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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2019-11-18 17:12:40 +0900 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-11-18 19:08:02 -0300 |
| commit | 66f69b2197167cb99330c77a550da50f1f597abc (patch) | |
| tree | d804ea39d77cac08c62a62b755f8176d0e9ba771 /tools/perf/util/probe-finder.c | |
| parent | 72363540c009db5014252a1a15e149d30f88bcc3 (diff) | |
| download | lwn-66f69b2197167cb99330c77a550da50f1f597abc.tar.gz lwn-66f69b2197167cb99330c77a550da50f1f597abc.zip | |
perf probe: Support DW_AT_const_value constant value
Support DW_AT_const_value for variable assignment instead of location.
Note that this requires ftrace supporting immediate value.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Link: http://lore.kernel.org/lkml/157406476012.24476.16096289871757175775.stgit@devnote2
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.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index f12ad507a822..33e90054ad84 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -177,6 +177,17 @@ static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr, if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL) goto static_var; + /* Constant value */ + if (dwarf_attr(vr_die, DW_AT_const_value, &attr) && + immediate_value_is_supported()) { + Dwarf_Sword snum; + + dwarf_formsdata(&attr, &snum); + ret = asprintf(&tvar->value, "\\%ld", (long)snum); + + return ret < 0 ? -ENOMEM : 0; + } + /* TODO: handle more than 1 exprs */ if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL) return -EINVAL; /* Broken DIE ? */ |