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A problem exists in enabling silent stream when connection type is
DisplayPort. Silent stream programming is completed when a new DP
receiver is connected, but infoframe transmission does not actually
start until PCM is opened for the first time. This can result in audible
gap of multiple seconds. This only affects the first PCM open.
Fix the issue by properly assigning a converter to the silent stream,
and modifying the required stream ID programming sequence.
This change only affects Intel display audio codecs.
BugLink: https://github.com/thesofproject/linux/issues/2468
Fixes: 951894cf30f4 ("ALSA: hda/hdmi: Add Intel silent stream support")
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20201210174445.3134104-1-kai.vehmanen@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Now that unshare_files happens in begin_new_exec after the point of no
return, io_uring_task_cancel can also happen later.
Effectively this means io_uring activities for a task are only canceled
when exec succeeds.
Link: https://lkml.kernel.org/r/878saih2op.fsf@x220.int.ebiederm.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Oleg Nesterov recently asked[1] why is there an unshare_files in
do_coredump. After digging through all of the callers of lookup_fd it
turns out that it is
arch/powerpc/platforms/cell/spufs/coredump.c:coredump_next_context
that needs the unshare_files in do_coredump.
Looking at the history[2] this code was also the only piece of coredump code
that required the unshare_files when the unshare_files was added.
Looking at that code it turns out that cell is also the only
architecture that implements elf_coredump_extra_notes_size and
elf_coredump_extra_notes_write.
I looked at the gdb repo[3] support for cell has been removed[4] in binutils
2.34. Geoff Levand reports he is still getting questions on how to
run modern kernels on the PS3, from people using 3rd party firmware so
this code is not dead. According to Wikipedia the last PS3 shipped in
Japan sometime in 2017. So it will probably be a little while before
everyone's hardware dies.
Add some comments briefly documenting the coredump code that exists
only to support cell spufs to make it easier to understand the
coredump code. Eventually the hardware will be dead, or their won't
be userspace tools, or the coredump code will be refactored and it
will be too difficult to update a dead architecture and these comments
make it easy to tell where to pull to remove cell spufs support.
[1] https://lkml.kernel.org/r/20201123175052.GA20279@redhat.com
[2] 179e037fc137 ("do_coredump(): make sure that descriptor table isn't shared")
[3] git://sourceware.org/git/binutils-gdb.git
[4] abf516c6931a ("Remove Cell Broadband Engine debugging support").
Link: https://lkml.kernel.org/r/87h7pdnlzv.fsf_-_@x220.int.ebiederm.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Change the Input Source enumerated control's strings to make it play
nice with pulseaudio.
Fixes: 7cb9d94c05de9 ("ALSA: hda/ca0132: add alt_select_in/out for R3Di + SBZ")
Cc: <stable@kernel.org>
Signed-off-by: Connor McAdams <conmanx360@gmail.com>
Link: https://lore.kernel.org/r/20201208195223.424753-2-conmanx360@gmail.com
Link: https://lore.kernel.org/r/20201210173550.2968-2-conmanx360@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The Windows driver sets the pincfg for the AE-5's rear-headphone to
report as a microphone. This causes issues with Pulseaudio mistakenly
believing there is no headphone plugged in. In Linux, we should instead
set it to be a headphone.
Fixes: a6b0961b39896 ("ALSA: hda/ca0132 - fix AE-5 pincfg")
Cc: <stable@kernel.org>
Signed-off-by: Connor McAdams <conmanx360@gmail.com>
Link: https://lore.kernel.org/r/20201208195223.424753-1-conmanx360@gmail.com
Link: https://lore.kernel.org/r/20201210173550.2968-1-conmanx360@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Steinberg UR22 (with USB ID 0499:1509) requires the implicit feedback
for the proper playback, otherwise it causes occasional cracks.
This patch adds the corresponding the quirk table entry with the
recently added generic implicit fb support.
Reported-and-tested-by: Kilian <meschi@posteo.de>
Link: https://lore.kernel.org/r/20201209161835.13625-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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It seems that the HD-audio clear and reconfig sysfs don't work any
longer after the recent driver core change. There are multiple issues
around that: the linked list corruption and the dead device handling.
The former issue is fixed by another patch for the driver core itself,
while the latter patch needs to be addressed in HD-audio side.
This patch corresponds to the latter, it recovers those broken
functions by replacing the device detach and attach actions with the
standard core API functions, which are almost equivalent with unbind
and bind actions.
Fixes: 654888327e9f ("driver core: Avoid binding drivers to dead devices")
Cc: <stable@vger.kernel.org>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209207
Link: https://lore.kernel.org/r/20201209150119.7705-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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A while ago it was reported that posix file locking goes wrong when a
multi-threaded process calls exec. I looked into the history and this
is definitely a regression, that should be fixed if we can.
This set of changes cleanups of the code in exec so hopefully this code
will not regress again. Then it adds helpers and fixes the users of
files_struct so the reference count is only incremented if COPY_FILES is
passed to clone (or if io_uring takes a reference). Then it removes
helpers (get_files_struct, __install_fd, __alloc_fd, __close_fd) that
are no longer needed and if used would encourage code that increments
the count of files_struct somewhere besides in clone when COPY_FILES is
passed.
In addition to fixing the bug in exec and simplifing the code this set
of changes by virtue of getting files_struct.count correct it optimizes
fdget. With proc and other places not temporarily increasing the count
on files_struct __fget_light should succeed more often in being able to
return a struct file without touching it's reference count.
Fixing the count in files_struct was suggested by Oleg[1].
For those that are interested in the history of this issue I have
included as much of it as I could find in the first change.
Since v1:
- Renamed the functions
__fcheck_files -> files_lookup_fd_raw
fcheck_files -> files_lookup_fd_locked
fcheck_files -> files_lookup_fd_rcu
fcheck_files -> lookup_fd_rcu
fcheck_task -> task_lookup_fd_rcu
fnext_task -> task_lookup_next_fd_rcu
__close_fd_get_file -> close_fd_get_file
- Simplified get_file_raw_ptr
- Removed ksys_close
- Examined the penalty for taking task_lock. The helper
task_lookup_next_fd_rcu takes task_lock each iteration. Concern was
expressed that this might be a problem. The function tid_fd_mode
isn called from tid_fd_revalidate which is called when ever a file
descriptor file is stat'ed, opened, or otherwise accessed. The
function tid_fd_mode histrocally called get_files_struct which took
and dropped task_lock. So the volume of task_lock calls is already
proportional to the number of file descriptors. A micro benchmark
did not see the move to task_lookup_next_fd_rcu making a difference
in performance. Which suggests that the change to taking the task
lock for every file descriptor found in task_lookup_next_fd will not
be a problem.
- Reviewed the code for conflicts with io_uring (especially the
removal of get_files_struct). To my surprise no conflicts were
found as io_uring does not use standard helpers but instead rolls
it's own version of get_files_struct by hand.
Documentation/filesystems/files.rst | 8 +-
arch/powerpc/platforms/cell/spufs/coredump.c | 2 +-
drivers/android/binder.c | 2 +-
fs/autofs/dev-ioctl.c | 5 +-
fs/coredump.c | 5 +-
fs/exec.c | 29 +++----
fs/file.c | 124 +++++++++++++--------------
fs/io_uring.c | 2 +-
fs/locks.c | 14 +--
fs/notify/dnotify/dnotify.c | 2 +-
fs/open.c | 2 +-
fs/proc/fd.c | 48 ++++-------
include/linux/fdtable.h | 40 +++++----
include/linux/syscalls.h | 12 ---
kernel/bpf/syscall.c | 20 +----
kernel/bpf/task_iter.c | 44 +++-------
kernel/fork.c | 12 +--
kernel/kcmp.c | 29 ++-----
18 files changed, 153 insertions(+), 247 deletions(-)
Eric W. Biederman (25):
exec: Don't open code get_close_on_exec
exec: Move unshare_files to fix posix file locking during exec
exec: Simplify unshare_files
exec: Remove reset_files_struct
kcmp: In kcmp_epoll_target use fget_task
bpf: In bpf_task_fd_query use fget_task
proc/fd: In proc_fd_link use fget_task
file: Rename __fcheck_files to files_lookup_fd_raw
file: Factor files_lookup_fd_locked out of fcheck_files
file: Replace fcheck_files with files_lookup_fd_rcu
file: Rename fcheck lookup_fd_rcu
file: Implement task_lookup_fd_rcu
proc/fd: In tid_fd_mode use task_lookup_fd_rcu
kcmp: In get_file_raw_ptr use task_lookup_fd_rcu
file: Implement task_lookup_next_fd_rcu
proc/fd: In proc_readfd_common use task_lookup_next_fd_rcu
bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu
proc/fd: In fdinfo seq_show don't use get_files_struct
file: Merge __fd_install into fd_install
file: In f_dupfd read RLIMIT_NOFILE once.
file: Merge __alloc_fd into alloc_fd
file: Rename __close_fd to close_fd and remove the files parameter
file: Replace ksys_close with close_fd
file: Rename __close_fd_get_file close_fd_get_file
file: Remove get_files_struct
[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
v1: https://lkml.kernel.org/r/87ft8l6ic3.fsf@x220.int.ebiederm.org
Reported-by: Jeff Layton <jlayton@redhat.com>
Reported-by: Daniel P. Berrangé <berrange@redhat.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/87r1on1v62.fsf@x220.int.ebiederm.org
Link: https://lists.openvz.org/pipermail/criu/2020-November/045123.html
Link: https://marc.info/?l=openvz-criu&m=160591423214257
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Replace a comma between expression statements by a semicolon.
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201209135550.2004-1-zhengyongjun3@huawei.com
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git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media fixes from Mauro Carvalho Chehab:
"A couple of fixes:
- videobuf2: fix a DMABUF bug, preventing it to properly handle cache
sync/flush
- vidtv: an usage after free and a few sparse/smatch warning fixes
- pulse8-cec: a duplicate free and a bug related to new firmware
usage
- mtk-cir: fix a regression on a clock setting"
* tag 'media/v5.10-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
media: vidtv: fix some warnings
media: vidtv: fix kernel-doc markups
media: [next] media: vidtv: fix a read from an object after it has been freed
media: vb2: set cache sync hints when init buffers
media: pulse8-cec: add support for FW v10 and up
media: pulse8-cec: fix duplicate free at disconnect or probe error
media: mtk-cir: fix calculation of chk period
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Added retry mechanism to ensure VMM enable bit is set during the
block transfer of data between host and WILC FW.
Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201208103739.28597-1-ajay.kathat@microchip.com
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git://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/iwlwifi-next
iwlwifi patches intended for v5.11
* A few fixes and improvements in the FW debugging framework;
* A fix in the HE capabilities settings;
* Small fix in the logs for SAR;
* Move queue code to a common place;
* Support for 6GHz;
* Improve validation of firmware notifications;
* Debugging improvements and fixes;
* Replace terminology with inclusive words determined by the guidelines;
* Convert copyright notices to SPDX tags;
* Added more validations for firmware notifications;
* A couple of debugging/recovery fixes;
* Added some more validations for firmware notifications;
* Support for a new type of HW;
* A couple of channel switch fixes;
* Support new FW reset handshake;
* Add a couple of RX handlers that were accidentally left out;
* Some other clean-ups and small fixes;
# gpg: Signature made Thu 10 Dec 2020 12:19:59 AM EET using RSA key ID 1A3CC5FA
# gpg: Good signature from "Luciano Roth Coelho (Luca) <luca@coelho.fi>"
# gpg: aka "Luciano Roth Coelho (Intel) <luciano.coelho@intel.com>"
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When discussing[1] exec and posix file locks it was realized that none
of the callers of get_files_struct fundamentally needed to call
get_files_struct, and that by switching them to helper functions
instead it will both simplify their code and remove unnecessary
increments of files_struct.count. Those unnecessary increments can
result in exec unnecessarily unsharing files_struct which breaking
posix locks, and it can result in fget_light having to fallback to
fget reducing system performance.
Now that get_files_struct has no more users and can not cause the
problems for posix file locking and fget_light remove get_files_struct
so that it does not gain any new users.
[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-13-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-24-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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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>
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Now that ksys_close is exactly identical to close_fd replace
the one caller of ksys_close with close_fd.
[1] https://lkml.kernel.org/r/20200818112020.GA17080@infradead.org
Suggested-by: Christoph Hellwig <hch@infradead.org>
Link: https://lkml.kernel.org/r/20201120231441.29911-22-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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The function __close_fd was added to support binder[1]. Now that
binder has been fixed to no longer need __close_fd[2] all calls
to __close_fd pass current->files.
Therefore transform the files parameter into a local variable
initialized to current->files, and rename __close_fd to close_fd to
reflect this change, and keep it in sync with the similar changes to
__alloc_fd, and __fd_install.
This removes the need for callers to care about the extra care that
needs to be take if anything except current->files is passed, by
limiting the callers to only operation on current->files.
[1] 483ce1d4b8c3 ("take descriptor-related part of close() to file.c")
[2] 44d8047f1d87 ("binder: use standard functions to allocate fds")
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-17-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-21-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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The function __alloc_fd was added to support binder[1]. With binder
fixed[2] there are no more users.
As alloc_fd just calls __alloc_fd with "files=current->files",
merge them together by transforming the files parameter into a
local variable initialized to current->files.
[1] dcfadfa4ec5a ("new helper: __alloc_fd()")
[2] 44d8047f1d87 ("binder: use standard functions to allocate fds")
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-16-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-20-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Simplify the code, and remove the chance of races by reading
RLIMIT_NOFILE only once in f_dupfd.
Pass the read value of RLIMIT_NOFILE into alloc_fd which is the other
location the rlimit was read in f_dupfd. As f_dupfd is the only
caller of alloc_fd this changing alloc_fd is trivially safe.
Further this causes alloc_fd to take all of the same arguments as
__alloc_fd except for the files_struct argument.
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-15-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-19-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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The function __fd_install was added to support binder[1]. With binder
fixed[2] there are no more users.
As fd_install just calls __fd_install with "files=current->files",
merge them together by transforming the files parameter into a
local variable initialized to current->files.
[1] f869e8a7f753 ("expose a low-level variant of fd_install() for binder")
[2] 44d8047f1d87 ("binder: use standard functions to allocate fds")
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1:https://lkml.kernel.org/r/20200817220425.9389-14-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-18-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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When discussing[1] exec and posix file locks it was realized that none
of the callers of get_files_struct fundamentally needed to call
get_files_struct, and that by switching them to helper functions
instead it will both simplify their code and remove unnecessary
increments of files_struct.count. Those unnecessary increments can
result in exec unnecessarily unsharing files_struct which breaking
posix locks, and it can result in fget_light having to fallback to
fget reducing system performance.
Instead hold task_lock for the duration that task->files needs to be
stable in seq_show. The task_lock was already taken in
get_files_struct, and so skipping get_files_struct performs less work
overall, and avoids the problems with the files_struct reference
count.
[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-12-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-17-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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When discussing[1] exec and posix file locks it was realized that none
of the callers of get_files_struct fundamentally needed to call
get_files_struct, and that by switching them to helper functions
instead it will both simplify their code and remove unnecessary
increments of files_struct.count. Those unnecessary increments can
result in exec unnecessarily unsharing files_struct which breaking
posix locks, and it can result in fget_light having to fallback to
fget reducing system performance.
Using task_lookup_next_fd_rcu simplifies task_file_seq_get_next, by
moving the checking for the maximum file descritor into the generic
code, and by remvoing the need for capturing and releasing a reference
on files_struct. As the reference count of files_struct no longer
needs to be maintained bpf_iter_seq_task_file_info can have it's files
member removed and task_file_seq_get_next no longer needs it's fstruct
argument.
The curr_fd local variable does need to become unsigned to be used
with fnext_task. As curr_fd is assigned from and assigned a u32
making curr_fd an unsigned int won't cause problems and might prevent
them.
[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-11-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-16-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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When discussing[1] exec and posix file locks it was realized that none
of the callers of get_files_struct fundamentally needed to call
get_files_struct, and that by switching them to helper functions
instead it will both simplify their code and remove unnecessary
increments of files_struct.count. Those unnecessary increments can
result in exec unnecessarily unsharing files_struct which breaking
posix locks, and it can result in fget_light having to fallback to
fget reducing system performance.
Using task_lookup_next_fd_rcu simplifies proc_readfd_common, by moving
the checking for the maximum file descritor into the generic code, and
by remvoing the need for capturing and releasing a reference on
files_struct.
As task_lookup_fd_rcu may update the fd ctx->pos has been changed
to be the fd +2 after task_lookup_fd_rcu returns.
[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Andy Lavr <andy.lavr@gmail.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-10-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-15-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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As a companion to fget_task and task_lookup_fd_rcu implement
task_lookup_next_fd_rcu that will return the struct file for the first
file descriptor number that is equal or greater than the fd argument
value, or NULL if there is no such struct file.
This allows file descriptors of foreign processes to be iterated
through safely, without needed to increment the count on files_struct.
Some concern[1] has been expressed that this function takes the task_lock
for each iteration and thus for each file descriptor. This place
where this function will be called in a commonly used code path is for
listing /proc/<pid>/fd. I did some small benchmarks and did not see
any measurable performance differences. For ordinary users ls is
likely to stat each of the directory entries and tid_fd_mode called
from tid_fd_revalidae has always taken the task lock for each file
descriptor. So this does not look like it will be a big change in
practice.
At some point is will probably be worth changing put_files_struct to
free files_struct after an rcu grace period so that task_lock won't be
needed at all.
[1] https://lkml.kernel.org/r/20200817220425.9389-10-ebiederm@xmission.com
v1: https://lkml.kernel.org/r/20200817220425.9389-9-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-14-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Modify get_file_raw_ptr to use task_lookup_fd_rcu. The helper
task_lookup_fd_rcu does the work of taking the task lock and verifying
that task->files != NULL and then calls files_lookup_fd_rcu. So let
use the helper to make a simpler implementation of get_file_raw_ptr.
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Link: https://lkml.kernel.org/r/20201120231441.29911-13-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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When discussing[1] exec and posix file locks it was realized that none
of the callers of get_files_struct fundamentally needed to call
get_files_struct, and that by switching them to helper functions
instead it will both simplify their code and remove unnecessary
increments of files_struct.count. Those unnecessary increments can
result in exec unnecessarily unsharing files_struct which breaking
posix locks, and it can result in fget_light having to fallback to
fget reducing system performance.
Instead of manually coding finding the files struct for a task and
then calling files_lookup_fd_rcu, use the helper task_lookup_fd_rcu
that combines those to steps. Making the code simpler and removing
the need to get a reference on a files_struct.
[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-7-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-12-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
As a companion to lookup_fd_rcu implement task_lookup_fd_rcu for
querying an arbitrary process about a specific file.
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200818103713.aw46m7vprsy4vlve@wittgenstein
Link: https://lkml.kernel.org/r/20201120231441.29911-11-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
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Also remove the confusing comment about checking if a fd exists. I
could not find one instance in the entire kernel that still matches
the description or the reason for the name fcheck.
The need for better names became apparent in the last round of
discussion of this set of changes[1].
[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-10-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
This change renames fcheck_files to files_lookup_fd_rcu. All of the
remaining callers take the rcu_read_lock before calling this function
so the _rcu suffix is appropriate. This change also tightens up the
debug check to verify that all callers hold the rcu_read_lock.
All callers that used to call files_check with the files->file_lock
held have now been changed to call files_lookup_fd_locked.
This change of name has helped remind me of which locks and which
guarantees are in place helping me to catch bugs later in the
patchset.
The need for better names became apparent in the last round of
discussion of this set of changes[1].
[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-9-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
To make it easy to tell where files->file_lock protection is being
used when looking up a file create files_lookup_fd_locked. Only allow
this function to be called with the file_lock held.
Update the callers of fcheck and fcheck_files that are called with the
files->file_lock held to call files_lookup_fd_locked instead.
Hopefully this makes it easier to quickly understand what is going on.
The need for better names became apparent in the last round of
discussion of this set of changes[1].
[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-8-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
The function fcheck despite it's comment is poorly named
as it has no callers that only check it's return value.
All of fcheck's callers use the returned file descriptor.
The same is true for fcheck_files and __fcheck_files.
A new less confusing name is needed. In addition the names
of these functions are confusing as they do not report
the kind of locks that are needed to be held when these
functions are called making error prone to use them.
To remedy this I am making the base functio name lookup_fd
and will and prefixes and sufficies to indicate the rest
of the context.
Name the function (previously called __fcheck_files) that proceeds
from a struct files_struct, looks up the struct file of a file
descriptor, and requires it's callers to verify all of the appropriate
locks are held files_lookup_fd_raw.
The need for better names became apparent in the last round of
discussion of this set of changes[1].
[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-7-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
When discussing[1] exec and posix file locks it was realized that none
of the callers of get_files_struct fundamentally needed to call
get_files_struct, and that by switching them to helper functions
instead it will both simplify their code and remove unnecessary
increments of files_struct.count. Those unnecessary increments can
result in exec unnecessarily unsharing files_struct which breaking
posix locks, and it can result in fget_light having to fallback to
fget reducing system performance.
Simplifying proc_fd_link is a little bit tricky. It is necessary to
know that there is a reference to fd_f ile while path_get is running.
This reference can either be guaranteed to exist either by locking the
fdtable as the code currently does or by taking a reference on the
file in question.
Use fget_task to remove the need for get_files_struct and
to take a reference to file in question.
[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-8-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-6-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
Use the helper fget_task to simplify bpf_task_fd_query.
As well as simplifying the code this removes one unnecessary increment of
struct files_struct. This unnecessary increment of files_struct.count can
result in exec unnecessarily unsharing files_struct and breaking posix
locks, and it can result in fget_light having to fallback to fget reducing
performance.
This simplification comes from the observation that none of the
callers of get_files_struct actually need to call get_files_struct
that was made when discussing[1] exec and posix file locks.
[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-5-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-5-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
Use the helper fget_task and simplify the code.
As well as simplifying the code this removes one unnecessary increment of
struct files_struct. This unnecessary increment of files_struct.count can
result in exec unnecessarily unsharing files_struct and breaking posix
locks, and it can result in fget_light having to fallback to fget reducing
performance.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-4-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-4-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
Now that exec no longer needs to restore the previous value of current->files
on error there are no more callers of reset_files_struct so remove it.
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-3-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-3-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
Now that exec no longer needs to return the unshared files to their
previous value there is no reason to return displaced.
Instead when unshare_fd creates a copy of the file table, call
put_files_struct before returning from unshare_files.
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-2-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-2-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
Many moons ago the binfmts were doing some very questionable things
with file descriptors and an unsharing of the file descriptor table
was added to make things better[1][2]. The helper steal_lockss was
added to avoid breaking the userspace programs[3][4][6].
Unfortunately it turned out that steal_locks did not work for network
file systems[5], so it was removed to see if anyone would
complain[7][8]. It was thought at the time that NPTL would not be
affected as the unshare_files happened after the other threads were
killed[8]. Unfortunately because there was an unshare_files in
binfmt_elf.c before the threads were killed this analysis was
incorrect.
This unshare_files in binfmt_elf.c resulted in the unshares_files
happening whenever threads were present. Which led to unshare_files
being moved to the start of do_execve[9].
Later the problems were rediscovered and the suggested approach was to
readd steal_locks under a different name[10]. I happened to be
reviewing patches and I noticed that this approach was a step
backwards[11].
I proposed simply moving unshare_files[12] and it was pointed
out that moving unshare_files without auditing the code was
also unsafe[13].
There were then several attempts to solve this[14][15][16] and I even
posted this set of changes[17]. Unfortunately because auditing all of
execve is time consuming this change did not make it in at the time.
Well now that I am cleaning up exec I have made the time to read
through all of the binfmts and the only playing with file descriptors
is either the security modules closing them in
security_bprm_committing_creds or is in the generic code in fs/exec.c.
None of it happens before begin_new_exec is called.
So move unshare_files into begin_new_exec, after the point of no
return. If memory is very very very low and the application calling
exec is sharing file descriptor tables between processes we might fail
past the point of no return. Which is unfortunate but no different
than any of the other places where we allocate memory after the point
of no return.
This movement allows another process that shares the file table, or
another thread of the same process and that closes files or changes
their close on exec behavior and races with execve to cause some
unexpected things to happen. There is only one time of check to time
of use race and it is just there so that execve fails instead of
an interpreter failing when it tries to open the file it is supposed
to be interpreting. Failing later if userspace is being silly is
not a problem.
With this change it the following discription from the removal
of steal_locks[8] finally becomes true.
Apps using NPTL are not affected, since all other threads are killed before
execve.
Apps using LinuxThreads are only affected if they
- have multiple threads during exec (LinuxThreads doesn't kill other
threads, the app may do it with pthread_kill_other_threads_np())
- rely on POSIX locks being inherited across exec
Both conditions are documented, but not their interaction.
Apps using clone() natively are affected if they
- use clone(CLONE_FILES)
- rely on POSIX locks being inherited across exec
I have investigated some paths to make it possible to solve this
without moving unshare_files but they all look more complicated[18].
Reported-by: Daniel P. Berrangé <berrange@redhat.com>
Reported-by: Jeff Layton <jlayton@redhat.com>
History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
[1] 02cda956de0b ("[PATCH] unshare_files"
[2] 04e9bcb4d106 ("[PATCH] use new unshare_files helper")
[3] 088f5d7244de ("[PATCH] add steal_locks helper")
[4] 02c541ec8ffa ("[PATCH] use new steal_locks helper")
[5] https://lkml.kernel.org/r/E1FLIlF-0007zR-00@dorka.pomaz.szeredi.hu
[6] https://lkml.kernel.org/r/0060321191605.GB15997@sorel.sous-sol.org
[7] https://lkml.kernel.org/r/E1FLwjC-0000kJ-00@dorka.pomaz.szeredi.hu
[8] c89681ed7d0e ("[PATCH] remove steal_locks()")
[9] fd8328be874f ("[PATCH] sanitize handling of shared descriptor tables in failing execve()")
[10] https://lkml.kernel.org/r/20180317142520.30520-1-jlayton@kernel.org
[11] https://lkml.kernel.org/r/87r2nwqk73.fsf@xmission.com
[12] https://lkml.kernel.org/r/87bmfgvg8w.fsf@xmission.com
[13] https://lkml.kernel.org/r/20180322111424.GE30522@ZenIV.linux.org.uk
[14] https://lkml.kernel.org/r/20180827174722.3723-1-jlayton@kernel.org
[15] https://lkml.kernel.org/r/20180830172423.21964-1-jlayton@kernel.org
[16] https://lkml.kernel.org/r/20180914105310.6454-1-jlayton@kernel.org
[17] https://lkml.kernel.org/r/87a7ohs5ow.fsf@xmission.com
[18] https://lkml.kernel.org/r/87pn8c1uj6.fsf_-_@x220.int.ebiederm.org
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-1-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-1-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
Al Viro pointed out that using the phrase "close_on_exec(fd,
rcu_dereference_raw(current->files->fdt))" instead of wrapping it in
rcu_read_lock(), rcu_read_unlock() is a very questionable
optimization[1].
Once wrapped with rcu_read_lock()/rcu_read_unlock() that phrase
becomes equivalent the helper function get_close_on_exec so
simplify the code and make it more robust by simply using
get_close_on_exec.
[1] https://lkml.kernel.org/r/20201207222214.GA4115853@ZenIV.linux.org.uk
Suggested-by: Al Viro <viro@ftp.linux.org.uk>
Link: https://lkml.kernel.org/r/87k0tqr6zi.fsf_-_@x220.int.ebiederm.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
Edgar reported [1] AMD Raven iGPU errors on several of his systems. There
is no root cause. Turn off ATS on these systems to avoid the issue.
[1] https://lore.kernel.org/linux-iommu/MWHPR10MB1310CDB6829DDCF5EA84A14689150@MWHPR10MB1310.namprd10.prod.outlook.com/
[bhelgaas: commit log]
Link: https://lore.kernel.org/r/MWHPR10MB131082779A86BE4CCCF190B789CB0@MWHPR10MB1310.namprd10.prod.outlook.com
Reported-by: Edgar Merger <Edgar.Merger@emerson.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
|
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Simplify the return expression.
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201210135432.1249-1-zhengyongjun3@huawei.com
|
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Commit 66f57b871efc ("RDMA/restrack: Support all QP types") extends
ib_create_qp() to a named ib_create_named_qp(), which takes the caller's
name as argument, but it did not add the new argument description to the
function's kerneldoc.
make htmldocs warns:
./drivers/infiniband/core/verbs.c:1206: warning: Function parameter or member 'caller' not described in 'ib_create_named_qp'
Add a description for this new argument based on the description of the
same argument in other related functions.
Fixes: 66f57b871efc ("RDMA/restrack: Support all QP types")
Link: https://lore.kernel.org/r/20201207173255.13355-1-lukas.bulwahn@gmail.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
|
|
The K3 J721E family of SoCs have a revised version of the AM65x ICSSG IP
and contains two instances of this newer ICSSG IP. Each ICSSG processor
subsystem contains 2 primary PRU cores, 2 auxiliary PRU cores called RTUs,
and 2 new auxiliary cores called Transmit PRUs (Tx_PRUs).
Enhance the existing PRU remoteproc driver to support these new PRU
and RTU cores by using specific compatibles. The cores have the same
memory copying limitations as on AM65x, so reuses the custom memcpy
function within the driver's ELF loader implementation. The initial
names for the firmware images for each PRU core are retrieved from
DT nodes, and can be adjusted through sysfs if required.
Signed-off-by: Suman Anna <s-anna@ti.com>
Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20201208141002.17777-7-grzegorz.jaszczyk@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
|
|
The K3 AM65x family of SoCs have the next generation of the PRU-ICSS
processor subsystem, commonly referred to as ICSSG. Each ICSSG processor
subsystem on AM65x SR1.0 contains two primary PRU cores and two new
auxiliary PRU cores called RTUs. The AM65x SR2.0 SoCs have a revised
ICSSG IP that is based off the subsequent IP revision used on J721E
SoCs. This IP instance has two new custom auxiliary PRU cores called
Transmit PRUs (Tx_PRUs) in addition to the existing PRUs and RTUs.
Each RTU and Tx_PRU cores have their own dedicated IRAM (smaller than
a PRU), Control and debug feature sets, but is different in terms of
sub-modules integrated around it and does not have the full capabilities
associated with a PRU core. The RTU core is typically used to aid a
PRU core in accelerating data transfers, while the Tx_PRU cores is
normally used to control the TX L2 FIFO if enabled in Ethernet
applications. Both can also be used to run independent applications.
The RTU and Tx_PRU cores though share the same Data RAMs as the PRU
cores, so the memories have to be partitioned carefully between different
applications. The new cores also support a new sub-module called Task
Manager to support two different context thread executions.
Enhance the existing PRU remoteproc driver to support these new PRU, RTU
and Tx PRU cores by using specific compatibles. The initial names for the
firmware images for each PRU core are retrieved from DT nodes, and can
be adjusted through sysfs if required.
The PRU remoteproc driver has to be specifically modified to use a
custom memcpy function within its ELF loader implementation for these
new cores in order to overcome a limitation with copying data into each
of the core's IRAM memories. These memory ports support only 4-byte
writes, and any sub-word order byte writes clear out the remaining
bytes other than the bytes being written within the containing word.
The default ARM64 memcpy also cannot be used as it throws an exception
when the preferred 8-byte copy operation is attempted. This choice is
made by using a state flag that is set only on K3 SoCs.
Signed-off-by: Suman Anna <s-anna@ti.com>
Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20201208141002.17777-6-grzegorz.jaszczyk@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
|
|
The remoteproc core creates certain standard debugfs entries,
that does not give a whole lot of useful information for the
PRUs. The PRU remoteproc driver is enhanced to add additional
debugfs entries for PRU. These will be auto-cleaned up when
the parent rproc debug directory is removed.
The enhanced debugfs support adds two new entries: 'regs' and
'single_step'. The 'regs' dumps out the useful CTRL sub-module
registers as well as each of the 32 GPREGs and CT_REGs registers.
The GPREGs and CT_REGs though are printed only when the PRU is
halted and accessible as per the IP design.
The 'single_step' utilizes the single-step execution of the PRU
cores. Writing a non-zero value performs a single step, and a
zero value restores the PRU to execute in the same mode as the
mode before the first single step. (note: if the PRU is halted
because of a halt instruction, then no change occurs).
Logic for setting the PC and jumping over a halt instruction shall
be added in the future.
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20201208141002.17777-5-grzegorz.jaszczyk@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
|
|
The firmware blob can contain optional ELF sections: .resource_table
section and .pru_irq_map one. The second one contains the PRUSS
interrupt mapping description, which needs to be setup before powering
on the PRU core. To avoid RAM wastage this ELF section is not mapped to
any ELF segment (by the firmware linker) and therefore is not loaded to
PRU memory.
The PRU interrupt configuration is handled within the PRUSS INTC irqchip
driver and leverages the system events to interrupt channels and host
interrupts mapping configuration. Relevant irq routing information is
passed through a special .pru_irq_map ELF section (for interrupts routed
to and used by PRU cores) or via the PRU application's device tree node
(for interrupts routed to and used by the main CPU). The mappings are
currently programmed during the booting/shutdown of the PRU.
The interrupt configuration passed through .pru_irq_map ELF section is
optional. It varies on specific firmware functionality and therefore
have to be unwinded during PRU stop and performed again during
PRU start.
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Co-developed-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Link: https://lore.kernel.org/r/20201208141002.17777-4-grzegorz.jaszczyk@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
|
|
The Programmable Real-Time Unit Subsystem (PRUSS) consists of
dual 32-bit RISC cores (Programmable Real-Time Units, or PRUs)
for program execution. This patch adds a remoteproc platform
driver for managing the individual PRU RISC cores life cycle.
The PRUs do not have a unified address space (have an Instruction
RAM and a primary Data RAM at both 0x0). The PRU remoteproc driver
therefore uses a custom remoteproc core ELF loader ops. The added
.da_to_va ops is only used to provide translations for the PRU
Data RAMs. This remoteproc driver does not have support for error
recovery and system suspend/resume features. Different compatibles
are used to allow providing scalability for instance-specific device
data if needed. The driver uses a default firmware-name retrieved
from device-tree for each PRU core, and the firmwares are expected
to be present in the standard Linux firmware search paths. They can
also be adjusted by userspace if required through the sysfs interface
provided by the remoteproc core.
The PRU remoteproc driver uses a client-driven boot methodology: it
does _not_ support auto-boot so that the PRU load and boot is dictated
by the corresponding client drivers for achieving various usecases.
This allows flexibility for the client drivers or applications to set
a firmware name (if needed) based on their desired functionality and
boot the PRU. The sysfs bind and unbind attributes have also been
suppressed so that the PRU devices cannot be unbound and thereby
shutdown a PRU from underneath a PRU client driver.
The driver currently supports the AM335x, AM437x, AM57xx and 66AK2G
SoCs, and support for other TI SoCs will be added in subsequent
patches.
Co-developed-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20201208141002.17777-3-grzegorz.jaszczyk@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
|
|
The Programmable Real-Time Unit and Industrial Communication Subsystem
(PRU-ICSS or simply PRUSS) on various TI SoCs consists of dual 32-bit
RISC cores (Programmable Real-Time Units, or PRUs) for program execution.
The K3 AM65x amd J721E SoCs have the next generation of the PRU-ICSS IP,
commonly called ICSSG. The ICSSG IP on AM65x SoCs has two PRU cores,
two auxiliary custom PRU cores called Real Time Units (RTUs). The K3
AM65x SR2.0 and J721E SoCs have a revised version of the ICSSG IP, and
include two additional custom auxiliary PRU cores called Transmit PRUs
(Tx_PRUs).
This patch adds the bindings for these PRU cores. The binding covers the
OMAP architecture SoCs - AM33xx, AM437x and AM57xx; Keystone 2 architecture
based 66AK2G SoC; and the K3 architecture based SoCs - AM65x and J721E. The
Davinci based OMAPL138 SoCs will be covered in a future patch.
Reviewed-by: Rob Herring <robh@kernel.org>
Co-developed-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Link: https://lore.kernel.org/r/20201208141002.17777-2-grzegorz.jaszczyk@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
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The MBA software controller (mba_sc) is a feedback loop which
periodically reads MBM counters and tries to restrict the bandwidth
below a user-specified value. It tags along the MBM counter overflow
handler to do the updates with 1s interval in mbm_update() and
update_mba_bw().
The purpose of mbm_update() is to periodically read the MBM counters to
make sure that the hardware counter doesn't wrap around more than once
between user samplings. mbm_update() calls __mon_event_count() for local
bandwidth updating when mba_sc is not enabled, but calls mbm_bw_count()
instead when mba_sc is enabled. __mon_event_count() will not be called
for local bandwidth updating in MBM counter overflow handler, but it is
still called when reading MBM local bandwidth counter file
'mbm_local_bytes', the call path is as below:
rdtgroup_mondata_show()
mon_event_read()
mon_event_count()
__mon_event_count()
In __mon_event_count(), m->chunks is updated by delta chunks which is
calculated from previous MSR value (m->prev_msr) and current MSR value.
When mba_sc is enabled, m->chunks is also updated in mbm_update() by
mistake by the delta chunks which is calculated from m->prev_bw_msr
instead of m->prev_msr. But m->chunks is not used in update_mba_bw() in
the mba_sc feedback loop.
When reading MBM local bandwidth counter file, m->chunks was changed
unexpectedly by mbm_bw_count(). As a result, the incorrect local
bandwidth counter which calculated from incorrect m->chunks is shown to
the user.
Fix this by removing incorrect m->chunks updating in mbm_bw_count() in
MBM counter overflow handler, and always calling __mon_event_count() in
mbm_update() to make sure that the hardware local bandwidth counter
doesn't wrap around.
Test steps:
# Run workload with aggressive memory bandwidth (e.g., 10 GB/s)
git clone https://github.com/intel/intel-cmt-cat && cd intel-cmt-cat
&& make
./tools/membw/membw -c 0 -b 10000 --read
# Enable MBA software controller
mount -t resctrl resctrl -o mba_MBps /sys/fs/resctrl
# Create control group c1
mkdir /sys/fs/resctrl/c1
# Set MB throttle to 6 GB/s
echo "MB:0=6000;1=6000" > /sys/fs/resctrl/c1/schemata
# Write PID of the workload to tasks file
echo `pidof membw` > /sys/fs/resctrl/c1/tasks
# Read local bytes counters twice with 1s interval, the calculated
# local bandwidth is not as expected (approaching to 6 GB/s):
local_1=`cat /sys/fs/resctrl/c1/mon_data/mon_L3_00/mbm_local_bytes`
sleep 1
local_2=`cat /sys/fs/resctrl/c1/mon_data/mon_L3_00/mbm_local_bytes`
echo "local b/w (bytes/s):" `expr $local_2 - $local_1`
Before fix:
local b/w (bytes/s): 11076796416
After fix:
local b/w (bytes/s): 5465014272
Fixes: ba0f26d8529c (x86/intel_rdt/mba_sc: Prepare for feedback loop)
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/1607063279-19437-1-git-send-email-xiaochen.shen@intel.com
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
kvm/arm64 fixes for 5.10, take #5
- Don't leak page tables on PTE update
- Correctly invalidate TLBs on table to block transition
- Only update permissions if the fault level matches the
expected mapping size
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Change Zhu's working email to his private one.
Link: https://lore.kernel.org/r/20201203190659.126932-1-leon@kernel.org
Signed-off-by: Zhu Yanjun <yanjunz@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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A semicolon is not needed after a switch statement.
Link: https://lore.kernel.org/r/20201031134638.2135060-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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