commit 7fef099702 upstream.
The implementation of 'current' on x86 is very intentionally special: it
is a very common thing to look up, and it uses 'this_cpu_read_stable()'
to get the current thread pointer efficiently from per-cpu storage.
And the keyword in there is 'stable': the current thread pointer never
changes as far as a single thread is concerned. Even if when a thread
is preempted, or moved to another CPU, or even across an explicit call
'schedule()' that thread will still have the same value for 'current'.
It is, after all, the kernel base pointer to thread-local storage.
That's why it's stable to begin with, but it's also why it's important
enough that we have that special 'this_cpu_read_stable()' access for it.
So this is all done very intentionally to allow the compiler to treat
'current' as a value that never visibly changes, so that the compiler
can do CSE and combine multiple different 'current' accesses into one.
However, there is obviously one very special situation when the
currently running thread does actually change: inside the scheduler
itself.
So the scheduler code paths are special, and do not have a 'current'
thread at all. Instead there are _two_ threads: the previous and the
next thread - typically called 'prev' and 'next' (or prev_p/next_p)
internally.
So this is all actually quite straightforward and simple, and not all
that complicated.
Except for when you then have special code that is run in scheduler
context, that code then has to be aware that 'current' isn't really a
valid thing. Did you mean 'prev'? Did you mean 'next'?
In fact, even if then look at the code, and you use 'current' after the
new value has been assigned to the percpu variable, we have explicitly
told the compiler that 'current' is magical and always stable. So the
compiler is quite free to use an older (or newer) value of 'current',
and the actual assignment to the percpu storage is not relevant even if
it might look that way.
Which is exactly what happened in the resctl code, that blithely used
'current' in '__resctrl_sched_in()' when it really wanted the new
process state (as implied by the name: we're scheduling 'into' that new
resctl state). And clang would end up just using the old thread pointer
value at least in some configurations.
This could have happened with gcc too, and purely depends on random
compiler details. Clang just seems to have been more aggressive about
moving the read of the per-cpu current_task pointer around.
The fix is trivial: just make the resctl code adhere to the scheduler
rules of using the prev/next thread pointer explicitly, instead of using
'current' in a situation where it just wasn't valid.
That same code is then also used outside of the scheduler context (when
a thread resctl state is explicitly changed), and then we will just pass
in 'current' as that pointer, of course. There is no ambiguity in that
case.
The fix may be trivial, but noticing and figuring out what went wrong
was not. The credit for that goes to Stephane Eranian.
Reported-by: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/lkml/20230303231133.1486085-1-eranian@google.com/
Link: https://lore.kernel.org/lkml/alpine.LFD.2.01.0908011214330.3304@localhost.localdomain/
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Stephane Eranian <eranian@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0603a47bd3 ]
If wait_for_completion_timeout() times-out in _cdns_xfer_msg() it
is possible that something could have been written to the RX FIFO.
In this case, we should drain the RX FIFO so that anything in it
doesn't carry over and mess up the next transfer.
Obviously, if we got to this state something went wrong, and we
don't really know the state of everything. The cleanup in this
situation cannot be bullet-proof but we should attempt to avoid
breaking future transaction, if only to reduce the amount of
error noise when debugging the failure from a kernel log.
Note that this patch only implements the draining for blocking
(non-deferred) transfers. The deferred API doesn't have any proper
handling of error conditions and would need some re-design before
implementing cleanup. That is a task for a separate patch...
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20221202161812.4186897-4-rf@opensource.cirrus.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 827c32d0df ]
The response_buf was declared much larger (128 entries) than the number
of responses that could ever be written into it. The Cadence IP is
configurable up to a maximum of 32 entries, and the datasheet says
that RX_FIFO_AVAIL can be 2 larger than this. So allow up to 34
responses.
Also add checking in cdns_read_response() to prevent overflowing
reponse_buf if RX_FIFO_AVAIL contains an unexpectedly large number.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20221202161812.4186897-3-rf@opensource.cirrus.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2cc73c5712 ]
iommu_attach_group() attaches all devices in a group to domain and then
sets group domain (group->domain). Current code (__iommu_attach_group())
does not handle error path. This creates problem as devices to domain
attachment is in inconsistent state.
Flow:
- During boot iommu attach devices to default domain
- Later some device driver (like amd/iommu_v2 or vfio) tries to attach
device to new domain.
- In iommu_attach_group() path we detach device from current domain.
Then it tries to attach devices to new domain.
- If it fails to attach device to new domain then device to domain link
is broken.
- iommu_attach_group() returns error.
- At this stage iommu_attach_group() caller thinks, attaching device to
new domain failed and devices are still attached to old domain.
- But in reality device to old domain link is broken. It will result
in all sort of failures (like IO page fault) later.
To recover from this situation, we need to attach all devices back to the
old domain. Also log warning if it fails attach device back to old domain.
Suggested-by: Lu Baolu <baolu.lu@linux.intel.com>
Reported-by: Matt Fagnani <matt.fagnani@bell.net>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Matt Fagnani <matt.fagnani@bell.net>
Link: https://lore.kernel.org/r/20230215052642.6016-1-vasant.hegde@amd.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865
Link: https://lore.kernel.org/lkml/15d0f9ff-2a56-b3e9-5b45-e6b23300ae3b@leemhuis.info/
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 876e480da2 ]
Clang can do some aggressive inlining, which provides it with greater
visibility into the sizes of various objects that are passed into
helpers. Specifically, compare_netdev_and_ip() can see through the type
given to the "sa" argument, which means it can generate code for "struct
sockaddr_in" that would have been passed to ipv6_addr_cmp() (that expects
to operate on the larger "struct sockaddr_in6"), which would result in a
compile-time buffer overflow condition detected by memcmp(). Logically,
this state isn't reachable due to the sa_family assignment two callers
above and the check in compare_netdev_and_ip(). Instead, provide a
compile-time check on sizes so the size-mismatched code will be elided
when inlining. Avoids the following warning from Clang:
../include/linux/fortify-string.h:652:4: error: call to '__read_overflow' declared with 'error' attribute: detected read beyond size of object (1st parameter)
__read_overflow();
^
note: In function 'cma_netevent_callback'
note: which inlined function 'node_from_ndev_ip'
1 error generated.
When the underlying object size is not known (e.g. with GCC and older
Clang), the result of __builtin_object_size() is SIZE_MAX, which will also
compile away, leaving the code as it was originally.
Link: https://lore.kernel.org/r/20230208232549.never.139-kees@kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1687
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org> # build
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 82b34b0800 ]
The Qualcomm PCI bridge device (Device ID 0x010e) found in chipsets such as
SC8280XP used in Lenovo Thinkpad X13s, does not set the Command Completed
bit unless writes to the Slot Command register change "Control" bits.
This results in timeouts like below during boot and resume from suspend:
pcieport 0002:00:00.0: pciehp: Timeout on hotplug command 0x03c0 (issued 2020 msec ago)
...
pcieport 0002:00:00.0: pciehp: Timeout on hotplug command 0x13f1 (issued 107724 msec ago)
Add the device to the Command Completed quirk to mark commands "completed"
immediately unless they change the "Control" bits.
Link: https://lore.kernel.org/r/20230213144922.89982-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7180c1d086 ]
Previously we distributed spare resources only upon hot-add, so if the
initial root bus scan found devices that had not been fully configured by
the BIOS, we allocated only enough resources to cover what was then
present. If some of those devices were hotplug bridges, we did not leave
any additional resource space for future expansion.
Distribute the available resources for root buses, too, to make this work
the same way as the normal hotplug case.
A previous commit to do this was reverted due to a regression reported by
Jonathan Cameron:
e96e27fc6f ("PCI: Distribute available resources for root buses, too")
5632e2beaf ("Revert "PCI: Distribute available resources for root buses, too"")
This commit changes pci_bridge_resources_not_assigned() to work with
bridges that do not have all the resource windows programmed by the boot
firmware (previously we expected all I/O, memory and prefetchable memory
were programmed).
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216000
Link: https://lore.kernel.org/r/20220905080232.36087-5-mika.westerberg@linux.intel.com
Link: https://lore.kernel.org/r/20230131092405.29121-4-mika.westerberg@linux.intel.com
Reported-by: Chris Chiu <chris.chiu@canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9db0b9b6a1 ]
A PCI bridge may reside on a bus with other devices as well. The resource
distribution code does not take this into account and therefore it expands
the bridge resource windows too much, not leaving space for the other
devices (or functions of a multifunction device). This leads to an issue
that Jonathan reported when running QEMU with the following topology (QEMU
parameters):
-device pcie-root-port,port=0,id=root_port13,chassis=0,slot=2 \
-device x3130-upstream,id=sw1,bus=root_port13,multifunction=on \
-device e1000,bus=root_port13,addr=0.1 \
-device xio3130-downstream,id=fun1,bus=sw1,chassis=0,slot=3 \
-device e1000,bus=fun1
The first e1000 NIC here is another function in the switch upstream port.
This leads to following errors:
pci 0000:00:04.0: bridge window [mem 0x10200000-0x103fffff] to [bus 02-04]
pci 0000:02:00.0: bridge window [mem 0x10200000-0x103fffff] to [bus 03-04]
pci 0000:02:00.1: BAR 0: failed to assign [mem size 0x00020000]
e1000 0000:02:00.1: can't ioremap BAR 0: [??? 0x00000000 flags 0x0]
Fix this by taking into account bridge windows, device BARs and SR-IOV PF
BARs on the bus (PF BARs include space for VF BARS so only account PF
BARs), including the ones belonging to bridges themselves if it has any.
Link: https://lore.kernel.org/linux-pci/20221014124553.0000696f@huawei.com/
Link: https://lore.kernel.org/linux-pci/6053736d-1923-41e7-def9-7585ce1772d9@ixsystems.com/
Link: https://lore.kernel.org/r/20230131092405.29121-3-mika.westerberg@linux.intel.com
Reported-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reported-by: Alexander Motin <mav@ixsystems.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ce33e64c17 ]
The allocation of PageBuffer is 512 bytes in size, but the dereferencing
of struct ms_bootblock_idi (also size 512) happens at a calculated offset
within the allocation, which means the object could potentially extend
beyond the end of the allocation. Avoid this case by just allocating
enough space to catch any accesses beyond the end. Seen with GCC 13:
../drivers/usb/storage/ene_ub6250.c: In function 'ms_lib_process_bootblock':
../drivers/usb/storage/ene_ub6250.c:1050:44: warning: array subscript 'struct ms_bootblock_idi[0]' is partly outside array bounds of 'unsigned char[512]' [-Warray-bounds=]
1050 | if (le16_to_cpu(idi->wIDIgeneralConfiguration) != MS_IDI_GENERAL_CONF)
| ^~
../include/uapi/linux/byteorder/little_endian.h:37:51: note: in definition of macro '__le16_to_cpu'
37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
| ^
../drivers/usb/storage/ene_ub6250.c:1050:29: note: in expansion of macro 'le16_to_cpu'
1050 | if (le16_to_cpu(idi->wIDIgeneralConfiguration) != MS_IDI_GENERAL_CONF)
| ^~~~~~~~~~~
In file included from ../drivers/usb/storage/ene_ub6250.c:5:
In function 'kmalloc',
inlined from 'ms_lib_process_bootblock' at ../drivers/usb/storage/ene_ub6250.c:942:15:
../include/linux/slab.h:580:24: note: at offset [256, 512] into object of size 512 allocated by 'kmalloc_trace'
580 | return kmalloc_trace(
| ^~~~~~~~~~~~~~
581 | kmalloc_caches[kmalloc_type(flags)][index],
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
582 | flags, size);
| ~~~~~~~~~~~~
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230204183546.never.849-kees@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0fbd2cda92 ]
Walking the dram->cs array was seen as accesses beyond the first array
item by the compiler. Instead, use the array index directly. This allows
for run-time bounds checking under CONFIG_UBSAN_BOUNDS as well. Seen
with GCC 13 with -fstrict-flex-arrays:
In function 'xhci_mvebu_mbus_config',
inlined from 'xhci_mvebu_mbus_init_quirk' at ../drivers/usb/host/xhci-mvebu.c:66:2:
../drivers/usb/host/xhci-mvebu.c:37:28: warning: array subscript 0 is outside array bounds of 'const struct mbus_dram_window[0]' [-Warray-bounds=]
37 | writel(((cs->size - 1) & 0xffff0000) | (cs->mbus_attr << 8) |
| ~~^~~~~~
Cc: Mathias Nyman <mathias.nyman@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230204183651.never.663-kees@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8b3517f88f ]
Except for isochronous-configured devices, software may set
Max_Read_Request_Size (MRRS) to any value up to 4096. If a device issues a
read request with size greater than the completer's Max_Payload_Size (MPS),
the completer is required to break the response into multiple completions.
Instead of correctly responding with multiple completions to a large read
request, some LS7A Root Ports respond with a Completer Abort. To prevent
this, the MRRS must be limited to an implementation-specific value.
The OS cannot detect that value, so rely on BIOS to configure MRRS before
booting, and quirk the Root Ports so we never set an MRRS larger than that
BIOS value for any downstream device.
N.B. Hot-added devices are not configured by BIOS, and they power up with
MRRS = 512 bytes, so these devices will be limited to 512 bytes. If the
LS7A limit is smaller, those hot-added devices may not work correctly, but
per [1], hotplug is not supported with this chipset revision.
[1] https://lore.kernel.org/r/073638a7-ae68-2847-ac3d-29e5e760d6af@loongson.cn
[bhelgaas: commit log]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216884
Link: https://lore.kernel.org/r/20230201043018.778499-3-chenhuacai@loongson.cn
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c8f71b49ee ]
The GPIO controller component of the sc16is7xx driver is setup too
early, which can result in a race condition where another device tries
to utilise the GPIO lines before the sc16is7xx device has finished
initialising.
This issue manifests itself as an Oops when the GPIO lines are configured:
Unable to handle kernel read from unreadable memory at virtual address
...
pc : sc16is7xx_gpio_direction_output+0x68/0x108 [sc16is7xx]
lr : sc16is7xx_gpio_direction_output+0x4c/0x108 [sc16is7xx]
...
Call trace:
sc16is7xx_gpio_direction_output+0x68/0x108 [sc16is7xx]
gpiod_direction_output_raw_commit+0x64/0x318
gpiod_direction_output+0xb0/0x170
create_gpio_led+0xec/0x198
gpio_led_probe+0x16c/0x4f0
platform_drv_probe+0x5c/0xb0
really_probe+0xe8/0x448
driver_probe_device+0xe8/0x138
__device_attach_driver+0x94/0x118
bus_for_each_drv+0x8c/0xe0
__device_attach+0x100/0x1b8
device_initial_probe+0x28/0x38
bus_probe_device+0xa4/0xb0
deferred_probe_work_func+0x90/0xe0
process_one_work+0x1c4/0x480
worker_thread+0x54/0x430
kthread+0x138/0x150
ret_from_fork+0x10/0x1c
This patch moves the setup of the GPIO controller functions to later in the
probe function, ensuring the sc16is7xx device has already finished
initialising by the time other devices try to make use of the GPIO lines.
The error handling has also been reordered to reflect the new
initialisation order.
Co-developed-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
Signed-off-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
Signed-off-by: Isaac True <isaac.true@canonical.com>
Link: https://lore.kernel.org/r/20221130105529.698385-1-isaac.true@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c4c81db5cf ]
LPUART IP has a bug that it treats the CTS as higher priority than the
break signal, which cause the break signal sending through UARTCTRL_SBK
may impacted by the CTS input if the HW flow control is enabled.
Add this workaround patch to fix the IP bug, we can disable CTS before
asserting SBK to avoid any interference from CTS, and re-enable it when
break off.
Such as for the bluetooth chip power save feature, host can let the BT
chip get into sleep state by sending a UART break signal, and wake it up
by turning off the UART break. If the BT chip enters the sleep mode
successfully, it will pull up the CTS line, if the BT chip is woken up,
it will pull down the CTS line. If without this workaround patch, the
UART TX pin cannot send the break signal successfully as it affected by
the BT CTS pin. After adding this patch, the BT power save feature can
work well.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20221214031137.28815-2-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 198102c910 ]
The cacheinfo sets up the shared_cpu_map by checking whether the caches
with the same index are shared between CPUs. However, this will trigger
slab-out-of-bounds access if the CPUs do not have the same cache hierarchy.
Another problem is the mismatched shared_cpu_map when the shared cache does
not have the same index between CPUs.
CPU0 I D L3
index 0 1 2 x
^ ^ ^ ^
index 0 1 2 3
CPU1 I D L2 L3
This patch checks each cache is shared with all caches on other CPUs.
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Link: https://lore.kernel.org/r/20230117105133.4445-2-yongxuan.wang@sifive.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
