The patch titled
Subject: mm/damon/dbgfs: fix missed use of damon_dbgfs_lock
has been added to the -mm tree. Its filename is
mm-damon-dbgfs-fix-missed-use-of-damon_dbgfs_lock.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-damon-dbgfs-fix-missed-use-of-…
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-damon-dbgfs-fix-missed-use-of-…
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: SeongJae Park <sj(a)kernel.org>
Subject: mm/damon/dbgfs: fix missed use of damon_dbgfs_lock
DAMON debugfs is supposed to protect dbgfs_ctxs, dbgfs_nr_ctxs, and
dbgfs_dirs using damon_dbgfs_lock. However, some of the code is accessing
the variables without the protection. This commit fixes it by protecting
all such accesses.
Link: https://lkml.kernel.org/r/20211110145758.16558-3-sj@kernel.org
Fixes: 75c1c2b53c78 ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/damon/dbgfs.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
--- a/mm/damon/dbgfs.c~mm-damon-dbgfs-fix-missed-use-of-damon_dbgfs_lock
+++ a/mm/damon/dbgfs.c
@@ -877,12 +877,14 @@ static ssize_t dbgfs_monitor_on_write(st
return -EINVAL;
}
+ mutex_lock(&damon_dbgfs_lock);
if (!strncmp(kbuf, "on", count)) {
int i;
for (i = 0; i < dbgfs_nr_ctxs; i++) {
if (damon_targets_empty(dbgfs_ctxs[i])) {
kfree(kbuf);
+ mutex_unlock(&damon_dbgfs_lock);
return -EINVAL;
}
}
@@ -892,6 +894,7 @@ static ssize_t dbgfs_monitor_on_write(st
} else {
ret = -EINVAL;
}
+ mutex_unlock(&damon_dbgfs_lock);
if (!ret)
ret = count;
@@ -944,15 +947,16 @@ static int __init __damon_dbgfs_init(voi
static int __init damon_dbgfs_init(void)
{
- int rc;
+ int rc = -ENOMEM;
+ mutex_lock(&damon_dbgfs_lock);
dbgfs_ctxs = kmalloc(sizeof(*dbgfs_ctxs), GFP_KERNEL);
if (!dbgfs_ctxs)
- return -ENOMEM;
+ goto out;
dbgfs_ctxs[0] = dbgfs_new_ctx();
if (!dbgfs_ctxs[0]) {
kfree(dbgfs_ctxs);
- return -ENOMEM;
+ goto out;
}
dbgfs_nr_ctxs = 1;
@@ -963,6 +967,8 @@ static int __init damon_dbgfs_init(void)
pr_err("%s: dbgfs init failed\n", __func__);
}
+out:
+ mutex_unlock(&damon_dbgfs_lock);
return rc;
}
_
Patches currently in -mm which might be from sj(a)kernel.org are
mm-damon-dbgfs-use-__gfp_nowarn-for-user-specified-size-buffer-allocation.patch
mm-damon-dbgfs-fix-missed-use-of-damon_dbgfs_lock.patch
The patch titled
Subject: mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation
has been added to the -mm tree. Its filename is
mm-damon-dbgfs-use-__gfp_nowarn-for-user-specified-size-buffer-allocation.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-damon-dbgfs-use-__gfp_nowarn-f…
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-damon-dbgfs-use-__gfp_nowarn-f…
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: SeongJae Park <sj(a)kernel.org>
Subject: mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation
Patch series "DAMON fixes".
This patch (of 2):
DAMON users can trigger below warning in '__alloc_pages()' by invoking
write() to some DAMON debugfs files with arbitrarily high count argument,
because DAMON debugfs interface allocates some buffers based on the
user-specified 'count'.
if (unlikely(order >= MAX_ORDER)) {
WARN_ON_ONCE(!(gfp & __GFP_NOWARN));
return NULL;
}
Because the DAMON debugfs interface code checks failure of the
'kmalloc()', this commit simply suppresses the warnings by adding
'__GFP_NOWARN' flag.
Link: https://lkml.kernel.org/r/20211110145758.16558-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211110145758.16558-2-sj@kernel.org
Fixes: 4bc05954d007 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/damon/dbgfs.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/mm/damon/dbgfs.c~mm-damon-dbgfs-use-__gfp_nowarn-for-user-specified-size-buffer-allocation
+++ a/mm/damon/dbgfs.c
@@ -32,7 +32,7 @@ static char *user_input_str(const char _
if (*ppos)
return ERR_PTR(-EINVAL);
- kbuf = kmalloc(count + 1, GFP_KERNEL);
+ kbuf = kmalloc(count + 1, GFP_KERNEL | __GFP_NOWARN);
if (!kbuf)
return ERR_PTR(-ENOMEM);
@@ -133,7 +133,7 @@ static ssize_t dbgfs_schemes_read(struct
char *kbuf;
ssize_t len;
- kbuf = kmalloc(count, GFP_KERNEL);
+ kbuf = kmalloc(count, GFP_KERNEL | __GFP_NOWARN);
if (!kbuf)
return -ENOMEM;
@@ -452,7 +452,7 @@ static ssize_t dbgfs_init_regions_read(s
char *kbuf;
ssize_t len;
- kbuf = kmalloc(count, GFP_KERNEL);
+ kbuf = kmalloc(count, GFP_KERNEL | __GFP_NOWARN);
if (!kbuf)
return -ENOMEM;
@@ -578,7 +578,7 @@ static ssize_t dbgfs_kdamond_pid_read(st
char *kbuf;
ssize_t len;
- kbuf = kmalloc(count, GFP_KERNEL);
+ kbuf = kmalloc(count, GFP_KERNEL | __GFP_NOWARN);
if (!kbuf)
return -ENOMEM;
_
Patches currently in -mm which might be from sj(a)kernel.org are
mm-damon-dbgfs-use-__gfp_nowarn-for-user-specified-size-buffer-allocation.patch
mm-damon-dbgfs-fix-missed-use-of-damon_dbgfs_lock.patch
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 86432a6dca9bed79111990851df5756d3eb5f57c Mon Sep 17 00:00:00 2001
From: Gao Xiang <hsiangkao(a)linux.alibaba.com>
Date: Thu, 4 Nov 2021 02:20:06 +0800
Subject: [PATCH] erofs: fix unsafe pagevec reuse of hooked pclusters
There are pclusters in runtime marked with Z_EROFS_PCLUSTER_TAIL
before actual I/O submission. Thus, the decompression chain can be
extended if the following pcluster chain hooks such tail pcluster.
As the related comment mentioned, if some page is made of a hooked
pcluster and another followed pcluster, it can be reused for in-place
I/O (since I/O should be submitted anyway):
_______________________________________________________________
| tail (partial) page | head (partial) page |
|_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________|
However, it's by no means safe to reuse as pagevec since if such
PRIMARY_HOOKED pclusters finally move into bypass chain without I/O
submission. It's somewhat hard to reproduce with LZ4 and I just found
it (general protection fault) by ro_fsstressing a LZMA image for long
time.
I'm going to actively clean up related code together with multi-page
folio adaption in the next few months. Let's address it directly for
easier backporting for now.
Call trace for reference:
z_erofs_decompress_pcluster+0x10a/0x8a0 [erofs]
z_erofs_decompress_queue.isra.36+0x3c/0x60 [erofs]
z_erofs_runqueue+0x5f3/0x840 [erofs]
z_erofs_readahead+0x1e8/0x320 [erofs]
read_pages+0x91/0x270
page_cache_ra_unbounded+0x18b/0x240
filemap_get_pages+0x10a/0x5f0
filemap_read+0xa9/0x330
new_sync_read+0x11b/0x1a0
vfs_read+0xf1/0x190
Link: https://lore.kernel.org/r/20211103182006.4040-1-xiang@kernel.org
Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support")
Cc: <stable(a)vger.kernel.org> # 4.19+
Reviewed-by: Chao Yu <chao(a)kernel.org>
Signed-off-by: Gao Xiang <hsiangkao(a)linux.alibaba.com>
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 11c7a1aaebad..eb51df4a9f77 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -373,8 +373,8 @@ static bool z_erofs_try_inplace_io(struct z_erofs_collector *clt,
/* callers must be with collection lock held */
static int z_erofs_attach_page(struct z_erofs_collector *clt,
- struct page *page,
- enum z_erofs_page_type type)
+ struct page *page, enum z_erofs_page_type type,
+ bool pvec_safereuse)
{
int ret;
@@ -384,9 +384,9 @@ static int z_erofs_attach_page(struct z_erofs_collector *clt,
z_erofs_try_inplace_io(clt, page))
return 0;
- ret = z_erofs_pagevec_enqueue(&clt->vector, page, type);
+ ret = z_erofs_pagevec_enqueue(&clt->vector, page, type,
+ pvec_safereuse);
clt->cl->vcnt += (unsigned int)ret;
-
return ret ? 0 : -EAGAIN;
}
@@ -729,7 +729,8 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED);
retry:
- err = z_erofs_attach_page(clt, page, page_type);
+ err = z_erofs_attach_page(clt, page, page_type,
+ clt->mode >= COLLECT_PRIMARY_FOLLOWED);
/* should allocate an additional short-lived page for pagevec */
if (err == -EAGAIN) {
struct page *const newpage =
@@ -737,7 +738,7 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
set_page_private(newpage, Z_EROFS_SHORTLIVED_PAGE);
err = z_erofs_attach_page(clt, newpage,
- Z_EROFS_PAGE_TYPE_EXCLUSIVE);
+ Z_EROFS_PAGE_TYPE_EXCLUSIVE, true);
if (!err)
goto retry;
}
diff --git a/fs/erofs/zpvec.h b/fs/erofs/zpvec.h
index dfd7fe0503bb..b05464f4a808 100644
--- a/fs/erofs/zpvec.h
+++ b/fs/erofs/zpvec.h
@@ -106,11 +106,18 @@ static inline void z_erofs_pagevec_ctor_init(struct z_erofs_pagevec_ctor *ctor,
static inline bool z_erofs_pagevec_enqueue(struct z_erofs_pagevec_ctor *ctor,
struct page *page,
- enum z_erofs_page_type type)
+ enum z_erofs_page_type type,
+ bool pvec_safereuse)
{
- if (!ctor->next && type)
- if (ctor->index + 1 == ctor->nr)
+ if (!ctor->next) {
+ /* some pages cannot be reused as pvec safely without I/O */
+ if (type == Z_EROFS_PAGE_TYPE_EXCLUSIVE && !pvec_safereuse)
+ type = Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED;
+
+ if (type != Z_EROFS_PAGE_TYPE_EXCLUSIVE &&
+ ctor->index + 1 == ctor->nr)
return false;
+ }
if (ctor->index >= ctor->nr)
z_erofs_pagevec_ctor_pagedown(ctor, false);
The patch below does not apply to the 5.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 0706f74f719e6e72c3a862ab2990796578fa73cc Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy(a)kernel.org>
Date: Wed, 10 Nov 2021 00:01:45 +0900
Subject: [PATCH] MIPS: fix *-pkg builds for loongson2ef platform
Since commit 805b2e1d427a ("kbuild: include Makefile.compiler only when
compiler is needed"), package builds for the loongson2f platform fail.
$ make ARCH=mips CROSS_COMPILE=mips64-linux- lemote2f_defconfig bindeb-pkg
[ snip ]
sh ./scripts/package/builddeb
arch/mips/loongson2ef//Platform:36: *** only binutils >= 2.20.2 have needed option -mfix-loongson2f-nop. Stop.
cp: cannot stat '': No such file or directory
make[5]: *** [scripts/Makefile.package:87: intdeb-pkg] Error 1
make[4]: *** [Makefile:1558: intdeb-pkg] Error 2
make[3]: *** [debian/rules:13: binary-arch] Error 2
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
make[2]: *** [scripts/Makefile.package:83: bindeb-pkg] Error 2
make[1]: *** [Makefile:1558: bindeb-pkg] Error 2
make: *** [Makefile:350: __build_one_by_one] Error 2
The reason is because "make image_name" fails.
$ make ARCH=mips CROSS_COMPILE=mips64-linux- image_name
arch/mips/loongson2ef//Platform:36: *** only binutils >= 2.20.2 have needed option -mfix-loongson2f-nop. Stop.
In general, adding $(error ...) in the parse stage is troublesome,
and it is pointless to check toolchains even if we are not building
anything. Do not include Kbuild.platform in such cases.
Fixes: 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed")
Reported-by: Jason Self <jason(a)bluehome.net>
Signed-off-by: Masahiro Yamada <masahiroy(a)kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend(a)alpha.franken.de>
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index ea3cd080a1c7..f7b58da2f388 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -254,7 +254,9 @@ endif
#
# Board-dependent options and extra files
#
+ifdef need-compiler
include $(srctree)/arch/mips/Kbuild.platforms
+endif
ifdef CONFIG_PHYSICAL_START
load-y = $(CONFIG_PHYSICAL_START)
commit 0706f74f719e6e72c3a862ab2990796578fa73cc upstream.
Since commit 805b2e1d427a ("kbuild: include Makefile.compiler only when
compiler is needed"), package builds for the loongson2f platform fail.
$ make ARCH=mips CROSS_COMPILE=mips64-linux- lemote2f_defconfig bindeb-pkg
[ snip ]
sh ./scripts/package/builddeb
arch/mips/loongson2ef//Platform:36: *** only binutils >= 2.20.2 have needed option -mfix-loongson2f-nop. Stop.
cp: cannot stat '': No such file or directory
make[5]: *** [scripts/Makefile.package:87: intdeb-pkg] Error 1
make[4]: *** [Makefile:1558: intdeb-pkg] Error 2
make[3]: *** [debian/rules:13: binary-arch] Error 2
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
make[2]: *** [scripts/Makefile.package:83: bindeb-pkg] Error 2
make[1]: *** [Makefile:1558: bindeb-pkg] Error 2
make: *** [Makefile:350: __build_one_by_one] Error 2
The reason is because "make image_name" fails.
$ make ARCH=mips CROSS_COMPILE=mips64-linux- image_name
arch/mips/loongson2ef//Platform:36: *** only binutils >= 2.20.2 have needed option -mfix-loongson2f-nop. Stop.
In general, adding $(error ...) in the parse stage is troublesome,
and it is pointless to check toolchains even if we are not building
anything. Do not include Kbuild.platform in such cases.
Fixes: 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed")
Reported-by: Jason Self <jason(a)bluehome.net>
Signed-off-by: Masahiro Yamada <masahiroy(a)kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend(a)alpha.franken.de>
---
arch/mips/Makefile | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 653befc1b176..0dfef0beaaaa 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -254,7 +254,9 @@ endif
#
# Board-dependent options and extra files
#
+ifdef need-compiler
include arch/mips/Kbuild.platforms
+endif
ifdef CONFIG_PHYSICAL_START
load-y = $(CONFIG_PHYSICAL_START)
--
2.30.2