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/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* Copyright (C) 2015 Naveen N. Rao, IBM Corporation
*/
#include "debug.h"
#include "symbol.h"
#include "map.h"
#include "probe-event.h"
#ifdef HAVE_LIBELF_SUPPORT
bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
{
return ehdr.e_type == ET_EXEC ||
ehdr.e_type == ET_REL ||
ehdr.e_type == ET_DYN;
}
#endif
#if !defined(_CALL_ELF) || _CALL_ELF != 2
int arch__choose_best_symbol(struct symbol *syma,
struct symbol *symb __maybe_unused)
{
char *sym = syma->name;
/* Skip over any initial dot */
if (*sym == '.')
sym++;
/* Avoid "SyS" kernel syscall aliases */
if (strlen(sym) >= 3 && !strncmp(sym, "SyS", 3))
return SYMBOL_B;
if (strlen(sym) >= 10 && !strncmp(sym, "compat_SyS", 10))
return SYMBOL_B;
return SYMBOL_A;
}
/* Allow matching against dot variants */
int arch__compare_symbol_names(const char *namea, const char *nameb)
{
/* Skip over initial dot */
if (*namea == '.')
namea++;
if (*nameb == '.')
nameb++;
return strcmp(namea, nameb);
}
#endif
#if defined(_CALL_ELF) && _CALL_ELF == 2
#ifdef HAVE_LIBELF_SUPPORT
void arch__sym_update(struct symbol *s, GElf_Sym *sym)
{
s->arch_sym = sym->st_other;
}
#endif
#define PPC64LE_LEP_OFFSET 8
void arch__fix_tev_from_maps(struct perf_probe_event *pev,
struct probe_trace_event *tev, struct map *map,
struct symbol *sym)
{
int lep_offset;
/*
* When probing at a function entry point, we normally always want the
* LEP since that catches calls to the function through both the GEP and
* the LEP. Hence, we would like to probe at an offset of 8 bytes if
* the user only specified the function entry.
*
* However, if the user specifies an offset, we fall back to using the
* GEP since all userspace applications (objdump/readelf) show function
* disassembly with offsets from the GEP.
*
* In addition, we shouldn't specify an offset for kretprobes.
*/
if (pev->point.offset || pev->point.retprobe || !map || !sym)
return;
lep_offset = PPC64_LOCAL_ENTRY_OFFSET(sym->arch_sym);
if (map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS)
tev->point.offset += PPC64LE_LEP_OFFSET;
else if (lep_offset) {
if (pev->uprobes)
tev->point.address += lep_offset;
else
tev->point.offset += lep_offset;
}
}
#ifdef HAVE_LIBELF_SUPPORT
void arch__post_process_probe_trace_events(struct perf_probe_event *pev,
int ntevs)
{
struct probe_trace_event *tev;
struct map *map;
struct symbol *sym = NULL;
struct rb_node *tmp;
int i = 0;
map = get_target_map(pev->target, pev->uprobes);
if (!map || map__load(map, NULL) < 0)
return;
for (i = 0; i < ntevs; i++) {
tev = &pev->tevs[i];
map__for_each_symbol(map, sym, tmp) {
if (map->unmap_ip(map, sym->start) == tev->point.address)
arch__fix_tev_from_maps(pev, tev, map, sym);
}
}
}
#endif /* HAVE_LIBELF_SUPPORT */
#endif
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