Commit 5f81b95f authored Sep 30, 2015 by Andrew Donnellan Committed by Michael Ellerman Oct 01, 2015

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: 6f7f0b3d ("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>

parent 52adee58

drivers/misc/cxl/file.c

+10 −3

Original line number	Diff line number	Diff line
		@@ -120,9 +120,16 @@ int afu_release(struct inode inode, struct file file)
		__func__, ctx->pe);
		cxl_context_detach(ctx);


		/*
		* 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);