diff options
| author | Sowmini Varadhan <sowmini.varadhan@oracle.com> | 2015-09-22 14:59:20 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-22 14:43:15 -0700 |
| commit | 455a35d039d0a84d021721cdde2384ec36c0b6e0 (patch) | |
| tree | e36dcac9af425b64420b7eeef08098b98ab17e2b /lib | |
| parent | 9a36019b8e0a6064614e6227d26c144e88c635ea (diff) | |
lib/iommu-common.c: do not try to deref a null iommu->lazy_flush() pointer when n < pool->hint
commit d046b770c9fc36ccb19c27afdb8322220108cbc7 upstream.
The check for invoking iommu->lazy_flush() from iommu_tbl_range_alloc()
has to be refactored so that we only call ->lazy_flush() if it is
non-null.
I had a sparc kernel that was crashing when I was trying to process some
very large perf.data files- the crash happens when the scsi driver calls
into dma_4v_map_sg and thus the iommu_tbl_range_alloc().
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/iommu-common.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/lib/iommu-common.c b/lib/iommu-common.c index df30632f0bef..4fdeee02e0a9 100644 --- a/lib/iommu-common.c +++ b/lib/iommu-common.c @@ -21,8 +21,7 @@ static DEFINE_PER_CPU(unsigned int, iommu_hash_common); static inline bool need_flush(struct iommu_map_table *iommu) { - return (iommu->lazy_flush != NULL && - (iommu->flags & IOMMU_NEED_FLUSH) != 0); + return ((iommu->flags & IOMMU_NEED_FLUSH) != 0); } static inline void set_flush(struct iommu_map_table *iommu) @@ -211,7 +210,8 @@ unsigned long iommu_tbl_range_alloc(struct device *dev, goto bail; } } - if (n < pool->hint || need_flush(iommu)) { + if (iommu->lazy_flush && + (n < pool->hint || need_flush(iommu))) { clear_flush(iommu); iommu->lazy_flush(iommu); } |