ crc_interrupt_context_test(test, v);
}
static __always_inline void
crc_benchmark(struct kunit *test,
u64 (*crc_func)(u64 crc, const u8 *p, size_t len))
--
2.50.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 3/3] lib/crc: Use underlying functions instead of crypto_simd_usable()
2025-08-11 18:26 [PATCH 0/3] Test CRC computation in interrupt contexts Eric Biggers
2025-08-11 18:26 ` [PATCH 1/3] kunit, lib/crypto: Move run_irq_test() to common header Eric Biggers
2025-08-11 18:26 ` [PATCH 2/3] lib/crc: crc_kunit: Test CRC computation in interrupt contexts Eric Biggers
@ 2025-08-11 18:26 ` Eric Biggers
2025-08-21 3:37 ` [PATCH 0/3] Test CRC computation in interrupt contexts Eric Biggers
3 siblings, 0 replies; 5+ messages in thread
From: Eric Biggers @ 2025-08-11 18:26 UTC (permalink / raw)
To: linux-kernel
Cc: linux-crypto, Ard Biesheuvel, linux-kselftest, kunit-dev,
Eric Biggers
Since crc_kunit now tests the fallback code paths without using
crypto_simd_disabled_for_test, make the CRC code just use the underlying
may_use_simd() and irq_fpu_usable() functions directly instead of
crypto_simd_usable(). This eliminates an unnecessary layer.
Take the opportunity to add likely() and unlikely() annotations as well.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
lib/crc/arm/crc-t10dif.h | 6 ++----
lib/crc/arm/crc32.h | 6 ++----
lib/crc/arm64/crc-t10dif.h | 6 ++----
lib/crc/arm64/crc32.h | 11 ++++++-----
lib/crc/powerpc/crc-t10dif.h | 5 +++--
lib/crc/powerpc/crc32.h | 5 +++--
lib/crc/x86/crc-pclmul-template.h | 3 +--
lib/crc/x86/crc32.h | 2 +-
8 files changed, 20 insertions(+), 24 deletions(-)
diff --git a/lib/crc/arm/crc-t10dif.h b/lib/crc/arm/crc-t10dif.h
index 2edf7e9681d05..1a969f4024d47 100644
--- a/lib/crc/arm/crc-t10dif.h
+++ b/lib/crc/arm/crc-t10dif.h
@@ -3,12 +3,10 @@
* Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions instructions
*
* Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
*/
-#include <crypto/internal/simd.h>
-
#include <asm/neon.h>
#include <asm/simd.h>
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_pmull);
@@ -21,19 +19,19 @@ asmlinkage void crc_t10dif_pmull8(u16 init_crc, const u8 *buf, size_t len,
static inline u16 crc_t10dif_arch(u16 crc, const u8 *data, size_t length)
{
if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE) {
if (static_branch_likely(&have_pmull)) {
- if (crypto_simd_usable()) {
+ if (likely(may_use_simd())) {
kernel_neon_begin();
crc = crc_t10dif_pmull64(crc, data, length);
kernel_neon_end();
return crc;
}
} else if (length > CRC_T10DIF_PMULL_CHUNK_SIZE &&
static_branch_likely(&have_neon) &&
- crypto_simd_usable()) {
+ likely(may_use_simd())) {
u8 buf[16] __aligned(16);
kernel_neon_begin();
crc_t10dif_pmull8(crc, data, length, buf);
kernel_neon_end();
diff --git a/lib/crc/arm/crc32.h b/lib/crc/arm/crc32.h
index 018007e162a2b..ae71aa60b7a74 100644
--- a/lib/crc/arm/crc32.h
+++ b/lib/crc/arm/crc32.h
@@ -5,12 +5,10 @@
* Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
*/
#include <linux/cpufeature.h>
-#include <crypto/internal/simd.h>
-
#include <asm/hwcap.h>
#include <asm/neon.h>
#include <asm/simd.h>
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_crc32);
@@ -32,11 +30,11 @@ static inline u32 crc32_le_scalar(u32 crc, const u8 *p, size_t len)
}
static inline u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
{
if (len >= PMULL_MIN_LEN + 15 &&
- static_branch_likely(&have_pmull) && crypto_simd_usable()) {
+ static_branch_likely(&have_pmull) && likely(may_use_simd())) {
size_t n = -(uintptr_t)p & 15;
/* align p to 16-byte boundary */
if (n) {
crc = crc32_le_scalar(crc, p, n);
@@ -61,11 +59,11 @@ static inline u32 crc32c_scalar(u32 crc, const u8 *p, size_t len)
}
static inline u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
{
if (len >= PMULL_MIN_LEN + 15 &&
- static_branch_likely(&have_pmull) && crypto_simd_usable()) {
+ static_branch_likely(&have_pmull) && likely(may_use_simd())) {
size_t n = -(uintptr_t)p & 15;
/* align p to 16-byte boundary */
if (n) {
crc = crc32c_scalar(crc, p, n);
diff --git a/lib/crc/arm64/crc-t10dif.h b/lib/crc/arm64/crc-t10dif.h
index c4521a7f1ee9b..435a990ec43c2 100644
--- a/lib/crc/arm64/crc-t10dif.h
+++ b/lib/crc/arm64/crc-t10dif.h
@@ -5,12 +5,10 @@
* Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
*/
#include <linux/cpufeature.h>
-#include <crypto/internal/simd.h>
-
#include <asm/neon.h>
#include <asm/simd.h>
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_asimd);
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_pmull);
@@ -23,19 +21,19 @@ asmlinkage u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len);
static inline u16 crc_t10dif_arch(u16 crc, const u8 *data, size_t length)
{
if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE) {
if (static_branch_likely(&have_pmull)) {
- if (crypto_simd_usable()) {
+ if (likely(may_use_simd())) {
kernel_neon_begin();
crc = crc_t10dif_pmull_p64(crc, data, length);
kernel_neon_end();
return crc;
}
} else if (length > CRC_T10DIF_PMULL_CHUNK_SIZE &&
static_branch_likely(&have_asimd) &&
- crypto_simd_usable()) {
+ likely(may_use_simd())) {
u8 buf[16];
kernel_neon_begin();
crc_t10dif_pmull_p8(crc, data, length, buf);
kernel_neon_end();
diff --git a/lib/crc/arm64/crc32.h b/lib/crc/arm64/crc32.h
index 6e5dec45f05d2..31e649cd40a2f 100644
--- a/lib/crc/arm64/crc32.h
+++ b/lib/crc/arm64/crc32.h
@@ -3,12 +3,10 @@
#include <asm/alternative.h>
#include <asm/cpufeature.h>
#include <asm/neon.h>
#include <asm/simd.h>
-#include <crypto/internal/simd.h>
-
// The minimum input length to consider the 4-way interleaved code path
static const size_t min_len = 1024;
asmlinkage u32 crc32_le_arm64(u32 crc, unsigned char const *p, size_t len);
asmlinkage u32 crc32c_le_arm64(u32 crc, unsigned char const *p, size_t len);
@@ -21,11 +19,12 @@ asmlinkage u32 crc32_be_arm64_4way(u32 crc, unsigned char const *p, size_t len);
static inline u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
{
if (!alternative_has_cap_likely(ARM64_HAS_CRC32))
return crc32_le_base(crc, p, len);
- if (len >= min_len && cpu_have_named_feature(PMULL) && crypto_simd_usable()) {
+ if (len >= min_len && cpu_have_named_feature(PMULL) &&
+ likely(may_use_simd())) {
kernel_neon_begin();
crc = crc32_le_arm64_4way(crc, p, len);
kernel_neon_end();
p += round_down(len, 64);
@@ -41,11 +40,12 @@ static inline u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
static inline u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
{
if (!alternative_has_cap_likely(ARM64_HAS_CRC32))
return crc32c_base(crc, p, len);
- if (len >= min_len && cpu_have_named_feature(PMULL) && crypto_simd_usable()) {
+ if (len >= min_len && cpu_have_named_feature(PMULL) &&
+ likely(may_use_simd())) {
kernel_neon_begin();
crc = crc32c_le_arm64_4way(crc, p, len);
kernel_neon_end();
p += round_down(len, 64);
@@ -61,11 +61,12 @@ static inline u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
static inline u32 crc32_be_arch(u32 crc, const u8 *p, size_t len)
{
if (!alternative_has_cap_likely(ARM64_HAS_CRC32))
return crc32_be_base(crc, p, len);
- if (len >= min_len && cpu_have_named_feature(PMULL) && crypto_simd_usable()) {
+ if (len >= min_len && cpu_have_named_feature(PMULL) &&
+ likely(may_use_simd())) {
kernel_neon_begin();
crc = crc32_be_arm64_4way(crc, p, len);
kernel_neon_end();
p += round_down(len, 64);
diff --git a/lib/crc/powerpc/crc-t10dif.h b/lib/crc/powerpc/crc-t10dif.h
index 59e16804a6eae..e033d5f57bae2 100644
--- a/lib/crc/powerpc/crc-t10dif.h
+++ b/lib/crc/powerpc/crc-t10dif.h
@@ -4,12 +4,12 @@
*
* Copyright 2017, Daniel Axtens, IBM Corporation.
* [based on crc32c-vpmsum_glue.c]
*/
+#include <asm/simd.h>
#include <asm/switch_to.h>
-#include <crypto/internal/simd.h>
#include <linux/cpufeature.h>
#include <linux/jump_label.h>
#include <linux/preempt.h>
#include <linux/uaccess.h>
@@ -27,11 +27,12 @@ static inline u16 crc_t10dif_arch(u16 crci, const u8 *p, size_t len)
unsigned int prealign;
unsigned int tail;
u32 crc = crci;
if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) ||
- !static_branch_likely(&have_vec_crypto) || !crypto_simd_usable())
+ !static_branch_likely(&have_vec_crypto) ||
+ unlikely(!may_use_simd()))
return crc_t10dif_generic(crc, p, len);
if ((unsigned long)p & VMX_ALIGN_MASK) {
prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK);
crc = crc_t10dif_generic(crc, p, prealign);
diff --git a/lib/crc/powerpc/crc32.h b/lib/crc/powerpc/crc32.h
index 811cc2e6ed24d..cc8fa3913d4e0 100644
--- a/lib/crc/powerpc/crc32.h
+++ b/lib/crc/powerpc/crc32.h
@@ -1,8 +1,8 @@
// SPDX-License-Identifier: GPL-2.0-only
+#include <asm/simd.h>
#include <asm/switch_to.h>
-#include <crypto/internal/simd.h>
#include <linux/cpufeature.h>
#include <linux/jump_label.h>
#include <linux/preempt.h>
#include <linux/uaccess.h>
@@ -22,11 +22,12 @@ static inline u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
{
unsigned int prealign;
unsigned int tail;
if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) ||
- !static_branch_likely(&have_vec_crypto) || !crypto_simd_usable())
+ !static_branch_likely(&have_vec_crypto) ||
+ unlikely(!may_use_simd()))
return crc32c_base(crc, p, len);
if ((unsigned long)p & VMX_ALIGN_MASK) {
prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK);
crc = crc32c_base(crc, p, prealign);
diff --git a/lib/crc/x86/crc-pclmul-template.h b/lib/crc/x86/crc-pclmul-template.h
index 35c950d7010c2..02744831c6fac 100644
--- a/lib/crc/x86/crc-pclmul-template.h
+++ b/lib/crc/x86/crc-pclmul-template.h
@@ -10,11 +10,10 @@
#ifndef _CRC_PCLMUL_TEMPLATE_H
#define _CRC_PCLMUL_TEMPLATE_H
#include <asm/cpufeatures.h>
#include <asm/simd.h>
-#include <crypto/internal/simd.h>
#include <linux/static_call.h>
#include "crc-pclmul-consts.h"
#define DECLARE_CRC_PCLMUL_FUNCS(prefix, crc_t) \
crc_t prefix##_pclmul_sse(crc_t crc, const u8 *p, size_t len, \
@@ -55,11 +54,11 @@ static inline bool have_avx512(void)
* the dcache than the table-based code is, a 16-byte cutoff seems to work well.
*/
#define CRC_PCLMUL(crc, p, len, prefix, consts, have_pclmulqdq) \
do { \
if ((len) >= 16 && static_branch_likely(&(have_pclmulqdq)) && \
- crypto_simd_usable()) { \
+ likely(irq_fpu_usable())) { \
const void *consts_ptr; \
\
consts_ptr = (consts).fold_across_128_bits_consts; \
kernel_fpu_begin(); \
crc = static_call(prefix##_pclmul)((crc), (p), (len), \
diff --git a/lib/crc/x86/crc32.h b/lib/crc/x86/crc32.h
index cea2c96d08d09..2c4a5976654ad 100644
--- a/lib/crc/x86/crc32.h
+++ b/lib/crc/x86/crc32.h
@@ -42,11 +42,11 @@ static inline u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
if (!static_branch_likely(&have_crc32))
return crc32c_base(crc, p, len);
if (IS_ENABLED(CONFIG_X86_64) && len >= CRC32C_PCLMUL_BREAKEVEN &&
- static_branch_likely(&have_pclmulqdq) && crypto_simd_usable()) {
+ static_branch_likely(&have_pclmulqdq) && likely(irq_fpu_usable())) {
/*
* Long length, the vector registers are usable, and the CPU is
* 64-bit and supports both CRC32 and PCLMULQDQ instructions.
* It is worthwhile to divide the data into multiple streams,
* CRC them independently, and combine them using PCLMULQDQ.
--
2.50.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH 0/3] Test CRC computation in interrupt contexts
2025-08-11 18:26 [PATCH 0/3] Test CRC computation in interrupt contexts Eric Biggers
` (2 preceding siblings ...)
2025-08-11 18:26 ` [PATCH 3/3] lib/crc: Use underlying functions instead of crypto_simd_usable() Eric Biggers
@ 2025-08-21 3:37 ` Eric Biggers
3 siblings, 0 replies; 5+ messages in thread
From: Eric Biggers @ 2025-08-21 3:37 UTC (permalink / raw)
To: linux-kernel; +Cc: linux-crypto, Ard Biesheuvel, linux-kselftest, kunit-dev
On Mon, Aug 11, 2025 at 11:26:28AM -0700, Eric Biggers wrote:
> This series updates crc_kunit to use the same interrupt context testing
> strategy that I used in the crypto KUnit tests. I.e., test CRC
> computation in hardirq, softirq, and task context concurrently. This
> detect issues related to use of the FPU/SIMD/vector registers.
>
> To allow lib/crc/tests/ and lib/crypto/tests/ to share code, move the
> needed helper function to include/kunit/run-in-irq-context.h.
> include/kunit/ seems like the most relevant location for this sort of
> thing, but let me know if there is any other preference.
>
> The third patch replaces the calls to crypto_simd_usable() in lib/crc/
> with calls to the underlying functions, now that we have a better
> solution that doesn't rely on the test injecting values. (Note that
> crc_kunit wasn't actually using the injection solution, anyway.)
>
> I'd like to take this series via crc-next.
>
> Eric Biggers (3):
> kunit, lib/crypto: Move run_irq_test() to common header
> lib/crc: crc_kunit: Test CRC computation in interrupt contexts
> lib/crc: Use underlying functions instead of crypto_simd_usable()
>
> include/kunit/run-in-irq-context.h | 129 ++++++++++++++++++++++++++
> lib/crc/arm/crc-t10dif.h | 6 +-
> lib/crc/arm/crc32.h | 6 +-
> lib/crc/arm64/crc-t10dif.h | 6 +-
> lib/crc/arm64/crc32.h | 11 ++-
> lib/crc/powerpc/crc-t10dif.h | 5 +-
> lib/crc/powerpc/crc32.h | 5 +-
> lib/crc/tests/crc_kunit.c | 62 +++++++++++--
> lib/crc/x86/crc-pclmul-template.h | 3 +-
> lib/crc/x86/crc32.h | 2 +-
> lib/crypto/tests/hash-test-template.h | 123 +-----------------------
> 11 files changed, 206 insertions(+), 152 deletions(-)
> create mode 100644 include/kunit/run-in-irq-context.h
Applied to https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git/log/?h=crc-next
But, reviews and acks would be greatly appreciated!
- Eric
^ permalink raw reply [flat|nested] 5+ messages in thread