x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

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) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 581 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/utdecode.c b/drivers/acpi/acpica/utdecode.c
new file mode 100644
index 000000000..10482caac
--- /dev/null
+++ b/drivers/acpi/acpica/utdecode.c
@@ -0,0 +1,581 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/******************************************************************************
+ *
+ * Module Name: utdecode - Utility decoding routines (value-to-string)
+ *
+ * Copyright (C) 2000 - 2026, Intel Corp.
+ *
+ *****************************************************************************/
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+#include "acnamesp.h"
+#include "amlcode.h"
+
+#define _COMPONENT          ACPI_UTILITIES
+ACPI_MODULE_NAME("utdecode")
+
+/*
+ * Properties of the ACPI Object Types, both internal and external.
+ * The table is indexed by values of acpi_object_type
+ */
+const u8 acpi_gbl_ns_properties[ACPI_NUM_NS_TYPES] = {
+	ACPI_NS_NORMAL,		/* 00 Any              */
+	ACPI_NS_NORMAL,		/* 01 Number           */
+	ACPI_NS_NORMAL,		/* 02 String           */
+	ACPI_NS_NORMAL,		/* 03 Buffer           */
+	ACPI_NS_NORMAL,		/* 04 Package          */
+	ACPI_NS_NORMAL,		/* 05 field_unit       */
+	ACPI_NS_NEWSCOPE,	/* 06 Device           */
+	ACPI_NS_NORMAL,		/* 07 Event            */
+	ACPI_NS_NEWSCOPE,	/* 08 Method           */
+	ACPI_NS_NORMAL,		/* 09 Mutex            */
+	ACPI_NS_NORMAL,		/* 10 Region           */
+	ACPI_NS_NEWSCOPE,	/* 11 Power            */
+	ACPI_NS_NEWSCOPE,	/* 12 Processor        */
+	ACPI_NS_NEWSCOPE,	/* 13 Thermal          */
+	ACPI_NS_NORMAL,		/* 14 buffer_field     */
+	ACPI_NS_NORMAL,		/* 15 ddb_handle       */
+	ACPI_NS_NORMAL,		/* 16 Debug Object     */
+	ACPI_NS_NORMAL,		/* 17 def_field        */
+	ACPI_NS_NORMAL,		/* 18 bank_field       */
+	ACPI_NS_NORMAL,		/* 19 index_field      */
+	ACPI_NS_NORMAL,		/* 20 Reference        */
+	ACPI_NS_NORMAL,		/* 21 Alias            */
+	ACPI_NS_NORMAL,		/* 22 method_alias     */
+	ACPI_NS_NORMAL,		/* 23 Notify           */
+	ACPI_NS_NORMAL,		/* 24 Address Handler  */
+	ACPI_NS_NEWSCOPE | ACPI_NS_LOCAL,	/* 25 Resource Desc    */
+	ACPI_NS_NEWSCOPE | ACPI_NS_LOCAL,	/* 26 Resource Field   */
+	ACPI_NS_NEWSCOPE,	/* 27 Scope            */
+	ACPI_NS_NORMAL,		/* 28 Extra            */
+	ACPI_NS_NORMAL,		/* 29 Data             */
+	ACPI_NS_NORMAL		/* 30 Invalid          */
+};
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_get_region_name
+ *
+ * PARAMETERS:  Space ID            - ID for the region
+ *
+ * RETURN:      Decoded region space_id name
+ *
+ * DESCRIPTION: Translate a Space ID into a name string (Debug only)
+ *
+ ******************************************************************************/
+
+/* Region type decoding */
+
+const char *acpi_gbl_region_types[ACPI_NUM_PREDEFINED_REGIONS] = {
+	"SystemMemory",		/* 0x00 */
+	"SystemIO",		/* 0x01 */
+	"PCI_Config",		/* 0x02 */
+	"EmbeddedControl",	/* 0x03 */
+	"SMBus",		/* 0x04 */
+	"SystemCMOS",		/* 0x05 */
+	"PCIBARTarget",		/* 0x06 */
+	"IPMI",			/* 0x07 */
+	"GeneralPurposeIo",	/* 0x08 */
+	"GenericSerialBus",	/* 0x09 */
+	"PCC",			/* 0x0A */
+	"PlatformRtMechanism"	/* 0x0B */
+};
+
+const char *acpi_ut_get_region_name(u8 space_id)
+{
+
+	if (space_id >= ACPI_USER_REGION_BEGIN) {
+		return ("UserDefinedRegion");
+	} else if (space_id == ACPI_ADR_SPACE_DATA_TABLE) {
+		return ("DataTable");
+	} else if (space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
+		return ("FunctionalFixedHW");
+	} else if (space_id >= ACPI_NUM_PREDEFINED_REGIONS) {
+		return ("InvalidSpaceId");
+	}
+
+	return (acpi_gbl_region_types[space_id]);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_get_event_name
+ *
+ * PARAMETERS:  event_id            - Fixed event ID
+ *
+ * RETURN:      Decoded event ID name
+ *
+ * DESCRIPTION: Translate a Event ID into a name string (Debug only)
+ *
+ ******************************************************************************/
+
+/* Event type decoding */
+
+static const char *acpi_gbl_event_types[ACPI_NUM_FIXED_EVENTS] = {
+	"PM_Timer",
+	"GlobalLock",
+	"PowerButton",
+	"SleepButton",
+	"RealTimeClock",
+};
+
+const char *acpi_ut_get_event_name(u32 event_id)
+{
+
+	if (event_id > ACPI_EVENT_MAX) {
+		return ("InvalidEventID");
+	}
+
+	return (acpi_gbl_event_types[event_id]);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_get_type_name
+ *
+ * PARAMETERS:  type                - An ACPI object type
+ *
+ * RETURN:      Decoded ACPI object type name
+ *
+ * DESCRIPTION: Translate a Type ID into a name string (Debug only)
+ *
+ ******************************************************************************/
+
+/*
+ * Elements of acpi_gbl_ns_type_names below must match
+ * one-to-one with values of acpi_object_type
+ *
+ * The type ACPI_TYPE_ANY (Untyped) is used as a "don't care" when searching;
+ * when stored in a table it really means that we have thus far seen no
+ * evidence to indicate what type is actually going to be stored for this
+ & entry.
+ */
+static const char acpi_gbl_bad_type[] = "UNDEFINED";
+
+/* Printable names of the ACPI object types */
+
+static const char *acpi_gbl_ns_type_names[] = {
+	/* 00 */ "Untyped",
+	/* 01 */ "Integer",
+	/* 02 */ "String",
+	/* 03 */ "Buffer",
+	/* 04 */ "Package",
+	/* 05 */ "FieldUnit",
+	/* 06 */ "Device",
+	/* 07 */ "Event",
+	/* 08 */ "Method",
+	/* 09 */ "Mutex",
+	/* 10 */ "Region",
+	/* 11 */ "Power",
+	/* 12 */ "Processor",
+	/* 13 */ "Thermal",
+	/* 14 */ "BufferField",
+	/* 15 */ "DdbHandle",
+	/* 16 */ "DebugObject",
+	/* 17 */ "RegionField",
+	/* 18 */ "BankField",
+	/* 19 */ "IndexField",
+	/* 20 */ "Reference",
+	/* 21 */ "Alias",
+	/* 22 */ "MethodAlias",
+	/* 23 */ "Notify",
+	/* 24 */ "AddrHandler",
+	/* 25 */ "ResourceDesc",
+	/* 26 */ "ResourceFld",
+	/* 27 */ "Scope",
+	/* 28 */ "Extra",
+	/* 29 */ "Data",
+	/* 30 */ "Invalid"
+};
+
+const char *acpi_ut_get_type_name(acpi_object_type type)
+{
+
+	if (type > ACPI_TYPE_INVALID) {
+		return (acpi_gbl_bad_type);
+	}
+
+	return (acpi_gbl_ns_type_names[type]);
+}
+
+const char *acpi_ut_get_object_type_name(union acpi_operand_object *obj_desc)
+{
+	ACPI_FUNCTION_TRACE(ut_get_object_type_name);
+
+	if (!obj_desc) {
+		ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Null Object Descriptor\n"));
+		return_STR("[NULL Object Descriptor]");
+	}
+
+	/* These descriptor types share a common area */
+
+	if ((ACPI_GET_DESCRIPTOR_TYPE(obj_desc) != ACPI_DESC_TYPE_OPERAND) &&
+	    (ACPI_GET_DESCRIPTOR_TYPE(obj_desc) != ACPI_DESC_TYPE_NAMED)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
+				  "Invalid object descriptor type: 0x%2.2X [%s] (%p)\n",
+				  ACPI_GET_DESCRIPTOR_TYPE(obj_desc),
+				  acpi_ut_get_descriptor_name(obj_desc),
+				  obj_desc));
+
+		return_STR("Invalid object");
+	}
+
+	return_STR(acpi_ut_get_type_name(obj_desc->common.type));
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_get_node_name
+ *
+ * PARAMETERS:  object               - A namespace node
+ *
+ * RETURN:      ASCII name of the node
+ *
+ * DESCRIPTION: Validate the node and return the node's ACPI name.
+ *
+ ******************************************************************************/
+
+const char *acpi_ut_get_node_name(void *object)
+{
+	struct acpi_namespace_node *node = (struct acpi_namespace_node *)object;
+
+	/* Must return a string of exactly 4 characters == ACPI_NAMESEG_SIZE */
+
+	if (!object) {
+		return ("NULL");
+	}
+
+	/* Check for Root node */
+
+	if ((object == ACPI_ROOT_OBJECT) || (object == acpi_gbl_root_node)) {
+		return ("\"\\\" ");
+	}
+
+	/* Descriptor must be a namespace node */
+
+	if (ACPI_GET_DESCRIPTOR_TYPE(node) != ACPI_DESC_TYPE_NAMED) {
+		return ("####");
+	}
+
+	/*
+	 * Ensure name is valid. The name was validated/repaired when the node
+	 * was created, but make sure it has not been corrupted.
+	 */
+	acpi_ut_repair_name(node->name.ascii);
+
+	/* Return the name */
+
+	return (node->name.ascii);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_get_descriptor_name
+ *
+ * PARAMETERS:  object               - An ACPI object
+ *
+ * RETURN:      Decoded name of the descriptor type
+ *
+ * DESCRIPTION: Validate object and return the descriptor type
+ *
+ ******************************************************************************/
+
+/* Printable names of object descriptor types */
+
+static const char *acpi_gbl_desc_type_names[] = {
+	/* 00 */ "Not a Descriptor",
+	/* 01 */ "Cached Object",
+	/* 02 */ "State-Generic",
+	/* 03 */ "State-Update",
+	/* 04 */ "State-Package",
+	/* 05 */ "State-Control",
+	/* 06 */ "State-RootParseScope",
+	/* 07 */ "State-ParseScope",
+	/* 08 */ "State-WalkScope",
+	/* 09 */ "State-Result",
+	/* 10 */ "State-Notify",
+	/* 11 */ "State-Thread",
+	/* 12 */ "Tree Walk State",
+	/* 13 */ "Parse Tree Op",
+	/* 14 */ "Operand Object",
+	/* 15 */ "Namespace Node"
+};
+
+const char *acpi_ut_get_descriptor_name(void *object)
+{
+
+	if (!object) {
+		return ("NULL OBJECT");
+	}
+
+	if (ACPI_GET_DESCRIPTOR_TYPE(object) > ACPI_DESC_TYPE_MAX) {
+		return ("Not a Descriptor");
+	}
+
+	return (acpi_gbl_desc_type_names[ACPI_GET_DESCRIPTOR_TYPE(object)]);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_get_reference_name
+ *
+ * PARAMETERS:  object               - An ACPI reference object
+ *
+ * RETURN:      Decoded name of the type of reference
+ *
+ * DESCRIPTION: Decode a reference object sub-type to a string.
+ *
+ ******************************************************************************/
+
+/* Printable names of reference object sub-types */
+
+static const char *acpi_gbl_ref_class_names[] = {
+	/* 00 */ "Local",
+	/* 01 */ "Argument",
+	/* 02 */ "RefOf",
+	/* 03 */ "Index",
+	/* 04 */ "DdbHandle",
+	/* 05 */ "Named Object",
+	/* 06 */ "Debug"
+};
+
+const char *acpi_ut_get_reference_name(union acpi_operand_object *object)
+{
+
+	if (!object) {
+		return ("NULL Object");
+	}
+
+	if (ACPI_GET_DESCRIPTOR_TYPE(object) != ACPI_DESC_TYPE_OPERAND) {
+		return ("Not an Operand object");
+	}
+
+	if (object->common.type != ACPI_TYPE_LOCAL_REFERENCE) {
+		return ("Not a Reference object");
+	}
+
+	if (object->reference.class > ACPI_REFCLASS_MAX) {
+		return ("Unknown Reference class");
+	}
+
+	return (acpi_gbl_ref_class_names[object->reference.class]);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_get_mutex_name
+ *
+ * PARAMETERS:  mutex_id        - The predefined ID for this mutex.
+ *
+ * RETURN:      Decoded name of the internal mutex
+ *
+ * DESCRIPTION: Translate a mutex ID into a name string (Debug only)
+ *
+ ******************************************************************************/
+
+/* Names for internal mutex objects, used for debug output */
+
+static const char *acpi_gbl_mutex_names[ACPI_NUM_MUTEX] = {
+	"ACPI_MTX_Interpreter",
+	"ACPI_MTX_Namespace",
+	"ACPI_MTX_Tables",
+	"ACPI_MTX_Events",
+	"ACPI_MTX_Caches",
+	"ACPI_MTX_Memory",
+};
+
+const char *acpi_ut_get_mutex_name(u32 mutex_id)
+{
+
+	if (mutex_id > ACPI_MAX_MUTEX) {
+		return ("Invalid Mutex ID");
+	}
+
+	return (acpi_gbl_mutex_names[mutex_id]);
+}
+
+#if defined(ACPI_DEBUG_OUTPUT) || defined(ACPI_DEBUGGER)
+
+/*
+ * Strings and procedures used for debug only
+ */
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_get_notify_name
+ *
+ * PARAMETERS:  notify_value    - Value from the Notify() request
+ *
+ * RETURN:      Decoded name for the notify value
+ *
+ * DESCRIPTION: Translate a Notify Value to a notify namestring.
+ *
+ ******************************************************************************/
+
+/* Names for Notify() values, used for debug output */
+
+static const char *acpi_gbl_generic_notify[ACPI_GENERIC_NOTIFY_MAX + 1] = {
+	/* 00 */ "Bus Check",
+	/* 01 */ "Device Check",
+	/* 02 */ "Device Wake",
+	/* 03 */ "Eject Request",
+	/* 04 */ "Device Check Light",
+	/* 05 */ "Frequency Mismatch",
+	/* 06 */ "Bus Mode Mismatch",
+	/* 07 */ "Power Fault",
+	/* 08 */ "Capabilities Check",
+	/* 09 */ "Device PLD Check",
+	/* 0A */ "Reserved",
+	/* 0B */ "System Locality Update",
+								/* 0C */ "Reserved (was previously Shutdown Request)",
+								/* Reserved in ACPI 6.0 */
+	/* 0D */ "System Resource Affinity Update",
+								/* 0E */ "Heterogeneous Memory Attributes Update",
+								/* ACPI 6.2 */
+						/* 0F */ "Error Disconnect Recover"
+						/* ACPI 6.3 */
+};
+
+static const char *acpi_gbl_device_notify[5] = {
+	/* 80 */ "Status Change",
+	/* 81 */ "Information Change",
+	/* 82 */ "Device-Specific Change",
+	/* 83 */ "Device-Specific Change",
+	/* 84 */ "Reserved"
+};
+
+static const char *acpi_gbl_processor_notify[5] = {
+	/* 80 */ "Performance Capability Change",
+	/* 81 */ "C-State Change",
+	/* 82 */ "Throttling Capability Change",
+	/* 83 */ "Guaranteed Change",
+	/* 84 */ "Minimum Excursion"
+};
+
+static const char *acpi_gbl_thermal_notify[5] = {
+	/* 80 */ "Thermal Status Change",
+	/* 81 */ "Thermal Trip Point Change",
+	/* 82 */ "Thermal Device List Change",
+	/* 83 */ "Thermal Relationship Change",
+	/* 84 */ "Reserved"
+};
+
+const char *acpi_ut_get_notify_name(u32 notify_value, acpi_object_type type)
+{
+
+	/* 00 - 0F are "common to all object types" (from ACPI Spec) */
+
+	if (notify_value <= ACPI_GENERIC_NOTIFY_MAX) {
+		return (acpi_gbl_generic_notify[notify_value]);
+	}
+
+	/* 10 - 7F are reserved */
+
+	if (notify_value <= ACPI_MAX_SYS_NOTIFY) {
+		return ("Reserved");
+	}
+
+	/* 80 - 84 are per-object-type */
+
+	if (notify_value <= ACPI_SPECIFIC_NOTIFY_MAX) {
+		switch (type) {
+		case ACPI_TYPE_ANY:
+		case ACPI_TYPE_DEVICE:
+			return (acpi_gbl_device_notify[notify_value - 0x80]);
+
+		case ACPI_TYPE_PROCESSOR:
+			return (acpi_gbl_processor_notify[notify_value - 0x80]);
+
+		case ACPI_TYPE_THERMAL:
+			return (acpi_gbl_thermal_notify[notify_value - 0x80]);
+
+		default:
+			return ("Target object type does not support notifies");
+		}
+	}
+
+	/* 84 - BF are device-specific */
+
+	if (notify_value <= ACPI_MAX_DEVICE_SPECIFIC_NOTIFY) {
+		return ("Device-Specific");
+	}
+
+	/* C0 and above are hardware-specific */
+
+	return ("Hardware-Specific");
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_get_argument_type_name
+ *
+ * PARAMETERS:  arg_type            - an ARGP_* parser argument type
+ *
+ * RETURN:      Decoded ARGP_* type
+ *
+ * DESCRIPTION: Decode an ARGP_* parser type, as defined in the amlcode.h file,
+ *              and used in the acopcode.h file. For example, ARGP_TERMARG.
+ *              Used for debug only.
+ *
+ ******************************************************************************/
+
+static const char *acpi_gbl_argument_type[20] = {
+	/* 00 */ "Unknown ARGP",
+	/* 01 */ "ByteData",
+	/* 02 */ "ByteList",
+	/* 03 */ "CharList",
+	/* 04 */ "DataObject",
+	/* 05 */ "DataObjectList",
+	/* 06 */ "DWordData",
+	/* 07 */ "FieldList",
+	/* 08 */ "Name",
+	/* 09 */ "NameString",
+	/* 0A */ "ObjectList",
+	/* 0B */ "PackageLength",
+	/* 0C */ "SuperName",
+	/* 0D */ "Target",
+	/* 0E */ "TermArg",
+	/* 0F */ "TermList",
+	/* 10 */ "WordData",
+	/* 11 */ "QWordData",
+	/* 12 */ "SimpleName",
+	/* 13 */ "NameOrRef"
+};
+
+const char *acpi_ut_get_argument_type_name(u32 arg_type)
+{
+
+	if (arg_type > ARGP_MAX) {
+		return ("Unknown ARGP");
+	}
+
+	return (acpi_gbl_argument_type[arg_type]);
+}
+
+#endif
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_valid_object_type
+ *
+ * PARAMETERS:  type            - Object type to be validated
+ *
+ * RETURN:      TRUE if valid object type, FALSE otherwise
+ *
+ * DESCRIPTION: Validate an object type
+ *
+ ******************************************************************************/
+
+u8 acpi_ut_valid_object_type(acpi_object_type type)
+{
+
+	if (type > ACPI_TYPE_LOCAL_MAX) {
+
+		/* Note: Assumes all TYPEs are contiguous (external/local) */
+
+		return (FALSE);
+	}
+
+	return (TRUE);
+}