linux/tools/perf/arch/powerpc/util/sym-handling.c
Naveen N. Rao 7b6ff0bdbf perf probe ppc64le: Fixup function entry if using kallsyms lookup
On powerpc ABIv2, if no debug-info is found and we use kallsyms, we need
to fixup the function entry to point to the local entry point. Use
offset of 8 since current toolchains always generate 2 instructions (8
bytes).

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/92253021e77a104b23b615c8c23bf9501dfe60bf.1430217967.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-05-04 12:43:47 -03:00

83 lines
1.8 KiB
C

/*
* 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;
}
#if defined(_CALL_ELF) && _CALL_ELF == 2
void arch__elf_sym_adjust(GElf_Sym *sym)
{
sym->st_value += PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
}
#endif
#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
bool arch__prefers_symtab(void)
{
return true;
}
#define PPC64LE_LEP_OFFSET 8
void arch__fix_tev_from_maps(struct perf_probe_event *pev,
struct probe_trace_event *tev, struct map *map)
{
/*
* ppc64 ABIv2 local entry point is currently always 2 instructions
* (8 bytes) after the global entry point.
*/
if (!pev->uprobes && map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS) {
tev->point.address += PPC64LE_LEP_OFFSET;
tev->point.offset += PPC64LE_LEP_OFFSET;
}
}
#endif