The branch main has been updated by wulf:
URL:
https://cgit.FreeBSD.org/src/commit/?id=613723bac219cb08ac1ad0afd3e07850d7fccc10
commit 613723bac219cb08ac1ad0afd3e07850d7fccc10
Author: Austin Shafer <asha...@badland.io>
AuthorDate: 2024-06-06 20:42:06 +0000
Commit: Vladimir Kondratyev <w...@freebsd.org>
CommitDate: 2024-06-06 20:42:06 +0000
linuxkpi: Allow ida_destroy and idr_destroy to be called multiple times
This fixes some weird behavior triggered by nvidia-drm.ko: some DRM
cleanup functions will be called multiple times, leading to a double
free. drm_mode_config_cleanup will be called twice, causing ida_destroy
to be called twice. Although calling the cleanup twice doesn't seem
very clean, on Linux this seems to be permissable as it handles it
just fine. Not doing these checks causes mutex panics and double frees.
In order to preserve this behavior this change checks if the objects
have already been destroyed and bails if so. This fixes the panic seen
when unloading the nvidia-drm driver.
MFC after: 1 week
Reviewed by: bz, manu
Differential revision: https://reviews.freebsd.org/D44865
---
sys/compat/linuxkpi/common/src/linux_idr.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/sys/compat/linuxkpi/common/src/linux_idr.c
b/sys/compat/linuxkpi/common/src/linux_idr.c
index 583e2c237198..59c375194689 100644
--- a/sys/compat/linuxkpi/common/src/linux_idr.c
+++ b/sys/compat/linuxkpi/common/src/linux_idr.c
@@ -178,6 +178,14 @@ idr_destroy(struct idr *idr)
{
struct idr_layer *il, *iln;
+ /*
+ * This idr can be reused, and this function might be called multiple
times
+ * without a idr_init(). Check if this is the case. If we do not do
this
+ * then the mutex will panic while asserting that it is valid.
+ */
+ if (mtx_initialized(&idr->lock) == 0)
+ return;
+
idr_remove_all(idr);
mtx_lock(&idr->lock);
for (il = idr->free; il != NULL; il = iln) {
@@ -802,4 +810,5 @@ ida_destroy(struct ida *ida)
{
idr_destroy(&ida->idr);
free(ida->free_bitmap, M_IDR);
+ ida->free_bitmap = NULL;
}
