| Age | Commit message (Collapse) | Author |
|---|
|
Current perf can report both virtual addresses and physical addresses,
but not the MMU page size. Without the MMU page size information of the
utilized page, users cannot decide whether to promote/demote large pages
to optimize memory usage.
Add a new sample type for the data MMU page size.
Current perf already has a facility to collect data virtual addresses.
A page walker is required to walk the pages tables and calculate the
MMU page size from a given virtual address.
On some platforms, e.g., X86, the page walker is invoked in an NMI
handler. So the page walker must be NMI-safe and low overhead. Besides,
the page walker should work for both user and kernel virtual address.
The existing generic page walker, e.g., walk_page_range_novma(), is a
little bit complex and doesn't guarantee the NMI-safe. The follow_page()
is only for user-virtual address.
Add a new function perf_get_page_size() to walk the page tables and
calculate the MMU page size. In the function:
- Interrupts have to be disabled to prevent any teardown of the page
tables.
- For user space threads, the current->mm is used for the page walker.
For kernel threads and the like, the current->mm is NULL. The init_mm
is used for the page walker. The active_mm is not used here, because
it can be NULL.
Quote from Peter Zijlstra,
"context_switch() can set prev->active_mm to NULL when it transfers it
to @next. It does this before @current is updated. So an NMI that
comes in between this active_mm swizzling and updating @current will
see !active_mm."
- The MMU page size is calculated from the page table level.
The method should work for all architectures, but it has only been
verified on X86. Should there be some architectures, which support perf,
where the method doesn't work, it can be fixed later separately.
Reporting the wrong page size would not be fatal for the architecture.
Some under discussion features may impact the method in the future.
Quote from Dave Hansen,
"There are lots of weird things folks are trying to do with the page
tables, like Address Space Isolation. For instance, if you get a
perf NMI when running userspace, current->mm->pgd is *different* than
the PGD that was in use when userspace was running. It's close enough
today, but it might not stay that way."
If the case happens later, lots of consecutive page walk errors will
happen. The worst case is that lots of page-size '0' are returned, which
would not be fatal.
In the perf tool, a check is implemented to detect this case. Once it
happens, a kernel patch could be implemented accordingly then.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201001135749.2804-2-kan.liang@linux.intel.com
|
|
exit_mm should issue memory barriers after user-space memory accesses,
before clearing current->mm, to order user-space memory accesses
performed prior to exit_mm before clearing tsk->mm, which has the
effect of skipping the membarrier private expedited IPIs.
exit_mm should also update the runqueue's membarrier_state so
membarrier global expedited IPIs are not sent when they are not
needed.
The membarrier system call can be issued concurrently with do_exit
if we have thread groups created with CLONE_VM but not CLONE_THREAD.
Here is the scenario I have in mind:
Two thread groups are created, A and B. Thread group B is created by
issuing clone from group A with flag CLONE_VM set, but not CLONE_THREAD.
Let's assume we have a single thread within each thread group (Thread A
and Thread B).
The AFAIU we can have:
Userspace variables:
int x = 0, y = 0;
CPU 0 CPU 1
Thread A Thread B
(in thread group A) (in thread group B)
x = 1
barrier()
y = 1
exit()
exit_mm()
current->mm = NULL;
r1 = load y
membarrier()
skips CPU 0 (no IPI) because its current mm is NULL
r2 = load x
BUG_ON(r1 == 1 && r2 == 0)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201020134715.13909-2-mathieu.desnoyers@efficios.com
|
|
Add TIF_NOTIFY_SIGNAL handling in the generic entry code, which if set,
will return true if signal_pending() is used in a wait loop. That causes an
exit of the loop so that notify_signal tracehooks can be run. If the wait
loop is currently inside a system call, the system call is restarted once
task_work has been processed.
In preparation for only having arch_do_signal() handle syscall restarts if
_TIF_SIGPENDING isn't set, rename it to arch_do_signal_or_restart(). Pass
in a boolean that tells the architecture specific signal handler if it
should attempt to get a signal, or just process a potential syscall
restart.
For !CONFIG_GENERIC_ENTRY archs, add the TIF_NOTIFY_SIGNAL handling to
get_signal(). This is done to minimize the needed architecture changes to
support this feature.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20201026203230.386348-3-axboe@kernel.dk
|
|
This is in preparation for maintaining signal_pending() as the decider of
whether or not a schedule() loop should be broken, or continue sleeping.
This is different than the core signal use cases, which really need to know
whether an actual signal is pending or not. task_sigpending() returns
non-zero if TIF_SIGPENDING is set.
Only core kernel use cases should care about the distinction between
the two, make sure those use the task_sigpending() helper.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20201026203230.386348-2-axboe@kernel.dk
|
|
Commit e679654a704e ("bpf: Fix a rcu_sched stall issue with
bpf task/task_file iterator") tries to fix rcu stalls warning
which is caused by bpf task_file iterator when running
"bpftool prog".
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: \x097-....: (20999 ticks this GP) idle=302/1/0x4000000000000000 softirq=1508852/1508852 fqs=4913
\x09(t=21031 jiffies g=2534773 q=179750)
NMI backtrace for cpu 7
CPU: 7 PID: 184195 Comm: bpftool Kdump: loaded Tainted: G W 5.8.0-00004-g68bfc7f8c1b4 #6
Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A17 05/03/2019
Call Trace:
<IRQ>
dump_stack+0x57/0x70
nmi_cpu_backtrace.cold+0x14/0x53
? lapic_can_unplug_cpu.cold+0x39/0x39
nmi_trigger_cpumask_backtrace+0xb7/0xc7
rcu_dump_cpu_stacks+0xa2/0xd0
rcu_sched_clock_irq.cold+0x1ff/0x3d9
? tick_nohz_handler+0x100/0x100
update_process_times+0x5b/0x90
tick_sched_timer+0x5e/0xf0
__hrtimer_run_queues+0x12a/0x2a0
hrtimer_interrupt+0x10e/0x280
__sysvec_apic_timer_interrupt+0x51/0xe0
asm_call_on_stack+0xf/0x20
</IRQ>
sysvec_apic_timer_interrupt+0x6f/0x80
...
task_file_seq_next+0x52/0xa0
bpf_seq_read+0xb9/0x320
vfs_read+0x9d/0x180
ksys_read+0x5f/0xe0
do_syscall_64+0x38/0x60
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The fix is to limit the number of bpf program runs to be
one million. This fixed the program in most cases. But
we also found under heavy load, which can increase the wallclock
time for bpf_seq_read(), the warning may still be possible.
For example, calling bpf_delay() in the "while" loop of
bpf_seq_read(), which will introduce artificial delay,
the warning will show up in my qemu run.
static unsigned q;
volatile unsigned *p = &q;
volatile unsigned long long ll;
static void bpf_delay(void)
{
int i, j;
for (i = 0; i < 10000; i++)
for (j = 0; j < 10000; j++)
ll += *p;
}
There are two ways to fix this issue. One is to reduce the above
one million threshold to say 100,000 and hopefully rcu warning will
not show up any more. Another is to introduce a target feature
which enables bpf_seq_read() calling cond_resched().
This patch took second approach as the first approach may cause
more -EAGAIN failures for read() syscalls. Note that not all bpf_iter
targets can permit cond_resched() in bpf_seq_read() as some, e.g.,
netlink seq iterator, rcu read lock critical section spans through
seq_ops->next() -> seq_ops->show() -> seq_ops->next().
For the kernel code with the above hack, "bpftool p" roughly takes
38 seconds to finish on my VM with 184 bpf program runs.
Using the following command, I am able to collect the number of
context switches:
perf stat -e context-switches -- ./bpftool p >& log
Without this patch,
69 context-switches
With this patch,
75 context-switches
This patch added additional 6 context switches, roughly every 6 seconds
to reschedule, to avoid lengthy no-rescheduling which may cause the
above RCU warnings.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201028061054.1411116-1-yhs@fb.com
|
|
Architectures like x86 have their MSI messages in various bits of the data,
address_lo and address_hi field. Composing or decomposing these messages
with bitmasks and shifts is possible, but unreadable gunk.
Allow architectures to provide an architecture specific representation for
each member of msi_msg. Provide empty defaults for each and stick them into
an union.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201024213535.443185-12-dwmw2@infradead.org
|
|
`width` and `height` are defined as unsigned in our UAPI font descriptor
`struct console_font`. Make them unsigned in our kernel font descriptor
`struct font_desc`, too.
Also, change the corresponding printk() format identifiers from `%d` to
`%u`, in sti_select_fbfont().
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20201028105647.1210161-1-yepeilin.cs@gmail.com
|
|
This patch removes the MIC drivers from the kernel tree
since the corresponding devices have been discontinued.
Removing the dma and char-misc changes in one patch and
merging via the char-misc tree is best to avoid any
potential build breakage.
Cc: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/8c1443136563de34699d2c084df478181c205db4.1603854416.git.sudeep.dutt@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
The kernel-doc markup that documents _fc_replay_callback is
missing an asterisk, causing this warning:
../include/linux/jbd2.h:1271: warning: Function parameter or member 'j_fc_replay_callback' not described in 'journal_s'
When building the docs.
Fixes: 609f928af48f ("jbd2: fast commit recovery path")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/6055927ada2015b55b413cdd2670533bdc9a8da2.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
This patch reserves a field in the jbd2 superblock for number of fast
commit blocks. When this value is non-zero, Ext4 uses this field to
set the number of fast commit blocks.
Fixes: 6866d7b3f2bb ("ext4/jbd2: add fast commit initialization")
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201027044915.2553163-2-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Changeset a435b9a14356 ("locking/refcount: Provide __refcount API to obtain the old value")
added a set of functions starting with __ that have a new
parameter, adding a series of new warnings:
$ ./scripts/kernel-doc -none include/linux/refcount.h
include/linux/refcount.h:169: warning: Function parameter or member 'oldp' not described in '__refcount_add_not_zero'
include/linux/refcount.h:208: warning: Function parameter or member 'oldp' not described in '__refcount_add'
include/linux/refcount.h:239: warning: Function parameter or member 'oldp' not described in '__refcount_inc_not_zero'
include/linux/refcount.h:261: warning: Function parameter or member 'oldp' not described in '__refcount_inc'
include/linux/refcount.h:291: warning: Function parameter or member 'oldp' not described in '__refcount_sub_and_test'
include/linux/refcount.h:327: warning: Function parameter or member 'oldp' not described in '__refcount_dec_and_test'
include/linux/refcount.h:347: warning: Function parameter or member 'oldp' not described in '__refcount_dec'
The issue is that the kernel-doc markups are now misplaced,
as they should be added just before the functions.
So, move the kernel-doc markups to the proper places,
in order to drop the warnings.
It should be noticed that git show produces a crappy output,
for this patch without "--patience" flag.
Fixes: a435b9a14356 ("locking/refcount: Provide __refcount API to obtain the old value")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/7985c31d1ace591bc5e1faa05c367f1295b78afd.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
|
|
Sphinx 3 now checks for duplicated function declarations:
.../Documentation/networking/kapi:143: ../include/linux/phy.h:163: WARNING: Duplicate C declaration, also defined in 'networking/kapi'.
Declaration is 'unsigned int phy_supported_speeds (struct phy_device *phy, unsigned int *speeds, unsigned int size)'.
.../Documentation/networking/kapi:143: ../include/linux/phy.h:1034: WARNING: Duplicate C declaration, also defined in 'networking/kapi'.
Declaration is 'int phy_read_mmd (struct phy_device *phydev, int devad, u32 regnum)'.
.../Documentation/networking/kapi:143: ../include/linux/phy.h:1076: WARNING: Duplicate C declaration, also defined in 'networking/kapi'.
Declaration is 'int __phy_read_mmd (struct phy_device *phydev, int devad, u32 regnum)'.
.../Documentation/networking/kapi:143: ../include/linux/phy.h:1088: WARNING: Duplicate C declaration, also defined in 'networking/kapi'.
Declaration is 'int phy_write_mmd (struct phy_device *phydev, int devad, u32 regnum, u16 val)'.
.../Documentation/networking/kapi:143: ../include/linux/phy.h:1100: WARNING: Duplicate C declaration, also defined in 'networking/kapi'.
Declaration is 'int __phy_write_mmd (struct phy_device *phydev, int devad, u32 regnum, u16 val)'.
It turns that both the C and the H files have the same
kernel-doc markup for the same functions. Let's drop the
at the header file, keeping the one closer to the code.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/75e9a357f9a716833d2094b04898754876365e68.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
|
|
Changeset a8cf7f272b5a ("mm: add find_lock_head") renamed the
index parameter, but forgot to update the kernel-doc markups
accordingly.
Fixes: a8cf7f272b5a ("mm: add find_lock_head")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/dce89b296a4f5f9f8f798d5e76b6736c14a916ac.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
|
|
As reported by kernel-doc:
./include/linux/blk-mq.h:267: warning: Function parameter or member 'active_queues_shared_sbitmap' not described in 'blk_mq_tag_set'
There is now a new member for struct blk_mq_tag_set. Add a
description for it, based on the commit that introduced it.
Fixes: f1b49fdc1c64 ("blk-mq: Record active_queues_shared_sbitmap per tag_set for when using shared sbitmap")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/8e513153b83eefc05e358f51f2632b592c3f6772.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
|
|
Now that all gpiolib irqchip users have been over to use
the irqchip template, we can finally retire the old code
path and leave just one way in to the irqchip: set up the
template when registering the gpio_chip. For a while
we had two code paths for this which was a bit confusing.
This brings this work to a conclusion, there is now one
way of doing this.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Link: https://lore.kernel.org/r/20201019134046.65101-1-linus.walleij@linaro.org
|
|
has_opp_table isn't used anymore, remove it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/08ec1ee1d4252a266956abb5f1e0e0026d753564.1603867487.git.viresh.kumar@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
|
|
Geert reports that commit be2881824ae9eb92 ("arm64/build: Assert for
unwanted sections") results in build errors on arm64 for configurations
that have CONFIG_MODULES disabled.
The commit in question added ASSERT()s to the arm64 linker script to
ensure that linker generated sections such as .got.plt etc are empty,
but as it turns out, there are corner cases where the linker does emit
content into those sections. More specifically, weak references to
function symbols (which can remain unsatisfied, and can therefore not
be emitted as relative references) will be emitted as GOT and PLT
entries when linking the kernel in PIE mode (which is the case when
CONFIG_RELOCATABLE is enabled, which is on by default).
What happens is that code such as
struct device *(*fn)(struct device *dev);
struct device *iommu_device;
fn = symbol_get(mdev_get_iommu_device);
if (fn) {
iommu_device = fn(dev);
essentially gets converted into the following when CONFIG_MODULES is off:
struct device *iommu_device;
if (&mdev_get_iommu_device) {
iommu_device = mdev_get_iommu_device(dev);
where mdev_get_iommu_device is emitted as a weak symbol reference into
the object file. The first reference is decorated with an ordinary
ABS64 data relocation (which yields 0x0 if the reference remains
unsatisfied). However, the indirect call is turned into a direct call
covered by a R_AARCH64_CALL26 relocation, which is converted into a
call via a PLT entry taking the target address from the associated
GOT entry.
Given that such GOT and PLT entries are unnecessary for fully linked
binaries such as the kernel, let's give these weak symbol references
hidden visibility, so that the linker knows that the weak reference
via R_AARCH64_CALL26 can simply remain unsatisfied.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Fangrui Song <maskray@google.com>
Acked-by: Jessica Yu <jeyu@kernel.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20201027151132.14066-1-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
|
|
gcc warns a few thousand times about the isdigit() shadow:
include/linux/ctype.h:26:19: warning: declaration of 'isdigit' shadows a built-in function [-Wshadow]
As there is already a compiler builtin, just use that, and make
it clear we do that by defining a macro. Unfortunately, clang
does not have the isdigit() builtin, so this has to be conditional.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
|
|
gf_early_console_putchar() uses __raw_writel() but the standard driver
uses writel()/readl(). This means we can't use both on the same machine
as the device is either big-endian, little-endian or native-endian.
As android implementation defines the endianness of the device is the one
of the architecture replace all writel()/readl() by
__raw_writel()/__raw_readl()
https://android.googlesource.com/platform/external/qemu/+/refs/heads/emu-master-dev/hw/char/goldfish_tty.c#222
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Link: https://lore.kernel.org/r/20201010004749.1201695-1-laurent@vivier.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
There is a common comment marked, instead, with kernel-doc
notation.
Also, some identifiers have different names between their
prototypes and the kernel-doc markup.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Felipe Balbi <balbi@kernel.org>
Link: https://lore.kernel.org/r/0b964be3884def04fcd20ea5c12cb90d0014871c.1603469755.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
The UX360CA has a WMI device id 0x00060062, which reports whether the
lid is flipped in tablet mode (1) or in normal laptop mode (0).
Add a quirk (quirk_asus_use_lid_flip_devid) for devices on which this
WMI device should be used to figure out the SW_TABLET_MODE state, as
opposed to the quirk_asus_use_kbd_dock_devid.
Additionally, the device needs to be queried on resume and restore
because the firmware does not generate an event if the laptop is put to
sleep while in tablet mode, flipped to normal mode, and later awoken.
It is assumed other UX360* models have the same WMI device. As such, the
quirk is applied to devices with DMI_MATCH(DMI_PRODUCT_NAME, "UX360").
More devices with this feature need to be tested and added accordingly.
The reason for using an allowlist via the quirk mechanism is that the new
WMI device (0x00060062) is also present on some models which do not have
a 360 degree hinge (at least FX503VD and GL503VD from Hans' DSTS
collection) and therefore its presence cannot be relied on.
Signed-off-by: Samuel Čavoj <samuel@cavoj.net>
Cc: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20201020220944.1075530-1-samuel@cavoj.net
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
|
|
According to the SMCCC spec[1](7.5.2 Discovery) the
ARM_SMCCC_ARCH_WORKAROUND_1 function id only returns 0, 1, and
SMCCC_RET_NOT_SUPPORTED.
0 is "workaround required and safe to call this function"
1 is "workaround not required but safe to call this function"
SMCCC_RET_NOT_SUPPORTED is "might be vulnerable or might not be, who knows, I give up!"
SMCCC_RET_NOT_SUPPORTED might as well mean "workaround required, except
calling this function may not work because it isn't implemented in some
cases". Wonderful. We map this SMC call to
0 is SPECTRE_MITIGATED
1 is SPECTRE_UNAFFECTED
SMCCC_RET_NOT_SUPPORTED is SPECTRE_VULNERABLE
For KVM hypercalls (hvc), we've implemented this function id to return
SMCCC_RET_NOT_SUPPORTED, 0, and SMCCC_RET_NOT_REQUIRED. One of those
isn't supposed to be there. Per the code we call
arm64_get_spectre_v2_state() to figure out what to return for this
feature discovery call.
0 is SPECTRE_MITIGATED
SMCCC_RET_NOT_REQUIRED is SPECTRE_UNAFFECTED
SMCCC_RET_NOT_SUPPORTED is SPECTRE_VULNERABLE
Let's clean this up so that KVM tells the guest this mapping:
0 is SPECTRE_MITIGATED
1 is SPECTRE_UNAFFECTED
SMCCC_RET_NOT_SUPPORTED is SPECTRE_VULNERABLE
Note: SMCCC_RET_NOT_AFFECTED is 1 but isn't part of the SMCCC spec
Fixes: c118bbb52743 ("arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://developer.arm.com/documentation/den0028/latest [1]
Link: https://lore.kernel.org/r/20201023154751.1973872-1-swboyd@chromium.org
Signed-off-by: Will Deacon <will@kernel.org>
|
|
add dummy functions to avoid build failure when header files
are included, but drivers are not built.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
|
|
When there are no audit rules registered, mandatory records (config,
etc.) are missing their accompanying records (syscall, proctitle, etc.).
This is due to audit context dummy set on syscall entry based on absence
of rules that signals that no other records are to be printed. Clear the dummy
bit if any record is generated, open coding this in audit_log_start().
The proctitle context and dummy checks are pointless since the
proctitle record will not be printed if no syscall records are printed.
The fds array is reset to -1 after the first syscall to indicate it
isn't valid any more, but was never set to -1 when the context was
allocated to indicate it wasn't yet valid.
Check ctx->pwd in audit_log_name().
The audit_inode* functions can be called without going through
getname_flags() or getname_kernel() that sets audit_names and cwd, so
set the cwd in audit_alloc_name() if it has not already been done so due to
audit_names being valid and purge all other audit_getcwd() calls.
Revert the LSM dump_common_audit_data() LSM_AUDIT_DATA_* cases from the
ghak96 patch since they are no longer necessary due to cwd coverage in
audit_alloc_name().
Thanks to bauen1 <j2468h@googlemail.com> for reporting LSM situations in
which context->cwd is not valid, inadvertantly fixed by the ghak96 patch.
Please see upstream github issue
https://github.com/linux-audit/audit-kernel/issues/120
This is also related to upstream github issue
https://github.com/linux-audit/audit-kernel/issues/96
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Generally, a cpufreq driver may need to update some internal upper
and lower frequency boundaries on policy max and min changes,
respectively, but currently this does not work if the target
frequency does not change along with the policy limit.
Namely, if the target frequency does not change along with the
policy min or max, the "target_freq == policy->cur" check in
__cpufreq_driver_target() prevents driver callbacks from being
invoked and they do not even have a chance to update the
corresponding internal boundary.
This particularly affects the "powersave" and "performance"
governors that always set the target frequency to one of the
policy limits and it never changes when the other limit is updated.
To allow cpufreq the drivers needing to update internal frequency
boundaries on policy limits changes to avoid this issue, introduce
a new driver flag, CPUFREQ_NEED_UPDATE_LIMITS, that (when set) will
neutralize the check mentioned above.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
|
|
There are thousands of warnings about one macro in a W=2 build:
include/linux/filter.h:561:6: warning: declaration of 'ret' shadows a previous local [-Wshadow]
Prefix all the locals in that macro with __ to avoid most of
these warnings.
Fixes: 492ecee892c2 ("bpf: enable program stats")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201026162110.3710415-1-arnd@kernel.org
|
|
There are no users of this headers file in the kernel.
All users are likely migrated to device tree which is a good thing.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Harvey Hunt <harveyhuntnexus@gmail.com>
Cc: linux-mips@vger.kernel.org
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
|
|
When a mlx5 core devlink instance is reloaded in different net namespace,
its associated IB device is deleted and recreated.
Example sequence is:
$ ip netns add foo
$ devlink dev reload pci/0000:00:08.0 netns foo
$ ip netns del foo
mlx5 IB device needs to attach and detach the netdevice to it through the
netdev notifier chain during load and unload sequence. A below call graph
of the unload flow.
cleanup_net()
down_read(&pernet_ops_rwsem); <- first sem acquired
ops_pre_exit_list()
pre_exit()
devlink_pernet_pre_exit()
devlink_reload()
mlx5_devlink_reload_down()
mlx5_unload_one()
[...]
mlx5_ib_remove()
mlx5_ib_unbind_slave_port()
mlx5_remove_netdev_notifier()
unregister_netdevice_notifier()
down_write(&pernet_ops_rwsem);<- recurrsive lock
Hence, when net namespace is deleted, mlx5 reload results in deadlock.
When deadlock occurs, devlink mutex is also held. This not only deadlocks
the mlx5 device under reload, but all the processes which attempt to
access unrelated devlink devices are deadlocked.
Hence, fix this by mlx5 ib driver to register for per net netdev notifier
instead of global one, which operats on the net namespace without holding
the pernet_ops_rwsem.
Fixes: 4383cfcc65e7 ("net/mlx5: Add devlink reload")
Link: https://lore.kernel.org/r/20201026134359.23150-1-parav@nvidia.com
Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
|
|
On some platforms (eg armv7 due to the CONFIG_ARM_DMA_MEM_BUFFERABLE)
MMIO R/W operations always add memory barriers which can increase load,
decrease battery life or in general reduce performance unnecessarily
on devices which access a lot of configuration registers and where
ordering does not matter (eg. media accelerators like the Verisilicon /
Hantro video decoders).
Drivers used to call the relaxed MMIO variants directly but since they
are now accessing the MMIO registers via regmaps (to compensate for
different VPU HW reg layouts via regmap fields), there is a need for a
relaxed API / config to preserve existing behaviour.
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Link: https://lore.kernel.org/r/20201014203024.954369-1-adrian.ratiu@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The change removes the platform_data include/definition. It only contains
some values for the MICBIAS.
These are moved into 'dt-bindings/sound/adi,adau1977.h' so that they can be
used inside device-trees. When moving then, they need to be converted to
pre-compiler defines, so that the DT compiler can understand them.
The driver then, also needs to include the new
'dt-bindings/sound/adi,adau1977.h' file.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201019105313.24862-1-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Like it is done for SET_PERSONALITY with ARM, which requires the ELF
header to select correct personality parameters, x86 requires the
headers when selecting which VDSO to load, instead of relying on the
going-away TIF_IA32/X32 flags.
Add an indirection macro to arch_setup_additional_pages(), that x86 can
reimplement to receive the extra parameter just for ELF files. This
requires no changes to other architectures, who can continue to use the
original arch_setup_additional_pages for ELF and non-ELF binaries.
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201004032536.1229030-8-krisman@collabora.com
|
|
Like it is done for SET_PERSONALITY with x86, which requires the ELF header
to select correct personality parameters, x86 requires the headers on
compat_start_thread() to choose starting CS for ELF32 binaries, instead of
relying on the going-away TIF_IA32/X32 flags.
Add an indirection macro to ELF invocations of START_THREAD, that x86 can
reimplement to receive the extra parameter just for ELF files. This
requires no changes to other architectures who don't need the header
information, they can continue to use the original start_thread for ELF and
non-ELF binaries, and it prevents affecting non-ELF code paths for x86.
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201004032536.1229030-6-krisman@collabora.com
|
|
UBSAN reports:
Undefined behaviour in ./include/linux/time64.h:127:27
signed integer overflow:
17179869187 * 1000000000 cannot be represented in type 'long long int'
Call Trace:
timespec64_to_ns include/linux/time64.h:127 [inline]
set_cpu_itimer+0x65c/0x880 kernel/time/itimer.c:180
do_setitimer+0x8e/0x740 kernel/time/itimer.c:245
__x64_sys_setitimer+0x14c/0x2c0 kernel/time/itimer.c:336
do_syscall_64+0xa1/0x540 arch/x86/entry/common.c:295
Commit bd40a175769d ("y2038: itimer: change implementation to timespec64")
replaced the original conversion which handled time clamping correctly with
timespec64_to_ns() which has no overflow protection.
Fix it in timespec64_to_ns() as this is not necessarily limited to the
usage in itimers.
[ tglx: Added comment and adjusted the fixes tag ]
Fixes: 361a3bf00582 ("time64: Add time64.h header and define struct timespec64")
Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1598952616-6416-1-git-send-email-prime.zeng@hisilicon.com
|
|
Commit d46f9fbec719 ("bus: ti-sysc: Use optional clocks on for enable and
wait for softreset bit") started showing a "OCP softreset timed out"
warning on enable if the interconnect target module is not out of reset.
This caused the warning to be often triggered for i2c and hdq while the
devices are working properly.
Turns out that some interconnect target modules seem to have an unusable
reset status bits unless the module specific reset quirks are activated.
Let's just skip the reset status check for those modules as we only want
to activate the reset quirks when doing a reset, and not on enable. This
way we don't see the bogus "OCP softreset timed out" warnings during boot.
Fixes: d46f9fbec719 ("bus: ti-sysc: Use optional clocks on for enable and wait for softreset bit")
Signed-off-by: Tony Lindgren <tony@atomide.com>
|
|
The devfreq structure instance contains the governor_name and a governor
instance. When need to show the governor name, better to use the name
of devfreq_governor structure. So, governor_name variable in struct devfreq
is a redundant and unneeded variable. Remove the redundant governor_name
of struct devfreq and then use the name of devfreq_governor instance.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
|
|
Move the head of epitem list out of struct file; for epoll ones it's
moved into struct eventpoll (->refs there), for non-epoll - into
the new object (struct epitem_head). In place of ->f_ep_links we
leave a pointer to the list head (->f_ep).
->f_ep is protected by ->f_lock and it's zeroed as soon as the list
of epitems becomes empty (that can happen only in ep_remove() by
now).
The list of files for reverse path check is *not* going through
struct file now - it's a single-linked list going through epitem_head
instances. It's terminated by ERR_PTR(-1) (== EP_UNACTIVE_POINTER),
so the elements of list can be distinguished by head->next != NULL.
epitem_head instances are allocated at ep_insert() time (by
attach_epitem()) and freed either by ep_remove() (if it empties
the set of epitems *and* epitem_head does not belong to the
reverse path check list) or by clear_tfile_check_list() when
the list is emptied (if the set of epitems is empty by that
point). Allocations are done from a separate slab - minimal kmalloc()
size is too large on some architectures.
As the result, we trim struct file _and_ get rid of the games with
temporary file references.
Locking and barriers are interesting (aren't they always); see unlist_file()
and ep_remove() for details. The non-obvious part is that ep_remove() needs
to decide if it will be the one to free the damn thing *before* actually
storing NULL to head->epitems.first - that's what smp_load_acquire is for
in there. unlist_file() lockless path is safe, since we hit it only if
we observe NULL in head->epitems.first and whoever had done that store is
guaranteed to have observed non-NULL in head->next. IOW, their last access
had been the store of NULL into ->epitems.first and we can safely free
the sucker. OTOH, we are under rcu_read_lock() and both epitem and
epitem->file have their freeing RCU-delayed. So if we see non-NULL
->epitems.first, we can grab ->f_lock (all epitems in there share the
same struct file) and safely recheck the emptiness of ->epitems; again,
->next is still non-NULL, so ep_remove() couldn't have freed head yet.
->f_lock serializes us wrt ep_remove(); the rest is trivial.
Note that once head->epitems becomes NULL, nothing can get inserted into
it - the only remaining reference to head after that point is from the
reverse path check list.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
we don't care about the order of elements there
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.
Remove the quote operator # from compiler_attributes.h __section macro.
Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.
Conversion done using the script at:
https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Commit 453431a54934 ("mm, treewide: rename kzfree() to
kfree_sensitive()") renamed kzfree() to kfree_sensitive(),
but it left a compatibility definition of kzfree() to avoid
being too disruptive.
Since then a few more instances of kzfree() have slipped in.
Just get rid of them and remove the compatibility definition
once and for all.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Thomas Gleixner:
"Just a trivial fix for kernel-doc warnings"
* tag 'locking-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/seqlocks: Fix kernel-doc warnings
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull more parisc updates from Helge Deller:
- During this merge window O_NONBLOCK was changed to become 000200000,
but we missed that the syscalls timerfd_create(), signalfd4(),
eventfd2(), pipe2(), inotify_init1() and userfaultfd() do a strict
bit-wise check of the flags parameter.
To provide backward compatibility with existing userspace we
introduce parisc specific wrappers for those syscalls which filter
out the old O_NONBLOCK value and replaces it with the new one.
- Prevent HIL bus driver to get stuck when keyboard or mouse isn't
attached
- Improve error return codes when setting rtc time
- Minor documentation fix in pata_ns87415.c
* 'parisc-5.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
ata: pata_ns87415.c: Document support on parisc with superio chip
parisc: Add wrapper syscalls to fix O_NONBLOCK flag usage
hil/parisc: Disable HIL driver when it gets stuck
parisc: Improve error return codes when setting rtc time
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom
Pull random32 updates from Willy Tarreau:
"Make prandom_u32() less predictable.
This is the cleanup of the latest series of prandom_u32
experimentations consisting in using SipHash instead of Tausworthe to
produce the randoms used by the network stack.
The changes to the files were kept minimal, and the controversial
commit that used to take noise from the fast_pool (f227e3ec3b5c) was
reverted. Instead, a dedicated "net_rand_noise" per_cpu variable is
fed from various sources of activities (networking, scheduling) to
perturb the SipHash state using fast, non-trivially predictable data,
instead of keeping it fully deterministic. The goal is essentially to
make any occasional memory leakage or brute-force attempt useless.
The resulting code was verified to be very slightly faster on x86_64
than what is was with the controversial commit above, though this
remains barely above measurement noise. It was also tested on i386 and
arm, and build- tested only on arm64"
Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
* tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom:
random32: add a selftest for the prandom32 code
random32: add noise from network and scheduling activity
random32: make prandom_u32() output unpredictable
|
|
Pull block fixes from Jens Axboe:
- NVMe pull request from Christoph
- rdma error handling fixes (Chao Leng)
- fc error handling and reconnect fixes (James Smart)
- fix the qid displace when tracing ioctl command (Keith Busch)
- don't use BLK_MQ_REQ_NOWAIT for passthru (Chaitanya Kulkarni)
- fix MTDT for passthru (Logan Gunthorpe)
- blacklist Write Same on more devices (Kai-Heng Feng)
- fix an uninitialized work struct (zhenwei pi)"
- lightnvm out-of-bounds fix (Colin)
- SG allocation leak fix (Doug)
- rnbd fixes (Gioh, Guoqing, Jack)
- zone error translation fixes (Keith)
- kerneldoc markup fix (Mauro)
- zram lockdep fix (Peter)
- Kill unused io_context members (Yufen)
- NUMA memory allocation cleanup (Xianting)
- NBD config wakeup fix (Xiubo)
* tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block: (27 commits)
block: blk-mq: fix a kernel-doc markup
nvme-fc: shorten reconnect delay if possible for FC
nvme-fc: wait for queues to freeze before calling update_hr_hw_queues
nvme-fc: fix error loop in create_hw_io_queues
nvme-fc: fix io timeout to abort I/O
null_blk: use zone status for max active/open
nvmet: don't use BLK_MQ_REQ_NOWAIT for passthru
nvmet: cleanup nvmet_passthru_map_sg()
nvmet: limit passthru MTDS by BIO_MAX_PAGES
nvmet: fix uninitialized work for zero kato
nvme-pci: disable Write Zeroes on Sandisk Skyhawk
nvme: use queuedata for nvme_req_qid
nvme-rdma: fix crash due to incorrect cqe
nvme-rdma: fix crash when connect rejected
block: remove unused members for io_context
blk-mq: remove the calling of local_memory_node()
zram: Fix __zram_bvec_{read,write}() locking order
skd_main: remove unused including <linux/version.h>
sgl_alloc_order: fix memory leak
lightnvm: fix out-of-bounds write to array devices->info[]
...
|
|
Pull io_uring fixes from Jens Axboe:
- fsize was missed in previous unification of work flags
- Few fixes cleaning up the flags unification creds cases (Pavel)
- Fix NUMA affinities for completely unplugged/replugged node for io-wq
- Two fallout fixes from the set_fs changes. One local to io_uring, one
for the splice entry point that io_uring uses.
- Linked timeout fixes (Pavel)
- Removal of ->flush() ->files work-around that we don't need anymore
with referenced files (Pavel)
- Various cleanups (Pavel)
* tag 'io_uring-5.10-2020-10-24' of git://git.kernel.dk/linux-block:
splice: change exported internal do_splice() helper to take kernel offset
io_uring: make loop_rw_iter() use original user supplied pointers
io_uring: remove req cancel in ->flush()
io-wq: re-set NUMA node affinities if CPUs come online
io_uring: don't reuse linked_timeout
io_uring: unify fsize with def->work_flags
io_uring: fix racy REQ_F_LINK_TIMEOUT clearing
io_uring: do poll's hash_node init in common code
io_uring: inline io_poll_task_handler()
io_uring: remove extra ->file check in poll prep
io_uring: make cached_cq_overflow non atomic_t
io_uring: inline io_fail_links()
io_uring: kill ref get/drop in personality init
io_uring: flags-based creds init in queue
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
"Assorted stuff all over the place (the largest group here is
Christoph's stat cleanups)"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: remove KSTAT_QUERY_FLAGS
fs: remove vfs_stat_set_lookup_flags
fs: move vfs_fstatat out of line
fs: implement vfs_stat and vfs_lstat in terms of vfs_fstatat
fs: remove vfs_statx_fd
fs: omfs: use kmemdup() rather than kmalloc+memcpy
[PATCH] reduce boilerplate in fsid handling
fs: Remove duplicated flag O_NDELAY occurring twice in VALID_OPEN_FLAGS
selftests: mount: add nosymfollow tests
Add a "nosymfollow" mount option.
|
|
Pull dma-mapping fixes from Christoph Hellwig:
- document the new dma_{alloc,free}_pages() API
- two fixups for the dma-mapping.h split
* tag 'dma-mapping-5.10-1' of git://git.infradead.org/users/hch/dma-mapping:
dma-mapping: document dma_{alloc,free}_pages
dma-mapping: move more functions to dma-map-ops.h
ARM/sa1111: add a missing include of dma-map-ops.h
|
|
With the removal of the interrupt perturbations in previous random32
change (random32: make prandom_u32() output unpredictable), the PRNG
has become 100% deterministic again. While SipHash is expected to be
way more robust against brute force than the previous Tausworthe LFSR,
there's still the risk that whoever has even one temporary access to
the PRNG's internal state is able to predict all subsequent draws till
the next reseed (roughly every minute). This may happen through a side
channel attack or any data leak.
This patch restores the spirit of commit f227e3ec3b5c ("random32: update
the net random state on interrupt and activity") in that it will perturb
the internal PRNG's statee using externally collected noise, except that
it will not pick that noise from the random pool's bits nor upon
interrupt, but will rather combine a few elements along the Tx path
that are collectively hard to predict, such as dev, skb and txq
pointers, packet length and jiffies values. These ones are combined
using a single round of SipHash into a single long variable that is
mixed with the net_rand_state upon each invocation.
The operation was inlined because it produces very small and efficient
code, typically 3 xor, 2 add and 2 rol. The performance was measured
to be the same (even very slightly better) than before the switch to
SipHash; on a 6-core 12-thread Core i7-8700k equipped with a 40G NIC
(i40e), the connection rate dropped from 556k/s to 555k/s while the
SYN cookie rate grew from 5.38 Mpps to 5.45 Mpps.
Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
Cc: George Spelvin <lkml@sdf.org>
Cc: Amit Klein <aksecurity@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tytso@mit.edu
Cc: Florian Westphal <fw@strlen.de>
Cc: Marc Plumb <lkml.mplumb@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
|
|
Non-cryptographic PRNGs may have great statistical properties, but
are usually trivially predictable to someone who knows the algorithm,
given a small sample of their output. An LFSR like prandom_u32() is
particularly simple, even if the sample is widely scattered bits.
It turns out the network stack uses prandom_u32() for some things like
random port numbers which it would prefer are *not* trivially predictable.
Predictability led to a practical DNS spoofing attack. Oops.
This patch replaces the LFSR with a homebrew cryptographic PRNG based
on the SipHash round function, which is in turn seeded with 128 bits
of strong random key. (The authors of SipHash have *not* been consulted
about this abuse of their algorithm.) Speed is prioritized over security;
attacks are rare, while performance is always wanted.
Replacing all callers of prandom_u32() is the quick fix.
Whether to reinstate a weaker PRNG for uses which can tolerate it
is an open question.
Commit f227e3ec3b5c ("random32: update the net random state on interrupt
and activity") was an earlier attempt at a solution. This patch replaces
it.
Reported-by: Amit Klein <aksecurity@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tytso@mit.edu
Cc: Florian Westphal <fw@strlen.de>
Cc: Marc Plumb <lkml.mplumb@gmail.com>
Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity")
Signed-off-by: George Spelvin <lkml@sdf.org>
Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
[ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions
to prandom.h for later use; merged George's prandom_seed() proposal;
inlined siprand_u32(); replaced the net_rand_state[] array with 4
members to fix a build issue; cosmetic cleanups to make checkpatch
happy; fixed RANDOM32_SELFTEST build ]
Signed-off-by: Willy Tarreau <w@1wt.eu>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull more RISC-V updates from Palmer Dabbelt:
"Just a single patch set: the remainder of Christoph's work to remove
set_fs, including the RISC-V portion"
* tag 'riscv-for-linus-5.10-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: remove address space overrides using set_fs()
riscv: implement __get_kernel_nofault and __put_user_nofault
riscv: refactor __get_user and __put_user
riscv: use memcpy based uaccess for nommu again
asm-generic: make the set_fs implementation optional
asm-generic: add nommu implementations of __{get,put}_kernel_nofault
asm-generic: improve the nommu {get,put}_user handling
uaccess: provide a generic TASK_SIZE_MAX definition
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC-related driver updates from Olof Johansson:
"Various driver updates for platforms. A bulk of this is smaller fixes
or cleanups, but some of the new material this time around is:
- Support for Nvidia Tegra234 SoC
- Ring accelerator support for TI AM65x
- PRUSS driver for TI platforms
- Renesas support for R-Car V3U SoC
- Reset support for Cortex-M4 processor on i.MX8MQ
There are also new socinfo entries for a handful of different SoCs and
platforms"
* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (131 commits)
drm/mediatek: reduce clear event
soc: mediatek: cmdq: add clear option in cmdq_pkt_wfe api
soc: mediatek: cmdq: add jump function
soc: mediatek: cmdq: add write_s_mask value function
soc: mediatek: cmdq: add write_s value function
soc: mediatek: cmdq: add read_s function
soc: mediatek: cmdq: add write_s_mask function
soc: mediatek: cmdq: add write_s function
soc: mediatek: cmdq: add address shift in jump
soc: mediatek: mtk-infracfg: Fix kerneldoc
soc: amlogic: pm-domains: use always-on flag
reset: sti: reset-syscfg: fix struct description warnings
reset: imx7: add the cm4 reset for i.MX8MQ
dt-bindings: reset: imx8mq: add m4 reset
reset: Fix and extend kerneldoc
reset: reset-zynqmp: Added support for Versal platform
dt-bindings: reset: Updated binding for Versal reset driver
reset: imx7: Support module build
soc: fsl: qe: Remove unnessesary check in ucc_set_tdm_rxtx_clk
soc: fsl: qman: convert to use be32_add_cpu()
...
|
