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 --- lib/test_ubsan.c | 174 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) create mode 100644 lib/test_ubsan.c (limited to 'lib/test_ubsan.c') diff --git a/lib/test_ubsan.c b/lib/test_ubsan.c new file mode 100644 index 000000000..a4b6f52b9 --- /dev/null +++ b/lib/test_ubsan.c @@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include + +typedef void(*test_ubsan_fp)(void); + +#define UBSAN_TEST(config, ...) do { \ + pr_info("%s " __VA_ARGS__ "%s(%s=%s)\n", __func__, \ + sizeof(" " __VA_ARGS__) > 2 ? " " : "", \ + #config, IS_ENABLED(config) ? "y" : "n"); \ + } while (0) + +static void test_ubsan_add_overflow(void) +{ + volatile int val = INT_MAX; + + UBSAN_TEST(CONFIG_UBSAN_INTEGER_WRAP); + val += 2; +} + +static void test_ubsan_sub_overflow(void) +{ + volatile int val = INT_MIN; + volatile int val2 = 2; + + UBSAN_TEST(CONFIG_UBSAN_INTEGER_WRAP); + val -= val2; +} + +static void test_ubsan_mul_overflow(void) +{ + volatile int val = INT_MAX / 2; + + UBSAN_TEST(CONFIG_UBSAN_INTEGER_WRAP); + val *= 3; +} + +static void test_ubsan_negate_overflow(void) +{ + volatile int val = INT_MIN; + + UBSAN_TEST(CONFIG_UBSAN_INTEGER_WRAP); + val = -val; +} + +static void test_ubsan_divrem_overflow(void) +{ + volatile int val = 16; + volatile int val2 = 0; + + UBSAN_TEST(CONFIG_UBSAN_DIV_ZERO); + val /= val2; +} + +static void test_ubsan_truncate_signed(void) +{ + volatile long val = LONG_MAX; + volatile int val2 = 0; + + UBSAN_TEST(CONFIG_UBSAN_INTEGER_WRAP); + val2 = val; +} + +static void test_ubsan_shift_out_of_bounds(void) +{ + volatile int neg = -1, wrap = 4; + volatile int val1 = 10; + volatile int val2 = INT_MAX; + + UBSAN_TEST(CONFIG_UBSAN_SHIFT, "negative exponent"); + val1 <<= neg; + + UBSAN_TEST(CONFIG_UBSAN_SHIFT, "left overflow"); + val2 <<= wrap; +} + +static void test_ubsan_out_of_bounds(void) +{ + int i = 4, j = 4, k = -1; + volatile struct { + char above[4]; /* Protect surrounding memory. */ + int arr[4]; + char below[4]; /* Protect surrounding memory. */ + } data; + + OPTIMIZER_HIDE_VAR(i); + OPTIMIZER_HIDE_VAR(j); + OPTIMIZER_HIDE_VAR(k); + + UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "above"); + data.arr[j] = i; + + UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "below"); + data.arr[k] = i; +} + +enum ubsan_test_enum { + UBSAN_TEST_ZERO = 0, + UBSAN_TEST_ONE, + UBSAN_TEST_MAX, +}; + +static void test_ubsan_load_invalid_value(void) +{ + volatile char *dst, *src; + bool val, val2, *ptr; + enum ubsan_test_enum eval, eval2, *eptr; + unsigned char c = 0xff; + + UBSAN_TEST(CONFIG_UBSAN_BOOL, "bool"); + dst = (char *)&val; + src = &c; + *dst = *src; + + ptr = &val2; + val2 = val; + + UBSAN_TEST(CONFIG_UBSAN_ENUM, "enum"); + dst = (char *)&eval; + src = &c; + *dst = *src; + + eptr = &eval2; + eval2 = eval; +} + +static void test_ubsan_misaligned_access(void) +{ + volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5}; + volatile int *ptr, val = 6; + + UBSAN_TEST(CONFIG_UBSAN_ALIGNMENT); + ptr = (int *)(arr + 1); + *ptr = val; +} + +static const test_ubsan_fp test_ubsan_array[] = { + test_ubsan_add_overflow, + test_ubsan_sub_overflow, + test_ubsan_mul_overflow, + test_ubsan_negate_overflow, + test_ubsan_truncate_signed, + test_ubsan_shift_out_of_bounds, + test_ubsan_out_of_bounds, + test_ubsan_load_invalid_value, + test_ubsan_misaligned_access, +}; + +/* Excluded because they Oops the module. */ +static __used const test_ubsan_fp skip_ubsan_array[] = { + test_ubsan_divrem_overflow, +}; + +static int __init test_ubsan_init(void) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++) + test_ubsan_array[i](); + + return 0; +} +module_init(test_ubsan_init); + +static void __exit test_ubsan_exit(void) +{ + /* do nothing */ +} +module_exit(test_ubsan_exit); + +MODULE_AUTHOR("Jinbum Park "); +MODULE_DESCRIPTION("UBSAN unit test"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1