Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Naveen N. Rao | d233209 | 2015-04-28 17:35:35 +0530 | [diff] [blame] | 2 | /* |
Naveen N. Rao | d233209 | 2015-04-28 17:35:35 +0530 | [diff] [blame] | 3 | * |
| 4 | * Copyright (C) 2015 Naveen N. Rao, IBM Corporation |
| 5 | */ |
| 6 | |
| 7 | #include "debug.h" |
| 8 | #include "symbol.h" |
Naveen N. Rao | 031b84c | 2015-04-28 17:35:37 +0530 | [diff] [blame] | 9 | #include "map.h" |
Naveen N. Rao | d5c2e2c | 2015-04-28 17:35:39 +0530 | [diff] [blame] | 10 | #include "probe-event.h" |
Naveen N. Rao | 44ca934 | 2017-03-08 13:56:10 +0530 | [diff] [blame] | 11 | #include "probe-file.h" |
Naveen N. Rao | d233209 | 2015-04-28 17:35:35 +0530 | [diff] [blame] | 12 | |
| 13 | #ifdef HAVE_LIBELF_SUPPORT |
| 14 | bool elf__needs_adjust_symbols(GElf_Ehdr ehdr) |
| 15 | { |
| 16 | return ehdr.e_type == ET_EXEC || |
| 17 | ehdr.e_type == ET_REL || |
| 18 | ehdr.e_type == ET_DYN; |
| 19 | } |
Ananth N Mavinakayanahalli | c50fc0a | 2015-04-28 17:35:38 +0530 | [diff] [blame] | 20 | |
Naveen N. Rao | d233209 | 2015-04-28 17:35:35 +0530 | [diff] [blame] | 21 | #endif |
Naveen N. Rao | fb6d594 | 2015-04-28 17:35:36 +0530 | [diff] [blame] | 22 | |
Naveen N. Rao | fb6d594 | 2015-04-28 17:35:36 +0530 | [diff] [blame] | 23 | int arch__choose_best_symbol(struct symbol *syma, |
| 24 | struct symbol *symb __maybe_unused) |
| 25 | { |
| 26 | char *sym = syma->name; |
| 27 | |
Sandipan Das | fa69416 | 2018-08-28 14:38:48 +0530 | [diff] [blame] | 28 | #if !defined(_CALL_ELF) || _CALL_ELF != 2 |
Naveen N. Rao | fb6d594 | 2015-04-28 17:35:36 +0530 | [diff] [blame] | 29 | /* Skip over any initial dot */ |
| 30 | if (*sym == '.') |
| 31 | sym++; |
Sandipan Das | fa69416 | 2018-08-28 14:38:48 +0530 | [diff] [blame] | 32 | #endif |
Naveen N. Rao | fb6d594 | 2015-04-28 17:35:36 +0530 | [diff] [blame] | 33 | |
| 34 | /* Avoid "SyS" kernel syscall aliases */ |
| 35 | if (strlen(sym) >= 3 && !strncmp(sym, "SyS", 3)) |
| 36 | return SYMBOL_B; |
| 37 | if (strlen(sym) >= 10 && !strncmp(sym, "compat_SyS", 10)) |
| 38 | return SYMBOL_B; |
| 39 | |
| 40 | return SYMBOL_A; |
| 41 | } |
Naveen N. Rao | 031b84c | 2015-04-28 17:35:37 +0530 | [diff] [blame] | 42 | |
Sandipan Das | fa69416 | 2018-08-28 14:38:48 +0530 | [diff] [blame] | 43 | #if !defined(_CALL_ELF) || _CALL_ELF != 2 |
Naveen N. Rao | 031b84c | 2015-04-28 17:35:37 +0530 | [diff] [blame] | 44 | /* Allow matching against dot variants */ |
| 45 | int arch__compare_symbol_names(const char *namea, const char *nameb) |
| 46 | { |
| 47 | /* Skip over initial dot */ |
| 48 | if (*namea == '.') |
| 49 | namea++; |
| 50 | if (*nameb == '.') |
| 51 | nameb++; |
| 52 | |
| 53 | return strcmp(namea, nameb); |
| 54 | } |
Paul Clarke | d8040645 | 2017-04-25 13:15:49 -0500 | [diff] [blame] | 55 | |
| 56 | int arch__compare_symbol_names_n(const char *namea, const char *nameb, |
| 57 | unsigned int n) |
| 58 | { |
| 59 | /* Skip over initial dot */ |
| 60 | if (*namea == '.') |
| 61 | namea++; |
| 62 | if (*nameb == '.') |
| 63 | nameb++; |
| 64 | |
| 65 | return strncmp(namea, nameb, n); |
| 66 | } |
Masami Hiramatsu | 4b3a271 | 2017-12-09 01:28:12 +0900 | [diff] [blame] | 67 | |
| 68 | const char *arch__normalize_symbol_name(const char *name) |
| 69 | { |
| 70 | /* Skip over initial dot */ |
| 71 | if (name && *name == '.') |
| 72 | name++; |
| 73 | return name; |
| 74 | } |
Naveen N. Rao | fb6d594 | 2015-04-28 17:35:36 +0530 | [diff] [blame] | 75 | #endif |
Naveen N. Rao | d5c2e2c | 2015-04-28 17:35:39 +0530 | [diff] [blame] | 76 | |
| 77 | #if defined(_CALL_ELF) && _CALL_ELF == 2 |
Naveen N. Rao | 7b6ff0b | 2015-04-28 17:35:40 +0530 | [diff] [blame] | 78 | |
Naveen N. Rao | 0b3c226 | 2016-04-12 14:40:50 +0530 | [diff] [blame] | 79 | #ifdef HAVE_LIBELF_SUPPORT |
| 80 | void arch__sym_update(struct symbol *s, GElf_Sym *sym) |
| 81 | { |
| 82 | s->arch_sym = sym->st_other; |
| 83 | } |
| 84 | #endif |
| 85 | |
Naveen N. Rao | 7b6ff0b | 2015-04-28 17:35:40 +0530 | [diff] [blame] | 86 | #define PPC64LE_LEP_OFFSET 8 |
| 87 | |
| 88 | void arch__fix_tev_from_maps(struct perf_probe_event *pev, |
Naveen N. Rao | 0b3c226 | 2016-04-12 14:40:50 +0530 | [diff] [blame] | 89 | struct probe_trace_event *tev, struct map *map, |
| 90 | struct symbol *sym) |
Naveen N. Rao | 7b6ff0b | 2015-04-28 17:35:40 +0530 | [diff] [blame] | 91 | { |
Naveen N. Rao | 0b3c226 | 2016-04-12 14:40:50 +0530 | [diff] [blame] | 92 | int lep_offset; |
| 93 | |
Naveen N. Rao | 7b6ff0b | 2015-04-28 17:35:40 +0530 | [diff] [blame] | 94 | /* |
Naveen N. Rao | 239aeba | 2016-04-12 14:40:49 +0530 | [diff] [blame] | 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. |
| 99 | * |
| 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. |
Naveen N. Rao | 7b6ff0b | 2015-04-28 17:35:40 +0530 | [diff] [blame] | 103 | */ |
Naveen N. Rao | 44ca934 | 2017-03-08 13:56:10 +0530 | [diff] [blame] | 104 | if (pev->point.offset || !map || !sym) |
Naveen N. Rao | 239aeba | 2016-04-12 14:40:49 +0530 | [diff] [blame] | 105 | return; |
| 106 | |
Naveen N. Rao | 44ca934 | 2017-03-08 13:56:10 +0530 | [diff] [blame] | 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()) |
| 111 | #endif |
| 112 | return; |
| 113 | } |
| 114 | |
Naveen N. Rao | 0b3c226 | 2016-04-12 14:40:50 +0530 | [diff] [blame] | 115 | lep_offset = PPC64_LOCAL_ENTRY_OFFSET(sym->arch_sym); |
| 116 | |
Naveen N. Rao | 239aeba | 2016-04-12 14:40:49 +0530 | [diff] [blame] | 117 | if (map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS) |
Naveen N. Rao | 7b6ff0b | 2015-04-28 17:35:40 +0530 | [diff] [blame] | 118 | tev->point.offset += PPC64LE_LEP_OFFSET; |
Naveen N. Rao | 0b3c226 | 2016-04-12 14:40:50 +0530 | [diff] [blame] | 119 | else if (lep_offset) { |
| 120 | if (pev->uprobes) |
| 121 | tev->point.address += lep_offset; |
| 122 | else |
| 123 | tev->point.offset += lep_offset; |
| 124 | } |
Naveen N. Rao | 7b6ff0b | 2015-04-28 17:35:40 +0530 | [diff] [blame] | 125 | } |
Ravi Bangoria | 99e608b | 2016-08-09 01:23:25 -0500 | [diff] [blame] | 126 | |
Ravi Bangoria | f046f3d | 2016-08-11 14:43:59 -0300 | [diff] [blame] | 127 | #ifdef HAVE_LIBELF_SUPPORT |
Ravi Bangoria | 99e608b | 2016-08-09 01:23:25 -0500 | [diff] [blame] | 128 | void arch__post_process_probe_trace_events(struct perf_probe_event *pev, |
| 129 | int ntevs) |
| 130 | { |
| 131 | struct probe_trace_event *tev; |
| 132 | struct map *map; |
| 133 | struct symbol *sym = NULL; |
| 134 | struct rb_node *tmp; |
| 135 | int i = 0; |
| 136 | |
Krister Johansen | 544abd4 | 2017-07-05 18:48:10 -0700 | [diff] [blame] | 137 | map = get_target_map(pev->target, pev->nsi, pev->uprobes); |
Arnaldo Carvalho de Melo | be39db9 | 2016-09-01 19:25:52 -0300 | [diff] [blame] | 138 | if (!map || map__load(map) < 0) |
Ravi Bangoria | 99e608b | 2016-08-09 01:23:25 -0500 | [diff] [blame] | 139 | return; |
| 140 | |
| 141 | for (i = 0; i < ntevs; i++) { |
| 142 | tev = &pev->tevs[i]; |
| 143 | map__for_each_symbol(map, sym, tmp) { |
Sandipan Das | 354b064 | 2018-08-09 21:49:29 +0530 | [diff] [blame] | 144 | if (map->unmap_ip(map, sym->start) == tev->point.address) { |
Ravi Bangoria | 99e608b | 2016-08-09 01:23:25 -0500 | [diff] [blame] | 145 | arch__fix_tev_from_maps(pev, tev, map, sym); |
Sandipan Das | 354b064 | 2018-08-09 21:49:29 +0530 | [diff] [blame] | 146 | break; |
| 147 | } |
Ravi Bangoria | 99e608b | 2016-08-09 01:23:25 -0500 | [diff] [blame] | 148 | } |
| 149 | } |
| 150 | } |
Ravi Bangoria | f046f3d | 2016-08-11 14:43:59 -0300 | [diff] [blame] | 151 | #endif /* HAVE_LIBELF_SUPPORT */ |
Ravi Bangoria | 99e608b | 2016-08-09 01:23:25 -0500 | [diff] [blame] | 152 | |
Naveen N. Rao | d5c2e2c | 2015-04-28 17:35:39 +0530 | [diff] [blame] | 153 | #endif |