2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License, version 2, as
4 * published by the Free Software Foundation.
6 * Copyright (C) 2015 Naveen N. Rao, IBM Corporation
12 #include "probe-event.h"
13 #include "probe-file.h"
15 #ifdef HAVE_LIBELF_SUPPORT
16 bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
18 return ehdr.e_type == ET_EXEC ||
19 ehdr.e_type == ET_REL ||
20 ehdr.e_type == ET_DYN;
25 #if !defined(_CALL_ELF) || _CALL_ELF != 2
26 int arch__choose_best_symbol(struct symbol *syma,
27 struct symbol *symb __maybe_unused)
29 char *sym = syma->name;
31 /* Skip over any initial dot */
35 /* Avoid "SyS" kernel syscall aliases */
36 if (strlen(sym) >= 3 && !strncmp(sym, "SyS", 3))
38 if (strlen(sym) >= 10 && !strncmp(sym, "compat_SyS", 10))
44 /* Allow matching against dot variants */
45 int arch__compare_symbol_names(const char *namea, const char *nameb)
47 /* Skip over initial dot */
53 return strcmp(namea, nameb);
56 int arch__compare_symbol_names_n(const char *namea, const char *nameb,
59 /* Skip over initial dot */
65 return strncmp(namea, nameb, n);
68 const char *arch__normalize_symbol_name(const char *name)
70 /* Skip over initial dot */
71 if (name && *name == '.')
77 #if defined(_CALL_ELF) && _CALL_ELF == 2
79 #ifdef HAVE_LIBELF_SUPPORT
80 void arch__sym_update(struct symbol *s, GElf_Sym *sym)
82 s->arch_sym = sym->st_other;
86 #define PPC64LE_LEP_OFFSET 8
88 void arch__fix_tev_from_maps(struct perf_probe_event *pev,
89 struct probe_trace_event *tev, struct map *map,
95 * When probing at a function entry point, we normally always want the
96 * LEP since that catches calls to the function through both the GEP and
97 * the LEP. Hence, we would like to probe at an offset of 8 bytes if
98 * the user only specified the function entry.
100 * However, if the user specifies an offset, we fall back to using the
101 * GEP since all userspace applications (objdump/readelf) show function
102 * disassembly with offsets from the GEP.
104 if (pev->point.offset || !map || !sym)
107 /* For kretprobes, add an offset only if the kernel supports it */
108 if (!pev->uprobes && pev->point.retprobe) {
109 #ifdef HAVE_LIBELF_SUPPORT
110 if (!kretprobe_offset_is_supported())
115 lep_offset = PPC64_LOCAL_ENTRY_OFFSET(sym->arch_sym);
117 if (map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS)
118 tev->point.offset += PPC64LE_LEP_OFFSET;
119 else if (lep_offset) {
121 tev->point.address += lep_offset;
123 tev->point.offset += lep_offset;
127 #ifdef HAVE_LIBELF_SUPPORT
128 void arch__post_process_probe_trace_events(struct perf_probe_event *pev,
131 struct probe_trace_event *tev;
133 struct symbol *sym = NULL;
137 map = get_target_map(pev->target, pev->nsi, pev->uprobes);
138 if (!map || map__load(map) < 0)
141 for (i = 0; i < ntevs; i++) {
143 map__for_each_symbol(map, sym, tmp) {
144 if (map->unmap_ip(map, sym->start) == tev->point.address) {
145 arch__fix_tev_from_maps(pev, tev, map, sym);
151 #endif /* HAVE_LIBELF_SUPPORT */