From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/phy/phy-common-props-test.c | 422 ++++++++++++++++++++++++++++++++++++ 1 file changed, 422 insertions(+) create mode 100644 drivers/phy/phy-common-props-test.c (limited to 'drivers/phy/phy-common-props-test.c') diff --git a/drivers/phy/phy-common-props-test.c b/drivers/phy/phy-common-props-test.c new file mode 100644 index 000000000..e937ec8a4 --- /dev/null +++ b/drivers/phy/phy-common-props-test.c @@ -0,0 +1,422 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * phy-common-props-test.c -- Unit tests for PHY common properties API + * + * Copyright 2025-2026 NXP + */ +#include +#include +#include +#include + +/* Test: rx-polarity property is missing */ +static void phy_test_rx_polarity_is_missing(struct kunit *test) +{ + static const struct property_entry entries[] = { + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_rx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_NORMAL); + + fwnode_remove_software_node(node); +} + +/* Test: rx-polarity has more values than rx-polarity-names */ +static void phy_test_rx_polarity_more_values_than_names(struct kunit *test) +{ + static const u32 rx_pol[] = { PHY_POL_NORMAL, PHY_POL_INVERT, PHY_POL_NORMAL }; + static const char * const rx_pol_names[] = { "sgmii", "2500base-x" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("rx-polarity", rx_pol), + PROPERTY_ENTRY_STRING_ARRAY("rx-polarity-names", rx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_rx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + fwnode_remove_software_node(node); +} + +/* Test: rx-polarity has 1 value and rx-polarity-names does not exist */ +static void phy_test_rx_polarity_single_value_no_names(struct kunit *test) +{ + static const u32 rx_pol[] = { PHY_POL_INVERT }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("rx-polarity", rx_pol), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_rx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_INVERT); + + fwnode_remove_software_node(node); +} + +/* Test: rx-polarity-names has more values than rx-polarity */ +static void phy_test_rx_polarity_more_names_than_values(struct kunit *test) +{ + static const u32 rx_pol[] = { PHY_POL_NORMAL, PHY_POL_INVERT }; + static const char * const rx_pol_names[] = { "sgmii", "2500base-x", "1000base-x" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("rx-polarity", rx_pol), + PROPERTY_ENTRY_STRING_ARRAY("rx-polarity-names", rx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_rx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + fwnode_remove_software_node(node); +} + +/* Test: rx-polarity and rx-polarity-names have same length, find the name */ +static void phy_test_rx_polarity_find_by_name(struct kunit *test) +{ + static const u32 rx_pol[] = { PHY_POL_NORMAL, PHY_POL_INVERT, PHY_POL_AUTO }; + static const char * const rx_pol_names[] = { "sgmii", "2500base-x", "usb-ss" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("rx-polarity", rx_pol), + PROPERTY_ENTRY_STRING_ARRAY("rx-polarity-names", rx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_rx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_NORMAL); + + ret = phy_get_manual_rx_polarity(node, "2500base-x", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_INVERT); + + ret = phy_get_rx_polarity(node, "usb-ss", BIT(PHY_POL_AUTO), + PHY_POL_AUTO, &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_AUTO); + + fwnode_remove_software_node(node); +} + +/* Test: same length, name not found, no "default" - error */ +static void phy_test_rx_polarity_name_not_found_no_default(struct kunit *test) +{ + static const u32 rx_pol[] = { PHY_POL_NORMAL, PHY_POL_INVERT }; + static const char * const rx_pol_names[] = { "2500base-x", "1000base-x" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("rx-polarity", rx_pol), + PROPERTY_ENTRY_STRING_ARRAY("rx-polarity-names", rx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_rx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + fwnode_remove_software_node(node); +} + +/* Test: same length, name not found, but "default" exists */ +static void phy_test_rx_polarity_name_not_found_with_default(struct kunit *test) +{ + static const u32 rx_pol[] = { PHY_POL_NORMAL, PHY_POL_INVERT }; + static const char * const rx_pol_names[] = { "2500base-x", "default" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("rx-polarity", rx_pol), + PROPERTY_ENTRY_STRING_ARRAY("rx-polarity-names", rx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_rx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_INVERT); + + fwnode_remove_software_node(node); +} + +/* Test: polarity found but value is unsupported */ +static void phy_test_rx_polarity_unsupported_value(struct kunit *test) +{ + static const u32 rx_pol[] = { PHY_POL_AUTO }; + static const char * const rx_pol_names[] = { "sgmii" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("rx-polarity", rx_pol), + PROPERTY_ENTRY_STRING_ARRAY("rx-polarity-names", rx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_rx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, -EOPNOTSUPP); + + fwnode_remove_software_node(node); +} + +/* Test: tx-polarity property is missing */ +static void phy_test_tx_polarity_is_missing(struct kunit *test) +{ + static const struct property_entry entries[] = { + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_tx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_NORMAL); + + fwnode_remove_software_node(node); +} + +/* Test: tx-polarity has more values than tx-polarity-names */ +static void phy_test_tx_polarity_more_values_than_names(struct kunit *test) +{ + static const u32 tx_pol[] = { PHY_POL_NORMAL, PHY_POL_INVERT, PHY_POL_NORMAL }; + static const char * const tx_pol_names[] = { "sgmii", "2500base-x" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("tx-polarity", tx_pol), + PROPERTY_ENTRY_STRING_ARRAY("tx-polarity-names", tx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_tx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + fwnode_remove_software_node(node); +} + +/* Test: tx-polarity has 1 value and tx-polarity-names does not exist */ +static void phy_test_tx_polarity_single_value_no_names(struct kunit *test) +{ + static const u32 tx_pol[] = { PHY_POL_INVERT }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("tx-polarity", tx_pol), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_tx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_INVERT); + + fwnode_remove_software_node(node); +} + +/* Test: tx-polarity-names has more values than tx-polarity */ +static void phy_test_tx_polarity_more_names_than_values(struct kunit *test) +{ + static const u32 tx_pol[] = { PHY_POL_NORMAL, PHY_POL_INVERT }; + static const char * const tx_pol_names[] = { "sgmii", "2500base-x", "1000base-x" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("tx-polarity", tx_pol), + PROPERTY_ENTRY_STRING_ARRAY("tx-polarity-names", tx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_tx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + fwnode_remove_software_node(node); +} + +/* Test: tx-polarity and tx-polarity-names have same length, find the name */ +static void phy_test_tx_polarity_find_by_name(struct kunit *test) +{ + static const u32 tx_pol[] = { PHY_POL_NORMAL, PHY_POL_INVERT, PHY_POL_NORMAL }; + static const char * const tx_pol_names[] = { "sgmii", "2500base-x", "1000base-x" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("tx-polarity", tx_pol), + PROPERTY_ENTRY_STRING_ARRAY("tx-polarity-names", tx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_tx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_NORMAL); + + ret = phy_get_manual_tx_polarity(node, "2500base-x", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_INVERT); + + ret = phy_get_manual_tx_polarity(node, "1000base-x", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_NORMAL); + + fwnode_remove_software_node(node); +} + +/* Test: same length, name not found, no "default" - error */ +static void phy_test_tx_polarity_name_not_found_no_default(struct kunit *test) +{ + static const u32 tx_pol[] = { PHY_POL_NORMAL, PHY_POL_INVERT }; + static const char * const tx_pol_names[] = { "2500base-x", "1000base-x" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("tx-polarity", tx_pol), + PROPERTY_ENTRY_STRING_ARRAY("tx-polarity-names", tx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_tx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + fwnode_remove_software_node(node); +} + +/* Test: same length, name not found, but "default" exists */ +static void phy_test_tx_polarity_name_not_found_with_default(struct kunit *test) +{ + static const u32 tx_pol[] = { PHY_POL_NORMAL, PHY_POL_INVERT }; + static const char * const tx_pol_names[] = { "2500base-x", "default" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("tx-polarity", tx_pol), + PROPERTY_ENTRY_STRING_ARRAY("tx-polarity-names", tx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_tx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val, PHY_POL_INVERT); + + fwnode_remove_software_node(node); +} + +/* Test: polarity found but value is unsupported (AUTO for TX) */ +static void phy_test_tx_polarity_unsupported_value(struct kunit *test) +{ + static const u32 tx_pol[] = { PHY_POL_AUTO }; + static const char * const tx_pol_names[] = { "sgmii" }; + static const struct property_entry entries[] = { + PROPERTY_ENTRY_U32_ARRAY("tx-polarity", tx_pol), + PROPERTY_ENTRY_STRING_ARRAY("tx-polarity-names", tx_pol_names), + {} + }; + struct fwnode_handle *node; + unsigned int val; + int ret; + + node = fwnode_create_software_node(entries, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node); + + ret = phy_get_manual_tx_polarity(node, "sgmii", &val); + KUNIT_EXPECT_EQ(test, ret, -EOPNOTSUPP); + + fwnode_remove_software_node(node); +} + +static struct kunit_case phy_common_props_test_cases[] = { + KUNIT_CASE(phy_test_rx_polarity_is_missing), + KUNIT_CASE(phy_test_rx_polarity_more_values_than_names), + KUNIT_CASE(phy_test_rx_polarity_single_value_no_names), + KUNIT_CASE(phy_test_rx_polarity_more_names_than_values), + KUNIT_CASE(phy_test_rx_polarity_find_by_name), + KUNIT_CASE(phy_test_rx_polarity_name_not_found_no_default), + KUNIT_CASE(phy_test_rx_polarity_name_not_found_with_default), + KUNIT_CASE(phy_test_rx_polarity_unsupported_value), + KUNIT_CASE(phy_test_tx_polarity_is_missing), + KUNIT_CASE(phy_test_tx_polarity_more_values_than_names), + KUNIT_CASE(phy_test_tx_polarity_single_value_no_names), + KUNIT_CASE(phy_test_tx_polarity_more_names_than_values), + KUNIT_CASE(phy_test_tx_polarity_find_by_name), + KUNIT_CASE(phy_test_tx_polarity_name_not_found_no_default), + KUNIT_CASE(phy_test_tx_polarity_name_not_found_with_default), + KUNIT_CASE(phy_test_tx_polarity_unsupported_value), + {} +}; + +static struct kunit_suite phy_common_props_test_suite = { + .name = "phy-common-props", + .test_cases = phy_common_props_test_cases, +}; + +kunit_test_suite(phy_common_props_test_suite); + +MODULE_DESCRIPTION("Test module for PHY common properties API"); +MODULE_AUTHOR("Vladimir Oltean "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1