git: 446e0f2e6c79 - 2021Q4 - games/gzdoom: fix wildmidi crash
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Date: Thu, 16 Dec 2021 05:45:48 UTC
The branch 2021Q4 has been updated by kevans:
URL: https://cgit.FreeBSD.org/ports/commit/?id=446e0f2e6c79e2fbf012861c91e678a389c8852f
commit 446e0f2e6c79e2fbf012861c91e678a389c8852f
Author: Kyle Evans <kevans@FreeBSD.org>
AuthorDate: 2021-12-16 05:36:04 +0000
Commit: Kyle Evans <kevans@FreeBSD.org>
CommitDate: 2021-12-16 05:40:55 +0000
games/gzdoom: fix wildmidi crash
get_patch_data() may recurse on itself, which is not OK to do while
using std::lock_guard<>. Move the contents of get_patch_data() to a
get_patch_data_locked() that may recurse on itself.
This is a direct commit to quarterly, as this has since been fixed by
the version present in main. Specifically, a later refactoring ends up
dropping the patch_lock entirely after get_patch_data() and friends are
pushed into an Instruments class anyways.
Based on triage work and an initial patch by wpaul@.
---
.../patch-src_sound_wildmidi_wildmidi__lib.cpp | 49 ++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/games/gzdoom/files/patch-src_sound_wildmidi_wildmidi__lib.cpp b/games/gzdoom/files/patch-src_sound_wildmidi_wildmidi__lib.cpp
new file mode 100644
index 000000000000..eaa3681841db
--- /dev/null
+++ b/games/gzdoom/files/patch-src_sound_wildmidi_wildmidi__lib.cpp
@@ -0,0 +1,49 @@
+--- src/sound/wildmidi/wildmidi_lib.cpp.orig 2019-05-04 19:58:35 UTC
++++ src/sound/wildmidi/wildmidi_lib.cpp
+@@ -1318,11 +1318,9 @@ static int load_sample(struct _patch *sample_patch) {
+ }
+
+ static struct _patch *
+-get_patch_data(unsigned short patchid) {
++get_patch_data_locked(unsigned short patchid) {
+ struct _patch *search_patch;
+
+- std::lock_guard<std::mutex> lock(patch_lock);
+-
+ search_patch = patch[patchid & 0x007F];
+
+ if (search_patch == NULL) {
+@@ -1335,12 +1333,32 @@ get_patch_data(unsigned short patchid) {
+ }
+ search_patch = search_patch->next;
+ }
+ if ((patchid >> 8) != 0) {
+- return (get_patch_data(patchid & 0x00FF));
++ return (get_patch_data_locked(patchid & 0x00FF));
+ }
+ return NULL;
+ }
+
++static struct _patch *
++get_patch_data(unsigned short patchid) {
++ struct _patch *patch;
++
++ /*
++ * Uh, hey, no, sorry pal, you can't use this
++ * construction here. This function can call itself
++ * recursively, which means you will recursively
++ * try to acquire the patch_lock mutex, which is
++ * not allowed with lock_guard.
++ */
++
++/* std::lock_guard<std::mutex> lock(patch_lock); */
++
++ patch_lock.lock();
++ patch = get_patch_data_locked(patchid);
++ patch_lock.unlock();
++ return (patch);
++}
++
+ static void load_patch(struct _mdi *mdi, unsigned short patchid) {
+ unsigned int i;
+ struct _patch *tmp_patch = NULL;