diff options
| author | Joerg Roedel <jroedel@suse.de> | 2019-10-18 11:34:22 +0200 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2019-10-18 16:52:37 +0200 |
| commit | 46ac18c347b00be29b265c28209b0f3c38a1f142 (patch) | |
| tree | ec59ad83cad68ff3994928323dc38762397db82c /drivers/iommu | |
| parent | ec21f17a9437e11bb29e5fa375aa31b472793c15 (diff) | |
iommu/amd: Check PM_LEVEL_SIZE() condition in locked section
The increase_address_space() function has to check the PM_LEVEL_SIZE()
condition again under the domain->lock to avoid a false trigger of the
WARN_ON_ONCE() and to avoid that the address space is increase more
often than necessary.
Reported-by: Qian Cai <cai@lca.pw>
Fixes: 754265bcab78 ("iommu/amd: Fix race in increase_address_space()")
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/amd_iommu.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index bcd89ea50a8b..dd555078258c 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1464,6 +1464,7 @@ static void free_pagetable(struct protection_domain *domain) * to 64 bits. */ static bool increase_address_space(struct protection_domain *domain, + unsigned long address, gfp_t gfp) { unsigned long flags; @@ -1472,8 +1473,8 @@ static bool increase_address_space(struct protection_domain *domain, spin_lock_irqsave(&domain->lock, flags); - if (WARN_ON_ONCE(domain->mode == PAGE_MODE_6_LEVEL)) - /* address space already 64 bit large */ + if (address <= PM_LEVEL_SIZE(domain->mode) || + WARN_ON_ONCE(domain->mode == PAGE_MODE_6_LEVEL)) goto out; pte = (void *)get_zeroed_page(gfp); @@ -1506,7 +1507,7 @@ static u64 *alloc_pte(struct protection_domain *domain, BUG_ON(!is_power_of_2(page_size)); while (address > PM_LEVEL_SIZE(domain->mode)) - *updated = increase_address_space(domain, gfp) || *updated; + *updated = increase_address_space(domain, address, gfp) || *updated; level = domain->mode - 1; pte = &domain->pt_root[PM_LEVEL_INDEX(level, address)]; |