[PATCH 10/10] tools, perf: Add asprintf replacement

[Andi Kleen]

From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

asprintf corrupts memory on some older glibc versions.
Provide a replacement. This fixes various segfaults
with --branch-history on older Fedoras.

v2: Remove bogus hunk.
    Support arbitrary size (Geert Uytterhoeven)
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
 tools/perf/Makefile.perf    |  1 +
 tools/perf/builtin-report.c |  1 +
 tools/perf/util/asprintf.c  | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 36 insertions(+)
 create mode 100644 tools/perf/util/asprintf.c

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index aecf61dc..9db4ff1 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -395,6 +395,7 @@ LIB_OBJS += $(OUTPUT)util/vdso.o
 LIB_OBJS += $(OUTPUT)util/stat.o
 LIB_OBJS += $(OUTPUT)util/record.o
 LIB_OBJS += $(OUTPUT)util/srcline.o
+LIB_OBJS += $(OUTPUT)util/asprintf.o
 LIB_OBJS += $(OUTPUT)util/data.o
 LIB_OBJS += $(OUTPUT)util/tsc.o
 LIB_OBJS += $(OUTPUT)util/cloexec.o
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index fb272ff..493f011 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -762,6 +762,7 @@ repeat:
 	}
 	if (branch_call_mode) {
 		callchain_param.branch_callstack = 1;
+		callchain_param.key = CCKEY_ADDRESS;
 		symbol_conf.use_callchain = true;
 		callchain_register_param(&callchain_param);
 		if (sort_order == NULL)
diff --git a/tools/perf/util/asprintf.c b/tools/perf/util/asprintf.c
new file mode 100644
index 0000000..6177ee8
--- /dev/null
+++ b/tools/perf/util/asprintf.c
@@ -0,0 +1,34 @@
+/* Replacement for asprintf as it's buggy in older glibc versions */
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+
+int vasprintf(char **str, const char *fmt, va_list ap)
+{
+	va_list ao;
+	char buf[1024];
+	int len;
+
+	va_copy(ao, ap);
+	len = vsnprintf(buf, sizeof(buf), fmt, ap);
+	*str = malloc(len + 1);
+	if (!*str)
+		return -1;
+	if ((size_t)len < sizeof(buf)) {
+		strcpy(*str, buf);
+		return len;
+	}
+	return vsnprintf(*str, len + 1, fmt, ao);
+}
+
+int asprintf(char **str, const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, fmt);
+	ret = vasprintf(str, fmt, ap);
+	va_end(ap);
+	return ret;
+}
-- 
1.9.3

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