The console_list_lock provides synchronization for console list and
console->flags updates. All call sites that were using the console_lock
for this synchronization have either switched to use the
console_list_lock or the SRCU list iterator.
Remove console_lock usage for console list updates and console->flags
updates.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-40-john.ogness@linutronix.de
With commit 9e124fe16ff2("xen: Enable console tty by default in domU
if it's not a dummy") a hack was implemented to make sure that the
tty console remains the console behind the /dev/console device. The
main problem with the hack is that, after getting the console pointer
to the tty console, it is assumed the pointer is still valid after
releasing the console_sem. This assumption is incorrect and unsafe.
Make the hack safe by introducing a new function
console_force_preferred_locked() and perform the full operation
under the console_list_lock.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-33-john.ogness@linutronix.de
Currently it is not possible for drivers to detect if they have
already successfully registered their console. Several drivers
have multiple paths that lead to console registration. To avoid
attempting a 2nd registration (which leads to a WARN), drivers
are implementing their own solution.
Introduce console_is_registered() so drivers can easily identify
if their console is currently registered. A _locked() variant
is also provided if the caller is already holding the
console_list_lock.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-22-john.ogness@linutronix.de
Use srcu console list iteration for console list traversal. It is
acceptable because the consoles might come and go at any time.
Strict synchronizing with console registration code would not bring
any advantage over srcu.
Document why the console_lock is still necessary. Note that this
is a preparatory change for when console_lock no longer provides
synchronization for the console list.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-21-john.ogness@linutronix.de
Guarantee safe iteration of the console list by using SRCU.
Note that in the case of a handover, the SRCU read lock is also
released. This is documented in the function description and as
comments in the code. It is a bit tricky, but this preserves the
lockdep lock ordering for the context handing over the
console_lock:
console_lock()
| mutex_acquire(&console_lock_dep_map) <-- console lock
|
console_unlock()
| console_flush_all()
| | srcu_read_lock(&console_srcu) <-- srcu lock
| | console_emit_next_record()
| | | console_lock_spinning_disable_and_check()
| | | | srcu_read_unlock(&console_srcu) <-- srcu unlock
| | | | mutex_release(&console_lock_dep_map) <-- console unlock
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-16-john.ogness@linutronix.de
After switching to SRCU for console list iteration, some readers
will begin readings console->flags as a data race. Locklessly
reading console->flags provides a consistent value because there
is at most one CPU modifying console->flags and that CPU is
using only read-modify-write operations.
Introduce a wrapper for SRCU iterators to read console flags.
Introduce a matching wrapper to write to flags of registered
consoles. Writing to flags of registered consoles is synchronized
by the console_list_lock.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-13-john.ogness@linutronix.de
Currently there exist races in register_console(), where the types
of registered consoles are checked (without holding the console_lock)
and then after acquiring the console_lock, it is assumed that the list
has not changed. Also, some code that performs console_unregister()
make similar assumptions.
It might be possible to fix these races using the console_lock. But
it would require a complex analysis of all console drivers to make
sure that the console_lock is not taken in match() and setup()
callbacks. And we really prefer to split up and reduce the
responsibilities of console_lock rather than expand its complexity.
Therefore, introduce a new console_list_lock to provide full
synchronization for any console list changes.
In addition, also use console_list_lock for synchronization of
console->flags updates. All flags are either static or modified only
during the console registration. There are only two exceptions.
The first exception is CON_ENABLED, which is also modified by
console_start()/console_stop(). Therefore, these functions must
also take the console_list_lock.
The second exception is when the flags are modified by the console
driver init code before the console is registered. These will be
ignored because they are not visible to the rest of the system
via the console_drivers list.
Note that one of the various responsibilities of the console_lock is
also intended to provide console list and console->flags
synchronization. Later changes will update call sites relying on the
console_lock for these purposes. Once all call sites have been
updated, the console_lock will be relieved of synchronizing
console_list and console->flags updates.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/87sficwokr.fsf@jogness.linutronix.de
It used to be that all consoles were synchronized with respect to
which message they were printing. After commit a699449bb1 ("printk:
refactor and rework printing logic"), all consoles have their own
@seq for tracking which message they are on. That commit also changed
how the initial sequence number was chosen. Instead of choosing the
next non-printed message, it chose the sequence number of the next
message that will be added to the ringbuffer.
That change created a possibility that a non-boot console taking over
for a boot console might skip messages if the boot console was behind
and did not have a chance to catch up before being unregistered.
Since it is not known which boot console is the same device, flush
all consoles and, if necessary, start with the message of the enabled
boot console that is the furthest behind. If no boot consoles are
enabled, begin with the next message that will be added to the
ringbuffer.
Also, since boot consoles are meant to be used at boot time, handle
them the same as CON_PRINTBUFFER to ensure that no initial messages
are skipped.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-7-john.ogness@linutronix.de
The code to initialize @seq for a new console needs to consider
more factors when choosing an initial value. Move the code into
a helper function console_init_seq() "as is" so this code can
be expanded without causing register_console() to become too
long. A later commit will implement the additional code.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-6-john.ogness@linutronix.de
This commit adds lockdep checks for illegal use of synchronize_srcu()
within same-type SRCU read-side critical sections and within normal
RCU read-side critical sections. It also makes synchronize_srcu()
be a no-op during early boot.
These changes bring Tiny synchronize_srcu() into line with both Tree
synchronize_srcu() and Tiny synchronize_rcu().
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: John Ogness <john.ogness@linutronix.de>
Kernels configured with CONFIG_PRINTK=n and CONFIG_SRCU=n get build
failures. This causes trouble for deep embedded systems. But given
that there are more than 25 instances of "select SRCU" in the kernel,
it is hard to believe that there are many kernels running in production
without SRCU. This commit therefore makes SRCU mandatory. The SRCU
Kconfig option remains for backwards compatibility, and will be removed
when it is no longer used.
[ paulmck: Update per kernel test robot feedback. ]
Reported-by: John Ogness <john.ogness@linutronix.de>
Reported-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Currently the NMI safety debugging is only performed on architectures
that don't support NMI-safe this_cpu_inc().
Reorder the code so that other architectures like x86 also detect bad
uses.
[ paulmck: Apply kernel test robot, Stephen Rothwell, and Zqiang feedback. ]
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tell about the need to protect against concurrent updaters who may
overflow the GP counter behind the current update.
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Using the NMI-unsafe reader API from within an NMI handler is very likely
to be buggy for three reasons:
1) NMIs aren't strictly re-entrant (a pending nested NMI will execute at
the end of the current one) so it should be fine to use a non-atomic
increment here. However, breakpoints can still interrupt NMIs and if
a breakpoint callback has a reader on that same ssp, a racy increment
can happen.
2) If the only reader site for a given srcu_struct structure is in an
NMI handler, then RCU should be used instead of SRCU.
3) Because of the previous reason (2), an srcu_struct structure having
an SRCU read side critical section in an NMI handler is likely to
have another one from a task context.
For all these reasons, warn if an NMI-unsafe reader API is used from an
NMI handler.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
On strict load-store architectures, the use of this_cpu_inc() by
srcu_read_lock() and srcu_read_unlock() is not NMI-safe in TREE SRCU.
To see this suppose that an NMI arrives in the middle of srcu_read_lock(),
just after it has read ->srcu_lock_count, but before it has written
the incremented value back to memory. If that NMI handler also does
srcu_read_lock() and srcu_read_lock() on that same srcu_struct structure,
then upon return from that NMI handler, the interrupted srcu_read_lock()
will overwrite the NMI handler's update to ->srcu_lock_count, but
leave unchanged the NMI handler's update by srcu_read_unlock() to
->srcu_unlock_count.
This can result in a too-short SRCU grace period, which can in turn
result in arbitrary memory corruption.
If the NMI handler instead interrupts the srcu_read_unlock(), this
can result in eternal SRCU grace periods, which is not much better.
This commit therefore creates a pair of new srcu_read_lock_nmisafe()
and srcu_read_unlock_nmisafe() functions, which allow SRCU readers in
both NMI handlers and in process and IRQ context. It is bad practice
to mix the existing and the new _nmisafe() primitives on the same
srcu_struct structure. Use one set or the other, not both.
Just to underline that "bad practice" point, using srcu_read_lock() at
process level and srcu_read_lock_nmisafe() in your NMI handler will not,
repeat NOT, work. If you do not immediately understand why this is the
case, please review the earlier paragraphs in this commit log.
[ paulmck: Apply kernel test robot feedback. ]
[ paulmck: Apply feedback from Randy Dunlap. ]
[ paulmck: Apply feedback from John Ogness. ]
[ paulmck: Apply feedback from Frederic Weisbecker. ]
Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Petr Mladek <pmladek@suse.com>
Pull more random number generator updates from Jason Donenfeld:
"This time with some large scale treewide cleanups.
The intent of this pull is to clean up the way callers fetch random
integers. The current rules for doing this right are:
- If you want a secure or an insecure random u64, use get_random_u64()
- If you want a secure or an insecure random u32, use get_random_u32()
The old function prandom_u32() has been deprecated for a while
now and is just a wrapper around get_random_u32(). Same for
get_random_int().
- If you want a secure or an insecure random u16, use get_random_u16()
- If you want a secure or an insecure random u8, use get_random_u8()
- If you want secure or insecure random bytes, use get_random_bytes().
The old function prandom_bytes() has been deprecated for a while
now and has long been a wrapper around get_random_bytes()
- If you want a non-uniform random u32, u16, or u8 bounded by a
certain open interval maximum, use prandom_u32_max()
I say "non-uniform", because it doesn't do any rejection sampling
or divisions. Hence, it stays within the prandom_*() namespace, not
the get_random_*() namespace.
I'm currently investigating a "uniform" function for 6.2. We'll see
what comes of that.
By applying these rules uniformly, we get several benefits:
- By using prandom_u32_max() with an upper-bound that the compiler
can prove at compile-time is ≤65536 or ≤256, internally
get_random_u16() or get_random_u8() is used, which wastes fewer
batched random bytes, and hence has higher throughput.
- By using prandom_u32_max() instead of %, when the upper-bound is
not a constant, division is still avoided, because
prandom_u32_max() uses a faster multiplication-based trick instead.
- By using get_random_u16() or get_random_u8() in cases where the
return value is intended to indeed be a u16 or a u8, we waste fewer
batched random bytes, and hence have higher throughput.
This series was originally done by hand while I was on an airplane
without Internet. Later, Kees and I worked on retroactively figuring
out what could be done with Coccinelle and what had to be done
manually, and then we split things up based on that.
So while this touches a lot of files, the actual amount of code that's
hand fiddled is comfortably small"
* tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
prandom: remove unused functions
treewide: use get_random_bytes() when possible
treewide: use get_random_u32() when possible
treewide: use get_random_{u8,u16}() when possible, part 2
treewide: use get_random_{u8,u16}() when possible, part 1
treewide: use prandom_u32_max() when possible, part 2
treewide: use prandom_u32_max() when possible, part 1
Pull PSI updates from Ingo Molnar:
- Various performance optimizations, resulting in a 4%-9% speedup in
the mmtests/config-scheduler-perfpipe micro-benchmark.
- New interface to turn PSI on/off on a per cgroup level.
* tag 'sched-psi-2022-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/psi: Per-cgroup PSI accounting disable/re-enable interface
sched/psi: Cache parent psi_group to speed up group iteration
sched/psi: Consolidate cgroup_psi()
sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure
sched/psi: Remove NR_ONCPU task accounting
sched/psi: Optimize task switch inside shared cgroups again
sched/psi: Move private helpers to sched/stats.h
sched/psi: Save percpu memory when !psi_cgroups_enabled
sched/psi: Don't create cgroup PSI files when psi_disabled
sched/psi: Fix periodic aggregation shut off
Pull tracing fixes from Steven Rostedt:
- Found that the synthetic events were using strlen/strscpy() on values
that could have come from userspace, and that is bad.
Consolidate the string logic of kprobe and eprobe and extend it to
the synthetic events to safely process string addresses.
- Clean up content of text dump in ftrace_bug() where the output does
not make char reads into signed and sign extending the byte output.
- Fix some kernel docs in the ring buffer code.
* tag 'trace-v6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Fix reading strings from synthetic events
tracing: Add "(fault)" name injection to kernel probes
tracing: Move duplicate code of trace_kprobe/eprobe.c into header
ring-buffer: Fix kernel-doc
ftrace: Fix char print issue in print_ip_ins()
Pull non-MM updates from Andrew Morton:
- hfs and hfsplus kmap API modernization (Fabio Francesco)
- make crash-kexec work properly when invoked from an NMI-time panic
(Valentin Schneider)
- ntfs bugfixes (Hawkins Jiawei)
- improve IPC msg scalability by replacing atomic_t's with percpu
counters (Jiebin Sun)
- nilfs2 cleanups (Minghao Chi)
- lots of other single patches all over the tree!
* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
proc: test how it holds up with mapping'less process
mailmap: update Frank Rowand email address
ia64: mca: use strscpy() is more robust and safer
init/Kconfig: fix unmet direct dependencies
ia64: update config files
nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
fork: remove duplicate included header files
init/main.c: remove unnecessary (void*) conversions
proc: mark more files as permanent
nilfs2: remove the unneeded result variable
nilfs2: delete unnecessary checks before brelse()
checkpatch: warn for non-standard fixes tag style
usr/gen_init_cpio.c: remove unnecessary -1 values from int file
ipc/msg: mitigate the lock contention with percpu counter
percpu: add percpu_counter_add_local and percpu_counter_sub_local
fs/ocfs2: fix repeated words in comments
relay: use kvcalloc to alloc page array in relay_alloc_page_array
proc: make config PROC_CHILDREN depend on PROC_FS
fs: uninline inode_maybe_inc_iversion()
...
The follow commands caused a crash:
# cd /sys/kernel/tracing
# echo 's:open char file[]' > dynamic_events
# echo 'hist:keys=common_pid:file=filename:onchange($file).trace(open,$file)' > events/syscalls/sys_enter_openat/trigger'
# echo 1 > events/synthetic/open/enable
BOOM!
The problem is that the synthetic event field "char file[]" will read
the value given to it as a string without any memory checks to make sure
the address is valid. The above example will pass in the user space
address and the sythetic event code will happily call strlen() on it
and then strscpy() where either one will cause an oops when accessing
user space addresses.
Use the helper functions from trace_kprobe and trace_eprobe that can
read strings safely (and actually succeed when the address is from user
space and the memory is mapped in).
Now the above can show:
packagekitd-1721 [000] ...2. 104.597170: open: file=/usr/lib/rpm/fileattrs/cmake.attr
in:imjournal-978 [006] ...2. 104.599642: open: file=/var/lib/rsyslog/imjournal.state.tmp
packagekitd-1721 [000] ...2. 104.626308: open: file=/usr/lib/rpm/fileattrs/debuginfo.attr
Link: https://lkml.kernel.org/r/20221012104534.826549315@goodmis.org
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Fixes: bd82631d7c ("tracing: Add support for dynamic strings to synthetic events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Have the specific functions for kernel probes that read strings to inject
the "(fault)" name directly. trace_probes.c does this too (for uprobes)
but as the code to read strings are going to be used by synthetic events
(and perhaps other utilities), it simplifies the code by making sure those
other uses do not need to implement the "(fault)" name injection as well.
Link: https://lkml.kernel.org/r/20221012104534.644803645@goodmis.org
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Fixes: bd82631d7c ("tracing: Add support for dynamic strings to synthetic events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The functions:
fetch_store_strlen_user()
fetch_store_strlen()
fetch_store_string_user()
fetch_store_string()
are identical in both trace_kprobe.c and trace_eprobe.c. Move them into
a new header file trace_probe_kernel.h to share it. This code will later
be used by the synthetic events as well.
Marked for stable as a fix for a crash in synthetic events requires it.
Link: https://lkml.kernel.org/r/20221012104534.467668078@goodmis.org
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Fixes: bd82631d7c ("tracing: Add support for dynamic strings to synthetic events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pull interrupt updates from Thomas Gleixner:
"Core code:
- Provide a generic wrapper which can be utilized in drivers to
handle the problem of force threaded demultiplex interrupts on RT
enabled kernels. This avoids conditionals and horrible quirks in
drivers all over the place
- Fix up affected pinctrl and GPIO drivers to make them cleanly RT
safe
Interrupt drivers:
- A new driver for the FSL MU platform specific MSI implementation
- Make irqchip_init() available for pure ACPI based systems
- Provide a functional DT binding for the Realtek RTL interrupt chip
- The usual DT updates and small code improvements all over the
place"
* tag 'irq-core-2022-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
irqchip: IMX_MU_MSI should depend on ARCH_MXC
irqchip/imx-mu-msi: Fix wrong register offset for 8ulp
irqchip/ls-extirq: Fix invalid wait context by avoiding to use regmap
dt-bindings: irqchip: Describe the IMX MU block as a MSI controller
irqchip: Add IMX MU MSI controller driver
dt-bindings: irqchip: renesas,irqc: Add r8a779g0 support
irqchip/gic-v3: Fix typo in comment
dt-bindings: interrupt-controller: ti,sci-intr: Fix missing reg property in the binding
dt-bindings: irqchip: ti,sci-inta: Fix warning for missing #interrupt-cells
irqchip: Allow extra fields to be passed to IRQCHIP_PLATFORM_DRIVER_END
platform-msi: Export symbol platform_msi_create_irq_domain()
irqchip/realtek-rtl: use parent interrupts
dt-bindings: interrupt-controller: realtek,rtl-intc: require parents
irqchip/realtek-rtl: use irq_domain_add_linear()
irqchip: Make irqchip_init() usable on pure ACPI systems
bcma: gpio: Use generic_handle_irq_safe()
gpio: mlxbf2: Use generic_handle_irq_safe()
platform/x86: intel_int0002_vgpio: Use generic_handle_irq_safe()
ssb: gpio: Use generic_handle_irq_safe()
pinctrl: amd: Use generic_handle_irq_safe()
...
When ftrace bug happened, following log shows every hex data in
problematic ip address:
actual: ffffffe8:6b:ffffffd9:01:21
But so many 'f's seem a little confusing, and that is because format
'%x' being used to print signed chars in array 'ins'. As suggested
by Joe, change to use format "%*phC" to print array 'ins'.
After this patch, the log is like:
actual: e8:6b:d9:01:21
Link: https://lkml.kernel.org/r/20221011120352.1878494-1-zhengyejian1@huawei.com
Fixes: 6c14133d2d ("ftrace: Do not blindly read the ip address in ftrace_bug()")
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The prandom_bytes() function has been a deprecated inline wrapper around
get_random_bytes() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. This was done as a basic find and replace.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> # powerpc
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake
Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Acked-by: Helge Deller <deller@gmx.de> # for parisc
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:
@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)
@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@
- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);
// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@
((T)get_random_u32()@p & (LITERAL))
// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@
value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))
// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@
- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)
@collapse_ret@
type T;
identifier VAR;
expression E;
@@
{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}
@drop_var@
type T;
identifier VAR;
@@
{
- T VAR;
... when != VAR
}
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Pull gfs2 debugfs updates from Andreas Gruenbacher:
- Improve the way how the state of glocks is reported in debugfs for
glocks which are not held by processes, but rather by other resouces
like cached inodes or flocks.
* tag 'gfs2-nopid-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Mark the remaining process-independent glock holders as GL_NOPID
gfs2: Mark flock glock holders as GL_NOPID
gfs2: Add GL_NOPID flag for process-independent glock holders
gfs2: Add flocks to glockfd debugfs file
gfs2: Add glockfd debugfs file
Pull MM updates from Andrew Morton:
- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any
negative reports (or any positive ones, come to that).
- Also the Maple Tree from Liam Howlett. An overlapping range-based
tree for vmas. It it apparently slightly more efficient in its own
right, but is mainly targeted at enabling work to reduce mmap_lock
contention.
Liam has identified a number of other tree users in the kernel which
could be beneficially onverted to mapletrees.
Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
at [1]. This has yet to be addressed due to Liam's unfortunately
timed vacation. He is now back and we'll get this fixed up.
- Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
clang-generated instrumentation to detect used-unintialized bugs down
to the single bit level.
KMSAN keeps finding bugs. New ones, as well as the legacy ones.
- Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
memory into THPs.
- Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
support file/shmem-backed pages.
- userfaultfd updates from Axel Rasmussen
- zsmalloc cleanups from Alexey Romanov
- cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
memory-failure
- Huang Ying adds enhancements to NUMA balancing memory tiering mode's
page promotion, with a new way of detecting hot pages.
- memcg updates from Shakeel Butt: charging optimizations and reduced
memory consumption.
- memcg cleanups from Kairui Song.
- memcg fixes and cleanups from Johannes Weiner.
- Vishal Moola provides more folio conversions
- Zhang Yi removed ll_rw_block() :(
- migration enhancements from Peter Xu
- migration error-path bugfixes from Huang Ying
- Aneesh Kumar added ability for a device driver to alter the memory
tiering promotion paths. For optimizations by PMEM drivers, DRM
drivers, etc.
- vma merging improvements from Jakub Matěn.
- NUMA hinting cleanups from David Hildenbrand.
- xu xin added aditional userspace visibility into KSM merging
activity.
- THP & KSM code consolidation from Qi Zheng.
- more folio work from Matthew Wilcox.
- KASAN updates from Andrey Konovalov.
- DAMON cleanups from Kaixu Xia.
- DAMON work from SeongJae Park: fixes, cleanups.
- hugetlb sysfs cleanups from Muchun Song.
- Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]
* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
hugetlb: allocate vma lock for all sharable vmas
hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
hugetlb: fix vma lock handling during split vma and range unmapping
mglru: mm/vmscan.c: fix imprecise comments
mm/mglru: don't sync disk for each aging cycle
mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
mm: memcontrol: use do_memsw_account() in a few more places
mm: memcontrol: deprecate swapaccounting=0 mode
mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
mm/secretmem: remove reduntant return value
mm/hugetlb: add available_huge_pages() func
mm: remove unused inline functions from include/linux/mm_inline.h
selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
selftests/vm: add thp collapse shmem testing
selftests/vm: add thp collapse file and tmpfs testing
selftests/vm: modularize thp collapse memory operations
selftests/vm: dedup THP helpers
mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
mm/madvise: add file and shmem support to MADV_COLLAPSE
...
Pull more ACPI updates from Rafael Wysocki:
"These fix two issues, in APEI and in the int3472 driver, clean up the
ACPI thermal driver, add ACPI support for non-GPE system wakeup events
and make the system reboot code use the S5 (system off) state by
default.
Specifics:
- Fix ACPI device object reference counting in (recently updated)
skl_int3472_fill_clk_pdata() (Andy Shevchenko).
- Fix a memory leak in APEI by avoiding to add a task_work to kernel
threads running when an asynchronous error is detected (Shuai Xue).
- Add ACPI support for handling system wakeups via GPIO wake capable
IRQs in addition to GPEs (Raul E Rangel).
- Make the system reboot code put ACPI-enabled systems into the S5
(system off) state which is necessary for some platforms to work as
expected (Kai-Heng Feng).
- Make the white space usage in the ACPI thermal driver more
consistent and drop redundant code from it (Rafael Wysocki)"
* tag 'acpi-6.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI: thermal: Drop some redundant code
ACPI: thermal: Drop redundant parens from expressions
ACPI: thermal: Use white space more consistently
platform/x86: int3472: Don't leak reference on error
ACPI: APEI: do not add task_work to kernel thread to avoid memory leak
PM: ACPI: reboot: Reinstate S5 for reboot
kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE mode
ACPI: PM: Take wake IRQ into consideration when entering suspend-to-idle
i2c: acpi: Use ACPI wake capability bit to set wake_irq
ACPI: resources: Add wake_capable parameter to acpi_dev_irq_flags
gpiolib: acpi: Add wake_capable variants of acpi_dev_gpio_irq_get
Pull dma-mapping updates from Christoph Hellwig:
- fix a regression in the ARM dma-direct conversion (Christoph Hellwig)
- use memcpy_{from,to}_page (Fabio M. De Francesco)
- cleanup the swiotlb MAINTAINERS entry (Lukas Bulwahn)
- make SG table pool allocation less fragile (Masahiro Yamada)
- don't panic on swiotlb initialization failure (Robin Murphy)
* tag 'dma-mapping-6.1-2022-10-10' of git://git.infradead.org/users/hch/dma-mapping:
ARM/dma-mapping: remove the dma_coherent member of struct dev_archdata
ARM/dma-mappіng: don't override ->dma_coherent when set from a bus notifier
lib/sg_pool: change module_init(sg_pool_init) to subsys_initcall
MAINTAINERS: merge SWIOTLB SUBSYSTEM into DMA MAPPING HELPERS
swiotlb: don't panic!
swiotlb: replace kmap_atomic() with memcpy_{from,to}_page()
Pull bitmap updates from Yury Norov:
- Fix unsigned comparison to -1 in CPUMAP_FILE_MAX_BYTES (Phil Auld)
- cleanup nr_cpu_ids vs nr_cpumask_bits mess (me)
This series cleans that mess and adds new config FORCE_NR_CPUS that
allows to optimize cpumask subsystem if the number of CPUs is known
at compile-time.
- optimize find_bit() functions (me)
Reworks find_bit() functions based on new FIND_{FIRST,NEXT}_BIT()
macros.
- add find_nth_bit() (me)
Adds find_nth_bit(), which is ~70 times faster than bitcounting with
for_each() loop:
for_each_set_bit(bit, mask, size)
if (n-- == 0)
return bit;
Also adds bitmap_weight_and() to let people replace this pattern:
tmp = bitmap_alloc(nbits);
bitmap_and(tmp, map1, map2, nbits);
weight = bitmap_weight(tmp, nbits);
bitmap_free(tmp);
with a single bitmap_weight_and() call.
- repair cpumask_check() (me)
After switching cpumask to use nr_cpu_ids, cpumask_check() started
generating many false-positive warnings. This series fixes it.
- Add for_each_cpu_andnot() and for_each_cpu_andnot() (Valentin
Schneider)
Extends the API with one more function and applies it in sched/core.
* tag 'bitmap-6.1-rc1' of https://github.com/norov/linux: (28 commits)
sched/core: Merge cpumask_andnot()+for_each_cpu() into for_each_cpu_andnot()
lib/test_cpumask: Add for_each_cpu_and(not) tests
cpumask: Introduce for_each_cpu_andnot()
lib/find_bit: Introduce find_next_andnot_bit()
cpumask: fix checking valid cpu range
lib/bitmap: add tests for for_each() loops
lib/find: optimize for_each() macros
lib/bitmap: introduce for_each_set_bit_wrap() macro
lib/find_bit: add find_next{,_and}_bit_wrap
cpumask: switch for_each_cpu{,_not} to use for_each_bit()
net: fix cpu_max_bits_warn() usage in netif_attrmask_next{,_and}
cpumask: add cpumask_nth_{,and,andnot}
lib/bitmap: remove bitmap_ord_to_pos
lib/bitmap: add tests for find_nth_bit()
lib: add find_nth{,_and,_andnot}_bit()
lib/bitmap: add bitmap_weight_and()
lib/bitmap: don't call __bitmap_weight() in kernel code
tools: sync find_bit() implementation
lib/find_bit: optimize find_next_bit() functions
lib/find_bit: create find_first_zero_bit_le()
...
Pull tracing updates from Steven Rostedt:
"Major changes:
- Changed location of tracing repo from personal git repo to:
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
- Added Masami Hiramatsu as co-maintainer
- Updated MAINTAINERS file to separate out FTRACE as it is more than
just TRACING.
Minor changes:
- Added Mark Rutland as FTRACE reviewer
- Updated user_events to make it on its way to remove the BROKEN tag.
The changes should now be acceptable but will run it through a
cycle and hopefully we can remove the BROKEN tag next release.
- Added filtering to eprobes
- Added a delta time to the benchmark trace event
- Have the histogram and filter callbacks called via a switch
statement instead of indirect functions. This speeds it up to avoid
retpolines.
- Add a way to wake up ring buffer waiters waiting for the ring
buffer to fill up to its watermark.
- New ioctl() on the trace_pipe_raw file to wake up ring buffer
waiters.
- Wake up waiters when the ring buffer is disabled. A reader may
block when the ring buffer is disabled, but if it was blocked when
the ring buffer is disabled it should then wake up.
Fixes:
- Allow splice to read partially read ring buffer pages. This fixes
splice never moving forward.
- Fix inverted compare that made the "shortest" ring buffer wait
queue actually the longest.
- Fix a race in the ring buffer between resetting a page when a
writer goes to another page, and the reader.
- Fix ftrace accounting bug when function hooks are added at boot up
before the weak functions are set to "disabled".
- Fix bug that freed a user allocated snapshot buffer when enabling a
tracer.
- Fix possible recursive locks in osnoise tracer
- Fix recursive locking direct functions
- Other minor clean ups and fixes"
* tag 'trace-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (44 commits)
ftrace: Create separate entry in MAINTAINERS for function hooks
tracing: Update MAINTAINERS to reflect new tracing git repo
tracing: Do not free snapshot if tracer is on cmdline
ftrace: Still disable enabled records marked as disabled
tracing/user_events: Move pages/locks into groups to prepare for namespaces
tracing: Add Masami Hiramatsu as co-maintainer
tracing: Remove unused variable 'dups'
MAINTAINERS: add myself as a tracing reviewer
ring-buffer: Fix race between reset page and reading page
tracing/user_events: Update ABI documentation to align to bits vs bytes
tracing/user_events: Use bits vs bytes for enabled status page data
tracing/user_events: Use refcount instead of atomic for ref tracking
tracing/user_events: Ensure user provided strings are safely formatted
tracing/user_events: Use WRITE instead of READ for io vector import
tracing/user_events: Use NULL for strstr checks
tracing: Fix spelling mistake "preapre" -> "prepare"
tracing: Wake up waiters when tracing is disabled
tracing: Add ioctl() to force ring buffer waiters to wake up
tracing: Wake up ring buffer waiters on closing of the file
ring-buffer: Add ring_buffer_wake_waiters()
...
Pull sysctl updates from Luis Chamberlain:
"Just some boring cleanups on the sysctl front for this release"
* tag 'sysctl-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred}
kernel/sysctl.c: move sysctl_vals and sysctl_long_vals to sysctl.c
sysctl: remove max_extfrag_threshold
kernel/sysctl.c: remove unnecessary (void*) conversions
proc: remove initialization assignment
This ensures that no module record/or entry is added to the
unloaded_tainted_modules list if it does not carry a taint.
Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Fixes: 99bd995655 ("module: Introduce module unload taint tracking")
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull module updates from Luis Chamberlain:
- minor enhancement for sysfs compression string (David Disseldorp)
- debugfs interface to view unloaded tainted modules (Aaron Tomlin)
* tag 'modules-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
module/decompress: generate sysfs string at compile time
module: Add debugfs interface to view unloaded tainted modules
Pull Kbuild updates from Masahiro Yamada:
- Remove potentially incomplete targets when Kbuid is interrupted by
SIGINT etc in case GNU Make may miss to do that when stderr is piped
to another program.
- Rewrite the single target build so it works more correctly.
- Fix rpm-pkg builds with V=1.
- List top-level subdirectories in ./Kbuild.
- Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in
kallsyms.
- Avoid two different modules in lib/zstd/ having shared code, which
potentially causes building the common code as build-in and modular
back-and-forth.
- Unify two modpost invocations to optimize the build process.
- Remove head-y syntax in favor of linker scripts for placing
particular sections in the head of vmlinux.
- Bump the minimal GNU Make version to 3.82.
- Clean up misc Makefiles and scripts.
* tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits)
docs: bump minimal GNU Make version to 3.82
ia64: simplify esi object addition in Makefile
Revert "kbuild: Check if linker supports the -X option"
kbuild: rebuild .vmlinux.export.o when its prerequisite is updated
kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o
zstd: Fixing mixed module-builtin objects
kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols
kallsyms: take the input file instead of reading stdin
kallsyms: drop duplicated ignore patterns from kallsyms.c
kbuild: reuse mksysmap output for kallsyms
mksysmap: update comment about __crc_*
kbuild: remove head-y syntax
kbuild: use obj-y instead extra-y for objects placed at the head
kbuild: hide error checker logs for V=1 builds
kbuild: re-run modpost when it is updated
kbuild: unify two modpost invocations
kbuild: move vmlinux.o rule to the top Makefile
kbuild: move .vmlinux.objs rule to Makefile.modpost
kbuild: list sub-directories in ./Kbuild
Makefile.compiler: replace cc-ifversion with compiler-specific macros
...
