The translation caches may preserve obsolete data when the
mapping size is changed, suppose the following sequence which
can reveal the problem with high probability.
1.mmap(4GB,MAP_HUGETLB)
2.
while (1) {
(a) DMA MAP 0,0xa0000
(b) DMA UNMAP 0,0xa0000
(c) DMA MAP 0,0xc0000000
* DMA read IOVA 0 may failure here (Not present)
* if the problem occurs.
(d) DMA UNMAP 0,0xc0000000
}
The page table(only focus on IOVA 0) after (a) is:
PML4: 0x19db5c1003 entry:0xffff899bdcd2f000
PDPE: 0x1a1cacb003 entry:0xffff89b35b5c1000
PDE: 0x1a30a72003 entry:0xffff89b39cacb000
PTE: 0x21d200803 entry:0xffff89b3b0a72000
The page table after (b) is:
PML4: 0x19db5c1003 entry:0xffff899bdcd2f000
PDPE: 0x1a1cacb003 entry:0xffff89b35b5c1000
PDE: 0x1a30a72003 entry:0xffff89b39cacb000
PTE: 0x0 entry:0xffff89b3b0a72000
The page table after (c) is:
PML4: 0x19db5c1003 entry:0xffff899bdcd2f000
PDPE: 0x1a1cacb003 entry:0xffff89b35b5c1000
PDE: 0x21d200883 entry:0xffff89b39cacb000 (*)
Because the PDE entry after (b) is present, it won't be
flushed even if the iommu driver flush cache when unmap,
so the obsolete data may be preserved in cache, which
would cause the wrong translation at end.
However, we can see the PDE entry is finally switch to
2M-superpage mapping, but it does not transform
to 0x21d200883 directly:
1. PDE: 0x1a30a72003
2. __domain_mapping
dma_pte_free_pagetable
Set the PDE entry to ZERO
Set the PDE entry to 0x21d200883
So we must flush the cache after the entry switch to ZERO
to avoid the obsolete info be preserved.
Cc: David Woodhouse <dwmw2(a)infradead.org>
Cc: Lu Baolu <baolu.lu(a)linux.intel.com>
Cc: Nadav Amit <nadav.amit(a)gmail.com>
Cc: Alex Williamson <alex.williamson(a)redhat.com>
Cc: Kevin Tian <kevin.tian(a)intel.com>
Cc: Gonglei (Arei) <arei.gonglei(a)huawei.com>
Fixes: 6491d4d02893 ("intel-iommu: Free old page tables before creating superpage")
Cc: <stable(a)vger.kernel.org> # v3.0+
Link: https://lore.kernel.org/linux-iommu/670baaf8-4ff8-4e84-4be3-030b95ab5a5e@hu…
Suggested-by: Lu Baolu <baolu.lu(a)linux.intel.com>
Signed-off-by: Longpeng(Mike) <longpeng2(a)huawei.com>
---
drivers/iommu/intel/iommu.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index ee09323..cbcb434 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2342,9 +2342,20 @@ static inline int hardware_largepage_caps(struct dmar_domain *domain,
* removed to make room for superpage(s).
* We're adding new large pages, so make sure
* we don't remove their parent tables.
+ *
+ * We also need to flush the iotlb before creating
+ * superpage to ensure it does not perserves any
+ * obsolete info.
*/
- dma_pte_free_pagetable(domain, iov_pfn, end_pfn,
- largepage_lvl + 1);
+ if (dma_pte_present(pte)) {
+ int i;
+
+ dma_pte_free_pagetable(domain, iov_pfn, end_pfn,
+ largepage_lvl + 1);
+ for_each_domain_iommu(i, domain)
+ iommu_flush_iotlb_psi(g_iommus[i], domain,
+ iov_pfn, nr_pages, 0, 0);
+ }
} else {
pteval &= ~(uint64_t)DMA_PTE_LARGE_PAGE;
}
--
1.8.3.1
We are losing the reference to an allocated memory if try. Change the
order of the check to avoid that.
Cc: stable(a)vger.kernel.org
Fixes: 6d5f26f2e045 ("media: staging/intel-ipu3-v4l: reduce kernel stack usage")
Signed-off-by: Ricardo Ribalda <ribalda(a)chromium.org>
---
drivers/staging/media/ipu3/ipu3-v4l2.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/staging/media/ipu3/ipu3-v4l2.c b/drivers/staging/media/ipu3/ipu3-v4l2.c
index 60aa02eb7d2a..35a74d99322f 100644
--- a/drivers/staging/media/ipu3/ipu3-v4l2.c
+++ b/drivers/staging/media/ipu3/ipu3-v4l2.c
@@ -693,6 +693,13 @@ static int imgu_fmt(struct imgu_device *imgu, unsigned int pipe, int node,
if (inode == IMGU_NODE_STAT_3A || inode == IMGU_NODE_PARAMS)
continue;
+ /* CSS expects some format on OUT queue */
+ if (i != IPU3_CSS_QUEUE_OUT &&
+ !imgu_pipe->nodes[inode].enabled) {
+ fmts[i] = NULL;
+ continue;
+ }
+
if (try) {
fmts[i] = kmemdup(&imgu_pipe->nodes[inode].vdev_fmt.fmt.pix_mp,
sizeof(struct v4l2_pix_format_mplane),
@@ -705,10 +712,6 @@ static int imgu_fmt(struct imgu_device *imgu, unsigned int pipe, int node,
fmts[i] = &imgu_pipe->nodes[inode].vdev_fmt.fmt.pix_mp;
}
- /* CSS expects some format on OUT queue */
- if (i != IPU3_CSS_QUEUE_OUT &&
- !imgu_pipe->nodes[inode].enabled)
- fmts[i] = NULL;
}
if (!try) {
--
2.31.0.rc2.261.g7f71774620-goog
The patch titled
Subject: gcov: re-fix clang-11+ support
has been added to the -mm tree. Its filename is
gcov-re-fix-clang-11-support.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/gcov-re-fix-clang-11-support.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/gcov-re-fix-clang-11-support.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Nick Desaulniers <ndesaulniers(a)google.com>
Subject: gcov: re-fix clang-11+ support
LLVM changed the expected function signature for llvm_gcda_emit_function()
in the clang-11 release. Users of clang-11 or newer may have noticed
their kernels producing invalid coverage information:
$ llvm-cov gcov -a -c -u -f -b <input>.gcda -- gcno=<input>.gcno
1 <func>: checksum mismatch, \
(<lineno chksum A>, <cfg chksum B>) != (<lineno chksum A>, <cfg chksum C>)
2 Invalid .gcda File!
...
Fix up the function signatures so calling this function interprets its
parameters correctly and computes the correct cfg checksum. In
particular, in clang-11, the additional checksum is no longer optional.
Link: https://reviews.llvm.org/rG25544ce2df0daa4304c07e64b9c8b0f7df60c11d
Link: https://lkml.kernel.org/r/20210408184631.1156669-1-ndesaulniers@google.com
Reported-by: Prasad Sodagudi <psodagud(a)quicinc.com>
Tested-by: Prasad Sodagudi <psodagud(a)quicinc.com>
Signed-off-by: Nick Desaulniers <ndesaulniers(a)google.com>
Reviewed-by: Nathan Chancellor <nathan(a)kernel.org>
Cc: <stable(a)vger.kernel.org> [5.4+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
kernel/gcov/clang.c | 29 +++++++++++++++++++----------
1 file changed, 19 insertions(+), 10 deletions(-)
--- a/kernel/gcov/clang.c~gcov-re-fix-clang-11-support
+++ a/kernel/gcov/clang.c
@@ -70,7 +70,9 @@ struct gcov_fn_info {
u32 ident;
u32 checksum;
+#if CONFIG_CLANG_VERSION < 110000
u8 use_extra_checksum;
+#endif
u32 cfg_checksum;
u32 num_counters;
@@ -145,10 +147,8 @@ void llvm_gcda_emit_function(u32 ident,
list_add_tail(&info->head, ¤t_info->functions);
}
-EXPORT_SYMBOL(llvm_gcda_emit_function);
#else
-void llvm_gcda_emit_function(u32 ident, u32 func_checksum,
- u8 use_extra_checksum, u32 cfg_checksum)
+void llvm_gcda_emit_function(u32 ident, u32 func_checksum, u32 cfg_checksum)
{
struct gcov_fn_info *info = kzalloc(sizeof(*info), GFP_KERNEL);
@@ -158,12 +158,11 @@ void llvm_gcda_emit_function(u32 ident,
INIT_LIST_HEAD(&info->head);
info->ident = ident;
info->checksum = func_checksum;
- info->use_extra_checksum = use_extra_checksum;
info->cfg_checksum = cfg_checksum;
list_add_tail(&info->head, ¤t_info->functions);
}
-EXPORT_SYMBOL(llvm_gcda_emit_function);
#endif
+EXPORT_SYMBOL(llvm_gcda_emit_function);
void llvm_gcda_emit_arcs(u32 num_counters, u64 *counters)
{
@@ -293,11 +292,16 @@ int gcov_info_is_compatible(struct gcov_
!list_is_last(&fn_ptr2->head, &info2->functions)) {
if (fn_ptr1->checksum != fn_ptr2->checksum)
return false;
+#if CONFIG_CLANG_VERSION < 110000
if (fn_ptr1->use_extra_checksum != fn_ptr2->use_extra_checksum)
return false;
if (fn_ptr1->use_extra_checksum &&
fn_ptr1->cfg_checksum != fn_ptr2->cfg_checksum)
return false;
+#else
+ if (fn_ptr1->cfg_checksum != fn_ptr2->cfg_checksum)
+ return false;
+#endif
fn_ptr1 = list_next_entry(fn_ptr1, head);
fn_ptr2 = list_next_entry(fn_ptr2, head);
}
@@ -529,17 +533,22 @@ static size_t convert_to_gcda(char *buff
list_for_each_entry(fi_ptr, &info->functions, head) {
u32 i;
- u32 len = 2;
-
- if (fi_ptr->use_extra_checksum)
- len++;
pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION);
- pos += store_gcov_u32(buffer, pos, len);
+#if CONFIG_CLANG_VERSION < 110000
+ pos += store_gcov_u32(buffer, pos,
+ fi_ptr->use_extra_checksum ? 3 : 2);
+#else
+ pos += store_gcov_u32(buffer, pos, 3);
+#endif
pos += store_gcov_u32(buffer, pos, fi_ptr->ident);
pos += store_gcov_u32(buffer, pos, fi_ptr->checksum);
+#if CONFIG_CLANG_VERSION < 110000
if (fi_ptr->use_extra_checksum)
pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum);
+#else
+ pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum);
+#endif
pos += store_gcov_u32(buffer, pos, GCOV_TAG_COUNTER_BASE);
pos += store_gcov_u32(buffer, pos, fi_ptr->num_counters * 2);
_
Patches currently in -mm which might be from ndesaulniers(a)google.com are
gcov-re-fix-clang-11-support.patch
gcov-clang-drop-support-for-clang-10-and-older.patch