summaryrefslogtreecommitdiff
path: root/tools/perf/util/probe-finder.c
diff options
context:
space:
mode:
authorMasami Hiramatsu <mhiramat@kernel.org>2016-08-26 01:24:57 +0900
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-09-01 12:41:09 -0300
commit293d5b43948309434568f4dcbb36cce4c3c51bd5 (patch)
tree447e6c1434553309ce9e727ef07ea30197321783 /tools/perf/util/probe-finder.c
parent428aff82e92a29da0e4276623180f9a98f2d5b16 (diff)
perf probe: Support probing on offline cross-arch binary
Support probing on offline cross-architecture binary by adding getting the target machine arch from ELF and choose correct register string for the machine. Here is an example: ----- $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params' p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16 ----- Here, we can get probe/do_sys_open from above and append it to to the target machine's tracing/kprobe_events file in the tracefs mountput, usually /sys/kernel/debug/tracing/kprobe_events (or /sys/kernel/tracing/kprobe_events). Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/147214229717.23638.6440579792548044658.stgit@devbox [ Add definition for EM_AARCH64 to fix the build on at least centos 6, debian 7 & ubuntu 12.04.5 ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/probe-finder.c')
-rw-r--r--tools/perf/util/probe-finder.c27
1 files changed, 16 insertions, 11 deletions
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index ac4740f8ee3a..508b61c6e5fb 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -171,6 +171,7 @@ static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
*/
static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
+ unsigned int machine,
struct probe_trace_arg *tvar)
{
Dwarf_Attribute attr;
@@ -266,7 +267,7 @@ static_var:
if (!tvar)
return ret2;
- regs = get_arch_regstr(regn);
+ regs = get_dwarf_regstr(regn, machine);
if (!regs) {
/* This should be a bug in DWARF or this tool */
pr_warning("Mapping for the register number %u "
@@ -543,7 +544,7 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
dwarf_diename(vr_die));
ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
- &pf->sp_die, pf->tvar);
+ &pf->sp_die, pf->machine, pf->tvar);
if (ret == -ENOENT || ret == -EINVAL) {
pr_err("Failed to find the location of the '%s' variable at this address.\n"
" Perhaps it has been optimized out.\n"
@@ -1106,11 +1107,8 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
struct probe_finder *pf)
{
int ret = 0;
-
-#if _ELFUTILS_PREREQ(0, 142)
Elf *elf;
GElf_Ehdr ehdr;
- GElf_Shdr shdr;
if (pf->cfi_eh || pf->cfi_dbg)
return debuginfo__find_probe_location(dbg, pf);
@@ -1123,11 +1121,18 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
if (gelf_getehdr(elf, &ehdr) == NULL)
return -EINVAL;
- if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
- shdr.sh_type == SHT_PROGBITS)
- pf->cfi_eh = dwarf_getcfi_elf(elf);
+ pf->machine = ehdr.e_machine;
+
+#if _ELFUTILS_PREREQ(0, 142)
+ do {
+ GElf_Shdr shdr;
+
+ if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
+ shdr.sh_type == SHT_PROGBITS)
+ pf->cfi_eh = dwarf_getcfi_elf(elf);
- pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
+ pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
+ } while (0);
#endif
ret = debuginfo__find_probe_location(dbg, pf);
@@ -1155,7 +1160,7 @@ static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
(tag == DW_TAG_variable && vf->vars)) {
if (convert_variable_location(die_mem, vf->pf->addr,
vf->pf->fb_ops, &pf->sp_die,
- NULL) == 0) {
+ pf->machine, NULL) == 0) {
vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
if (vf->args[vf->nargs].var == NULL) {
vf->ret = -ENOMEM;
@@ -1318,7 +1323,7 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
tag == DW_TAG_variable) {
ret = convert_variable_location(die_mem, af->pf.addr,
af->pf.fb_ops, &af->pf.sp_die,
- NULL);
+ af->pf.machine, NULL);
if (ret == 0 || ret == -ERANGE) {
int ret2;
bool externs = !af->child;