diff options
| author | Andreas Herrmann <andreas.herrmann@calxeda.com> | 2013-10-01 16:39:07 +0400 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2013-10-09 17:14:40 +0400 |
| commit | 44a08de2aaf7f4cf86dfcf04bee32536e4a2b5b8 (patch) | |
| tree | fc1702688b2a1858d18ae2db0bab740030fa9ea6 /drivers/iommu | |
| parent | c55af7f719cbb0f0b28f42b3f98f662278f063c2 (diff) | |
| download | linux-44a08de2aaf7f4cf86dfcf04bee32536e4a2b5b8.tar.xz | |
iommu/arm-smmu: Check for num_context_irqs > 0 to avoid divide by zero exception
With the right (or wrong;-) definition of v1 SMMU node in DTB it is
possible to trigger a division by zero in arm_smmu_init_domain_context
(if number of context irqs is 0):
if (smmu->version == 1) {
root_cfg->irptndx = atomic_inc_return(&smmu->irptndx);
=> root_cfg->irptndx %= smmu->num_context_irqs;
} else {
Avoid this by checking for num_context_irqs > 0 when probing
for SMMU devices.
Signed-off-by: Andreas Herrmann <andreas.herrmann@calxeda.com>
[will: changed to dev_err on probe failure path]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/arm-smmu.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 1f79daa5f4b1..e4693cee5f2c 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1798,12 +1798,11 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev) smmu->num_context_irqs++; } - if (num_irqs < smmu->num_global_irqs) { - dev_warn(dev, "found %d interrupts but expected at least %d\n", - num_irqs, smmu->num_global_irqs); - smmu->num_global_irqs = num_irqs; + if (!smmu->num_context_irqs) { + dev_err(dev, "found %d interrupts but expected at least %d\n", + num_irqs, smmu->num_global_irqs + 1); + return -ENODEV; } - smmu->num_context_irqs = num_irqs - smmu->num_global_irqs; smmu->irqs = devm_kzalloc(dev, sizeof(*smmu->irqs) * num_irqs, GFP_KERNEL); |