4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Robin Murphy <[email protected]> commit 5d589d81acf974d23af98044aac56c6339d659f8 upstream. The existing msi-map code is fine for shifting the entire RID space upwards, but attempting finer-grained remapping reveals a bug. It turns out that we are mistakenly treating the msi-base part as an offset, not as a new base to remap onto, so things get squiffy when rid-base is nonzero. Fix this, and at the same time add a sanity check against having msi-map-mask clash with a nonzero rid-base, as that's another thing one can easily get wrong. Signed-off-by: Robin Murphy <[email protected]> Reviewed-by: Marc Zyngier <[email protected]> Tested-by: Stuart Yoder <[email protected]> Acked-by: Mark Rutland <[email protected]> Acked-by: David Daney <[email protected]> Signed-off-by: Rob Herring <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/of/irq.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/drivers/of/irq.c +++ b/drivers/of/irq.c @@ -636,6 +636,13 @@ static u32 __of_msi_map_rid(struct devic msi_base = be32_to_cpup(msi_map + 2); rid_len = be32_to_cpup(msi_map + 3); + if (rid_base & ~map_mask) { + dev_err(parent_dev, + "Invalid msi-map translation - msi-map-mask (0x%x) ignores rid-base (0x%x)\n", + map_mask, rid_base); + return rid_out; + } + msi_controller_node = of_find_node_by_phandle(phandle); matched = (masked_rid >= rid_base && @@ -655,7 +662,7 @@ static u32 __of_msi_map_rid(struct devic if (!matched) return rid_out; - rid_out = masked_rid + msi_base; + rid_out = masked_rid - rid_base + msi_base; dev_dbg(dev, "msi-map at: %s, using mask %08x, rid-base: %08x, msi-base: %08x, length: %08x, rid: %08x -> %08x\n", dev_name(parent_dev), map_mask, rid_base, msi_base,
