From Android 16 CDD:
[7.1.4.6/H-1-4] MUST report a GPU Frequency tracepoint as specified by
the format: power/gpu_frequency.
Bug: 457797217
Test: cat /sys/kernel/tracing/events/power/gpu_frequency/format
Change-Id: Ie8cd95cb8fe8471c2de19c48cdf57c8cf59f2370
Signed-off-by: Chia-I Wu <olv@google.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Chia-I Wuauthored and Sorayukiicommited 2026-05-15 18:04:22 +07:00
Move the source to a better place in Device Drivers -> Graphics support
now that its configurable.
v4:
- Move source location (Tvrtko)
v3:
- Patch introduced to replace per-driver config (Lucas)
Change-Id: I50da95e8b65029ddfa525b83a182e7bc54693a13
Signed-off-by: Juston Li <justonli@chromium.org>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250611225145.1739201-1-justonli@chromium.org
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Juston Liauthored and Sorayukiicommited 2026-05-15 18:04:22 +07:00
This change adds the below gpu memory tracepoint:
gpu_mem/gpu_mem_total: track global or proc gpu memory total usages
Per process tracking of total gpu memory usage in the gem layer is not
appropriate and hard to implement with trivial overhead. So for the gfx
device driver layer to track total gpu memory usage both globally and
per process in an easy and uniform way is to integrate the tracepoint in
this patch to the underlying varied implementations of gpu memory
tracking system from vendors.
Putting this tracepoint in the common trace events can not only help
wean the gfx drivers off of debugfs but also greatly help the downstream
Android gpu vendors because debugfs is to be deprecated in the upcoming
Android release. Then the gpu memory tracking of both Android kernel and
the upstream linux kernel can stay closely, which can benefit the whole
kernel eco-system in the long term.
Link: http://lkml.kernel.org/r/20200302235044.59163-1-zzyiwei@google.com
Bug: 154523335
Test: saw this tracepoint on Pixel after gfx driver integration
Change-Id: Ia6f273015c656e7a286041d850e83e49fd063aa4
(cherry picked from commit bbd9d05618a6d608c72640b1d3d651a75913456a)
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yiwei Zhang <zzyiwei@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Yiwei Zhangauthored and Sorayukiicommited 2026-05-15 18:04:21 +07:00
Android uses ashmem for sharing memory regions. We are looking forward
to migrating all usecases of ashmem to memfd so that we can possibly
remove the ashmem driver in the future from staging while also
benefiting from using memfd and contributing to it. Note staging drivers
are also not ABI and generally can be removed at anytime.
One of the main usecases Android has is the ability to create a region
and mmap it as writeable, then add protection against making any
"future" writes while keeping the existing already mmap'ed
writeable-region active. This allows us to implement a usecase where
receivers of the shared memory buffer can get a read-only view, while
the sender continues to write to the buffer.
See CursorWindow documentation in Android for more details:
https://developer.android.com/reference/android/database/CursorWindow
This usecase cannot be implemented with the existing F_SEAL_WRITE seal.
To support the usecase, this patch adds a new F_SEAL_FUTURE_WRITE seal
which prevents any future mmap and write syscalls from succeeding while
keeping the existing mmap active.
Verified with test program at: https://lore.kernel.org/patchwork/patch/1008117/
Backport link: https://lore.kernel.org/patchwork/patch/1014892/
Bug: 113362644
Change-Id: If7424db3b64372932d455f0219cd9df613fec1d4
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Joel Fernandesauthored and Sorayukiicommited 2026-05-15 18:04:21 +07:00
Being interrupted by a signal during binder ioctls is not unusual.
Commit 218225c05beaf02320f05a9b3b7041e27a0684f7 changed the interrupted
ioctl return code from ERESTARTSYS to EINTR, but the error logging check
was never updated:
[ 352.090265] binder: 6534:6552 ioctl c0306201 7a0f9fea10 returned -4
[ 352.090393] binder: 6534:7670 ioctl c0306201 7a6489da10 returned -4
[ 352.090432] binder: 6534:9501 ioctl c0306201 7a61377a10 returned -4
Update the return code to fix the log spam.
[orges]: this is not actually a duplicate commit. the log is pretty much
the same except it returns -512
Signed-off-by: Danny Lin <danny@kdrag0n.dev>
Signed-off-by: Oktapra Amtono <oktapra.amtono@gmail.com>
Signed-off-by: Forenche <prahul2003@gmail.com>
Signed-off-by: Cyber Knight <cyberknight755@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Danny Linauthored and Sorayukiicommited 2026-05-15 18:04:21 +07:00
In binder, using GFP_HIGHMEM will result in the allocated memory
not to be mapped in the kernel's virtual address space.
This prevents the kernel from being capable of directly
referring it.
Change-Id: I952dbc8ae205e47fa00ddf186ef306903f623367
Signed-off-by: Panchajanya1999 <panchajanya@azure-dev.live>
Signed-off-by: Forenche <prahul2003@gmail.com>
Signed-off-by: Cyber Knight <cyberknight755@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Panchajanya1999authored and Sorayukiicommited 2026-05-15 18:04:20 +07:00
Most of binder's memory allocations are tiny, and they're allocated
and freed extremely frequently. The latency from going through the page
allocator all the time for such small allocations ends up being quite
high, especially when the system is low on memory. Binder is
performance-critical, so this is suboptimal.
Instead of using kzalloc to allocate a struct every time, reserve caches
specifically for allocating each struct quickly.
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Signed-off-by: Danny Lin <danny@kdrag0n.dev>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Sultan Alsawafauthored and Sorayukiicommited 2026-05-15 18:04:20 +07:00
Binder code is very hot, so checking frequently to see if a debug
message should be printed is a waste of cycles. We're not debugging
binder, so just stub out the debug prints to compile them out entirely.
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Sultan Alsawafauthored and Sorayukiicommited 2026-05-15 18:04:20 +07:00
Provide userspace with a mechanism to discover features supported by
the binder driver to refrain from using any unsupported ones in the
first place. Starting with "oneway_spam_detection" only new features
are to be listed under binderfs and all previous ones are assumed to
be supported.
Assuming an instance of binderfs has been mounted at /dev/binderfs,
binder feature files can be found under /dev/binderfs/features/.
Usage example:
$ mkdir /dev/binderfs
$ mount -t binder binder /dev/binderfs
$ cat /dev/binderfs/features/oneway_spam_detection
1
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20210715031805.1725878-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Carlos Llamasauthored and Sorayukiicommited 2026-05-15 18:04:20 +07:00
The pointer n is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and can be removed.
Acked-by: Todd Kjos <tkjos@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200910151221.751464-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Colin Ian Kingauthored and Sorayukiicommited 2026-05-15 18:04:20 +07:00
The function close_fd_get_file is explicitly a variant of
__close_fd[1]. Now that __close_fd has been renamed close_fd, rename
close_fd_get_file to be consistent with close_fd.
When __alloc_fd, __close_fd and __fd_install were introduced the
double underscore indicated that the function took a struct
files_struct parameter. The function __close_fd_get_file never has so
the naming has always been inconsistent. This just cleans things up
so there are not any lingering mentions or references __close_fd left
in the code.
[1] 80cd795630d6 ("binder: fix use-after-free due to ksys_close() during fdget()")
Link: https://lkml.kernel.org/r/20201120231441.29911-23-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Eric W. Biedermanauthored and Sorayukiicommited 2026-05-15 18:04:20 +07:00
Since the original trace_binder_transaction_received cannot
precisely present the real finished time of transaction, adding a
trace_binder_txn_latency_free at the point of free transaction
may be more close to it.
Signed-off-by: Frankie.Chang <Frankie.Chang@mediatek.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/1605063764-12930-3-git-send-email-Frankie.Chang@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Frankie.Changauthored and Sorayukiicommited 2026-05-15 18:04:19 +07:00
Commit e00eb41c0c7b ("ANDROID: binder: add support for RT prio
inheritance.") added the use of MAX_USER_RT_PRIO to the binder.c code,
but that commit was never sent upstream.
In commit ae18ad281e82 ("sched: Remove MAX_USER_RT_PRIO"), that define
was taken away, so to fix up the build breakage, move the binder code to
use MAX_RT_PRIO instead of the now-removed MAX_USER_RT_PRIO define.
Hopefully this is correct, who knows, it's binder RT code! :)
Bug: 34461621
Bug: 37293077
Bug: 120446518
Fixes: e00eb41c0c7b ("ANDROID: binder: add support for RT prio inheritance.")
Fixes: ae18ad281e82 ("sched: Remove MAX_USER_RT_PRIO")
Cc: Martijn Coenen <maco@google.com>
Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: Alistair Strachan <astrachan@google.com>
Cc: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I66b85e99697fdde462ec2d2ade5c92d5917896a3
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Greg Kroah-Hartmanauthored and Sorayukiicommited 2026-05-15 18:04:19 +07:00
In the case of a failed transaction, only the thread and process id are
logged. Add the handle info for the reference to the target node in user
error log to aid debugging.
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Ramji Jiyani <ramjiyani@google.com>
Link: https://lore.kernel.org/r/20210802220446.1938347-1-ramjiyani@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Ramji Jiyaniauthored and Sorayukiicommited 2026-05-15 18:04:19 +07:00
Depending on the context, the error return value
here (extra_buffers_size < added_size) should be
negative.
Acked-by: Martijn Coenen <maco@android.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20201026110314.135481-1-zhangqilong3@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Zhang Qilongauthored and Sorayukiicommited 2026-05-15 18:04:19 +07:00
This was a "temporary" reversion to workaround what is believed to be a user-space issue.
Change-Id: I5322aecfe57cd8237e6657525eb33975c4840059
Bug: 166779391
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Todd Kjosauthored and Sorayukiicommited 2026-05-15 18:04:19 +07:00
if-else block
Remove braces for both if and else block as suggested by checkpatch.
Signed-off-by: Mrinal Pandey <mrinalmni@gmail.com>
Link: https://lore.kernel.org/r/20200724131403.dahfhdwa3wirzkxj@mrinalpandey
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Mrinal Pandeyauthored and Sorayukiicommited 2026-05-15 18:04:19 +07:00
Just one caller of this, and just use filp_close() there manually.
This is important to allow async close/removal of the fd.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Jens Axboeauthored and Sorayukiicommited 2026-05-15 18:04:18 +07:00
upstream commit: 80cd795630
this is a partial commit as binder was picked separately
Signed-off-by: Jebaitedneko <Jebaitedneko@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Jebaitednekoauthored and Sorayukiicommited 2026-05-15 18:04:18 +07:00
This is a partial revert of commit
29bc22ac5e5b ("binder: use euid from cred instead of using task").
Setting sender_euid using proc->cred caused some Android system test
regressions that need further investigation. It is a partial
reversion because subsequent patches rely on proc->cred.
Fixes: 29bc22ac5e5b ("binder: use euid from cred instead of using task")
Cc: stable@vger.kernel.org # 4.4+
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Change-Id: I9b1769a3510fed250bb21859ef8beebabe034c66
Link: https://lore.kernel.org/r/20211112180720.2858135-1-tkjos@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bug: 200688826
(cherry picked from commit c21a80ca0684ec2910344d72556c816cb8940c01
git: //git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git char-misc-linus)
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Todd Kjosauthored and Sorayukiicommited 2026-05-15 18:04:18 +07:00
commit 29bc22ac5e5bc63275e850f0c8fc549e3d0e306b upstream.
Save the 'struct cred' associated with a binder process
at initial open to avoid potential race conditions
when converting to an euid.
Set a transaction's sender_euid from the 'struct cred'
saved at binder_open() instead of looking up the euid
from the binder proc's 'struct task'. This ensures
the euid is associated with the security context that
of the task that opened binder.
Cc: stable@vger.kernel.org # 4.4+
Fixes: 457b9a6f09 ("Staging: android: add binder driver")
Signed-off-by: Todd Kjos <tkjos@google.com>
Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Suggested-by: Jann Horn <jannh@google.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Change-Id: I91922e7f359df5901749f1b09094c3c68d45aed4
Bug: 200688826
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Todd Kjosauthored and Sorayukiicommited 2026-05-15 18:04:18 +07:00
Commit b0a0c2615f6f ("epoll: wire up syscall epoll_pwait2") wired up
the 64 bit syscall instead of the compat variant in a couple of places.
Fixes: b0a0c2615f6f ("epoll: wire up syscall epoll_pwait2")
Change-Id: Ida2267e953240c036d64bc61177ee72bb20f35a3
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Heiko Carstensauthored and Sorayukiicommited 2026-05-15 18:04:17 +07:00
Split off from prev patch in the series that implements the syscall.
Link: https://lkml.kernel.org/r/20201121144401.3727659-4-willemdebruijn.kernel@gmail.com
Change-Id: I48dfae6f721b24ebc53de603e393289954a95908
Signed-off-by: Willem de Bruijn <willemb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Willem de Bruijnauthored and Sorayukiicommited 2026-05-15 18:04:17 +07:00
Add syscall epoll_pwait2, an epoll_wait variant with nsec resolution that
replaces int timeout with struct timespec. It is equivalent otherwise.
int epoll_pwait2(int fd, struct epoll_event *events,
int maxevents,
const struct timespec *timeout,
const sigset_t *sigset);
The underlying hrtimer is already programmed with nsec resolution.
pselect and ppoll also set nsec resolution timeout with timespec.
The sigset_t in epoll_pwait has a compat variant. epoll_pwait2 needs
the same.
For timespec, only support this new interface on 2038 aware platforms
that define __kernel_timespec_t. So no CONFIG_COMPAT_32BIT_TIME.
Link: https://lkml.kernel.org/r/20201121144401.3727659-3-willemdebruijn.kernel@gmail.com
Change-Id: I8cb4e756aacb4bee7cbe1c2cb5320a59e07626f8
Signed-off-by: Willem de Bruijn <willemb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Willem de Bruijnauthored and Sorayukiicommited 2026-05-15 18:04:17 +07:00
Patch series "add epoll_pwait2 syscall", v4.
Enable nanosecond timeouts for epoll.
Analogous to pselect and ppoll, introduce an epoll_wait syscall
variant that takes a struct timespec instead of int timeout.
This patch (of 4):
Make epoll more consistent with select/poll: pass along the timeout as
timespec64 pointer.
In anticipation of additional changes affecting all three polling
mechanisms:
- add epoll_pwait2 syscall with timespec semantics,
and share poll_select_set_timeout implementation.
- compute slack before conversion to absolute time,
to save one ktime_get_ts64 call.
Link: https://lkml.kernel.org/r/20201121144401.3727659-1-willemdebruijn.kernel@gmail.com
Link: https://lkml.kernel.org/r/20201121144401.3727659-2-willemdebruijn.kernel@gmail.com
Change-Id: Id5851ad620849d202d18a99351a98b8bc3b6820a
Signed-off-by: Willem de Bruijn <willemb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Willem de Bruijnauthored and Sorayukiicommited 2026-05-15 18:04:17 +07:00
Using the helper functions do_epoll_create() and do_epoll_wait() allows us
to remove in-kernel calls to the related syscall functions.
This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Change-Id: I73c8f43d7db845e0b7ec5ec00fbc575fbcb8ca5e
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Dominik Brodowskiauthored and Sorayukiicommited 2026-05-15 18:04:17 +07:00
It never looked too pleasant and it doesn't really buy us anything
anymore now that CLOSE_RANGE_CLOEXEC exists and we need to retake the
current maximum under the lock for it anyway. This also makes the logic
easier to follow.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Giuseppe Scrivano <gscrivan@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Change-Id: I72be5b078d7edc061318b0eda36a351e1dc01e56
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Christian Braunerauthored and Sorayukiicommited 2026-05-15 18:04:16 +07:00
syzbot reported a bug when putting the last reference to a tasks file
descriptor table. Debugging this showed we didn't recalculate the
current maximum fd number for CLOSE_RANGE_UNSHARE | CLOSE_RANGE_CLOEXEC
after we unshared the file descriptors table. So max_fd could exceed the
current fdtable maximum causing us to set excessive bits. As a concrete
example, let's say the user requested everything from fd 4 to ~0UL to be
closed and their current fdtable size is 256 with their highest open fd
being 4. With CLOSE_RANGE_UNSHARE the caller will end up with a new
fdtable which has room for 64 file descriptors since that is the lowest
fdtable size we accept. But now max_fd will still point to 255 and needs
to be adjusted. Fix this by retrieving the correct maximum fd value in
__range_cloexec().
Reported-by: syzbot+283ce5a46486d6acdbaf@syzkaller.appspotmail.com
Fixes: 582f1fb6b721 ("fs, close_range: add flag CLOSE_RANGE_CLOEXEC")
Fixes: fec8a6a69103 ("close_range: unshare all fds for CLOSE_RANGE_UNSHARE | CLOSE_RANGE_CLOEXEC")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Giuseppe Scrivano <gscrivan@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: stable@vger.kernel.org
Change-Id: Ib6aeb02d2b4556ba048cd4ca8150f9d2c29abdb3
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Christian Braunerauthored and Sorayukiicommited 2026-05-15 18:04:16 +07:00
After introducing CLOSE_RANGE_CLOEXEC syzbot reported a crash when
CLOSE_RANGE_CLOEXEC is specified in conjunction with CLOSE_RANGE_UNSHARE.
When CLOSE_RANGE_UNSHARE is specified the caller will receive a private
file descriptor table in case their file descriptor table is currently
shared.
For the case where the caller has requested all file descriptors to be
actually closed via e.g. close_range(3, ~0U, 0) the kernel knows that
the caller does not need any of the file descriptors anymore and will
optimize the close operation by only copying all files in the range from
0 to 3 and no others.
However, if the caller requested CLOSE_RANGE_CLOEXEC together with
CLOSE_RANGE_UNSHARE the caller wants to still make use of the file
descriptors so the kernel needs to copy all of them and can't optimize.
The original patch didn't account for this and thus could cause oopses
as evidenced by the syzbot report because it assumed that all fds had
been copied. Fix this by handling the CLOSE_RANGE_CLOEXEC case.
syzbot reported
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:71 [inline]
BUG: KASAN: null-ptr-deref in atomic64_read include/asm-generic/atomic-instrumented.h:837 [inline]
BUG: KASAN: null-ptr-deref in atomic_long_read include/asm-generic/atomic-long.h:29 [inline]
BUG: KASAN: null-ptr-deref in filp_close+0x22/0x170 fs/open.c:1274
Read of size 8 at addr 0000000000000077 by task syz-executor511/8522
CPU: 1 PID: 8522 Comm: syz-executor511 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x107/0x163 lib/dump_stack.c:120
__kasan_report mm/kasan/report.c:549 [inline]
kasan_report.cold+0x5/0x37 mm/kasan/report.c:562
check_memory_region_inline mm/kasan/generic.c:186 [inline]
check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
instrument_atomic_read include/linux/instrumented.h:71 [inline]
atomic64_read include/asm-generic/atomic-instrumented.h:837 [inline]
atomic_long_read include/asm-generic/atomic-long.h:29 [inline]
filp_close+0x22/0x170 fs/open.c:1274
close_files fs/file.c:402 [inline]
put_files_struct fs/file.c:417 [inline]
put_files_struct+0x1cc/0x350 fs/file.c:414
exit_files+0x12a/0x170 fs/file.c:435
do_exit+0xb4f/0x2a00 kernel/exit.c:818
do_group_exit+0x125/0x310 kernel/exit.c:920
get_signal+0x428/0x2100 kernel/signal.c:2792
arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
handle_signal_work kernel/entry/common.c:147 [inline]
exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
exit_to_user_mode_prepare+0x124/0x200 kernel/entry/common.c:201
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x447039
Code: Unable to access opcode bytes at RIP 0x44700f.
RSP: 002b:00007f1b1225cdb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00000000006dbc28 RCX: 0000000000447039
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00000000006dbc2c
RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
R13: 00007fff223b6bef R14: 00007f1b1225d9c0 R15: 00000000006dbc2c
==================================================================
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-and-tested-by: syzbot+96cfd2b22b3213646a93@syzkaller.appspotmail.com
Tested on:
commit: 10f7cddd selftests/core: add regression test for CLOSE_RAN..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git vfs
kernel config: https://syzkaller.appspot.com/x/.config?x=5d42216b510180e3
dashboard link: https://syzkaller.appspot.com/bug?extid=96cfd2b22b3213646a93
compiler: gcc (GCC) 10.1.0-syz 20200507
Reported-by: syzbot+96cfd2b22b3213646a93@syzkaller.appspotmail.com
Fixes: 582f1fb6b721 ("fs, close_range: add flag CLOSE_RANGE_CLOEXEC")
Cc: Giuseppe Scrivano <gscrivan@redhat.com>
Cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20201217213303.722643-1-christian.brauner@ubuntu.com
Change-Id: I92120c3f81e2811d3a2a1a76fa60cf2e75a56f42
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Christian Braunerauthored and Sorayukiicommited 2026-05-15 18:04:16 +07:00
When the flag CLOSE_RANGE_CLOEXEC is set, close_range doesn't
immediately close the files but it sets the close-on-exec bit.
It is useful for e.g. container runtimes that usually install a
seccomp profile "as late as possible" before execv'ing the container
process itself. The container runtime could either do:
1 2
- install_seccomp_profile(); - close_range(MIN_FD, MAX_INT, 0);
- close_range(MIN_FD, MAX_INT, 0); - install_seccomp_profile();
- execve(...); - execve(...);
Both alternative have some disadvantages.
In the first variant the seccomp_profile cannot block the close_range
syscall, as well as opendir/read/close/... for the fallback on older
kernels.
In the second variant, close_range() can be used only on the fds
that are not going to be needed by the runtime anymore, and it must be
potentially called multiple times to account for the different ranges
that must be closed.
Using close_range(..., ..., CLOSE_RANGE_CLOEXEC) solves these issues.
The runtime is able to use the existing open fds, the seccomp profile
can block close_range() and the syscalls used for its fallback.
Change-Id: I1c84a733698c2853a0126cd22960ada25b229c5a
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Link: https://lore.kernel.org/r/20201118104746.873084-2-gscrivan@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Giuseppe Scrivanoauthored and Sorayukiicommited 2026-05-15 18:04:16 +07:00
One of the use-cases of close_range() is to drop file descriptors just before
execve(). This would usually be expressed in the sequence:
unshare(CLONE_FILES);
close_range(3, ~0U);
as pointed out by Linus it might be desirable to have this be a part of
close_range() itself under a new flag CLOSE_RANGE_UNSHARE.
This expands {dup,unshare)_fd() to take a max_fds argument that indicates the
maximum number of file descriptors to copy from the old struct files. When the
user requests that all file descriptors are supposed to be closed via
close_range(min, max) then we can cap via unshare_fd(min) and hence don't need
to do any of the heavy fput() work for everything above min.
The patch makes it so that if CLOSE_RANGE_UNSHARE is requested and we do in
fact currently share our file descriptor table we create a new private copy.
We then close all fds in the requested range and finally after we're done we
install the new fd table.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: I0813045886501e40a45693ee1edad50bdf2b66e5
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Christian Braunerauthored and Sorayukiicommited 2026-05-15 18:04:16 +07:00
This adds the close_range() syscall. It allows to efficiently close a range
of file descriptors up to all file descriptors of a calling task.
I was contacted by FreeBSD as they wanted to have the same close_range()
syscall as we proposed here. We've coordinated this and in the meantime, Kyle
was fast enough to merge close_range() into FreeBSD already in April:
https://reviews.freebsd.org/D21627https://svnweb.freebsd.org/base?view=revision&revision=359836
and the current plan is to backport close_range() to FreeBSD 12.2 (cf. [2])
once its merged in Linux too. Python is in the process of switching to
close_range() on FreeBSD and they are waiting on us to merge this to switch on
Linux as well: https://bugs.python.org/issue38061
The syscall came up in a recent discussion around the new mount API and
making new file descriptor types cloexec by default. During this
discussion, Al suggested the close_range() syscall (cf. [1]). Note, a
syscall in this manner has been requested by various people over time.
First, it helps to close all file descriptors of an exec()ing task. This
can be done safely via (quoting Al's example from [1] verbatim):
/* that exec is sensitive */
unshare(CLONE_FILES);
/* we don't want anything past stderr here */
close_range(3, ~0U);
execve(....);
The code snippet above is one way of working around the problem that file
descriptors are not cloexec by default. This is aggravated by the fact that
we can't just switch them over without massively regressing userspace. For
a whole class of programs having an in-kernel method of closing all file
descriptors is very helpful (e.g. demons, service managers, programming
language standard libraries, container managers etc.).
(Please note, unshare(CLONE_FILES) should only be needed if the calling
task is multi-threaded and shares the file descriptor table with another
thread in which case two threads could race with one thread allocating file
descriptors and the other one closing them via close_range(). For the
general case close_range() before the execve() is sufficient.)
Second, it allows userspace to avoid implementing closing all file
descriptors by parsing through /proc/<pid>/fd/* and calling close() on each
file descriptor. From looking at various large(ish) userspace code bases
this or similar patterns are very common in:
- service managers (cf. [4])
- libcs (cf. [6])
- container runtimes (cf. [5])
- programming language runtimes/standard libraries
- Python (cf. [2])
- Rust (cf. [7], [8])
As Dmitry pointed out there's even a long-standing glibc bug about missing
kernel support for this task (cf. [3]).
In addition, the syscall will also work for tasks that do not have procfs
mounted and on kernels that do not have procfs support compiled in. In such
situations the only way to make sure that all file descriptors are closed
is to call close() on each file descriptor up to UINT_MAX or RLIMIT_NOFILE,
OPEN_MAX trickery (cf. comment [8] on Rust).
The performance is striking. For good measure, comparing the following
simple close_all_fds() userspace implementation that is essentially just
glibc's version in [6]:
static int close_all_fds(void)
{
int dir_fd;
DIR *dir;
struct dirent *direntp;
dir = opendir("/proc/self/fd");
if (!dir)
return -1;
dir_fd = dirfd(dir);
while ((direntp = readdir(dir))) {
int fd;
if (strcmp(direntp->d_name, ".") == 0)
continue;
if (strcmp(direntp->d_name, "..") == 0)
continue;
fd = atoi(direntp->d_name);
if (fd == dir_fd || fd == 0 || fd == 1 || fd == 2)
continue;
close(fd);
}
closedir(dir);
return 0;
}
to close_range() yields:
1. closing 4 open files:
- close_all_fds(): ~280 us
- close_range(): ~24 us
2. closing 1000 open files:
- close_all_fds(): ~5000 us
- close_range(): ~800 us
close_range() is designed to allow for some flexibility. Specifically, it
does not simply always close all open file descriptors of a task. Instead,
callers can specify an upper bound.
This is e.g. useful for scenarios where specific file descriptors are
created with well-known numbers that are supposed to be excluded from
getting closed.
For extra paranoia close_range() comes with a flags argument. This can e.g.
be used to implement extension. Once can imagine userspace wanting to stop
at the first error instead of ignoring errors under certain circumstances.
There might be other valid ideas in the future. In any case, a flag
argument doesn't hurt and keeps us on the safe side.
From an implementation side this is kept rather dumb. It saw some input
from David and Jann but all nonsense is obviously my own!
- Errors to close file descriptors are currently ignored. (Could be changed
by setting a flag in the future if needed.)
- __close_range() is a rather simplistic wrapper around __close_fd().
My reasoning behind this is based on the nature of how __close_fd() needs
to release an fd. But maybe I misunderstood specifics:
We take the files_lock and rcu-dereference the fdtable of the calling
task, we find the entry in the fdtable, get the file and need to release
files_lock before calling filp_close().
In the meantime the fdtable might have been altered so we can't just
retake the spinlock and keep the old rcu-reference of the fdtable
around. Instead we need to grab a fresh reference to the fdtable.
If my reasoning is correct then there's really no point in fancyfying
__close_range(): We just need to rcu-dereference the fdtable of the
calling task once to cap the max_fd value correctly and then go on
calling __close_fd() in a loop.
/* References */
[1]: https://lore.kernel.org/lkml/20190516165021.GD17978@ZenIV.linux.org.uk/
[2]: 9e4f2f3a6b/Modules/_posixsubprocess.c (L220)
[3]: https://sourceware.org/bugzilla/show_bug.cgi?id=10353#c7
[4]: 5238e95759/src/basic/fd-util.c (L217)
[5]: ddf4b77e11/src/lxc/start.c (L236)
[6]: https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/grantpt.c;h=2030e07fa6e652aac32c775b8c6e005844c3c4eb;hb=HEAD#l17
Note that this is an internal implementation that is not exported.
Currently, libc seems to not provide an exported version of this
because of missing kernel support to do this.
Note, in a recent patch series Florian made grantpt() a nop thereby
removing the code referenced here.
[7]: https://github.com/rust-lang/rust/issues/12148
[8]: 5f47c0613e/src/libstd/sys/unix/process2.rs (L303-L308)
Rust's solution is slightly different but is equally unperformant.
Rust calls getdtablesize() which is a glibc library function that
simply returns the current RLIMIT_NOFILE or OPEN_MAX values. Rust then
goes on to call close() on each fd. That's obviously overkill for most
tasks. Rarely, tasks - especially non-demons - hit RLIMIT_NOFILE or
OPEN_MAX.
Let's be nice and assume an unprivileged user with RLIMIT_NOFILE set
to 1024. Even in this case, there's a very high chance that in the
common case Rust is calling the close() syscall 1021 times pointlessly
if the task just has 0, 1, and 2 open.
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Change-Id: I2f7abcf9210a1e79855837d1b7c580cc7f7a38e2
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kyle Evans <self@kyle-evans.net>
Cc: Jann Horn <jannh@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Dmitry V. Levin <ldv@altlinux.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: linux-api@vger.kernel.org
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Christian Braunerauthored and Sorayukiicommited 2026-05-15 18:04:15 +07:00
Introduce MADV_WIPEONFORK semantics, which result in a VMA being empty
in the child process after fork. This differs from MADV_DONTFORK in one
important way.
If a child process accesses memory that was MADV_WIPEONFORK, it will get
zeroes. The address ranges are still valid, they are just empty.
If a child process accesses memory that was MADV_DONTFORK, it will get a
segmentation fault, since those address ranges are no longer valid in
the child after fork.
Since MADV_DONTFORK also seems to be used to allow very large programs
to fork in systems with strict memory overcommit restrictions, changing
the semantics of MADV_DONTFORK might break existing programs.
MADV_WIPEONFORK only works on private, anonymous VMAs.
The use case is libraries that store or cache information, and want to
know that they need to regenerate it in the child process after fork.
Examples of this would be:
- systemd/pulseaudio API checks (fail after fork) (replacing a getpid
check, which is too slow without a PID cache)
- PKCS#11 API reinitialization check (mandated by specification)
- glibc's upcoming PRNG (reseed after fork)
- OpenSSL PRNG (reseed after fork)
The security benefits of a forking server having a re-inialized PRNG in
every child process are pretty obvious. However, due to libraries
having all kinds of internal state, and programs getting compiled with
many different versions of each library, it is unreasonable to expect
calling programs to re-initialize everything manually after fork.
A further complication is the proliferation of clone flags, programs
bypassing glibc's functions to call clone directly, and programs calling
unshare, causing the glibc pthread_atfork hook to not get called.
It would be better to have the kernel take care of this automatically.
The patch also adds MADV_KEEPONFORK, to undo the effects of a prior
MADV_WIPEONFORK.
This is similar to the OpenBSD minherit syscall with MAP_INHERIT_ZERO:
https://man.openbsd.org/minherit.2
[akpm@linux-foundation.org: numerically order arch/parisc/include/uapi/asm/mman.h #defines]
Link: http://lkml.kernel.org/r/20170811212829.29186-3-riel@redhat.com
Signed-off-by: Rik van Riel <riel@redhat.com>
Reported-by: Florian Weimer <fweimer@redhat.com>
Reported-by: Colm MacCártaigh <colm@allcosts.net>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Cc: <linux-api@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Rik van Rielauthored and Sorayukiicommited 2026-05-15 18:04:15 +07:00
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