144 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			144 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
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/*
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 *
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 * Copyright (C) 2015 Naveen N. Rao, IBM Corporation
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 */
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#include "dso.h"
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#include "symbol.h"
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#include "map.h"
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#include "probe-event.h"
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#include "probe-file.h"
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int arch__choose_best_symbol(struct symbol *syma,
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			     struct symbol *symb __maybe_unused)
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{
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	char *sym = syma->name;
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#if !defined(_CALL_ELF) || _CALL_ELF != 2
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	/* Skip over any initial dot */
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	if (*sym == '.')
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		sym++;
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#endif
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	/* Avoid "SyS" kernel syscall aliases */
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	if (strlen(sym) >= 3 && !strncmp(sym, "SyS", 3))
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		return SYMBOL_B;
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	if (strlen(sym) >= 10 && !strncmp(sym, "compat_SyS", 10))
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		return SYMBOL_B;
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	return SYMBOL_A;
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}
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#if !defined(_CALL_ELF) || _CALL_ELF != 2
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/* Allow matching against dot variants */
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int arch__compare_symbol_names(const char *namea, const char *nameb)
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{
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	/* Skip over initial dot */
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	if (*namea == '.')
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		namea++;
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	if (*nameb == '.')
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		nameb++;
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	return strcmp(namea, nameb);
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}
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int arch__compare_symbol_names_n(const char *namea, const char *nameb,
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				 unsigned int n)
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{
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	/* Skip over initial dot */
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	if (*namea == '.')
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		namea++;
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	if (*nameb == '.')
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		nameb++;
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	return strncmp(namea, nameb, n);
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}
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const char *arch__normalize_symbol_name(const char *name)
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{
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	/* Skip over initial dot */
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	if (name && *name == '.')
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		name++;
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	return name;
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}
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#endif
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#if defined(_CALL_ELF) && _CALL_ELF == 2
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#ifdef HAVE_LIBELF_SUPPORT
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void arch__sym_update(struct symbol *s, GElf_Sym *sym)
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{
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	s->arch_sym = sym->st_other;
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}
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#endif
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#define PPC64LE_LEP_OFFSET	8
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void arch__fix_tev_from_maps(struct perf_probe_event *pev,
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			     struct probe_trace_event *tev, struct map *map,
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			     struct symbol *sym)
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{
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	int lep_offset;
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	/*
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	 * When probing at a function entry point, we normally always want the
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	 * LEP since that catches calls to the function through both the GEP and
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	 * the LEP. Hence, we would like to probe at an offset of 8 bytes if
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	 * the user only specified the function entry.
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	 *
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	 * However, if the user specifies an offset, we fall back to using the
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	 * GEP since all userspace applications (objdump/readelf) show function
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	 * disassembly with offsets from the GEP.
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	 */
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	if (pev->point.offset || !map || !sym)
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		return;
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	/* For kretprobes, add an offset only if the kernel supports it */
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	if (!pev->uprobes && pev->point.retprobe) {
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#ifdef HAVE_LIBELF_SUPPORT
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		if (!kretprobe_offset_is_supported())
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#endif
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			return;
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	}
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	lep_offset = PPC64_LOCAL_ENTRY_OFFSET(sym->arch_sym);
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	if (map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS)
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		tev->point.offset += PPC64LE_LEP_OFFSET;
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	else if (lep_offset) {
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		if (pev->uprobes)
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			tev->point.address += lep_offset;
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		else
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			tev->point.offset += lep_offset;
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	}
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}
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#ifdef HAVE_LIBELF_SUPPORT
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void arch__post_process_probe_trace_events(struct perf_probe_event *pev,
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					   int ntevs)
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{
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	struct probe_trace_event *tev;
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	struct map *map;
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	struct symbol *sym = NULL;
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	struct rb_node *tmp;
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	int i = 0;
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	map = get_target_map(pev->target, pev->nsi, pev->uprobes);
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	if (!map || map__load(map) < 0)
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		return;
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	for (i = 0; i < ntevs; i++) {
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		tev = &pev->tevs[i];
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		map__for_each_symbol(map, sym, tmp) {
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			if (map->unmap_ip(map, sym->start) == tev->point.address) {
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				arch__fix_tev_from_maps(pev, tev, map, sym);
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				break;
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			}
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		}
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	}
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}
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#endif /* HAVE_LIBELF_SUPPORT */
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#endif
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