powerpc/book3s64: Fix error handling in mm_iommu_do_alloc()

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The last jump to free_exit in mm_iommu_do_alloc() happens after page
pointers in struct mm_iommu_table_group_mem_t were already converted to
physical addresses. Thus calling put_page() on these physical addresses
will likely crash.

This moves the loop which calculates the pageshift and converts page
struct pointers to physical addresses later after the point when
we cannot fail; thus eliminating the need to convert pointers back.

Fixes: eb9d7a62c3 ("powerpc/mm_iommu: Fix potential deadlock")
Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191223060351.26359-1-aik@ozlabs.ru

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Alexey Kardashevskiy 2019-12-23 17:03:51 +11:00 • committed by Michael Ellerman

parent f344f0ab99

commit c4b78169e3

1 changed files with 21 additions and 18 deletions

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arch/powerpc/mm/book3s64/iommu_api.c

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