From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ingo Molnar <mingo@kernel.org>, Thomas Gleixner <tglx@linutronix.de>
Cc: Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
Clark Williams <williams@redhat.com>,
linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
Masami Hiramatsu <mhiramat@kernel.org>,
Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Tom Zanussi <tom.zanussi@linux.intel.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: [PATCH 23/25] perf probe: Support DW_AT_const_value constant value
Date: Tue, 19 Nov 2019 08:32:43 -0300 [thread overview]
Message-ID: <20191119113245.19593-24-acme@kernel.org> (raw)
In-Reply-To: <20191119113245.19593-1-acme@kernel.org>
From: Masami Hiramatsu <mhiramat@kernel.org>
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>
---
tools/perf/util/probe-file.c | 7 +++++++
tools/perf/util/probe-file.h | 1 +
tools/perf/util/probe-finder.c | 11 +++++++++++
3 files changed, 19 insertions(+)
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index a63f1a19b0e8..5003ba403345 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -1008,6 +1008,7 @@ enum ftrace_readme {
FTRACE_README_UPROBE_REF_CTR,
FTRACE_README_USER_ACCESS,
FTRACE_README_MULTIPROBE_EVENT,
+ FTRACE_README_IMMEDIATE_VALUE,
FTRACE_README_END,
};
@@ -1022,6 +1023,7 @@ static struct {
DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*[u]<offset>*"),
DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"),
+ DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"),
};
static bool scan_ftrace_readme(enum ftrace_readme type)
@@ -1092,3 +1094,8 @@ bool multiprobe_event_is_supported(void)
{
return scan_ftrace_readme(FTRACE_README_MULTIPROBE_EVENT);
}
+
+bool immediate_value_is_supported(void)
+{
+ return scan_ftrace_readme(FTRACE_README_IMMEDIATE_VALUE);
+}
diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h
index 850d1b52d60a..0dba88c0f5f0 100644
--- a/tools/perf/util/probe-file.h
+++ b/tools/perf/util/probe-file.h
@@ -72,6 +72,7 @@ bool kretprobe_offset_is_supported(void);
bool uprobe_ref_ctr_is_supported(void);
bool user_access_is_supported(void);
bool multiprobe_event_is_supported(void);
+bool immediate_value_is_supported(void);
#else /* ! HAVE_LIBELF_SUPPORT */
static inline struct probe_cache *probe_cache__new(const char *tgt __maybe_unused, struct nsinfo *nsi __maybe_unused)
{
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 ? */
--
2.21.0
next prev parent reply other threads:[~2019-11-19 11:34 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-19 11:32 [GIT PULL] perf/core improvements and fixes Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 01/25] perf vendor events arm64: Fix commas so PMU event files are valid JSON Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 02/25] perf vendor events power8: " Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 03/25] perf vendor events power9: " Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 04/25] perf scripts python: exported-sql-viewer.py: Fix use of TRUE with SQLite Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 05/25] perf maps: Purge the entries from maps->names in __maps__purge() Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 06/25] perf maps: Do not use an rbtree to sort by map name Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 07/25] perf map_groups: Add a front end cache for map lookups by name Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 08/25] perf map: No need to adjust the long name of modules Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 09/25] perf record: No need to process the synthesized MMAP events twice Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 10/25] perf machine: No need to check if kernel module maps pre-exist Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 11/25] perf map_groups: Auto sort maps by name, if needed Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 12/25] perf callchain: Fix segfault in thread__resolve_callchain_sample() Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 13/25] libtraceevent: Fix parsing of event %o and %X argument types Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 14/25] perf map: Use bitmap for booleans Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 15/25] perf map: Move seldom used ->flags field to second cacheline Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 16/25] x86/insn: perf tools: Add some instructions to the new instructions test Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 17/25] x86/insn: Add some Intel instructions to the opcode map Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 18/25] perf probe: Show correct statement line number by perf probe -l Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 19/25] perf probe: Verify given line is a representive line Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 20/25] perf probe: Do not show non representive lines by perf-probe -L Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 21/25] perf probe: Generate event name with line number Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 22/25] perf probe: Support multiprobe event Arnaldo Carvalho de Melo
2019-11-19 11:32 ` Arnaldo Carvalho de Melo [this message]
2019-11-19 11:32 ` [PATCH 24/25] perf probe: Trace a magic number if variable is not found Arnaldo Carvalho de Melo
2019-11-19 11:32 ` [PATCH 25/25] perf parse: Report initial event parsing error Arnaldo Carvalho de Melo
2019-11-19 12:00 ` [GIT PULL] perf/core improvements and fixes Ingo Molnar
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