435 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			435 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
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| /* Copyright (C) 2018 Netronome Systems, Inc. */
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| 
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| #ifndef _GNU_SOURCE
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| #define _GNU_SOURCE
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| #endif
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| #include <stdarg.h>
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| #include <stdio.h>
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| #include <stdlib.h>
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| #include <string.h>
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| #include <sys/types.h>
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| #include <bpf/libbpf.h>
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| #include <bpf/libbpf_internal.h>
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| 
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| #include "disasm.h"
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| #include "json_writer.h"
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| #include "main.h"
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| #include "xlated_dumper.h"
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| 
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| static int kernel_syms_cmp(const void *sym_a, const void *sym_b)
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| {
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| 	return ((struct kernel_sym *)sym_a)->address -
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| 	       ((struct kernel_sym *)sym_b)->address;
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| }
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| 
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| void kernel_syms_load(struct dump_data *dd)
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| {
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| 	struct kernel_sym *sym;
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| 	char buff[256];
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| 	void *tmp, *address;
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| 	FILE *fp;
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| 
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| 	fp = fopen("/proc/kallsyms", "r");
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| 	if (!fp)
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| 		return;
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| 
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| 	while (fgets(buff, sizeof(buff), fp)) {
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| 		tmp = libbpf_reallocarray(dd->sym_mapping, dd->sym_count + 1,
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| 					  sizeof(*dd->sym_mapping));
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| 		if (!tmp) {
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| out:
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| 			free(dd->sym_mapping);
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| 			dd->sym_mapping = NULL;
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| 			fclose(fp);
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| 			return;
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| 		}
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| 		dd->sym_mapping = tmp;
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| 		sym = &dd->sym_mapping[dd->sym_count];
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| 
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| 		/* module is optional */
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| 		sym->module[0] = '\0';
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| 		/* trim the square brackets around the module name */
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| 		if (sscanf(buff, "%p %*c %s [%[^]]s", &address, sym->name, sym->module) < 2)
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| 			continue;
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| 		sym->address = (unsigned long)address;
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| 		if (!strcmp(sym->name, "__bpf_call_base")) {
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| 			dd->address_call_base = sym->address;
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| 			/* sysctl kernel.kptr_restrict was set */
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| 			if (!sym->address)
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| 				goto out;
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| 		}
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| 		if (sym->address)
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| 			dd->sym_count++;
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| 	}
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| 
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| 	fclose(fp);
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| 
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| 	qsort(dd->sym_mapping, dd->sym_count,
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| 	      sizeof(*dd->sym_mapping), kernel_syms_cmp);
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| }
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| 
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| void kernel_syms_destroy(struct dump_data *dd)
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| {
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| 	free(dd->sym_mapping);
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| }
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| 
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| struct kernel_sym *kernel_syms_search(struct dump_data *dd,
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| 				      unsigned long key)
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| {
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| 	struct kernel_sym sym = {
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| 		.address = key,
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| 	};
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| 
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| 	return dd->sym_mapping ?
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| 	       bsearch(&sym, dd->sym_mapping, dd->sym_count,
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| 		       sizeof(*dd->sym_mapping), kernel_syms_cmp) : NULL;
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| }
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| 
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| static void __printf(2, 3) print_insn(void *private_data, const char *fmt, ...)
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| {
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| 	va_list args;
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| 
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| 	va_start(args, fmt);
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| 	vprintf(fmt, args);
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| 	va_end(args);
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| }
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| 
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| static void __printf(2, 3)
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| print_insn_for_graph(void *private_data, const char *fmt, ...)
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| {
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| 	char buf[64], *p;
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| 	va_list args;
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| 
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| 	va_start(args, fmt);
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| 	vsnprintf(buf, sizeof(buf), fmt, args);
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| 	va_end(args);
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| 
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| 	p = buf;
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| 	while (*p != '\0') {
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| 		if (*p == '\n') {
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| 			memmove(p + 3, p, strlen(buf) + 1 - (p - buf));
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| 			/* Align each instruction dump row left. */
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| 			*p++ = '\\';
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| 			*p++ = 'l';
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| 			/* Output multiline concatenation. */
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| 			*p++ = '\\';
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| 		} else if (*p == '<' || *p == '>' || *p == '|' || *p == '&') {
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| 			memmove(p + 1, p, strlen(buf) + 1 - (p - buf));
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| 			/* Escape special character. */
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| 			*p++ = '\\';
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| 		}
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| 
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| 		p++;
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| 	}
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| 
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| 	printf("%s", buf);
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| }
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| 
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| static void __printf(2, 3)
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| print_insn_json(void *private_data, const char *fmt, ...)
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| {
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| 	unsigned int l = strlen(fmt);
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| 	char chomped_fmt[l];
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| 	va_list args;
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| 
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| 	va_start(args, fmt);
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| 	if (l > 0) {
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| 		strncpy(chomped_fmt, fmt, l - 1);
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| 		chomped_fmt[l - 1] = '\0';
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| 	}
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| 	jsonw_vprintf_enquote(json_wtr, chomped_fmt, args);
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| 	va_end(args);
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| }
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| 
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| static const char *print_call_pcrel(struct dump_data *dd,
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| 				    struct kernel_sym *sym,
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| 				    unsigned long address,
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| 				    const struct bpf_insn *insn)
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| {
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| 	if (!dd->nr_jited_ksyms)
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| 		/* Do not show address for interpreted programs */
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| 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
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| 			"%+d", insn->off);
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| 	else if (sym)
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| 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
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| 			 "%+d#%s", insn->off, sym->name);
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| 	else
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| 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
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| 			 "%+d#0x%lx", insn->off, address);
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| 	return dd->scratch_buff;
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| }
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| 
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| static const char *print_call_helper(struct dump_data *dd,
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| 				     struct kernel_sym *sym,
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| 				     unsigned long address)
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| {
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| 	if (sym)
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| 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
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| 			 "%s", sym->name);
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| 	else
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| 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
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| 			 "0x%lx", address);
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| 	return dd->scratch_buff;
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| }
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| 
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| static const char *print_call(void *private_data,
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| 			      const struct bpf_insn *insn)
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| {
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| 	struct dump_data *dd = private_data;
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| 	unsigned long address = dd->address_call_base + insn->imm;
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| 	struct kernel_sym *sym;
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| 
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| 	if (insn->src_reg == BPF_PSEUDO_CALL &&
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| 	    (__u32) insn->imm < dd->nr_jited_ksyms && dd->jited_ksyms)
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| 		address = dd->jited_ksyms[insn->imm];
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| 
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| 	sym = kernel_syms_search(dd, address);
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| 	if (insn->src_reg == BPF_PSEUDO_CALL)
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| 		return print_call_pcrel(dd, sym, address, insn);
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| 	else
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| 		return print_call_helper(dd, sym, address);
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| }
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| 
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| static const char *print_imm(void *private_data,
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| 			     const struct bpf_insn *insn,
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| 			     __u64 full_imm)
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| {
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| 	struct dump_data *dd = private_data;
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| 
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| 	if (insn->src_reg == BPF_PSEUDO_MAP_FD)
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| 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
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| 			 "map[id:%u]", insn->imm);
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| 	else if (insn->src_reg == BPF_PSEUDO_MAP_VALUE)
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| 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
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| 			 "map[id:%u][0]+%u", insn->imm, (insn + 1)->imm);
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| 	else if (insn->src_reg == BPF_PSEUDO_MAP_IDX_VALUE)
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| 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
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| 			 "map[idx:%u]+%u", insn->imm, (insn + 1)->imm);
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| 	else if (insn->src_reg == BPF_PSEUDO_FUNC)
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| 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
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| 			 "subprog[%+d]", insn->imm);
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| 	else
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| 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
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| 			 "0x%llx", (unsigned long long)full_imm);
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| 	return dd->scratch_buff;
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| }
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| 
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| void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len,
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| 		      bool opcodes, bool linum)
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| {
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| 	const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo;
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| 	const struct bpf_insn_cbs cbs = {
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| 		.cb_print	= print_insn_json,
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| 		.cb_call	= print_call,
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| 		.cb_imm		= print_imm,
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| 		.private_data	= dd,
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| 	};
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| 	struct bpf_func_info *record;
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| 	struct bpf_insn *insn = buf;
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| 	struct btf *btf = dd->btf;
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| 	bool double_insn = false;
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| 	unsigned int nr_skip = 0;
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| 	char func_sig[1024];
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| 	unsigned int i;
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| 
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| 	jsonw_start_array(json_wtr);
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| 	record = dd->func_info;
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| 	for (i = 0; i < len / sizeof(*insn); i++) {
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| 		if (double_insn) {
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| 			double_insn = false;
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| 			continue;
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| 		}
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| 		double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
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| 
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| 		jsonw_start_object(json_wtr);
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| 
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| 		if (btf && record) {
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| 			if (record->insn_off == i) {
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| 				btf_dumper_type_only(btf, record->type_id,
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| 						     func_sig,
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| 						     sizeof(func_sig));
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| 				if (func_sig[0] != '\0') {
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| 					jsonw_name(json_wtr, "proto");
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| 					jsonw_string(json_wtr, func_sig);
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| 				}
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| 				record = (void *)record + dd->finfo_rec_size;
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| 			}
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| 		}
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| 
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| 		if (prog_linfo) {
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| 			const struct bpf_line_info *linfo;
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| 
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| 			linfo = bpf_prog_linfo__lfind(prog_linfo, i, nr_skip);
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| 			if (linfo) {
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| 				btf_dump_linfo_json(btf, linfo, linum);
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| 				nr_skip++;
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| 			}
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| 		}
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| 
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| 		jsonw_name(json_wtr, "disasm");
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| 		print_bpf_insn(&cbs, insn + i, true);
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| 
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| 		if (opcodes) {
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| 			jsonw_name(json_wtr, "opcodes");
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| 			jsonw_start_object(json_wtr);
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| 
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| 			jsonw_name(json_wtr, "code");
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| 			jsonw_printf(json_wtr, "\"0x%02hhx\"", insn[i].code);
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| 
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| 			jsonw_name(json_wtr, "src_reg");
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| 			jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].src_reg);
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| 
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| 			jsonw_name(json_wtr, "dst_reg");
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| 			jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].dst_reg);
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| 
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| 			jsonw_name(json_wtr, "off");
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| 			print_hex_data_json((uint8_t *)(&insn[i].off), 2);
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| 
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| 			jsonw_name(json_wtr, "imm");
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| 			if (double_insn && i < len - 1)
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| 				print_hex_data_json((uint8_t *)(&insn[i].imm),
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| 						    12);
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| 			else
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| 				print_hex_data_json((uint8_t *)(&insn[i].imm),
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| 						    4);
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| 			jsonw_end_object(json_wtr);
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| 		}
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| 		jsonw_end_object(json_wtr);
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| 	}
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| 	jsonw_end_array(json_wtr);
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| }
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| 
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| void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len,
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| 		       bool opcodes, bool linum)
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| {
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| 	const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo;
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| 	const struct bpf_insn_cbs cbs = {
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| 		.cb_print	= print_insn,
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| 		.cb_call	= print_call,
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| 		.cb_imm		= print_imm,
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| 		.private_data	= dd,
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| 	};
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| 	struct bpf_func_info *record;
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| 	struct bpf_insn *insn = buf;
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| 	struct btf *btf = dd->btf;
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| 	unsigned int nr_skip = 0;
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| 	bool double_insn = false;
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| 	char func_sig[1024];
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| 	unsigned int i;
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| 
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| 	record = dd->func_info;
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| 	for (i = 0; i < len / sizeof(*insn); i++) {
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| 		if (double_insn) {
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| 			double_insn = false;
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| 			continue;
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| 		}
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| 
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| 		if (btf && record) {
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| 			if (record->insn_off == i) {
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| 				btf_dumper_type_only(btf, record->type_id,
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| 						     func_sig,
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| 						     sizeof(func_sig));
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| 				if (func_sig[0] != '\0')
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| 					printf("%s:\n", func_sig);
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| 				record = (void *)record + dd->finfo_rec_size;
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| 			}
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| 		}
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| 
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| 		if (prog_linfo) {
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| 			const struct bpf_line_info *linfo;
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| 
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| 			linfo = bpf_prog_linfo__lfind(prog_linfo, i, nr_skip);
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| 			if (linfo) {
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| 				btf_dump_linfo_plain(btf, linfo, "; ",
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| 						     linum);
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| 				nr_skip++;
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| 			}
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| 		}
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| 
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| 		double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
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| 
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| 		printf("%4u: ", i);
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| 		print_bpf_insn(&cbs, insn + i, true);
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| 
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| 		if (opcodes) {
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| 			printf("       ");
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| 			fprint_hex(stdout, insn + i, 8, " ");
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| 			if (double_insn && i < len - 1) {
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| 				printf(" ");
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| 				fprint_hex(stdout, insn + i + 1, 8, " ");
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| 			}
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| 			printf("\n");
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| 		}
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| 	}
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| }
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| 
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| void dump_xlated_for_graph(struct dump_data *dd, void *buf_start, void *buf_end,
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| 			   unsigned int start_idx,
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| 			   bool opcodes, bool linum)
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| {
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| 	const struct bpf_insn_cbs cbs = {
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| 		.cb_print	= print_insn_for_graph,
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| 		.cb_call	= print_call,
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| 		.cb_imm		= print_imm,
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| 		.private_data	= dd,
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| 	};
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| 	const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo;
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| 	const struct bpf_line_info *last_linfo = NULL;
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| 	struct bpf_func_info *record = dd->func_info;
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| 	struct bpf_insn *insn_start = buf_start;
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| 	struct bpf_insn *insn_end = buf_end;
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| 	struct bpf_insn *cur = insn_start;
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| 	struct btf *btf = dd->btf;
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| 	bool double_insn = false;
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| 	char func_sig[1024];
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| 
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| 	for (; cur <= insn_end; cur++) {
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| 		unsigned int insn_off;
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| 
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| 		if (double_insn) {
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| 			double_insn = false;
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| 			continue;
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| 		}
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| 		double_insn = cur->code == (BPF_LD | BPF_IMM | BPF_DW);
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| 
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| 		insn_off = (unsigned int)(cur - insn_start + start_idx);
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| 		if (btf && record) {
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| 			if (record->insn_off == insn_off) {
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| 				btf_dumper_type_only(btf, record->type_id,
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| 						     func_sig,
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| 						     sizeof(func_sig));
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| 				if (func_sig[0] != '\0')
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| 					printf("; %s:\\l\\\n", func_sig);
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| 				record = (void *)record + dd->finfo_rec_size;
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| 			}
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| 		}
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| 
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| 		if (prog_linfo) {
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| 			const struct bpf_line_info *linfo;
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| 
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| 			linfo = bpf_prog_linfo__lfind(prog_linfo, insn_off, 0);
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| 			if (linfo && linfo != last_linfo) {
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| 				btf_dump_linfo_dotlabel(btf, linfo, linum);
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| 				last_linfo = linfo;
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| 			}
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| 		}
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| 
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| 		printf("%u: ", insn_off);
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| 		print_bpf_insn(&cbs, cur, true);
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| 
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| 		if (opcodes) {
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| 			printf("\\ \\ \\ \\ ");
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| 			fprint_hex(stdout, cur, 8, " ");
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| 			if (double_insn && cur <= insn_end - 1) {
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| 				printf(" ");
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| 				fprint_hex(stdout, cur + 1, 8, " ");
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| 			}
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| 			printf("\\l\\\n");
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| 		}
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| 
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| 		if (cur != insn_end)
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| 			printf("| ");
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| 	}
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| }
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