* [PATCH v3 0/3] a few cleanup and bugfixes about shmem
@ 2022-06-06 3:45 Chen Wandun
2022-06-06 3:45 ` [PATCH v3 1/3] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Chen Wandun @ 2022-06-06 3:45 UTC (permalink / raw)
To: hughd, akpm, linux-mm, linux-kernel, willy, david, wangkefeng.wang
Cc: chenwandun
v2 ==> v3:
patch1 return the errno from shmem_init_inodecache instead
of NULL on failure.
v1 ==> v2:
combine patch2 and patch3 into a single patch.
Chen Wandun (3):
mm/shmem: check return value of shmem_init_inodecache
mm/shmem: return error code directly for invalid addr
mm/shmem: rework calculation of inflated_addr in
shmem_get_unmapped_area
mm/shmem.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)
--
2.25.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v3 1/3] mm/shmem: check return value of shmem_init_inodecache
2022-06-06 3:45 [PATCH v3 0/3] a few cleanup and bugfixes about shmem Chen Wandun
@ 2022-06-06 3:45 ` Chen Wandun
2022-06-06 4:19 ` Hugh Dickins
2022-06-06 9:39 ` Muchun Song
2022-06-06 3:45 ` [PATCH v3 2/3] mm/shmem: return error code directly for invalid addr Chen Wandun
2022-06-06 3:45 ` [PATCH v3 3/3] mm/shmem: rework calculation of inflated_addr in shmem_get_unmapped_area Chen Wandun
2 siblings, 2 replies; 6+ messages in thread
From: Chen Wandun @ 2022-06-06 3:45 UTC (permalink / raw)
To: hughd, akpm, linux-mm, linux-kernel, willy, david, wangkefeng.wang
Cc: chenwandun
It will result in null pointer access if shmem_init_inodecache fail,
so check return value of shmem_init_inodecache
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
---
mm/shmem.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 12d45a03f7fc..7419ab219b97 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3775,11 +3775,16 @@ static void shmem_init_inode(void *foo)
inode_init_once(&info->vfs_inode);
}
-static void shmem_init_inodecache(void)
+static int shmem_init_inodecache(void)
{
shmem_inode_cachep = kmem_cache_create("shmem_inode_cache",
sizeof(struct shmem_inode_info),
0, SLAB_PANIC|SLAB_ACCOUNT, shmem_init_inode);
+
+ if (!shmem_inode_cachep)
+ return -ENOMEM;
+
+ return 0;
}
static void shmem_destroy_inodecache(void)
@@ -3923,7 +3928,9 @@ void __init shmem_init(void)
{
int error;
- shmem_init_inodecache();
+ error = shmem_init_inodecache();
+ if (error)
+ goto out2;
error = register_filesystem(&shmem_fs_type);
if (error) {
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v3 2/3] mm/shmem: return error code directly for invalid addr
2022-06-06 3:45 [PATCH v3 0/3] a few cleanup and bugfixes about shmem Chen Wandun
2022-06-06 3:45 ` [PATCH v3 1/3] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
@ 2022-06-06 3:45 ` Chen Wandun
2022-06-06 3:45 ` [PATCH v3 3/3] mm/shmem: rework calculation of inflated_addr in shmem_get_unmapped_area Chen Wandun
2 siblings, 0 replies; 6+ messages in thread
From: Chen Wandun @ 2022-06-06 3:45 UTC (permalink / raw)
To: hughd, akpm, linux-mm, linux-kernel, willy, david, wangkefeng.wang
Cc: chenwandun
Return error code directly for addr is not PAGE_SIZE aligned or
beyond TASK_SIZE, no need to check these cases in caller.
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
---
mm/shmem.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 7419ab219b97..48b7172f81d6 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2142,10 +2142,10 @@ unsigned long shmem_get_unmapped_area(struct file *file,
return addr;
if (IS_ERR_VALUE(addr))
return addr;
- if (addr & ~PAGE_MASK)
- return addr;
+ if (offset_in_page(addr))
+ return -EINVAL;
if (addr > TASK_SIZE - len)
- return addr;
+ return -ENOMEM;
if (shmem_huge == SHMEM_HUGE_DENY)
return addr;
@@ -2196,7 +2196,7 @@ unsigned long shmem_get_unmapped_area(struct file *file,
inflated_addr = get_area(NULL, uaddr, inflated_len, 0, flags);
if (IS_ERR_VALUE(inflated_addr))
return addr;
- if (inflated_addr & ~PAGE_MASK)
+ if (offset_in_page(inflated_addr))
return addr;
inflated_offset = inflated_addr & (HPAGE_PMD_SIZE-1);
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v3 3/3] mm/shmem: rework calculation of inflated_addr in shmem_get_unmapped_area
2022-06-06 3:45 [PATCH v3 0/3] a few cleanup and bugfixes about shmem Chen Wandun
2022-06-06 3:45 ` [PATCH v3 1/3] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
2022-06-06 3:45 ` [PATCH v3 2/3] mm/shmem: return error code directly for invalid addr Chen Wandun
@ 2022-06-06 3:45 ` Chen Wandun
2 siblings, 0 replies; 6+ messages in thread
From: Chen Wandun @ 2022-06-06 3:45 UTC (permalink / raw)
To: hughd, akpm, linux-mm, linux-kernel, willy, david, wangkefeng.wang
Cc: chenwandun
In function shmem_get_unmapped_area, inflated_offset and offset
are unsigned long, it will result in underflow when offset below
inflated_offset, a little confusing, no functional change.
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
---
mm/shmem.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 48b7172f81d6..ac277b11bdfa 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2200,9 +2200,12 @@ unsigned long shmem_get_unmapped_area(struct file *file,
return addr;
inflated_offset = inflated_addr & (HPAGE_PMD_SIZE-1);
- inflated_addr += offset - inflated_offset;
- if (inflated_offset > offset)
+ if (offset > inflated_offset)
+ inflated_addr += offset - inflated_offset;
+ else if (offset < inflated_offset) {
+ inflated_addr -= inflated_offset - offset;
inflated_addr += HPAGE_PMD_SIZE;
+ }
if (inflated_addr > TASK_SIZE - len)
return addr;
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v3 1/3] mm/shmem: check return value of shmem_init_inodecache
2022-06-06 3:45 ` [PATCH v3 1/3] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
@ 2022-06-06 4:19 ` Hugh Dickins
2022-06-06 9:39 ` Muchun Song
1 sibling, 0 replies; 6+ messages in thread
From: Hugh Dickins @ 2022-06-06 4:19 UTC (permalink / raw)
To: Chen Wandun
Cc: hughd, akpm, linux-mm, linux-kernel, willy, david, wangkefeng.wang
On Mon, 6 Jun 2022, Chen Wandun wrote:
> It will result in null pointer access if shmem_init_inodecache fail,
> so check return value of shmem_init_inodecache
>
> Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Thank you, but NAK.
It's a pity that you've been put to the trouble of sending a v3, sorry
about that: but if SLAB_PANIC no longer works, or panic() has taken to
returning, then that's what needs fixing, not shmem_init_inodecache().
Was this one supposed to be the bugfix? And I'm afraid I don't care
for your "cleanups" in 2/3 and 3/3 either: a matter of taste, and our
tastes differ.
I'd rather not spend the time on these: maybe look for somewhere else
to change around than mm/shmem.c? Or better, please help us all by
using your time to review the functional patches being posted.
Thanks,
Hugh
> ---
> mm/shmem.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 12d45a03f7fc..7419ab219b97 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -3775,11 +3775,16 @@ static void shmem_init_inode(void *foo)
> inode_init_once(&info->vfs_inode);
> }
>
> -static void shmem_init_inodecache(void)
> +static int shmem_init_inodecache(void)
> {
> shmem_inode_cachep = kmem_cache_create("shmem_inode_cache",
> sizeof(struct shmem_inode_info),
> 0, SLAB_PANIC|SLAB_ACCOUNT, shmem_init_inode);
> +
> + if (!shmem_inode_cachep)
> + return -ENOMEM;
> +
> + return 0;
> }
>
> static void shmem_destroy_inodecache(void)
> @@ -3923,7 +3928,9 @@ void __init shmem_init(void)
> {
> int error;
>
> - shmem_init_inodecache();
> + error = shmem_init_inodecache();
> + if (error)
> + goto out2;
>
> error = register_filesystem(&shmem_fs_type);
> if (error) {
> --
> 2.25.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v3 1/3] mm/shmem: check return value of shmem_init_inodecache
2022-06-06 3:45 ` [PATCH v3 1/3] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
2022-06-06 4:19 ` Hugh Dickins
@ 2022-06-06 9:39 ` Muchun Song
1 sibling, 0 replies; 6+ messages in thread
From: Muchun Song @ 2022-06-06 9:39 UTC (permalink / raw)
To: Chen Wandun
Cc: hughd, akpm, linux-mm, linux-kernel, willy, david, wangkefeng.wang
On Mon, Jun 06, 2022 at 11:45:28AM +0800, Chen Wandun wrote:
> It will result in null pointer access if shmem_init_inodecache fail,
> so check return value of shmem_init_inodecache
>
> Signed-off-by: Chen Wandun <chenwandun@huawei.com>
> ---
> mm/shmem.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 12d45a03f7fc..7419ab219b97 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -3775,11 +3775,16 @@ static void shmem_init_inode(void *foo)
> inode_init_once(&info->vfs_inode);
> }
>
> -static void shmem_init_inodecache(void)
> +static int shmem_init_inodecache(void)
> {
> shmem_inode_cachep = kmem_cache_create("shmem_inode_cache",
> sizeof(struct shmem_inode_info),
> 0, SLAB_PANIC|SLAB_ACCOUNT, shmem_init_inode);
NACK, we cannot dereference a NULL pointer since SLAB_PANIC is passed
to kmem_cache_create().
> +
> + if (!shmem_inode_cachep)
> + return -ENOMEM;
> +
> + return 0;
> }
>
> static void shmem_destroy_inodecache(void)
> @@ -3923,7 +3928,9 @@ void __init shmem_init(void)
> {
> int error;
>
> - shmem_init_inodecache();
> + error = shmem_init_inodecache();
> + if (error)
> + goto out2;
>
> error = register_filesystem(&shmem_fs_type);
> if (error) {
> --
> 2.25.1
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-06-06 9:40 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2022-06-06 3:45 [PATCH v3 0/3] a few cleanup and bugfixes about shmem Chen Wandun
2022-06-06 3:45 ` [PATCH v3 1/3] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
2022-06-06 4:19 ` Hugh Dickins
2022-06-06 9:39 ` Muchun Song
2022-06-06 3:45 ` [PATCH v3 2/3] mm/shmem: return error code directly for invalid addr Chen Wandun
2022-06-06 3:45 ` [PATCH v3 3/3] mm/shmem: rework calculation of inflated_addr in shmem_get_unmapped_area Chen Wandun
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