perf symbols: Record whether a dso is 64-bit

Add a flag to 'struct dso' to record if the dso is 64-bit or not.
Update the flag when reading the ELF.

This is needed for instruction decoding.  For example, x86 instruction
decoding depends on whether or not the 64-bit instruction set is used.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1405332185-4050-18-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

6 files changed, 29 insertions, 0 deletions

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 819f10414f08..fc006fed8877 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -703,6 +703,7 @@ struct dso *dso__new(const char *name)
                 dso->data.fd = -1;
                 dso->symtab_type = DSO_BINARY_TYPE__NOT_FOUND;
                 dso->binary_type = DSO_BINARY_TYPE__NOT_FOUND;
+                dso->is_64_bit = (sizeof(void *) == 8);
                 dso->loaded = 0;
                 dso->rel = 0;
                 dso->sorted_by_name = 0;
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index ad553ba257bf..c239e86541a3 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -90,6 +90,7 @@ struct dso {
         u8               annotate_warned:1;
         u8               short_name_allocated:1;
         u8               long_name_allocated:1;
+        u8               is_64_bit:1;
         u8               sorted_by_name;
         u8               loaded;
         u8               rel;
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index dce5ccf61f11..cef8f426356e 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -599,6 +599,8 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
                         goto out_elf_end;
         }
 
+        ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
+
         ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
                         NULL);
         if (ss->symshdr.sh_type != SHT_SYMTAB)
@@ -699,6 +701,7 @@ int dso__load_sym(struct dso *dso, struct map *map,
         bool remap_kernel = false, adjust_kernel_syms = false;
 
         dso->symtab_type = syms_ss->type;
+        dso->is_64_bit = syms_ss->is_64_bit;
         dso->rel = syms_ss->ehdr.e_type == ET_REL;
 
         /*
diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
index bd15f490d04f..101f55d407d0 100644
--- a/tools/perf/util/symbol-minimal.c
+++ b/tools/perf/util/symbol-minimal.c
@@ -288,6 +288,23 @@ int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
         return 0;
 }
 
+static int fd__is_64_bit(int fd)
+{
+        u8 e_ident[EI_NIDENT];
+
+        if (lseek(fd, 0, SEEK_SET))
+                return -1;
+
+        if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))
+                return -1;
+
+        if (memcmp(e_ident, ELFMAG, SELFMAG) ||
+            e_ident[EI_VERSION] != EV_CURRENT)
+                return -1;
+
+        return e_ident[EI_CLASS] == ELFCLASS64;
+}
+
 int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
                   struct symsrc *ss,
                   struct symsrc *runtime_ss __maybe_unused,
@@ -295,6 +312,11 @@ int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
                   int kmodule __maybe_unused)
 {
         unsigned char *build_id[BUILD_ID_SIZE];
+        int ret;
+
+        ret = fd__is_64_bit(ss->fd);
+        if (ret >= 0)
+                dso->is_64_bit = ret;
 
         if (filename__read_build_id(ss->name, build_id, BUILD_ID_SIZE) > 0) {
                 dso__set_build_id(dso, build_id);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 2e6a2e219eb9..ae2e4464afa7 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1065,6 +1065,7 @@ static int dso__load_kcore(struct dso *dso, struct map *map,
                               &is_64_bit);
         if (err)
                 goto out_err;
+        dso->is_64_bit = is_64_bit;
 
         if (list_empty(&md.maps)) {
                 err = -EINVAL;
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index a81877b1dee0..436169dd1d84 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -216,6 +216,7 @@ struct symsrc {
         GElf_Shdr dynshdr;
 
         bool adjust_symbols;
+        bool is_64_bit;
 #endif
 };