This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <[email protected]>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <[email protected]>
Pull more MM updates from Andrew Morton:
- "mm/vmscan: fix demotion targets checks in reclaim/demotion" fixes a
couple of issues in the demotion code - pages were failed demotion
and were finding themselves demoted into disallowed nodes (Bing Jiao)
- "Remove XA_ZERO from error recovery of dup_mmap()" fixes a rare
mapledtree race and performs a number of cleanups (Liam Howlett)
- "mm: add bitmap VMA flag helpers and convert all mmap_prepare to use
them" implements a lot of cleanups following on from the conversion
of the VMA flags into a bitmap (Lorenzo Stoakes)
- "support batch checking of references and unmapping for large folios"
implements batching to greatly improve the performance of reclaiming
clean file-backed large folios (Baolin Wang)
- "selftests/mm: add memory failure selftests" does as claimed (Miaohe
Lin)
* tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (36 commits)
mm/page_alloc: clear page->private in free_pages_prepare()
selftests/mm: add memory failure dirty pagecache test
selftests/mm: add memory failure clean pagecache test
selftests/mm: add memory failure anonymous page test
mm: rmap: support batched unmapping for file large folios
arm64: mm: implement the architecture-specific clear_flush_young_ptes()
arm64: mm: support batch clearing of the young flag for large folios
arm64: mm: factor out the address and ptep alignment into a new helper
mm: rmap: support batched checks of the references for large folios
tools/testing/vma: add VMA userland tests for VMA flag functions
tools/testing/vma: separate out vma_internal.h into logical headers
tools/testing/vma: separate VMA userland tests into separate files
mm: make vm_area_desc utilise vma_flags_t only
mm: update all remaining mmap_prepare users to use vma_flags_t
mm: update shmem_[kernel]_file_*() functions to use vma_flags_t
mm: update secretmem to use VMA flags on mmap_prepare
mm: update hugetlbfs to use VMA flags on mmap_prepare
mm: add basic VMA flag operation helper functions
tools: bitmap: add missing bitmap_[subset(), andnot()]
mm: add mk_vma_flags() bitmap flag macro helper
...
It really doesn't matter if the user/admin knows what the last too big
value is. Record how many times this case is triggered would be helpful.
Solve the existing issue where relay_reset() doesn't restore the value.
Store the counter in the per-cpu buffer structure instead of the global
buffer structure. It also solves the racy condition which is likely to
happen when a few of per-cpu buffers encounter the too big data case and
then access the global field last_toobig without lock protection.
Remove the printk in relay_close() since kernel module can directly call
relay_stats() as they want.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jason Xing <[email protected]>
Reviewed-by: Yushan Zhou <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Steven Rostedt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
When using relay mechanism, we often encounter the case where new data are
lost or old unconsumed data are overwritten because of slow reader.
Add 'full' field in per-cpu buffer structure to detect if the above case
is happening. Relay has two modes: 1) non-overwrite mode, 2) overwrite
mode. So buffer being full here respectively means: 1) relayfs doesn't
intend to accept new data and then simply drop them, or 2) relayfs is
going to start over again and overwrite old unread data with new data.
Note: this counter doesn't need any explicit lock to protect from being
modified by different threads for the better performance consideration.
Writers calling __relay_write/relay_write should consider how to use the
lock and ensure it performs under the lock protection, thus it's not
necessary to add a new small lock here.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jason Xing <[email protected]>
Reviewed-by: Yushan Zhou <[email protected]>
Reviewed-by: Jens Axboe <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Steven Rostedt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Patch series "relayfs: misc changes", v5.
The series mostly focuses on the error counters which helps every user
debug their own kernel module.
This patch (of 5):
prev_padding represents the unused space of certain subbuffer. If the
content of a call of relay_write() exceeds the limit of the remainder of
this subbuffer, it will skip storing in the rest space and record the
start point as buf->prev_padding in relay_switch_subbuf(). Since the buf
is a per-cpu big buffer, the point of prev_padding as a global value for
the whole buffer instead of a single subbuffer (whose padding info is
stored in buf->padding[]) seems meaningless from the real use cases, so we
don't bother to record it any more.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jason Xing <[email protected]>
Reviewed-by: Yushan Zhou <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Steven Rostedt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
The last use of relay_late_setup_files() was removed in 2018 by commit
2b47733045 ("drm/i915/guc: Merge log relay file and channel creation")
Remove it and the helper it used.
relay_late_setup_files() was used for eventually registering 'buffer only'
channels. With it gone, delete the docs that explain how to do that.
Which suggests it should be possible to lose the 'has_base_filename'
flags.
(Are there any other uses??)
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Dr. David Alan Gilbert <[email protected]>
Reviewed-by: Jens Axboe <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andriy Shevchenko <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Improve readability and maintainability by replacing a hard coded string
allocation and formatting by using the kasprintf() helper.
It also eliminates the GCC compiler warning (with CONFIG_WERROR=y, which
is default, it becomes an error:
kernel/relay.c:357:42: error: `snprintf' output may be truncated before the last format character [-Werror=format-truncation=]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Documentation/filesystems/relay.rst says to use
return debugfs_create_file(filename, mode, parent, buf,
&relay_file_operations);
and this is the only way relay_file_operations is used.
Thus: debugfs_create_file(&relay_file_operations)
-> __debugfs_create_file(&debugfs_full_proxy_file_operations,
&relay_file_operations)
-> dentry{inode: {i_fop: &debugfs_full_proxy_file_operations},
d_fsdata: &relay_file_operations
| DEBUGFS_FSDATA_IS_REAL_FOPS_BIT}
debugfs_full_proxy_file_operations.open is full_proxy_open, which extracts
the &relay_file_operations from the dentry, and allocates via
__full_proxy_fops_init() new fops, with trivial wrappers around release,
llseek, read, write, poll, and unlocked_ioctl, then replaces the fops on
the opened file therewith.
Naturally, all thusly-created debugfs files have .splice_read = NULL.
This was introduced in commit 49d200deaa ("debugfs: prevent access to
removed files' private data") from 2016-03-22.
AFAICT, relay_file_operations is the only struct file_operations used for
debugfs which defines a .splice_read callback. Hooking it up with
> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> index 5063434be0fc..952fcf5b2afa 100644
> --- a/fs/debugfs/file.c
> +++ b/fs/debugfs/file.c
> @@ -328,6 +328,11 @@ FULL_PROXY_FUNC(write, ssize_t, filp,
> loff_t *ppos),
> ARGS(filp, buf, size, ppos));
>
> +FULL_PROXY_FUNC(splice_read, long, in,
> + PROTO(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe,
> + size_t len, unsigned int flags),
> + ARGS(in, ppos, pipe, len, flags));
> +
> FULL_PROXY_FUNC(unlocked_ioctl, long, filp,
> PROTO(struct file *filp, unsigned int cmd, unsigned long arg),
> ARGS(filp, cmd, arg));
> @@ -382,6 +387,8 @@ static void __full_proxy_fops_init(struct file_operations *proxy_fops,
> proxy_fops->write = full_proxy_write;
> if (real_fops->poll)
> proxy_fops->poll = full_proxy_poll;
> + if (real_fops->splice_read)
> + proxy_fops->splice_read = full_proxy_splice_read;
> if (real_fops->unlocked_ioctl)
> proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl;
> }
shows it just doesn't work, and splicing always instantly returns empty
(subsequent reads actually return the contents).
No-one noticed it became dead code in 2016, who knows if it worked back
then. Clearly no-one cares; just delete it.
Link: https://lkml.kernel.org/r/dtexwpw6zcdx7dkx3xj5gyjp5syxmyretdcbcdtvrnukd4vvuh@tarta.nabijaczleweli.xyz
Signed-off-by: Ahelenia Ziemiańska <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Li kunyu <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Zhang Zhengming <[email protected]>
Cc: Zhao Lei <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
There is a crash in relay_file_read, as the var from
point to the end of last subbuf.
The oops looks something like:
pc : __arch_copy_to_user+0x180/0x310
lr : relay_file_read+0x20c/0x2c8
Call trace:
__arch_copy_to_user+0x180/0x310
full_proxy_read+0x68/0x98
vfs_read+0xb0/0x1d0
ksys_read+0x6c/0xf0
__arm64_sys_read+0x20/0x28
el0_svc_common.constprop.3+0x84/0x108
do_el0_svc+0x74/0x90
el0_svc+0x1c/0x28
el0_sync_handler+0x88/0xb0
el0_sync+0x148/0x180
We get the condition by analyzing the vmcore:
1). The last produced byte and last consumed byte
both at the end of the last subbuf
2). A softirq calls function(e.g __blk_add_trace)
to write relay buffer occurs when an program is calling
relay_file_read_avail().
relay_file_read
relay_file_read_avail
relay_file_read_consume(buf, 0, 0);
//interrupted by softirq who will write subbuf
....
return 1;
//read_start point to the end of the last subbuf
read_start = relay_file_read_start_pos
//avail is equal to subsize
avail = relay_file_read_subbuf_avail
//from points to an invalid memory address
from = buf->start + read_start
//system is crashed
copy_to_user(buffer, from, avail)
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 8d62fdebda ("relay file read: start-pos fix")
Signed-off-by: Zhang Zhengming <[email protected]>
Reviewed-by: Zhao Lei <[email protected]>
Reviewed-by: Zhou Kete <[email protected]>
Reviewed-by: Pengcheng Yang <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Pointer buf is being assigned a value that is not being read, buf is being
re-assigned in the next starement. The assignment is redundant and can be
removed.
Cleans up clang scan build warning:
kernel/relay.c:443:8: warning: Although the value stored to 'buf' is
used in the enclosing expression, the value is never actually read
from 'buf' [deadcode.DeadStores]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Colin Ian King <[email protected]>
Reviewed-by: Jens Axboe <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Kalle Valo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Patch series "relay: cleanup and const callbacks", v2.
None of the relay users require the use of mutable structs for callbacks,
however the relay code does. Instead of assigning default callbacks when
there is none, add callback wrappers to conditionally call the client
callbacks if available, and fall back to default behaviour (typically
no-op) otherwise.
This lets all relay users make their struct rchan_callbacks const data.
This series starts with a number of cleanups first based on Christoph's
feedback.
This patch (of 9):
No relay client uses the buf_mapped or buf_unmapped callbacks. Remove
them. This makes relay's vm_operations_struct close callback a dummy,
remove it as well.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/c69fff6e0cd485563604240bbfcc028434983bec.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <[email protected]>
Suggested-by: Christoph Hellwig <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Kalle Valo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
The variable 'consumed' is initialized with the consumed count but
immediately after that the consumed count is updated and assigned to
'consumed' again thus overwriting the previous value. So, drop the
unneeded initialization.
Signed-off-by: Sudip Mukherjee <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
alloc_percpu() may return NULL, which means chan->buf may be set to NULL.
In that case, when we do *per_cpu_ptr(chan->buf, ...), we dereference an
invalid pointer:
BUG: Unable to handle kernel data access at 0x7dae0000
Faulting instruction address: 0xc0000000003f3fec
...
NIP relay_open+0x29c/0x600
LR relay_open+0x270/0x600
Call Trace:
relay_open+0x264/0x600 (unreliable)
__blk_trace_setup+0x254/0x600
blk_trace_setup+0x68/0xa0
sg_ioctl+0x7bc/0x2e80
do_vfs_ioctl+0x13c/0x1300
ksys_ioctl+0x94/0x130
sys_ioctl+0x48/0xb0
system_call+0x5c/0x68
Check if alloc_percpu returns NULL.
This was found by syzkaller both on x86 and powerpc, and the reproducer
it found on powerpc is capable of hitting the issue as an unprivileged
user.
Fixes: 017c59c042 ("relay: Use per CPU constructs for the relay channel buffer pointers")
Reported-by: [email protected]
Reported-by: [email protected]
Reported-by: [email protected]
Reported-by: [email protected]
Signed-off-by: Daniel Axtens <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Michael Ellerman <[email protected]>
Reviewed-by: Andrew Donnellan <[email protected]>
Acked-by: David Rientjes <[email protected]>
Cc: Akash Goel <[email protected]>
Cc: Andrew Donnellan <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Salvatore Bonaccorso <[email protected]>
Cc: <[email protected]> [4.10+]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
And replace the arcane return value convention with a simple bool
where true means success and false means failure.
[AV: braino fix folded in]
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Al Viro <[email protected]>
Pull misc vfs updates from Al Viro:
"Assorted fixes (really no common topic here)"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: Make __vfs_write() static
vfs: fix preadv64v2 and pwritev64v2 compat syscalls with offset == -1
pipe: stop using ->can_merge
splice: don't merge into linked buffers
fs: move generic stat response attr handling to vfs_getattr_nosec
orangefs: don't reinitialize result_mask in ->getattr
fs/devpts: always delete dcache dentry-s in dput()
Al Viro pointed out that since there is only one pipe buffer type to which
new data can be appended, it isn't necessary to have a ->can_merge field in
struct pipe_buf_operations, we can just check for a magic type.
Suggested-by: Al Viro <[email protected]>
Signed-off-by: Jann Horn <[email protected]>
Signed-off-by: Al Viro <[email protected]>
If create_buf_file() returns an error, don't try to reference it later
as a valid dentry pointer.
This problem was exposed when debugfs started to return errors instead
of just NULL for some calls when they do not succeed properly.
Also, the check for WARN_ON(dentry) was just wrong :)
Reported-by: Kees Cook <[email protected]>
Reported-and-tested-by: [email protected]
Reported-by: Tetsuo Handa <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: David Rientjes <[email protected]>
Fixes: ff9fb72bc0 ("debugfs: return error values, not NULL")
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Pull splice updates from Al Viro:
"These actually missed the last cycle; the branch itself is from last
December"
* 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
make nr_pages calculation in default_file_splice_read() a bit less ugly
splice/tee/vmsplice: validate flags
splice_pipe_desc: kill ->flags
remove spd_release_page()
Now that %z is standartised in C99 there is no reason to support %Z.
Unlike %L it doesn't even make format strings smaller.
Use BUILD_BUG_ON in a couple ATM drivers.
In case anyone didn't notice lib/vsprintf.o is about half of SLUB which
is in my opinion is quite an achievement. Hopefully this patch inspires
someone else to trim vsprintf.c more.
Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Relay avoids calling wake_up_interruptible() for doing the wakeup of
readers/consumers, waiting for the generation of new data, from the
context of a process which produced the data. This is apparently done to
prevent the possibility of a deadlock in case Scheduler itself is is
generating data for the relay, after acquiring rq->lock.
The following patch used a timer (to be scheduled at next jiffy), for
delegating the wakeup to another context.
commit 7c9cb38302
Author: Tom Zanussi <[email protected]>
Date: Wed May 9 02:34:01 2007 -0700
relay: use plain timer instead of delayed work
relay doesn't need to use schedule_delayed_work() for waking readers
when a simple timer will do.
Scheduling a plain timer, at next jiffies boundary, to do the wakeup
causes a significant wakeup latency for the Userspace client, which makes
relay less suitable for the high-frequency low-payload use cases where the
data gets generated at a very high rate, like multiple sub buffers getting
filled within a milli second. Moreover the timer is re-scheduled on every
newly produced sub buffer so the timer keeps getting pushed out if sub
buffers are filled in a very quick succession (less than a jiffy gap
between filling of 2 sub buffers). As a result relay runs out of sub
buffers to store the new data.
By using irq_work it is ensured that wakeup of userspace client, blocked
in the poll call, is done at earliest (through self IPI or next timer
tick) enabling it to always consume the data in time. Also this makes
relay consistent with printk & ring buffers (trace), as they too use
irq_work for deferred wake up of readers.
[[email protected]: select CONFIG_IRQ_WORK]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: coding-style fixes]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Peter Zijlstra <[email protected]>
Signed-off-by: Akash Goel <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Linus Torvalds