[07/12] util/hexdump: Have qemu_hexdump_line() return heap allocated buffer

Commit Message

Philippe Mathieu-Daudé April 10, 2024, 4:06 p.m. UTC

Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
---
 include/qemu/cutils.h  | 10 +++++++---
 hw/virtio/vhost-vdpa.c |  5 +++--
 util/hexdump.c         | 12 ++++++++----
 3 files changed, 18 insertions(+), 9 deletions(-)

Patch

diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h
index 70ca4b876b..e8d6b86098 100644
--- a/include/qemu/cutils.h
+++ b/include/qemu/cutils.h
@@ -254,18 +254,22 @@  int parse_debug_env(const char *name, int max, int initial);
 
 /**
  * qemu_hexdump_line:
- * @line: Buffer to be filled by the hexadecimal/ASCII dump
  * @bufptr: Buffer to dump
  * @offset: Offset within @bufptr to start the dump
  * @len: Length of the bytes do dump
  * @ascii: Replace non-ASCII characters by the dot symbol
  *
  * Hexdump a line of a byte buffer into a hexadecimal/ASCII buffer
+ *
+ * The caller must use g_free() to free the returned data when it is
+ * no longer required.
+ *
+ * Returns: Hexadecimal/ASCII dump
  */
 #define QEMU_HEXDUMP_LINE_BYTES 16 /* Number of bytes to dump */
 #define QEMU_HEXDUMP_LINE_LEN 75   /* Number of characters in line */
-void qemu_hexdump_line(char *line, const void *bufptr, unsigned offset,
-                       unsigned int len, bool ascii);
+char *qemu_hexdump_line(const void *bufptr, unsigned offset,
+                        unsigned int len, bool ascii);
 
 /*
  * Hexdump a buffer to a file. An optional string prefix is added to every line
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index cf7cfa3f16..e61af86d9d 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -942,12 +942,13 @@  static void vhost_vdpa_dump_config(struct vhost_dev *dev, const uint8_t *config,
                                    uint32_t config_len)
 {
     int ofs, len;
-    char line[QEMU_HEXDUMP_LINE_LEN];
+    char *line;
 
     for (ofs = 0; ofs < config_len; ofs += 16) {
         len = config_len - ofs;
-        qemu_hexdump_line(line, config, ofs, len, false);
+        line = qemu_hexdump_line(config, ofs, len, false);
         trace_vhost_vdpa_dump_config(dev, line);
+        g_free(line);
     }
 }
 
diff --git a/util/hexdump.c b/util/hexdump.c
index 469083d8c0..b6f70e93bb 100644
--- a/util/hexdump.c
+++ b/util/hexdump.c
@@ -16,9 +16,10 @@ 
 #include "qemu/osdep.h"
 #include "qemu/cutils.h"
 
-void qemu_hexdump_line(char *line, const void *bufptr, unsigned offset,
-                       unsigned int len, bool ascii)
+char *qemu_hexdump_line(const void *bufptr, unsigned offset,
+                        unsigned int len, bool ascii)
 {
+    char linebuf[QEMU_HEXDUMP_LINE_BYTES], *line = linebuf;
     const char *buf = bufptr;
     int i, c;
 
@@ -48,18 +49,21 @@  void qemu_hexdump_line(char *line, const void *bufptr, unsigned offset,
         }
     }
     *line = '\0';
+
+    return g_strdup(linebuf);
 }
 
 void qemu_hexdump(FILE *fp, const char *prefix,
                   const void *bufptr, size_t size)
 {
     unsigned int ofs, len;
-    char line[QEMU_HEXDUMP_LINE_LEN];
+    char *line;
 
     for (ofs = 0; ofs < size; ofs += QEMU_HEXDUMP_LINE_BYTES) {
         len = size - ofs;
-        qemu_hexdump_line(line, bufptr, ofs, len, true);
+        line = qemu_hexdump_line(bufptr, ofs, len, true);
         fprintf(fp, "%s: %s\n", prefix, line);
+        g_free(line);
     }
 
 }