1 files changed, 95 insertions, 59 deletions

diff --git a/tools/perf/util/strbuf.c b/tools/perf/util/strbuf.c
index cfa906882e2c..a64a37628f12 100644
--- a/tools/perf/util/strbuf.c
+++ b/tools/perf/util/strbuf.c
@@ -1,14 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "cache.h"
+#include "debug.h"
+#include "strbuf.h"
 #include <linux/kernel.h>
-
-int prefixcmp(const char *str, const char *prefix)
-{
-	for (; ; str++, prefix++)
-		if (!*prefix)
-			return 0;
-		else if (*str != *prefix)
-			return (unsigned char)*prefix - (unsigned char)*str;
-}
+#include <linux/string.h>
+#include <linux/zalloc.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
 
 /*
  * Used as the default ->buf value, so that people can always assume
@@ -17,18 +17,19 @@ int prefixcmp(const char *str, const char *prefix)
  */
 char strbuf_slopbuf[1];
 
-void strbuf_init(struct strbuf *sb, ssize_t hint)
+int strbuf_init(struct strbuf *sb, ssize_t hint)
 {
 	sb->alloc = sb->len = 0;
 	sb->buf = strbuf_slopbuf;
 	if (hint)
-		strbuf_grow(sb, hint);
+		return strbuf_grow(sb, hint);
+	return 0;
 }
 
 void strbuf_release(struct strbuf *sb)
 {
 	if (sb->alloc) {
-		free(sb->buf);
+		zfree(&sb->buf);
 		strbuf_init(sb, 0);
 	}
 }
@@ -42,76 +43,109 @@ char *strbuf_detach(struct strbuf *sb, size_t *sz)
 	return res;
 }
 
-void strbuf_grow(struct strbuf *sb, size_t extra)
+int strbuf_grow(struct strbuf *sb, size_t extra)
 {
-	if (sb->len + extra + 1 <= sb->len)
-		die("you want to use way too much memory");
-	if (!sb->alloc)
-		sb->buf = NULL;
-	ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
-}
+	char *buf;
+	size_t nr = sb->len + extra + 1;
 
-static void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
-				   const void *data, size_t dlen)
-{
-	if (pos + len < pos)
-		die("you want to use way too much memory");
-	if (pos > sb->len)
-		die("`pos' is too far after the end of the buffer");
-	if (pos + len > sb->len)
-		die("`pos + len' is too far after the end of the buffer");
-
-	if (dlen >= len)
-		strbuf_grow(sb, dlen - len);
-	memmove(sb->buf + pos + dlen,
-			sb->buf + pos + len,
-			sb->len - pos - len);
-	memcpy(sb->buf + pos, data, dlen);
-	strbuf_setlen(sb, sb->len + dlen - len);
+	if (nr < sb->alloc)
+		return 0;
+
+	if (nr <= sb->len)
+		return -E2BIG;
+
+	if (alloc_nr(sb->alloc) > nr)
+		nr = alloc_nr(sb->alloc);
+
+	/*
+	 * Note that sb->buf == strbuf_slopbuf if sb->alloc == 0, and it is
+	 * a static variable. Thus we have to avoid passing it to realloc.
+	 */
+	buf = realloc(sb->alloc ? sb->buf : NULL, nr * sizeof(*buf));
+	if (!buf)
+		return -ENOMEM;
+
+	sb->buf = buf;
+	sb->alloc = nr;
+	return 0;
 }
 
-void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
+int strbuf_addch(struct strbuf *sb, int c)
 {
-	strbuf_splice(sb, pos, len, NULL, 0);
+	int ret = strbuf_grow(sb, 1);
+	if (ret)
+		return ret;
+
+	sb->buf[sb->len++] = c;
+	sb->buf[sb->len] = '\0';
+	return 0;
 }
 
-void strbuf_add(struct strbuf *sb, const void *data, size_t len)
+int strbuf_add(struct strbuf *sb, const void *data, size_t len)
 {
-	strbuf_grow(sb, len);
+	int ret = strbuf_grow(sb, len);
+	if (ret)
+		return ret;
+
 	memcpy(sb->buf + sb->len, data, len);
-	strbuf_setlen(sb, sb->len + len);
+	return strbuf_setlen(sb, sb->len + len);
 }
 
-void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
+static int strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap)
 {
-	int len;
-	va_list ap;
+	int len, ret;
+	va_list ap_saved;
 
-	if (!strbuf_avail(sb))
-		strbuf_grow(sb, 64);
-	va_start(ap, fmt);
+	if (!strbuf_avail(sb)) {
+		ret = strbuf_grow(sb, 64);
+		if (ret)
+			return ret;
+	}
+
+	va_copy(ap_saved, ap);
 	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
-	va_end(ap);
-	if (len < 0)
-		die("your vsnprintf is broken");
+	if (len < 0) {
+		va_end(ap_saved);
+		return len;
+	}
 	if (len > strbuf_avail(sb)) {
-		strbuf_grow(sb, len);
-		va_start(ap, fmt);
-		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
-		va_end(ap);
+		ret = strbuf_grow(sb, len);
+		if (ret) {
+			va_end(ap_saved);
+			return ret;
+		}
+		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);
 		if (len > strbuf_avail(sb)) {
-			die("this should not happen, your vsnprintf is broken");
+			pr_debug("this should not happen, your vsnprintf is broken");
+			va_end(ap_saved);
+			return -EINVAL;
 		}
 	}
-	strbuf_setlen(sb, sb->len + len);
+	va_end(ap_saved);
+	return strbuf_setlen(sb, sb->len + len);
+}
+
+int strbuf_addf(struct strbuf *sb, const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, fmt);
+	ret = strbuf_addv(sb, fmt, ap);
+	va_end(ap);
+	return ret;
 }
 
 ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
 {
 	size_t oldlen = sb->len;
 	size_t oldalloc = sb->alloc;
+	int ret;
+
+	ret = strbuf_grow(sb, hint ? hint : 8192);
+	if (ret)
+		return ret;
 
-	strbuf_grow(sb, hint ? hint : 8192);
 	for (;;) {
 		ssize_t cnt;
 
@@ -121,12 +155,14 @@ ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
 				strbuf_release(sb);
 			else
 				strbuf_setlen(sb, oldlen);
-			return -1;
+			return cnt;
 		}
 		if (!cnt)
 			break;
 		sb->len += cnt;
-		strbuf_grow(sb, 8192);
+		ret = strbuf_grow(sb, 8192);
+		if (ret)
+			return ret;
 	}
 
 	sb->buf[sb->len] = '\0';