[RFC PATCH 4/8] perf probe powerpc: Handle powerpc dot symbols

[Naveen N. Rao]

Fix up various perf aspects related to ppc64's usage of dot functions:
- ignore leading '.' when generating event names and when looking for
  existing events.
- use the proper prefix when ignoring SyS symbol lookups.

Signed-off-by: Naveen N. Rao <naveen.n.rao at linux.vnet.ibm.com>
---
 tools/perf/util/probe-event.c | 8 ++++++++
 tools/perf/util/symbol.c      | 6 ++++++
 2 files changed, 14 insertions(+)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index c7e01ef..d465f7c 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2080,6 +2080,10 @@ static int get_new_event_name(char *buf, size_t len, const char *base,
 {
 	int i, ret;
 
+	/* Skip the leading dot on powerpc */
+	if (*base == '.')
+		base++;
+
 	/* Try no suffix */
 	ret = e_snprintf(buf, len, "%s", base);
 	if (ret < 0) {
@@ -2538,6 +2542,10 @@ int del_perf_probe_events(struct strlist *dellist)
 			event = str;
 		}
 
+		/* Skip the leading dot on powerpc */
+		if (event && *event == '.')
+			event++;
+
 		ret = e_snprintf(buf, 128, "%s:%s", group, event);
 		if (ret < 0) {
 			pr_err("Failed to copy event.");
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 0783311..cc04475 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -137,6 +137,12 @@ static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
 	if (na >= 10 && !strncmp(syma->name, "compat_SyS", 10))
 		return SYMBOL_B;
 
+	/* On powerpc, ignore the dot variants */
+	if (na >= 4 && !strncmp(syma->name, ".SyS", 4))
+		return SYMBOL_B;
+	if (na >= 11 && !strncmp(syma->name, ".compat_SyS", 11))
+		return SYMBOL_B;
+
 	return SYMBOL_A;
 }
 
-- 
2.1.3