在 2016/5/10 18:34, Adrian Hunter 写道:
On 10/05/16 12:49, Hekuang wrote:
hi
在 2016/5/10 16:08, Adrian Hunter 写道:
On 10/05/16 10:40, He Kuang wrote:
32-bit programs can be run on 64-bit machines, so we should choose
unwind methods according to 'thread->map' instead of the host
architecture.
This patch adds methods to test whether a dso is 64-bit or 32-bit by
the class info in elf.
What about using dso->is_64_bit set by dso__load_sym() ?
I've noticed this variable, but it's value is not as its name said:
util/dso.c: 1067 dso->is_64_bit = (sizeof(void *) == 8);
That is just initialization i.e. before we know what it is we assume it is
the same as the host.
This is only related to the host architecture.
A closer one is 'is_64_bit' in 'struct symsrc', but the value is assigned
after dso
loaded. So I think we should provide individual methods to get that value.
Are you saying you don't load dsos? Or that is_64_bit is set incorrectly?
Yes, I know it's the inital value, but the correct value is
assigned in function dso__load_sym(), and have a look at the call
stack(gdb):
#0 dso__load_sym
#1 in dso__load
#2 in map__load
#3 in map__find_symbol
#4 in thread__find_addr_location
#5 in entry
#6 in get_entries
#7 in _Ux86__unwind__get_entries
#8 in thread__resolve_callchain
I think we should choose the right unwind method before
dso__load_sym(). i.e. line#7, which is called before dso__load_sym().
I'm not very familiar with this, what's your opinion?
Thanks.
Thanks.
Signed-off-by: He Kuang <heku...@huawei.com>
---
tools/perf/util/symbol-elf.c | 16 +++++++++++++++
tools/perf/util/symbol.c | 49
++++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/symbol.h | 2 ++
3 files changed, 67 insertions(+)
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 3f9d679..9f290b9 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -636,6 +636,22 @@ bool __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr)
return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL;
}
+int elf_is_64_bit(char *name)
+{
+ Elf *elf;
+ int fd;
+
+ fd = open(name, O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (elf == NULL)
+ return -1;
+
+ return (gelf_getclass(elf) == ELFCLASS64);
+}
+
int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
enum dso_binary_type type)
{
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 4630751..592bf8c 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1395,6 +1395,55 @@ static bool dso__is_compatible_symtab_type(struct
dso *dso, bool kmod,
}
}
+int dso_is_64_bit(struct dso *dso, struct map *map)
+{
+ char *name;
+ u_int i;
+ bool kmod;
+ char *root_dir = (char *) "";
+ struct machine *machine;
+
+ if (map->groups && map->groups->machine)
+ machine = map->groups->machine;
+ else
+ machine = NULL;
+
+ if (machine)
+ root_dir = machine->root_dir;
+
+ name = malloc(PATH_MAX);
+ if (!name)
+ return -1;
+
+ kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
+ dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
+ dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
+ dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
+
+ /*
+ * Iterate over candidate debug images.
+ * Keep track of "interesting" ones (those which have a symtab, dynsym,
+ * and/or opd section) for processing.
+ */
+ for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
+ enum dso_binary_type symtab_type = binary_type_symtab[i];
+
+ if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
+ continue;
+
+ if (dso__read_binary_type_filename(dso, symtab_type,
+ root_dir, name, PATH_MAX))
+ continue;
+
+ if (!is_regular_file(name))
+ continue;
+
+ return elf_is_64_bit(name);
+ }
+
+ return -1;
+}
+
int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
{
char *name;
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 4e6910e..d33fbf4 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -308,6 +308,8 @@ int setup_list(struct strlist **list, const char
*list_str,
const char *list_name);
int setup_intlist(struct intlist **list, const char *list_str,
const char *list_name);
+int elf_is_64_bit(char *name);
+int dso_is_64_bit(struct dso *dso, struct map *map);
#ifdef HAVE_LIBELF_SUPPORT
bool elf__needs_adjust_symbols(GElf_Ehdr ehdr);
