[PATCH 4.17 049/220] powerpc/powernv/ioda2: Remove redundant free of TCE pages

From: Greg Kroah-Hartman
Date: Sun Jul 01 2018 - 13:19:31 EST


4.17-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexey Kardashevskiy <aik@xxxxxxxxx>

commit 98fd72fe82527fd26618062b60cfd329451f2329 upstream.

When IODA2 creates a PE, it creates an IOMMU table with it_ops::free
set to pnv_ioda2_table_free() which calls pnv_pci_ioda2_table_free_pages().

Since iommu_tce_table_put() calls it_ops::free when the last reference
to the table is released, explicit call to pnv_pci_ioda2_table_free_pages()
is not needed so let's remove it.

This should fix double free in the case of PCI hotuplug as
pnv_pci_ioda2_table_free_pages() does not reset neither
iommu_table::it_base nor ::it_size.

This was not exposed by SRIOV as it uses different code path via
pnv_pcibios_sriov_disable().

IODA1 does not inialize it_ops::free so it does not have this issue.

Fixes: c5f7700bbd2e ("powerpc/powernv: Dynamically release PE")
Cc: stable@xxxxxxxxxxxxxxx # v4.8+
Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/platforms/powernv/pci-ioda.c | 1 -
1 file changed, 1 deletion(-)

--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -3642,7 +3642,6 @@ static void pnv_pci_ioda2_release_pe_dma
WARN_ON(pe->table_group.group);
}

- pnv_pci_ioda2_table_free_pages(tbl);
iommu_tce_table_put(tbl);
}