4.19-stable review patch. If anyone has any objections, please let me know.
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From: Michael Ellerman mpe@ellerman.id.au
[ Upstream commit d4bc0a264fb482b019c84fbc7202dd3cab059087 ]
The overflow/underflow conditions in pata_macio_qc_prep() should never happen. But if they do there's no need to kill the system entirely, a WARN and failing the IO request should be sufficient and might allow the system to keep running.
Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Damien Le Moal dlemoal@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ata/pata_macio.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/ata/pata_macio.c b/drivers/ata/pata_macio.c index 765b99319d3c..7beb5dd9ff87 100644 --- a/drivers/ata/pata_macio.c +++ b/drivers/ata/pata_macio.c @@ -537,7 +537,8 @@ static enum ata_completion_errors pata_macio_qc_prep(struct ata_queued_cmd *qc)
while (sg_len) { /* table overflow should never happen */ - BUG_ON (pi++ >= MAX_DCMDS); + if (WARN_ON_ONCE(pi >= MAX_DCMDS)) + return AC_ERR_SYSTEM;
len = (sg_len < MAX_DBDMA_SEG) ? sg_len : MAX_DBDMA_SEG; table->command = cpu_to_le16(write ? OUTPUT_MORE: INPUT_MORE); @@ -549,11 +550,13 @@ static enum ata_completion_errors pata_macio_qc_prep(struct ata_queued_cmd *qc) addr += len; sg_len -= len; ++table; + ++pi; } }
/* Should never happen according to Tejun */ - BUG_ON(!pi); + if (WARN_ON_ONCE(!pi)) + return AC_ERR_SYSTEM;
/* Convert the last command to an input/output */ table--;