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			There is a critical race condition in kprobe initialization that can lead to
NULL pointer dereference and kernel crash.
[1135630.084782] Unable to handle kernel paging request at virtual address 0000710a04630000
...
[1135630.260314] pstate: 404003c9 (nZcv DAIF +PAN -UAO)
[1135630.269239] pc : kprobe_perf_func+0x30/0x260
[1135630.277643] lr : kprobe_dispatcher+0x44/0x60
[1135630.286041] sp : ffffaeff4977fa40
[1135630.293441] x29: ffffaeff4977fa40 x28: ffffaf015340e400
[1135630.302837] x27: 0000000000000000 x26: 0000000000000000
[1135630.312257] x25: ffffaf029ed108a8 x24: ffffaf015340e528
[1135630.321705] x23: ffffaeff4977fc50 x22: ffffaeff4977fc50
[1135630.331154] x21: 0000000000000000 x20: ffffaeff4977fc50
[1135630.340586] x19: ffffaf015340e400 x18: 0000000000000000
[1135630.349985] x17: 0000000000000000 x16: 0000000000000000
[1135630.359285] x15: 0000000000000000 x14: 0000000000000000
[1135630.368445] x13: 0000000000000000 x12: 0000000000000000
[1135630.377473] x11: 0000000000000000 x10: 0000000000000000
[1135630.386411] x9 : 0000000000000000 x8 : 0000000000000000
[1135630.395252] x7 : 0000000000000000 x6 : 0000000000000000
[1135630.403963] x5 : 0000000000000000 x4 : 0000000000000000
[1135630.412545] x3 : 0000710a04630000 x2 : 0000000000000006
[1135630.421021] x1 : ffffaeff4977fc50 x0 : 0000710a04630000
[1135630.429410] Call trace:
[1135630.434828]  kprobe_perf_func+0x30/0x260
[1135630.441661]  kprobe_dispatcher+0x44/0x60
[1135630.448396]  aggr_pre_handler+0x70/0xc8
[1135630.454959]  kprobe_breakpoint_handler+0x140/0x1e0
[1135630.462435]  brk_handler+0xbc/0xd8
[1135630.468437]  do_debug_exception+0x84/0x138
[1135630.475074]  el1_dbg+0x18/0x8c
[1135630.480582]  security_file_permission+0x0/0xd0
[1135630.487426]  vfs_write+0x70/0x1c0
[1135630.493059]  ksys_write+0x5c/0xc8
[1135630.498638]  __arm64_sys_write+0x24/0x30
[1135630.504821]  el0_svc_common+0x78/0x130
[1135630.510838]  el0_svc_handler+0x38/0x78
[1135630.516834]  el0_svc+0x8/0x1b0
kernel/trace/trace_kprobe.c: 1308
0xffff3df8995039ec <kprobe_perf_func+0x2c>:     ldr     x21, [x24,#120]
include/linux/compiler.h: 294
0xffff3df8995039f0 <kprobe_perf_func+0x30>:     ldr     x1, [x21,x0]
kernel/trace/trace_kprobe.c
1308: head = this_cpu_ptr(call->perf_events);
1309: if (hlist_empty(head))
1310: 	return 0;
crash> struct trace_event_call -o
struct trace_event_call {
  ...
  [120] struct hlist_head *perf_events;  //(call->perf_event)
  ...
}
crash> struct trace_event_call ffffaf015340e528
struct trace_event_call {
  ...
  perf_events = 0xffff0ad5fa89f088, //this value is correct, but x21 = 0
  ...
}
Race Condition Analysis:
The race occurs between kprobe activation and perf_events initialization:
  CPU0                                    CPU1
  ====                                    ====
  perf_kprobe_init
    perf_trace_event_init
      tp_event->perf_events = list;(1)
      tp_event->class->reg (2)← KPROBE ACTIVE
                                          Debug exception triggers
                                          ...
                                          kprobe_dispatcher
                                            kprobe_perf_func (tk->tp.flags & TP_FLAG_PROFILE)
                                              head = this_cpu_ptr(call->perf_events)(3)
                                              (perf_events is still NULL)
Problem:
1. CPU0 executes (1) assigning tp_event->perf_events = list
2. CPU0 executes (2) enabling kprobe functionality via class->reg()
3. CPU1 triggers and reaches kprobe_dispatcher
4. CPU1 checks TP_FLAG_PROFILE - condition passes (step 2 completed)
5. CPU1 calls kprobe_perf_func() and crashes at (3) because
   call->perf_events is still NULL
CPU1 sees that kprobe functionality is enabled but does not see that
perf_events has been assigned.
Add pairing read and write memory barriers to guarantee that if CPU1
sees that kprobe functionality is enabled, it must also see that
perf_events has been assigned.
Link: https://lore.kernel.org/all/20251001022025.44626-1-chenyuan_fl@163.com/
Fixes: 50d7805607 ("tracing/kprobes: Add probe handler dispatcher to support perf and ftrace concurrent use")
Cc: stable@vger.kernel.org
Signed-off-by: Yuan Chen <chenyuan@kylinos.cn>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
		
	
			
		
			
				
	
	
		
			592 lines
		
	
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			592 lines
		
	
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
 | |
| /*
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|  * Common header file for probe-based Dynamic events.
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|  *
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|  * This code was copied from kernel/trace/trace_kprobe.h written by
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|  * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
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|  *
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|  * Updates to make this generic:
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|  * Copyright (C) IBM Corporation, 2010-2011
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|  * Author:     Srikar Dronamraju
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|  */
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| 
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| #include <linux/bitops.h>
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| #include <linux/btf.h>
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| #include <linux/cleanup.h>
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| #include <linux/kprobes.h>
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| #include <linux/limits.h>
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| #include <linux/perf_event.h>
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| #include <linux/ptrace.h>
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| #include <linux/seq_file.h>
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| #include <linux/slab.h>
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| #include <linux/smp.h>
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| #include <linux/string.h>
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| #include <linux/stringify.h>
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| #include <linux/tracefs.h>
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| #include <linux/types.h>
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| #include <linux/uaccess.h>
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| 
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| #include <asm/bitsperlong.h>
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| 
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| #include "trace.h"
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| #include "trace_output.h"
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| 
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| #define MAX_TRACE_ARGS		128
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| #define MAX_ARGSTR_LEN		63
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| #define MAX_ARRAY_LEN		64
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| #define MAX_ARG_NAME_LEN	32
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| #define MAX_BTF_ARGS_LEN	128
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| #define MAX_DENTRY_ARGS_LEN	256
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| #define MAX_STRING_SIZE		PATH_MAX
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| 
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| /* Reserved field names */
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| #define FIELD_STRING_IP		"__probe_ip"
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| #define FIELD_STRING_RETIP	"__probe_ret_ip"
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| #define FIELD_STRING_FUNC	"__probe_func"
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| 
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| #undef DEFINE_FIELD
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| #define DEFINE_FIELD(type, item, name, is_signed)			\
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| 	do {								\
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| 		ret = trace_define_field(event_call, #type, name,	\
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| 					 offsetof(typeof(field), item),	\
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| 					 sizeof(field.item), is_signed, \
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| 					 FILTER_OTHER);			\
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| 		if (ret)						\
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| 			return ret;					\
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| 	} while (0)
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| 
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| 
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| /* Flags for trace_probe */
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| #define TP_FLAG_TRACE		1
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| #define TP_FLAG_PROFILE		2
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| 
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| /* data_loc: data location, compatible with u32 */
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| #define make_data_loc(len, offs)	\
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| 	(((u32)(len) << 16) | ((u32)(offs) & 0xffff))
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| #define get_loc_len(dl)		((u32)(dl) >> 16)
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| #define get_loc_offs(dl)	((u32)(dl) & 0xffff)
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| 
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| static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
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| {
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| 	return (u8 *)ent + get_loc_offs(*dl);
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| }
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| 
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| static nokprobe_inline u32 update_data_loc(u32 loc, int consumed)
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| {
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| 	u32 maxlen = get_loc_len(loc);
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| 	u32 offset = get_loc_offs(loc);
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| 
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| 	return make_data_loc(maxlen - consumed, offset + consumed);
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| }
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| 
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| /* Printing function type */
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| typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
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| 
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| enum fetch_op {
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| 	FETCH_OP_NOP = 0,
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| 	// Stage 1 (load) ops
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| 	FETCH_OP_REG,		/* Register : .param = offset */
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| 	FETCH_OP_STACK,		/* Stack : .param = index */
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| 	FETCH_OP_STACKP,	/* Stack pointer */
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| 	FETCH_OP_RETVAL,	/* Return value */
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| 	FETCH_OP_IMM,		/* Immediate : .immediate */
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| 	FETCH_OP_COMM,		/* Current comm */
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| 	FETCH_OP_ARG,		/* Function argument : .param */
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| 	FETCH_OP_FOFFS,		/* File offset: .immediate */
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| 	FETCH_OP_DATA,		/* Allocated data: .data */
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| 	FETCH_OP_EDATA,		/* Entry data: .offset */
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| 	// Stage 2 (dereference) op
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| 	FETCH_OP_DEREF,		/* Dereference: .offset */
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| 	FETCH_OP_UDEREF,	/* User-space Dereference: .offset */
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| 	// Stage 3 (store) ops
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| 	FETCH_OP_ST_RAW,	/* Raw: .size */
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| 	FETCH_OP_ST_MEM,	/* Mem: .offset, .size */
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| 	FETCH_OP_ST_UMEM,	/* Mem: .offset, .size */
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| 	FETCH_OP_ST_STRING,	/* String: .offset, .size */
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| 	FETCH_OP_ST_USTRING,	/* User String: .offset, .size */
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| 	FETCH_OP_ST_SYMSTR,	/* Kernel Symbol String: .offset, .size */
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| 	FETCH_OP_ST_EDATA,	/* Store Entry Data: .offset */
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| 	// Stage 4 (modify) op
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| 	FETCH_OP_MOD_BF,	/* Bitfield: .basesize, .lshift, .rshift */
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| 	// Stage 5 (loop) op
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| 	FETCH_OP_LP_ARRAY,	/* Array: .param = loop count */
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| 	FETCH_OP_TP_ARG,	/* Trace Point argument */
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| 	FETCH_OP_END,
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| 	FETCH_NOP_SYMBOL,	/* Unresolved Symbol holder */
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| };
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| 
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| struct fetch_insn {
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| 	enum fetch_op op;
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| 	union {
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| 		unsigned int param;
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| 		struct {
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| 			unsigned int size;
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| 			int offset;
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| 		};
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| 		struct {
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| 			unsigned char basesize;
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| 			unsigned char lshift;
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| 			unsigned char rshift;
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| 		};
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| 		unsigned long immediate;
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| 		void *data;
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| 	};
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| };
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| 
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| /* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */
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| #define FETCH_INSN_MAX	16
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| #define FETCH_TOKEN_COMM	(-ECOMM)
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| 
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| /* Fetch type information table */
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| struct fetch_type {
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| 	const char		*name;		/* Name of type */
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| 	size_t			size;		/* Byte size of type */
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| 	bool			is_signed;	/* Signed flag */
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| 	bool			is_string;	/* String flag */
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| 	print_type_func_t	print;		/* Print functions */
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| 	const char		*fmt;		/* Format string */
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| 	const char		*fmttype;	/* Name in format file */
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| };
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| 
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| /* For defining macros, define string/string_size types */
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| typedef u32 string;
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| typedef u32 string_size;
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| 
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| #define PRINT_TYPE_FUNC_NAME(type)	print_type_##type
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| #define PRINT_TYPE_FMT_NAME(type)	print_type_format_##type
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| 
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| /* Printing  in basic type function template */
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| #define DECLARE_BASIC_PRINT_TYPE_FUNC(type)				\
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| int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
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| extern const char PRINT_TYPE_FMT_NAME(type)[]
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| 
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| DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
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| 
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| DECLARE_BASIC_PRINT_TYPE_FUNC(char);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(string);
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| DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);
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| 
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| /* Default (unsigned long) fetch type */
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| #define __DEFAULT_FETCH_TYPE(t) x##t
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| #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
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| #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
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| #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
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| 
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| #define __ADDR_FETCH_TYPE(t) u##t
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| #define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t)
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| #define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG)
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| 
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| #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, str, _fmttype)	\
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| 	{.name = _name,					\
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| 	 .size = _size,					\
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| 	 .is_signed = (bool)sign,			\
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| 	 .is_string = (bool)str,			\
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| 	 .print = PRINT_TYPE_FUNC_NAME(ptype),		\
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| 	 .fmt = PRINT_TYPE_FMT_NAME(ptype),		\
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| 	 .fmttype = _fmttype,				\
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| 	}
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| 
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| /* Non string types can use these macros */
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| #define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype)	\
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| 	__ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, 0, #_fmttype)
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| #define ASSIGN_FETCH_TYPE(ptype, ftype, sign)			\
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| 	_ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)
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| 
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| /* If ptype is an alias of atype, use this macro (show atype in format) */
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| #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign)		\
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| 	_ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
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| 
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| #define ASSIGN_FETCH_TYPE_END {}
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| #define MAX_ARRAY_LEN	64
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| 
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| #ifdef CONFIG_KPROBE_EVENTS
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| bool trace_kprobe_on_func_entry(struct trace_event_call *call);
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| bool trace_kprobe_error_injectable(struct trace_event_call *call);
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| #else
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| static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
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| {
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| 	return false;
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| }
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| 
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| static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
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| {
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| 	return false;
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| }
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| #endif /* CONFIG_KPROBE_EVENTS */
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| 
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| struct probe_arg {
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| 	struct fetch_insn	*code;
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| 	bool			dynamic;/* Dynamic array (string) is used */
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| 	unsigned int		offset;	/* Offset from argument entry */
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| 	unsigned int		count;	/* Array count */
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| 	const char		*name;	/* Name of this argument */
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| 	const char		*comm;	/* Command of this argument */
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| 	char			*fmt;	/* Format string if needed */
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| 	const struct fetch_type	*type;	/* Type of this argument */
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| };
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| 
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| struct probe_entry_arg {
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| 	struct fetch_insn	*code;
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| 	unsigned int		size;	/* The entry data size */
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| };
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| 
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| struct trace_uprobe_filter {
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| 	rwlock_t		rwlock;
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| 	int			nr_systemwide;
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| 	struct list_head	perf_events;
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| };
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| 
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| /* Event call and class holder */
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| struct trace_probe_event {
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| 	unsigned int			flags;	/* For TP_FLAG_* */
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| 	struct trace_event_class	class;
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| 	struct trace_event_call		call;
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| 	struct list_head 		files;
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| 	struct list_head		probes;
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| 	struct trace_uprobe_filter	filter[];
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| };
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| 
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| struct trace_probe {
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| 	struct list_head		list;
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| 	struct trace_probe_event	*event;
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| 	ssize_t				size;	/* trace entry size */
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| 	unsigned int			nr_args;
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| 	struct probe_entry_arg		*entry_arg;	/* This is only for return probe */
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| 	struct probe_arg		args[];
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| };
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| 
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| struct event_file_link {
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| 	struct trace_event_file		*file;
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| 	struct list_head		list;
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| };
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| 
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| static inline unsigned int trace_probe_load_flag(struct trace_probe *tp)
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| {
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| 	return smp_load_acquire(&tp->event->flags);
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| }
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| 
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| static inline bool trace_probe_test_flag(struct trace_probe *tp,
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| 					 unsigned int flag)
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| {
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| 	return !!(trace_probe_load_flag(tp) & flag);
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| }
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| 
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| static inline void trace_probe_set_flag(struct trace_probe *tp,
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| 					unsigned int flag)
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| {
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| 	smp_store_release(&tp->event->flags, tp->event->flags | flag);
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| }
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| 
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| static inline void trace_probe_clear_flag(struct trace_probe *tp,
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| 					  unsigned int flag)
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| {
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| 	tp->event->flags &= ~flag;
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| }
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| 
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| static inline bool trace_probe_is_enabled(struct trace_probe *tp)
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| {
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| 	return trace_probe_test_flag(tp, TP_FLAG_TRACE | TP_FLAG_PROFILE);
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| }
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| 
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| static inline const char *trace_probe_name(struct trace_probe *tp)
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| {
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| 	return trace_event_name(&tp->event->call);
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| }
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| 
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| static inline const char *trace_probe_group_name(struct trace_probe *tp)
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| {
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| 	return tp->event->call.class->system;
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| }
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| 
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| static inline struct trace_event_call *
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| 	trace_probe_event_call(struct trace_probe *tp)
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| {
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| 	return &tp->event->call;
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| }
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| 
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| static inline struct trace_probe_event *
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| trace_probe_event_from_call(struct trace_event_call *event_call)
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| {
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| 	return container_of(event_call, struct trace_probe_event, call);
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| }
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| 
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| static inline struct trace_probe *
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| trace_probe_primary_from_call(struct trace_event_call *call)
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| {
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| 	struct trace_probe_event *tpe = trace_probe_event_from_call(call);
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| 
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| 	return list_first_entry_or_null(&tpe->probes, struct trace_probe, list);
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| }
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| 
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| static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
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| {
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| 	return &tp->event->probes;
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| }
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| 
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| static inline bool trace_probe_has_sibling(struct trace_probe *tp)
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| {
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| 	struct list_head *list = trace_probe_probe_list(tp);
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| 
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| 	return !list_empty(list) && !list_is_singular(list);
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| }
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| 
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| static inline int trace_probe_unregister_event_call(struct trace_probe *tp)
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| {
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| 	/* tp->event is unregistered in trace_remove_event_call() */
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| 	return trace_remove_event_call(&tp->event->call);
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| }
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| 
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| static inline bool trace_probe_has_single_file(struct trace_probe *tp)
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| {
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| 	return !!list_is_singular(&tp->event->files);
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| }
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| 
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| int trace_probe_init(struct trace_probe *tp, const char *event,
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| 		     const char *group, bool alloc_filter, int nargs);
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| void trace_probe_cleanup(struct trace_probe *tp);
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| int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
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| void trace_probe_unlink(struct trace_probe *tp);
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| int trace_probe_register_event_call(struct trace_probe *tp);
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| int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file);
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| int trace_probe_remove_file(struct trace_probe *tp,
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| 			    struct trace_event_file *file);
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| struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
 | |
| 						struct trace_event_file *file);
 | |
| int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
 | |
| bool trace_probe_match_command_args(struct trace_probe *tp,
 | |
| 				    int argc, const char **argv);
 | |
| int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **));
 | |
| int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
 | |
| 		 u8 *data, void *field);
 | |
| 
 | |
| #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
 | |
| int traceprobe_get_entry_data_size(struct trace_probe *tp);
 | |
| /* This is a runtime function to store entry data */
 | |
| void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs);
 | |
| #else /* !CONFIG_HAVE_FUNCTION_ARG_ACCESS_API */
 | |
| static inline int traceprobe_get_entry_data_size(struct trace_probe *tp)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| #define store_trace_entry_data(edata, tp, regs) do { } while (0)
 | |
| #endif
 | |
| 
 | |
| #define trace_probe_for_each_link(pos, tp)	\
 | |
| 	list_for_each_entry(pos, &(tp)->event->files, list)
 | |
| #define trace_probe_for_each_link_rcu(pos, tp)	\
 | |
| 	list_for_each_entry_rcu(pos, &(tp)->event->files, list)
 | |
| 
 | |
| /*
 | |
|  * The flags used for parsing trace_probe arguments.
 | |
|  * TPARG_FL_RETURN, TPARG_FL_FENTRY and TPARG_FL_TEVENT are mutually exclusive.
 | |
|  * TPARG_FL_KERNEL and TPARG_FL_USER are also mutually exclusive.
 | |
|  * TPARG_FL_FPROBE and TPARG_FL_TPOINT are optional but it should be with
 | |
|  * TPARG_FL_KERNEL.
 | |
|  */
 | |
| #define TPARG_FL_RETURN BIT(0)
 | |
| #define TPARG_FL_KERNEL BIT(1)
 | |
| #define TPARG_FL_FENTRY BIT(2)
 | |
| #define TPARG_FL_TEVENT BIT(3)
 | |
| #define TPARG_FL_USER   BIT(4)
 | |
| #define TPARG_FL_FPROBE BIT(5)
 | |
| #define TPARG_FL_TPOINT BIT(6)
 | |
| #define TPARG_FL_LOC_MASK	GENMASK(4, 0)
 | |
| 
 | |
| static inline bool tparg_is_function_entry(unsigned int flags)
 | |
| {
 | |
| 	return (flags & TPARG_FL_LOC_MASK) == (TPARG_FL_KERNEL | TPARG_FL_FENTRY);
 | |
| }
 | |
| 
 | |
| static inline bool tparg_is_function_return(unsigned int flags)
 | |
| {
 | |
| 	return (flags & TPARG_FL_LOC_MASK) == (TPARG_FL_KERNEL | TPARG_FL_RETURN);
 | |
| }
 | |
| 
 | |
| struct traceprobe_parse_context {
 | |
| 	struct trace_event_call *event;
 | |
| 	/* BTF related parameters */
 | |
| 	const char *funcname;		/* Function name in BTF */
 | |
| 	const struct btf_type  *proto;	/* Prototype of the function */
 | |
| 	const struct btf_param *params;	/* Parameter of the function */
 | |
| 	s32 nr_params;			/* The number of the parameters */
 | |
| 	struct btf *btf;		/* The BTF to be used */
 | |
| 	const struct btf_type *last_type;	/* Saved type */
 | |
| 	u32 last_bitoffs;		/* Saved bitoffs */
 | |
| 	u32 last_bitsize;		/* Saved bitsize */
 | |
| 	struct trace_probe *tp;
 | |
| 	unsigned int flags;
 | |
| 	int offset;
 | |
| };
 | |
| 
 | |
| extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
 | |
| 				      const char *argv,
 | |
| 				      struct traceprobe_parse_context *ctx);
 | |
| const char **traceprobe_expand_meta_args(int argc, const char *argv[],
 | |
| 					 int *new_argc, char *buf, int bufsize,
 | |
| 					 struct traceprobe_parse_context *ctx);
 | |
| extern int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf);
 | |
| 
 | |
| extern int traceprobe_update_arg(struct probe_arg *arg);
 | |
| extern void traceprobe_free_probe_arg(struct probe_arg *arg);
 | |
| 
 | |
| /*
 | |
|  * If either traceprobe_parse_probe_arg() or traceprobe_expand_meta_args() is called,
 | |
|  * this MUST be called for clean up the context and return a resource.
 | |
|  */
 | |
| void traceprobe_finish_parse(struct traceprobe_parse_context *ctx);
 | |
| static inline void traceprobe_free_parse_ctx(struct traceprobe_parse_context *ctx)
 | |
| {
 | |
| 	traceprobe_finish_parse(ctx);
 | |
| 	kfree(ctx);
 | |
| }
 | |
| 
 | |
| DEFINE_FREE(traceprobe_parse_context, struct traceprobe_parse_context *,
 | |
| 	if (_T) traceprobe_free_parse_ctx(_T))
 | |
| 
 | |
| extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
 | |
| int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
 | |
| 				char *buf, int offset);
 | |
| 
 | |
| enum probe_print_type {
 | |
| 	PROBE_PRINT_NORMAL,
 | |
| 	PROBE_PRINT_RETURN,
 | |
| 	PROBE_PRINT_EVENT,
 | |
| };
 | |
| 
 | |
| extern int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype);
 | |
| 
 | |
| #ifdef CONFIG_PERF_EVENTS
 | |
| extern struct trace_event_call *
 | |
| create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
 | |
| 			  bool is_return);
 | |
| extern void destroy_local_trace_kprobe(struct trace_event_call *event_call);
 | |
| 
 | |
| extern struct trace_event_call *
 | |
| create_local_trace_uprobe(char *name, unsigned long offs,
 | |
| 			  unsigned long ref_ctr_offset, bool is_return);
 | |
| extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
 | |
| #endif
 | |
| extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
 | |
| 					size_t offset, struct trace_probe *tp);
 | |
| 
 | |
| #undef ERRORS
 | |
| #define ERRORS	\
 | |
| 	C(FILE_NOT_FOUND,	"Failed to find the given file"),	\
 | |
| 	C(NO_REGULAR_FILE,	"Not a regular file"),			\
 | |
| 	C(BAD_REFCNT,		"Invalid reference counter offset"),	\
 | |
| 	C(REFCNT_OPEN_BRACE,	"Reference counter brace is not closed"), \
 | |
| 	C(BAD_REFCNT_SUFFIX,	"Reference counter has wrong suffix"),	\
 | |
| 	C(BAD_UPROBE_OFFS,	"Invalid uprobe offset"),		\
 | |
| 	C(BAD_MAXACT_TYPE,	"Maxactive is only for function exit"),	\
 | |
| 	C(BAD_MAXACT,		"Invalid maxactive number"),		\
 | |
| 	C(MAXACT_TOO_BIG,	"Maxactive is too big"),		\
 | |
| 	C(BAD_PROBE_ADDR,	"Invalid probed address or symbol"),	\
 | |
| 	C(NON_UNIQ_SYMBOL,	"The symbol is not unique"),		\
 | |
| 	C(BAD_RETPROBE,		"Retprobe address must be an function entry"), \
 | |
| 	C(NO_TRACEPOINT,	"Tracepoint is not found"),		\
 | |
| 	C(BAD_TP_NAME,		"Invalid character in tracepoint name"),\
 | |
| 	C(BAD_ADDR_SUFFIX,	"Invalid probed address suffix"), \
 | |
| 	C(NO_GROUP_NAME,	"Group name is not specified"),		\
 | |
| 	C(GROUP_TOO_LONG,	"Group name is too long"),		\
 | |
| 	C(BAD_GROUP_NAME,	"Group name must follow the same rules as C identifiers"), \
 | |
| 	C(NO_EVENT_NAME,	"Event name is not specified"),		\
 | |
| 	C(EVENT_TOO_LONG,	"Event name is too long"),		\
 | |
| 	C(BAD_EVENT_NAME,	"Event name must follow the same rules as C identifiers"), \
 | |
| 	C(EVENT_EXIST,		"Given group/event name is already used by another event"), \
 | |
| 	C(RETVAL_ON_PROBE,	"$retval is not available on probe"),	\
 | |
| 	C(NO_RETVAL,		"This function returns 'void' type"),	\
 | |
| 	C(BAD_STACK_NUM,	"Invalid stack number"),		\
 | |
| 	C(BAD_ARG_NUM,		"Invalid argument number"),		\
 | |
| 	C(BAD_VAR,		"Invalid $-valiable specified"),	\
 | |
| 	C(BAD_REG_NAME,		"Invalid register name"),		\
 | |
| 	C(BAD_MEM_ADDR,		"Invalid memory address"),		\
 | |
| 	C(BAD_IMM,		"Invalid immediate value"),		\
 | |
| 	C(IMMSTR_NO_CLOSE,	"String is not closed with '\"'"),	\
 | |
| 	C(FILE_ON_KPROBE,	"File offset is not available with kprobe"), \
 | |
| 	C(BAD_FILE_OFFS,	"Invalid file offset value"),		\
 | |
| 	C(SYM_ON_UPROBE,	"Symbol is not available with uprobe"),	\
 | |
| 	C(TOO_MANY_OPS,		"Dereference is too much nested"), 	\
 | |
| 	C(DEREF_NEED_BRACE,	"Dereference needs a brace"),		\
 | |
| 	C(BAD_DEREF_OFFS,	"Invalid dereference offset"),		\
 | |
| 	C(DEREF_OPEN_BRACE,	"Dereference brace is not closed"),	\
 | |
| 	C(COMM_CANT_DEREF,	"$comm can not be dereferenced"),	\
 | |
| 	C(BAD_FETCH_ARG,	"Invalid fetch argument"),		\
 | |
| 	C(ARRAY_NO_CLOSE,	"Array is not closed"),			\
 | |
| 	C(BAD_ARRAY_SUFFIX,	"Array has wrong suffix"),		\
 | |
| 	C(BAD_ARRAY_NUM,	"Invalid array size"),			\
 | |
| 	C(ARRAY_TOO_BIG,	"Array number is too big"),		\
 | |
| 	C(BAD_TYPE,		"Unknown type is specified"),		\
 | |
| 	C(BAD_STRING,		"String accepts only memory argument"),	\
 | |
| 	C(BAD_SYMSTRING,	"Symbol String doesn't accept data/userdata"),	\
 | |
| 	C(BAD_BITFIELD,		"Invalid bitfield"),			\
 | |
| 	C(ARG_NAME_TOO_LONG,	"Argument name is too long"),		\
 | |
| 	C(NO_ARG_NAME,		"Argument name is not specified"),	\
 | |
| 	C(BAD_ARG_NAME,		"Argument name must follow the same rules as C identifiers"), \
 | |
| 	C(USED_ARG_NAME,	"This argument name is already used"),	\
 | |
| 	C(ARG_TOO_LONG,		"Argument expression is too long"),	\
 | |
| 	C(NO_ARG_BODY,		"No argument expression"),		\
 | |
| 	C(BAD_INSN_BNDRY,	"Probe point is not an instruction boundary"),\
 | |
| 	C(FAIL_REG_PROBE,	"Failed to register probe event"),\
 | |
| 	C(DIFF_PROBE_TYPE,	"Probe type is different from existing probe"),\
 | |
| 	C(DIFF_ARG_TYPE,	"Argument type or name is different from existing probe"),\
 | |
| 	C(SAME_PROBE,		"There is already the exact same probe event"),\
 | |
| 	C(NO_EVENT_INFO,	"This requires both group and event name to attach"),\
 | |
| 	C(BAD_ATTACH_EVENT,	"Attached event does not exist"),\
 | |
| 	C(BAD_ATTACH_ARG,	"Attached event does not have this field"),\
 | |
| 	C(NO_EP_FILTER,		"No filter rule after 'if'"),		\
 | |
| 	C(NOSUP_BTFARG,		"BTF is not available or not supported"),	\
 | |
| 	C(NO_BTFARG,		"This variable is not found at this probe point"),\
 | |
| 	C(NO_BTF_ENTRY,		"No BTF entry for this probe point"),	\
 | |
| 	C(BAD_VAR_ARGS,		"$arg* must be an independent parameter without name etc."),\
 | |
| 	C(NOFENTRY_ARGS,	"$arg* can be used only on function entry or exit"),	\
 | |
| 	C(DOUBLE_ARGS,		"$arg* can be used only once in the parameters"),	\
 | |
| 	C(ARGS_2LONG,		"$arg* failed because the argument list is too long"),	\
 | |
| 	C(ARGIDX_2BIG,		"$argN index is too big"),		\
 | |
| 	C(NO_PTR_STRCT,		"This is not a pointer to union/structure."),	\
 | |
| 	C(NOSUP_DAT_ARG,	"Non pointer structure/union argument is not supported."),\
 | |
| 	C(BAD_HYPHEN,		"Failed to parse single hyphen. Forgot '>'?"),	\
 | |
| 	C(NO_BTF_FIELD,		"This field is not found."),	\
 | |
| 	C(BAD_BTF_TID,		"Failed to get BTF type info."),\
 | |
| 	C(BAD_TYPE4STR,		"This type does not fit for string."),\
 | |
| 	C(NEED_STRING_TYPE,	"$comm and immediate-string only accepts string type"),\
 | |
| 	C(TOO_MANY_ARGS,	"Too many arguments are specified"),	\
 | |
| 	C(TOO_MANY_EARGS,	"Too many entry arguments specified"),
 | |
| 
 | |
| #undef C
 | |
| #define C(a, b)		TP_ERR_##a
 | |
| 
 | |
| /* Define TP_ERR_ */
 | |
| enum { ERRORS };
 | |
| 
 | |
| /* Error text is defined in trace_probe.c */
 | |
| 
 | |
| struct trace_probe_log {
 | |
| 	const char	*subsystem;
 | |
| 	const char	**argv;
 | |
| 	int		argc;
 | |
| 	int		index;
 | |
| };
 | |
| 
 | |
| void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
 | |
| void trace_probe_log_set_index(int index);
 | |
| void trace_probe_log_clear(void);
 | |
| void __trace_probe_log_err(int offset, int err);
 | |
| 
 | |
| #define trace_probe_log_err(offs, err)	\
 | |
| 	__trace_probe_log_err(offs, TP_ERR_##err)
 | |
| 
 | |
| struct uprobe_dispatch_data {
 | |
| 	struct trace_uprobe	*tu;
 | |
| 	unsigned long		bp_addr;
 | |
| };
 |