diff mbox series

[5/8] gdbstub: Dynamically allocate target.xml buffer

Message ID 20230903043030.20708-6-akihiko.odaki@daynix.com
State New
Headers show
Series gdbstub and TCG plugin improvements | expand

Commit Message

Akihiko Odaki Sept. 3, 2023, 4:30 a.m. UTC 
There is no guarantee that target.xml fits in 1024 bytes, and the fixed
buffer length requires tedious buffer overflow check. Dynamically
allocate the target.xml buffer to resolve these problems.

Suggested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
 gdbstub/internals.h |  2 +-
 gdbstub/gdbstub.c   | 44 ++++++++++++++++++++++++--------------------
 gdbstub/softmmu.c   |  2 +-
 3 files changed, 26 insertions(+), 22 deletions(-)
diff mbox series

Patch

diff --git a/gdbstub/internals.h b/gdbstub/internals.h
index f2b46cce41..4876ebd74f 100644
--- a/gdbstub/internals.h
+++ b/gdbstub/internals.h
@@ -33,7 +33,7 @@  typedef struct GDBProcess {
     uint32_t pid;
     bool attached;
 
-    char target_xml[1024];
+    char *target_xml;
 } GDBProcess;
 
 enum RSState {
diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 78711801db..3f97dc66e5 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -367,33 +367,37 @@  static const char *get_feature_xml(const char *p, const char **newp,
 
     name = NULL;
     if (strncmp(p, "target.xml", len) == 0) {
-        char *buf = process->target_xml;
-        const size_t buf_sz = sizeof(process->target_xml);
-
         /* Generate the XML description for this CPU.  */
-        if (!buf[0]) {
+        if (!process->target_xml) {
+            g_autoptr(GPtrArray) a = g_ptr_array_new_with_free_func(g_free);
             GDBRegisterState *r;
 
-            pstrcat(buf, buf_sz,
-                    "<?xml version=\"1.0\"?>"
-                    "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
-                    "<target>");
+            g_ptr_array_add(
+                a,
+                g_strdup("<?xml version=\"1.0\"?>"
+                         "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
+                         "<target>"));
             if (cc->gdb_arch_name) {
-                pstrcat(buf, buf_sz, "<architecture>");
-                pstrcat(buf, buf_sz, cc->gdb_arch_name(cpu));
-                pstrcat(buf, buf_sz, "</architecture>");
+                g_ptr_array_add(
+                    a,
+                    g_markup_printf_escaped("<architecture>%s</architecture>",
+                                            cc->gdb_arch_name(cpu)));
             }
-            pstrcat(buf, buf_sz, "<xi:include href=\"");
-            pstrcat(buf, buf_sz, cc->gdb_core_xml_file);
-            pstrcat(buf, buf_sz, "\"/>");
+            g_ptr_array_add(
+                a,
+                g_markup_printf_escaped("<xi:include href=\"%s\"/>",
+                                        cc->gdb_core_xml_file));
             for (r = cpu->gdb_regs; r; r = r->next) {
-                pstrcat(buf, buf_sz, "<xi:include href=\"");
-                pstrcat(buf, buf_sz, r->xml);
-                pstrcat(buf, buf_sz, "\"/>");
+                g_ptr_array_add(
+                    a,
+                    g_markup_printf_escaped("<xi:include href=\"%s\"/>",
+                                            r->xml));
             }
-            pstrcat(buf, buf_sz, "</target>");
+            g_ptr_array_add(a, g_strdup("</target>"));
+            g_ptr_array_add(a, NULL);
+            process->target_xml = g_strjoinv(NULL, (void *)a->pdata);
         }
-        return buf;
+        return process->target_xml;
     }
     if (cc->gdb_get_dynamic_xml) {
         char *xmlname = g_strndup(p, len);
@@ -2199,6 +2203,6 @@  void gdb_create_default_process(GDBState *s)
     process = &s->processes[s->process_num - 1];
     process->pid = pid;
     process->attached = false;
-    process->target_xml[0] = '\0';
+    process->target_xml = NULL;
 }
 
diff --git a/gdbstub/softmmu.c b/gdbstub/softmmu.c
index f509b7285d..5282324764 100644
--- a/gdbstub/softmmu.c
+++ b/gdbstub/softmmu.c
@@ -293,7 +293,7 @@  static int find_cpu_clusters(Object *child, void *opaque)
         assert(cluster->cluster_id != UINT32_MAX);
         process->pid = cluster->cluster_id + 1;
         process->attached = false;
-        process->target_xml[0] = '\0';
+        process->target_xml = NULL;
 
         return 0;
     }