cxl: Unmap MMIO regions when detaching a context
If we need to force detach a context (e.g. due to EEH or simply force
unbinding the driver) we should prevent the userspace contexts from
being able to access the Problem State Area MMIO region further, which
they may have mapped with mmap().
This patch unmaps any mapped MMIO regions when detaching a userspace
context.
Cc: stable@vger.kernel.org
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index 4aa31a3..51fd6b5 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c
@@ -34,7 +34,8 @@
/*
* Initialises a CXL context.
*/
-int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
+int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
+ struct address_space *mapping)
{
int i;
@@ -42,6 +43,8 @@
ctx->afu = afu;
ctx->master = master;
ctx->pid = NULL; /* Set in start work ioctl */
+ mutex_init(&ctx->mapping_lock);
+ ctx->mapping = mapping;
/*
* Allocate the segment table before we put it in the IDR so that we
@@ -147,6 +150,12 @@
afu_release_irqs(ctx);
flush_work(&ctx->fault_work); /* Only needed for dedicated process */
wake_up_all(&ctx->wq);
+
+ /* Release Problem State Area mapping */
+ mutex_lock(&ctx->mapping_lock);
+ if (ctx->mapping)
+ unmap_mapping_range(ctx->mapping, 0, 0, 1);
+ mutex_unlock(&ctx->mapping_lock);
}
/*
