From: Yunfei Wang <yf.wang(a)mediatek.com>
The data type of the return value of the iommu_map_sg_atomic
is ssize_t, but the data type of iova size is size_t,
e.g. one is int while the other is unsigned int.
When iommu_map_sg_atomic return value is compared with iova size,
it will force the signed int to be converted to unsigned int, if
iova map fails and iommu_map_sg_atomic return error code is less
than 0, then (ret < iova_len) is false, which will to cause not
do free iova, and the master can still successfully get the iova
of map fail, which is not expected.
Therefore, we need to check the return value of iommu_map_sg_atomic
in two cases according to whether it is less than 0.
Fixes: ad8f36e4b6b1 ("iommu: return full error code from iommu_map_sg[_atomic]()")
Signed-off-by: Yunfei Wang <yf.wang(a)mediatek.com>
Cc: <stable(a)vger.kernel.org> # 5.15.*
---
drivers/iommu/dma-iommu.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 09f6e1c0f9c0..2932281e93fc 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -776,6 +776,7 @@ static struct page **__iommu_dma_alloc_noncontiguous(struct device *dev,
unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
struct page **pages;
dma_addr_t iova;
+ ssize_t ret;
if (static_branch_unlikely(&iommu_deferred_attach_enabled) &&
iommu_deferred_attach(dev, domain))
@@ -813,8 +814,8 @@ static struct page **__iommu_dma_alloc_noncontiguous(struct device *dev,
arch_dma_prep_coherent(sg_page(sg), sg->length);
}
- if (iommu_map_sg_atomic(domain, iova, sgt->sgl, sgt->orig_nents, ioprot)
- < size)
+ ret = iommu_map_sg_atomic(domain, iova, sgt->sgl, sgt->orig_nents, ioprot);
+ if (ret < 0 || ret < size)
goto out_free_sg;
sgt->sgl->dma_address = iova;
@@ -1209,7 +1210,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
* implementation - it knows better than we do.
*/
ret = iommu_map_sg_atomic(domain, iova, sg, nents, prot);
- if (ret < iova_len)
+ if (ret < 0 || ret < iova_len)
goto out_free_iova;
return __finalise_sg(dev, sg, nents, iova);
--
2.18.0
The dmabuf file uses get_next_ino()(through dma_buf_getfile() ->
alloc_anon_inode()) to get an inode number and uses the same as a
directory name under /sys/kernel/dmabuf/buffers/<ino>. This directory is
used to collect the dmabuf stats and it is created through
dma_buf_stats_setup(). At current, failure to create this directory
entry can make the dma_buf_export() to fail.
Now, as the get_next_ino() can definitely give a repetitive inode no
causing the directory entry creation to fail with -EEXIST. This is a
problem on the systems where dmabuf stats functionality is enabled on
the production builds can make the dma_buf_export(), though the dmabuf
memory is allocated successfully, to fail just because it couldn't
create stats entry.
This issue we are able to see on the snapdragon system within 13 days
where there already exists a directory with inode no "122602" so
dma_buf_stats_setup() failed with -EEXIST as it is trying to create
the same directory entry.
To make the dentry name as unique, use the dmabuf fs specific inode
which is based on the simple atomic variable increment. There is tmpfs
subsystem too which relies on its own inode generation rather than
relying on the get_next_ino() for the same reason of avoiding the
duplicate inodes[1].
[1] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/patch/?id=…
Signed-off-by: Charan Teja Kalla <quic_charante(a)quicinc.com>
Cc: <stable(a)vger.kernel.org> # 5.15.x+
Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
Changes in V3-resend:
-- Collect all the tags and apply stable tag.
Changes in V3:
-- Used the atomic64 variable to have dmabuf files its own inodes.
-- Ensured no UAPI breakage as suggested by Christian.
Changes in V2:
-- Used the atomic64_t variable to generate a unique_id to be appended to inode
to have an unique directory with name <inode_number-unique_id> -- Suggested by christian
-- Updated the ABI documentation -- Identified by Greg.
-- Massaged the commit log.
-- https://lore.kernel.org/all/1652191562-18700-1-git-send-email-quic_charante…
Changes in V1:
-- Used the inode->i_ctime->tv_secs as an id appended to inode to create the
unique directory with name <inode_number-time_in_secs>.
-- https://lore.kernel.org/all/1652178212-22383-1-git-send-email-quic_charante…
drivers/dma-buf/dma-buf.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index a6fc96e..0ad5039 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -407,6 +407,7 @@ static inline int is_dma_buf_file(struct file *file)
static struct file *dma_buf_getfile(struct dma_buf *dmabuf, int flags)
{
+ static atomic64_t dmabuf_inode = ATOMIC64_INIT(0);
struct file *file;
struct inode *inode = alloc_anon_inode(dma_buf_mnt->mnt_sb);
@@ -416,6 +417,13 @@ static struct file *dma_buf_getfile(struct dma_buf *dmabuf, int flags)
inode->i_size = dmabuf->size;
inode_set_bytes(inode, dmabuf->size);
+ /*
+ * The ->i_ino acquired from get_next_ino() is not unique thus
+ * not suitable for using it as dentry name by dmabuf stats.
+ * Override ->i_ino with the unique and dmabuffs specific
+ * value.
+ */
+ inode->i_ino = atomic64_add_return(1, &dmabuf_inode);
file = alloc_file_pseudo(inode, dma_buf_mnt, "dmabuf",
flags, &dma_buf_fops);
if (IS_ERR(file))
--
2.7.4
The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: 280abe14b6e0a38de9cc86fe6a019523aadd8f70
Gitweb: https://git.kernel.org/tip/280abe14b6e0a38de9cc86fe6a019523aadd8f70
Author: Adrian-Ken Rueegsegger <ken(a)codelabs.ch>
AuthorDate: Mon, 09 May 2022 11:06:37 +02:00
Committer: Thomas Gleixner <tglx(a)linutronix.de>
CommitterDate: Fri, 13 May 2022 12:41:21 +02:00
x86/mm: Fix marking of unused sub-pmd ranges
The unused part precedes the new range spanned by the start, end parameters
of vmemmap_use_new_sub_pmd(). This means it actually goes from
ALIGN_DOWN(start, PMD_SIZE) up to start.
Use the correct address when applying the mark using memset.
Fixes: 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges")
Signed-off-by: Adrian-Ken Rueegsegger <ken(a)codelabs.ch>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Reviewed-by: Oscar Salvador <osalvador(a)suse.de>
Reviewed-by: David Hildenbrand <david(a)redhat.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20220509090637.24152-2-ken@codelabs.ch
---
arch/x86/mm/init_64.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 96d34eb..e294233 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -902,6 +902,8 @@ static void __meminit vmemmap_use_sub_pmd(unsigned long start, unsigned long end
static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
{
+ const unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
+
vmemmap_flush_unused_pmd();
/*
@@ -914,8 +916,7 @@ static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long
* Mark with PAGE_UNUSED the unused parts of the new memmap range
*/
if (!IS_ALIGNED(start, PMD_SIZE))
- memset((void *)start, PAGE_UNUSED,
- start - ALIGN_DOWN(start, PMD_SIZE));
+ memset((void *)page, PAGE_UNUSED, start - page);
/*
* We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of