* [PATCH 0/4] a few cleanup and bugfixes about shmem
@ 2022-06-01 12:44 Chen Wandun
2022-06-01 12:44 ` [PATCH 1/4] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
` (3 more replies)
0 siblings, 4 replies; 10+ messages in thread
From: Chen Wandun @ 2022-06-01 12:44 UTC (permalink / raw)
To: hughd, akpm, linux-mm, linux-kernel; +Cc: chenwandun
Chen Wandun (4):
mm/shmem: check return value of shmem_init_inodecache
mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned
mm/shmem: return error code directly
mm/shmem: rework calculation of inflated_addr in
shmem_get_unmapped_area
mm/shmem.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
--
2.25.1
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH 1/4] mm/shmem: check return value of shmem_init_inodecache
2022-06-01 12:44 [PATCH 0/4] a few cleanup and bugfixes about shmem Chen Wandun
@ 2022-06-01 12:44 ` Chen Wandun
2022-06-01 12:54 ` Matthew Wilcox
2022-06-01 12:44 ` [PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned Chen Wandun
` (2 subsequent siblings)
3 siblings, 1 reply; 10+ messages in thread
From: Chen Wandun @ 2022-06-01 12:44 UTC (permalink / raw)
To: hughd, akpm, linux-mm, linux-kernel; +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 | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index d55dd972023a..80c361c3d82c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3776,11 +3776,13 @@ static void shmem_init_inode(void *foo)
inode_init_once(&info->vfs_inode);
}
-static void shmem_init_inodecache(void)
+static struct kmem_cache *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);
+
+ return shmem_inode_cachep;
}
static void shmem_destroy_inodecache(void)
@@ -3924,7 +3926,10 @@ void __init shmem_init(void)
{
int error;
- shmem_init_inodecache();
+ if (!shmem_init_inodecache()) {
+ error = -ENOMEM;
+ goto out2;
+ }
error = register_filesystem(&shmem_fs_type);
if (error) {
--
2.25.1
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned
2022-06-01 12:44 [PATCH 0/4] a few cleanup and bugfixes about shmem Chen Wandun
2022-06-01 12:44 ` [PATCH 1/4] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
@ 2022-06-01 12:44 ` Chen Wandun
2022-06-01 13:37 ` David Hildenbrand
2022-06-01 12:44 ` [PATCH 3/4] mm/shmem: return error code directly Chen Wandun
2022-06-01 12:44 ` [PATCH 4/4] mm/shmem: rework calculation of inflated_addr in shmem_get_unmapped_area Chen Wandun
3 siblings, 1 reply; 10+ messages in thread
From: Chen Wandun @ 2022-06-01 12:44 UTC (permalink / raw)
To: hughd, akpm, linux-mm, linux-kernel; +Cc: chenwandun
If addr is not PAGE_SIZE aligned, return -EINVAL directly.
Besides, use macro offset_in_page to check addr is not
PAGE_SIZE aligned case.
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
---
mm/shmem.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 80c361c3d82c..1136dd7da9e5 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2143,8 +2143,8 @@ 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;
@@ -2197,7 +2197,7 @@ 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] 10+ messages in thread
* [PATCH 3/4] mm/shmem: return error code directly
2022-06-01 12:44 [PATCH 0/4] a few cleanup and bugfixes about shmem Chen Wandun
2022-06-01 12:44 ` [PATCH 1/4] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
2022-06-01 12:44 ` [PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned Chen Wandun
@ 2022-06-01 12:44 ` Chen Wandun
2022-06-01 12:44 ` [PATCH 4/4] mm/shmem: rework calculation of inflated_addr in shmem_get_unmapped_area Chen Wandun
3 siblings, 0 replies; 10+ messages in thread
From: Chen Wandun @ 2022-06-01 12:44 UTC (permalink / raw)
To: hughd, akpm, linux-mm, linux-kernel; +Cc: chenwandun
If [addr, addr + len) beyond TASK_SIZE, return error code directly.
No need to check this case in caller.
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
---
mm/shmem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 1136dd7da9e5..ca04f3975a8a 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2146,7 +2146,7 @@ unsigned long shmem_get_unmapped_area(struct file *file,
if (offset_in_page(addr))
return -EINVAL;
if (addr > TASK_SIZE - len)
- return addr;
+ return -ENOMEM;
if (shmem_huge == SHMEM_HUGE_DENY)
return addr;
--
2.25.1
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH 4/4] mm/shmem: rework calculation of inflated_addr in shmem_get_unmapped_area
2022-06-01 12:44 [PATCH 0/4] a few cleanup and bugfixes about shmem Chen Wandun
` (2 preceding siblings ...)
2022-06-01 12:44 ` [PATCH 3/4] mm/shmem: return error code directly Chen Wandun
@ 2022-06-01 12:44 ` Chen Wandun
3 siblings, 0 replies; 10+ messages in thread
From: Chen Wandun @ 2022-06-01 12:44 UTC (permalink / raw)
To: hughd, akpm, linux-mm, linux-kernel; +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 ca04f3975a8a..f12163bd0f69 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2201,9 +2201,12 @@ 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] 10+ messages in thread
* Re: [PATCH 1/4] mm/shmem: check return value of shmem_init_inodecache
2022-06-01 12:44 ` [PATCH 1/4] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
@ 2022-06-01 12:54 ` Matthew Wilcox
2022-06-01 13:34 ` Kefeng Wang
0 siblings, 1 reply; 10+ messages in thread
From: Matthew Wilcox @ 2022-06-01 12:54 UTC (permalink / raw)
To: Chen Wandun; +Cc: hughd, akpm, linux-mm, linux-kernel
On Wed, Jun 01, 2022 at 08:44:14PM +0800, Chen Wandun wrote:
> -static void shmem_init_inodecache(void)
> +static struct kmem_cache *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);
> +
> + return shmem_inode_cachep;
> }
>
> static void shmem_destroy_inodecache(void)
> @@ -3924,7 +3926,10 @@ void __init shmem_init(void)
> {
> int error;
>
> - shmem_init_inodecache();
> + if (!shmem_init_inodecache()) {
> + error = -ENOMEM;
> + goto out2;
> + }
better to return the errno from shmem_init_inodecache():
error = shmem_init_inodecache();
if (error)
goto out2;
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 1/4] mm/shmem: check return value of shmem_init_inodecache
2022-06-01 12:54 ` Matthew Wilcox
@ 2022-06-01 13:34 ` Kefeng Wang
0 siblings, 0 replies; 10+ messages in thread
From: Kefeng Wang @ 2022-06-01 13:34 UTC (permalink / raw)
To: Matthew Wilcox, Chen Wandun; +Cc: hughd, akpm, linux-mm, linux-kernel
On 2022/6/1 20:54, Matthew Wilcox wrote:
> On Wed, Jun 01, 2022 at 08:44:14PM +0800, Chen Wandun wrote:
>> -static void shmem_init_inodecache(void)
>> +static struct kmem_cache *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);
>> +
>> + return shmem_inode_cachep;
>> }
>>
>> static void shmem_destroy_inodecache(void)
>> @@ -3924,7 +3926,10 @@ void __init shmem_init(void)
>> {
>> int error;
>>
>> - shmem_init_inodecache();
>> + if (!shmem_init_inodecache()) {
>> + error = -ENOMEM;
>> + goto out2;
>> + }
> better to return the errno from shmem_init_inodecache():
>
> error = shmem_init_inodecache();
kmem_cache_create return a pointer to the cache on success, NULL on failure,
so error = -ENOMEM; is right :)
> if (error)
> goto out2;
>
> .
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned
2022-06-01 12:44 ` [PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned Chen Wandun
@ 2022-06-01 13:37 ` David Hildenbrand
2022-06-01 14:14 ` David Hildenbrand
0 siblings, 1 reply; 10+ messages in thread
From: David Hildenbrand @ 2022-06-01 13:37 UTC (permalink / raw)
To: Chen Wandun, hughd, akpm, linux-mm, linux-kernel
On 01.06.22 14:44, Chen Wandun wrote:
> If addr is not PAGE_SIZE aligned, return -EINVAL directly.
Why is this one to be treated in a special way compared to all of the
other related checks?
> Besides, use macro offset_in_page to check addr is not
> PAGE_SIZE aligned case.
Using offset_in_page() LGTM.
>
> Signed-off-by: Chen Wandun <chenwandun@huawei.com>
> ---
> mm/shmem.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 80c361c3d82c..1136dd7da9e5 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -2143,8 +2143,8 @@ 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;
>
> @@ -2197,7 +2197,7 @@ 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);
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned
2022-06-01 13:37 ` David Hildenbrand
@ 2022-06-01 14:14 ` David Hildenbrand
2022-06-05 2:05 ` Chen Wandun
0 siblings, 1 reply; 10+ messages in thread
From: David Hildenbrand @ 2022-06-01 14:14 UTC (permalink / raw)
To: Chen Wandun, hughd, akpm, linux-mm, linux-kernel
On 01.06.22 15:37, David Hildenbrand wrote:
> On 01.06.22 14:44, Chen Wandun wrote:
>> If addr is not PAGE_SIZE aligned, return -EINVAL directly.
>
> Why is this one to be treated in a special way compared to all of the
> other related checks?
Ah, I see you modify other places in other patches. Maybe just combine
all these return value changes into a single patch? That makes it look
less "special".
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned
2022-06-01 14:14 ` David Hildenbrand
@ 2022-06-05 2:05 ` Chen Wandun
0 siblings, 0 replies; 10+ messages in thread
From: Chen Wandun @ 2022-06-05 2:05 UTC (permalink / raw)
To: David Hildenbrand, hughd, akpm, linux-mm, linux-kernel
On 2022/6/1 22:14, David Hildenbrand wrote:
> On 01.06.22 15:37, David Hildenbrand wrote:
>> On 01.06.22 14:44, Chen Wandun wrote:
>>> If addr is not PAGE_SIZE aligned, return -EINVAL directly.
>> Why is this one to be treated in a special way compared to all of the
>> other related checks?
> Ah, I see you modify other places in other patches. Maybe just combine
> all these return value changes into a single patch? That makes it look
> less "special".
OK, patch 2 and patch 3 are used to return error value directly, I will
combine these patch
to a single patch in next version.
Thanks.
>
>
>
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2022-06-05 2:05 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
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2022-06-01 12:44 [PATCH 0/4] a few cleanup and bugfixes about shmem Chen Wandun
2022-06-01 12:44 ` [PATCH 1/4] mm/shmem: check return value of shmem_init_inodecache Chen Wandun
2022-06-01 12:54 ` Matthew Wilcox
2022-06-01 13:34 ` Kefeng Wang
2022-06-01 12:44 ` [PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned Chen Wandun
2022-06-01 13:37 ` David Hildenbrand
2022-06-01 14:14 ` David Hildenbrand
2022-06-05 2:05 ` Chen Wandun
2022-06-01 12:44 ` [PATCH 3/4] mm/shmem: return error code directly Chen Wandun
2022-06-01 12:44 ` [PATCH 4/4] mm/shmem: rework calculation of inflated_addr in shmem_get_unmapped_area Chen Wandun
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