cxl: fix leak of ctx->mapping when releasing kernel API contexts
When a context is created via the kernel API, ctx->mapping is allocated
within the kernel and thus needs to be freed when the context is freed.
reclaim_ctx() attempts to do this for contexts with the ctx->kernelapi flag
set, but afu_release() (which can be called from the kernel API through
cxl_fd_release()) sets ctx->mapping to NULL before calling
cxl_context_free() to free the context.
Add a check to afu_release() so that the mappings in contexts created via
the kernel API are left alone so reclaim_ctx() can free them.
Reported-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Fixes: 6f7f0b3df6d4 ("cxl: Add AFU virtual PHB and kernel API")
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c
index a30bf28..7ccd299 100644
--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -120,9 +120,16 @@
__func__, ctx->pe);
cxl_context_detach(ctx);
- mutex_lock(&ctx->mapping_lock);
- ctx->mapping = NULL;
- mutex_unlock(&ctx->mapping_lock);
+
+ /*
+ * Delete the context's mapping pointer, unless it's created by the
+ * kernel API, in which case leave it so it can be freed by reclaim_ctx()
+ */
+ if (!ctx->kernelapi) {
+ mutex_lock(&ctx->mapping_lock);
+ ctx->mapping = NULL;
+ mutex_unlock(&ctx->mapping_lock);
+ }
put_device(&ctx->afu->dev);