commit 4376a770c719f480dd6fad130db8eceeda8cdcb7
author Thomas Huth <thuth@redhat.com> Wed Feb 15 09:57:03 2023 +0100
committer Thomas Huth <thuth@redhat.com> Mon Feb 27 09:15:38 2023 +0100
tree f1bcdc32b0f5ed1a27e7de407dc3777678214cab
parent eb60026120081430d554c9cabaa36c4ac271fce0

target/s390x/arch_dump: Simplify memory allocation in s390x_write_elf64_notes()

We are not on a hot path here, so there is no real need for the logic
here with the split heap and stack space allocation. Simplify it by
always allocating memory from the heap.

Suggested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230215085703.746788-1-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

target/s390x/arch_dump.c

diff --git a/target/s390x/arch_dump.c b/target/s390x/arch_dump.c
index a7c44ba..cb98f48 100644
--- a/target/s390x/arch_dump.c
+++ b/target/s390x/arch_dump.c
@@ -227,25 +227,25 @@
                                        DumpState *s,
                                        const NoteFuncDesc *funcs)
 {
-    Note note, *notep;
+    g_autofree Note *notep = NULL;
     const NoteFuncDesc *nf;
-    int note_size, content_size;
+    int note_size, prev_size = 0, content_size;
     int ret = -1;
 
-    assert(strlen(note_name) < sizeof(note.name));
+    assert(strlen(note_name) < sizeof(notep->name));
 
     for (nf = funcs; nf->note_contents_func; nf++) {
-        notep = &note;
         if (nf->pvonly && !s390_is_pv()) {
             continue;
         }
 
         content_size = nf->note_size_func ? nf->note_size_func() : nf->contents_size;
-        note_size = sizeof(note) - sizeof(notep->contents) + content_size;
+        note_size = sizeof(Note) - sizeof(notep->contents) + content_size;
 
-        /* Notes with dynamic sizes need to allocate a note */
-        if (nf->note_size_func) {
+        if (prev_size < note_size) {
+            g_free(notep);
             notep = g_malloc(note_size);
+            prev_size = note_size;
         }
 
         memset(notep, 0, note_size);
@@ -258,15 +258,9 @@
         /* Get contents and write them out */
         (*nf->note_contents_func)(notep, cpu, id);
         ret = f(notep, note_size, s);
-
-        if (nf->note_size_func) {
-            g_free(notep);
-        }
-
         if (ret < 0) {
             return -1;
         }
-
     }
 
     return 0;