* [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 [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
* [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 [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 [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-06-06 9:39 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 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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