[ Upstream commit ab09da7570 ]
Building the kernel with O= is affected by stale in-tree build artifacts.
So, if the source tree is not clean, Kbuild displays the following:
$ make ARCH=um O=build defconfig
make[1]: Entering directory '/.../linux/build'
***
*** The source tree is not clean, please run 'make ARCH=um mrproper'
*** in /.../linux
***
make[2]: *** [/.../linux/Makefile:673: outputmakefile] Error 1
make[1]: *** [/.../linux/Makefile:248: __sub-make] Error 2
make[1]: Leaving directory '/.../linux/build'
make: *** [Makefile:248: __sub-make] Error 2
Usually, running 'make mrproper' is sufficient for cleaning the source
tree for out-of-tree builds.
However, building UML generates build artifacts not only in arch/um/,
but also in the SUBARCH directory (i.e., arch/x86/). If in-tree stale
files remain under arch/x86/, Kbuild will reuse them instead of creating
new ones under the specified build directory.
This commit makes 'make ARCH=um clean' recurse into the SUBARCH directory.
Reported-by: Shuah Khan <skhan@linuxfoundation.org>
Closes: https://lore.kernel.org/lkml/20250502172459.14175-1-skhan@linuxfoundation.org/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7edf0a4d3b upstream.
Update the vin-supply of the TLV71033 regulator from LM5141 (vsys_3v3)
to LM61460 (vsys_5v0) to match the schematics. Add a fixed regulator
node for the LM61460 5V supply to support this change.
AM68-SK schematics: https://www.ti.com/lit/zip/sprr463
Fixes: a266c180b3 ("arm64: dts: ti: k3-am68-sk: Add support for AM68 SK base board")
Cc: stable@vger.kernel.org
Signed-off-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Reviewed-by: Neha Malcom Francis <n-francis@ti.com>
Reviewed-by: Udit Kumar <u-kumar1@ti.com>
Link: https://lore.kernel.org/r/20250415111328.3847502-3-y-abhilashchandra@ti.com
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 295217420a upstream.
There is a typo in sm8350.dts where the node label
mmeory@85200000 should be memory@85200000.
This patch corrects the typo for clarity and consistency.
Fixes: b7e8f433a6 ("arm64: dts: qcom: Add basic devicetree support for SM8350 SoC")
Cc: stable@vger.kernel.org
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Link: https://lore.kernel.org/r/20250514114656.2307828-1-alok.a.tiwari@oracle.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7170130e4c upstream.
As Bert Karwatzki reported, the following recent commit causes a
performance regression on AMD iGPU and dGPU systems:
7ffb791423 ("x86/kaslr: Reduce KASLR entropy on most x86 systems")
It exposed a bug with nokaslr and zone device interaction.
The root cause of the bug is that, the GPU driver registers a zone
device private memory region. When KASLR is disabled or the above commit
is applied, the direct_map_physmem_end is set to much higher than 10 TiB
typically to the 64TiB address. When zone device private memory is added
to the system via add_pages(), it bumps up the max_pfn to the same
value. This causes dma_addressing_limited() to return true, since the
device cannot address memory all the way up to max_pfn.
This caused a regression for games played on the iGPU, as it resulted in
the DMA32 zone being used for GPU allocations.
Fix this by not bumping up max_pfn on x86 systems, when pgmap is passed
into add_pages(). The presence of pgmap is used to determine if device
private memory is being added via add_pages().
More details:
devm_request_mem_region() and request_free_mem_region() request for
device private memory. iomem_resource is passed as the base resource
with start and end parameters. iomem_resource's end depends on several
factors, including the platform and virtualization. On x86 for example
on bare metal, this value is set to boot_cpu_data.x86_phys_bits.
boot_cpu_data.x86_phys_bits can change depending on support for MKTME.
By default it is set to the same as log2(direct_map_physmem_end) which
is 46 to 52 bits depending on the number of levels in the page table.
The allocation routines used iomem_resource's end and
direct_map_physmem_end to figure out where to allocate the region.
[ arch/powerpc is also impacted by this problem, but this patch does not fix
the issue for PowerPC. ]
Testing:
1. Tested on a virtual machine with test_hmm for zone device inseration
2. A previous version of this patch was tested by Bert, please see:
https://lore.kernel.org/lkml/d87680bab997fdc9fb4e638983132af235d9a03a.camel@web.de/
[ mingo: Clarified the comments and the changelog. ]
Reported-by: Bert Karwatzki <spasswolf@web.de>
Tested-by: Bert Karwatzki <spasswolf@web.de>
Fixes: 7ffb791423 ("x86/kaslr: Reduce KASLR entropy on most x86 systems")
Signed-off-by: Balbir Singh <balbirs@nvidia.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Simona Vetter <simona@ffwll.ch>
Link: https://lore.kernel.org/r/20250401000752.249348-1-balbirs@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b3bee1e7c3 upstream.
Use -std=gnu11 for consistency with main kernel code.
It doesn't seem to change anything in vmlinux.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Link: https://lore.kernel.org/r/2058761e-12a4-4b2f-9690-3c3c1c9902a5@p183
Cc: Hendrik Donner <hd@os-cillation.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 573f99c758 ]
This reverts commit 531fdbeede.
Hardware that uses I2C wasn't designed with high speeds in mind, so
communication with PMIC via RSB can intermittently fail. Go back to I2C
as higher speed and efficiency isn't worth the trouble.
Fixes: 531fdbeede ("arm64: dts: allwinner: h6: Use RSB for AXP805 PMIC connection")
Link: https://github.com/LibreELEC/LibreELEC.tv/issues/7731
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://patch.msgid.link/20250413135848.67283-1-jernej.skrabec@gmail.com
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b04f0d89e8 upstream.
The two alarm LEDs of on the uDPU board are stopped working since
commit 78efa53e71 ("leds: Init leds class earlier").
The LEDs are driven by the GPIO{15,16} pins of the North Bridge
GPIO controller. These pins are part of the 'spi_quad' pin group
for which the 'spi' function is selected via the default pinctrl
state of the 'spi' node. This is wrong however, since in order to
allow controlling the LEDs, the pins should use the 'gpio' function.
Before the commit mentined above, the 'spi' function is selected
first by the pinctrl core before probing the spi driver, but then
it gets overridden to 'gpio' implicitly via the
devm_gpiod_get_index_optional() call from the 'leds-gpio' driver.
After the commit, the LED subsystem gets initialized before the
SPI subsystem, so the function of the pin group remains 'spi'
which in turn prevents controlling of the LEDs.
Despite the change of the initialization order, the root cause is
that the pinctrl state definition is wrong since its initial commit
0d45062cfc ("arm64: dts: marvell: Add device tree for uDPU board"),
To fix the problem, override the function in the 'spi_quad_pins'
node to 'gpio' and move the pinctrl state definition from the
'spi' node into the 'leds' node.
Cc: stable@vger.kernel.org # needs adjustment for < 6.1
Fixes: 0d45062cfc ("arm64: dts: marvell: Add device tree for uDPU board")
Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 598bdf4fef ]
Instead of using standard perf_event_attr->freq=0 and ->sample_period
fields, IBS event in 'sample period mode' can also be opened by setting
period value directly in perf_event_attr->config in a MaxCnt bit-field
format.
IBS OP MaxCnt bits are defined as:
(high bits) IbsOpCtl[26:20] = IbsOpMaxCnt[26:20]
(low bits) IbsOpCtl[15:0] = IbsOpMaxCnt[19:4]
Perf event sample period can be derived from MaxCnt bits as:
sample_period = (high bits) | ((low_bits) << 4);
However, current code just masks MaxCnt bits and shifts all of them,
including high bits, which is incorrect. Fix it.
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/r/20250115054438.1021-4-ravi.bangoria@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 46dcf85566 ]
IBS Op uses two counters: MaxCnt and CurCnt. MaxCnt is programmed with
the desired sample period. IBS hw generates sample when CurCnt reaches
to MaxCnt. The size of these counter used to be 20 bits but later they
were extended to 27 bits. The 7 bit extension is indicated by CPUID
Fn8000_001B_EAX[6 / OpCntExt].
perf_ibs->cnt_mask variable contains bit masks for MaxCnt and CurCnt.
But IBS driver does not set upper 7 bits of CurCnt in cnt_mask even
when OpCntExt CPUID bit is set. Fix this.
IBS driver uses cnt_mask[CurCnt] bits only while disabling an event.
Fortunately, CurCnt bits are not read from MSR while re-enabling the
event, instead MaxCnt is programmed with desired period and CurCnt is
set to 0. Hence, we did not see any issues so far.
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/r/20250115054438.1021-5-ravi.bangoria@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 385a59e7f7 ]
Add clock-output-names property to clock nodes, so that the resulting
clock name do not change when clock node name is changed.
Also, replace underscores with hyphens in the clock node names as per
dt-schema rule.
Signed-off-by: Naman Trivedi <naman.trivedimanojbhai@amd.com>
Acked-by: Senthil Nathan Thangaraj <senthilnathan.thangaraj@amd.com>
Link: https://lore.kernel.org/r/20241122095712.1166883-1-naman.trivedimanojbhai@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2ffb26afa6 ]
perf mem report aborts as below sometimes (during some corner
case) in powerpc:
# ./perf mem report 1>out
*** stack smashing detected ***: terminated
Aborted (core dumped)
The backtrace is as below:
__pthread_kill_implementation ()
raise ()
abort ()
__libc_message
__fortify_fail
__stack_chk_fail
hist_entry.lvl_snprintf
__sort__hpp_entry
__hist_entry__snprintf
hists.fprintf
cmd_report
cmd_mem
Snippet of code which triggers the issue
from tools/perf/util/sort.c
static int hist_entry__lvl_snprintf(struct hist_entry *he, char *bf,
size_t size, unsigned int width)
{
char out[64];
perf_mem__lvl_scnprintf(out, sizeof(out), he->mem_info);
return repsep_snprintf(bf, size, "%-*s", width, out);
}
The value of "out" is filled from perf_mem_data_src value.
Debugging this further showed that for some corner cases, the
value of "data_src" was pointing to wrong value. This resulted
in bigger size of string and causing stack check fail.
The perf mem data source values are captured in the sample via
isa207_get_mem_data_src function. The initial check is to fetch
the type of sampled instruction. If the type of instruction is
not valid (not a load/store instruction), the function returns.
Since 'commit e16fd7f2cb ("perf: Use sample_flags for data_src")',
data_src field is not initialized by the perf_sample_data_init()
function. If the PMU driver doesn't set the data_src value to zero if
type is not valid, this will result in uninitailised value for data_src.
The uninitailised value of data_src resulted in stack check fail
followed by abort for "perf mem report".
When requesting for data source information in the sample, the
instruction type is expected to be load or store instruction.
In ISA v3.0, due to hardware limitation, there are corner cases
where the instruction type other than load or store is observed.
In ISA v3.0 and before values "0" and "7" are considered reserved.
In ISA v3.1, value "7" has been used to indicate "larx/stcx".
Drop the sample if instruction type has reserved values for this
field with a ISA version check. Initialize data_src to zero in
isa207_get_mem_data_src if the instruction type is not load/store.
Reported-by: Disha Goel <disgoel@linux.vnet.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250121131621.39054-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6aa989ab2b ]
iommu_mem_notifier() is invoked when RAM is dynamically added/removed. This
notifier call is responsible to add/remove TCEs from the Dynamic DMA Window
(DDW) when TCEs are pre-mapped. TCEs are pre-mapped only for RAM and not
for persistent memory (pmemory). For DMA buffers in pmemory, TCEs are
dynamically mapped when the device driver instructs to do so.
The issue is 'daxctl' command is capable of adding pmemory as "System RAM"
after LPAR boot. The command to do so is -
daxctl reconfigure-device --mode=system-ram dax0.0 --force
This will dynamically add pmemory range to LPAR RAM eventually invoking
iommu_mem_notifier(). The address range of pmemory is way beyond the Max
RAM that the LPAR can have. Which means, this range is beyond the DDW
created for the device, at device initialization time.
As a result when TCEs are pre-mapped for the pmemory range, by
iommu_mem_notifier(), PHYP HCALL returns H_PARAMETER. This failed the
command, daxctl, to add pmemory as RAM.
The solution is to not pre-map TCEs for pmemory.
Signed-off-by: Gaurav Batra <gbatra@linux.ibm.com>
Tested-by: Donet Tom <donettom@linux.ibm.com>
Reviewed-by: Donet Tom <donettom@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250130183854.92258-1-gbatra@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c20ad96c9a ]
Notably, don't attempt to decode an immediate when MOD == 3.
Additionally have it return the instruction length, such that WARN
like bugs can more reliably skip to the correct instruction.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20250207122546.721120726@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 00a134fc2b ]
The pm-cps code has up until now used per-CPU variables indexed by core,
rather than CPU number, in order to share data amongst sibling CPUs (ie.
VPs/threads in a core). This works fine for single cluster systems, but
with multi-cluster systems a core number is no longer unique in the
system, leading to sharing between CPUs that are not actually siblings.
Avoid this issue by using per-CPU variables as they are more generally
used - ie. access them using CPU numbers rather than core numbers.
Sharing between siblings is then accomplished by:
- Assigning the same pointer to entries for each sibling CPU for the
nc_asm_enter & ready_count variables, which allow this by virtue of
being per-CPU pointers.
- Indexing by the first CPU set in a CPUs cpu_sibling_map in the case
of pm_barrier, for which we can't use the previous approach because
the per-CPU variable is not a pointer.
Signed-off-by: Paul Burton <paulburton@kernel.org>
Signed-off-by: Dragan Mladjenovic <dragan.mladjenovic@syrmia.com>
Signed-off-by: Aleksandar Rikalo <arikalo@gmail.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 756276ce78 ]
On MIPS system, most of the syscall function name begin with prefix
sys_. Some syscalls are special such as clone/fork, function name of
these begin with __sys_. Since scratch registers need be saved in
stack when these system calls happens.
With ftrace system call method, system call functions are declared with
SYSCALL_DEFINEx, metadata of the system call symbol name begins with
sys_. Here mips specific function arch_syscall_match_sym_name is used to
compare function name between sys_call_table[] and metadata of syscall
symbol.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7ffb791423 ]
When CONFIG_PCI_P2PDMA=y (which is basically enabled on all
large x86 distros), it maps the PFN's via a ZONE_DEVICE
mapping using devm_memremap_pages(). The mapped virtual
address range corresponds to the pci_resource_start()
of the BAR address and size corresponding to the BAR length.
When KASLR is enabled, the direct map range of the kernel is
reduced to the size of physical memory plus additional padding.
If the BAR address is beyond this limit, PCI peer to peer DMA
mappings fail.
Fix this by not shrinking the size of the direct map when
CONFIG_PCI_P2PDMA=y.
This reduces the total available entropy, but it's better than
the current work around of having to disable KASLR completely.
[ mingo: Clarified the changelog to point out the broad impact ... ]
Signed-off-by: Balbir Singh <balbirs@nvidia.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # drivers/pci/Kconfig
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/lkml/20250206023201.1481957-1-balbirs@nvidia.com/
Link: https://lore.kernel.org/r/20250206234234.1912585-1-balbirs@nvidia.com
--
arch/x86/mm/kaslr.c | 10 ++++++++--
drivers/pci/Kconfig | 6 ++++++
2 files changed, 14 insertions(+), 2 deletions(-)
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fe37c699ae ]
Depending on the type of panics, it was found that the
__register_nmi_handler() function can be called in NMI context from
nmi_shootdown_cpus() leading to a lockdep splat:
WARNING: inconsistent lock state
inconsistent {INITIAL USE} -> {IN-NMI} usage.
lock(&nmi_desc[0].lock);
<Interrupt>
lock(&nmi_desc[0].lock);
Call Trace:
_raw_spin_lock_irqsave
__register_nmi_handler
nmi_shootdown_cpus
kdump_nmi_shootdown_cpus
native_machine_crash_shutdown
__crash_kexec
In this particular case, the following panic message was printed before:
Kernel panic - not syncing: Fatal hardware error!
This message seemed to be given out from __ghes_panic() running in
NMI context.
The __register_nmi_handler() function which takes the nmi_desc lock
with irq disabled shouldn't be called from NMI context as this can
lead to deadlock.
The nmi_shootdown_cpus() function can only be invoked once. After the
first invocation, all other CPUs should be stuck in the newly added
crash_nmi_callback() and cannot respond to a second NMI.
Fix it by adding a new emergency NMI handler to the nmi_desc
structure and provide a new set_emergency_nmi_handler() helper to set
crash_nmi_callback() in any context. The new emergency handler will
preempt other handlers in the linked list. That will eliminate the need
to take any lock and serve the panic in NMI use case.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20250206191844.131700-1-longman@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e451630226 ]
Problem: Currently when running the "make isoimage" command there is an
error related to wrong parameters passed to the cp command:
"cp: missing destination file operand after 'arch/x86/boot/isoimage/'"
This is caused because FDINITRDS is an empty array.
Solution: Check if FDINITRDS is empty before executing the "cp" command,
similar to how it is done in the case of hdimage.
Signed-off-by: Nir Lichtman <nir@lichtman.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Link: https://lore.kernel.org/r/20250110120500.GA923218@lichtman.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bc4722c359 ]
For sama7g5 and sama7d65 backup mode, we encountered a "ZQ calibrate error"
during recalibrating the impedance in BootStrap.
We found that the impedance value saved in at91_suspend_finish() before
the DDR entered self-refresh mode did not match the resistor values. The
ZDATA field in the DDR3PHY_ZQ0CR0 register uses a modified gray code to
select the different impedance setting.
But these gray code are incorrect, a workaournd from design team fixed the
bug in the calibration logic. The ZDATA contains four independent impedance
elements, but the algorithm combined the four elements into one. The elements
were fixed using properly shifted offsets.
Signed-off-by: Li Bin <bin.li@microchip.com>
[nicolas.ferre@microchip.com: fix indentation and combine 2 patches]
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Tested-by: Ryan Wanner <Ryan.Wanner@microchip.com>
Tested-by: Durai Manickam KR <durai.manickamkr@microchip.com>
Tested-by: Andrei Simion <andrei.simion@microchip.com>
Signed-off-by: Ryan Wanner <Ryan.Wanner@microchip.com>
Link: https://lore.kernel.org/r/28b33f9bcd0ca60ceba032969fe054d38f2b9577.1740671156.git.Ryan.Wanner@microchip.com
Signed-off-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 98fdaeb296 ]
Change the default value of spectre v2 in user mode to respect the
CONFIG_MITIGATION_SPECTRE_V2 config option.
Currently, user mode spectre v2 is set to auto
(SPECTRE_V2_USER_CMD_AUTO) by default, even if
CONFIG_MITIGATION_SPECTRE_V2 is disabled.
Set the spectre_v2 value to auto (SPECTRE_V2_USER_CMD_AUTO) if the
Spectre v2 config (CONFIG_MITIGATION_SPECTRE_V2) is enabled, otherwise
set the value to none (SPECTRE_V2_USER_CMD_NONE).
Important to say the command line argument "spectre_v2_user" overwrites
the default value in both cases.
When CONFIG_MITIGATION_SPECTRE_V2 is not set, users have the flexibility
to opt-in for specific mitigations independently. In this scenario,
setting spectre_v2= will not enable spectre_v2_user=, and command line
options spectre_v2_user and spectre_v2 are independent when
CONFIG_MITIGATION_SPECTRE_V2=n.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Kaplan <David.Kaplan@amd.com>
Link: https://lore.kernel.org/r/20241031-x86_bugs_last_v2-v2-2-b7ff1dab840e@debian.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2b3db788f2 ]
PLLD is usually used as parent clock for internal video devices, like
DSI for example, while PLLD2 is used as parent for HDMI.
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Link: https://lore.kernel.org/r/20250226105615.61087-3-clamor95@gmail.com
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7e67ef889c ]
Similar to the PowerMac3,1, the PowerBook6,7 is missing the #size-cells
property on the i2s node.
Depends-on: commit 045b14ca5c ("of: WARN on deprecated #address-cells/#size-cells handling")
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
[maddy: added "commit" work in depends-on to avoid checkpatch error]
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/875xmizl6a.fsf@igel.home
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6d4bfe6d86 ]
Some discrete graphics cards such as the NVIDIA RTX A6000 support
resizable BARs. When connecting an A6000 card to the NVIDIA IGX Orin
platform, resizing the BAR1 aperture to 8GB fails because the current
device-tree configuration for the PCIe C5 slot cannot support this.
Fix this by updating the device-tree 'reg' and 'ranges' properties for
the PCIe C5 slot to support this.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20250116151903.476047-1-jonathanh@nvidia.com
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f34621f31e ]
According to the board schematics the enable pin of this regulator is
connected to gpio line #9 of the first instance of the TCA9539
GPIO expander, so adjust it.
Signed-off-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Link: https://lore.kernel.org/r/20250224-diogo-gpio_exp-v1-1-80fb84ac48c6@tecnico.ulisboa.pt
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bfb1d2b902 ]
pud_bad() is currently defined in terms of pud_table(). Although for some
configs, pud_table() is hard-coded to true i.e. when using 64K base pages
or when page table levels are less than 3.
pud_bad() is intended to check that the pud is configured correctly. Hence
let's open-code the same check that the full version of pud_table() uses
into pud_bad(). Then it always performs the check regardless of the config.
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20250221044227.1145393-7-anshuman.khandual@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e82cf3051e ]
When uml_reserved is updated, min_low_pfn must also be updated
accordingly. Otherwise, min_low_pfn will not accurately reflect
the lowest available PFN.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20250221041855.1156109-1-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cef721e0d5 ]
Doing this allows using registers as retrieved from an mcontext to be
pushed to a process using PTRACE_SETREGS.
It is not entirely clear to me why CSGSFS was masked. Doing so creates
issues when using the mcontext as process state in seccomp and simply
copying the register appears to work perfectly fine for ptrace.
Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Link: https://patch.msgid.link/20250224181827.647129-2-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 631ca8909f ]
At least with CONFIG_PHYSICAL_START=0x100000, if there is < 4 MiB of
contiguous free memory available at this point, the kernel will crash
and burn because memblock_phys_alloc_range() returns 0 on failure,
which leads memblock_phys_free() to throw the first 4 MiB of physical
memory to the wolves.
At a minimum it should fail gracefully with a meaningful diagnostic,
but in fact everything seems to work fine without the weird reserve
allocation.
Signed-off-by: Philip Redkin <me@rarity.fan>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/94b3e98f-96a7-3560-1f76-349eb95ccf7f@rarity.fan
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 91d5451d97 ]
The __ref_stack_chk_guard symbol doesn't exist on UP:
<stdin>:4:15: error: ‘__ref_stack_chk_guard’ undeclared here (not in a function)
Fix the #ifdef around the entry.S export.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Uros Bizjak <ubizjak@gmail.com>
Link: https://lore.kernel.org/r/20250123190747.745588-8-brgerst@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2c0391b29b ]
NOMMU kernels currently cannot access memory below the kernel link
address. Remove this restriction by setting PAGE_OFFSET to the actual
start of RAM, as determined from the devicetree. The kernel link address
must be a constant, so keep using CONFIG_PAGE_OFFSET for that purpose.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Jesse Taube <mr.bossman075@gmail.com>
Link: https://lore.kernel.org/r/20241026171441.3047904-3-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e18c09b204 ]
The HIP09 processor is vulnerable to the Spectre-BHB (Branch History
Buffer) attack, which can be exploited to leak information through
branch prediction side channels. This commit adds the MIDR of HIP09
to the list for software mitigation.
Signed-off-by: Jinqian Yang <yangjinqian1@huawei.com>
Link: https://lore.kernel.org/r/20250325141900.2057314-1-yangjinqian1@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e67e0eb6a9 upstream.
LoongArch's toolchain may change the default code model from normal to
medium. This is unnecessary for kernel, and generates some relocations
which cannot be handled by the module loader. So explicitly specify the
code model to normal in Makefile (for Rust 'normal' is 'small').
Cc: stable@vger.kernel.org
Tested-by: Haiyong Sun <sunhaiyong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a552e2ef5f upstream.
When BPF_TRAMP_F_CALL_ORIG is enabled, the address of a bpf_tramp_image
struct on the stack is passed during the size calculation pass and
an address on the heap is passed during code generation. This may
cause a heap buffer overflow if the heap address is tagged because
emit_a64_mov_i64() will emit longer code than it did during the size
calculation pass. The same problem could occur without tag-based
KASAN if one of the 16-bit words of the stack address happened to
be all-ones during the size calculation pass. Fix the problem by
assuming the worst case (4 instructions) when calculating the size
of the bpf_tramp_image address emission.
Fixes: 19d3c179a3 ("bpf, arm64: Fix trampoline for BPF_TRAMP_F_CALL_ORIG")
Signed-off-by: Peter Collingbourne <pcc@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://linux-review.googlesource.com/id/I1496f2bc24fba7a1d492e16e2b94cf43714f2d3c
Link: https://lore.kernel.org/bpf/20241018221644.3240898-1-pcc@google.com
[Minor context change fixed.]
Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 19d3c179a3 upstream.
When BPF_TRAMP_F_CALL_ORIG is set, the trampoline calls
__bpf_tramp_enter() and __bpf_tramp_exit() functions, passing them
the struct bpf_tramp_image *im pointer as an argument in R0.
The trampoline generation code uses emit_addr_mov_i64() to emit
instructions for moving the bpf_tramp_image address into R0, but
emit_addr_mov_i64() assumes the address to be in the vmalloc() space
and uses only 48 bits. Because bpf_tramp_image is allocated using
kzalloc(), its address can use more than 48-bits, in this case the
trampoline will pass an invalid address to __bpf_tramp_enter/exit()
causing a kernel crash.
Fix this by using emit_a64_mov_i64() in place of emit_addr_mov_i64()
as it can work with addresses that are greater than 48-bits.
Fixes: efc9909fdc ("bpf, arm64: Add bpf trampoline for arm64")
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Closes: https://lore.kernel.org/all/SJ0PR15MB461564D3F7E7A763498CA6A8CBDB2@SJ0PR15MB4615.namprd15.prod.outlook.com/
Link: https://lore.kernel.org/bpf/20240711151838.43469-1-puranjay@kernel.org
[Minor context change fixed.]
Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Due to a likely merge resolution error of backport commit 772934d906
("x86/its: FineIBT-paranoid vs ITS"), the function its_static_thunk() was
placed in the wrong ifdef block, causing a build error when
CONFIG_MITIGATION_ITS and CONFIG_FINEIBT are both disabled:
/linux-6.6/arch/x86/kernel/alternative.c:1452:5: error: redefinition of 'its_static_thunk'
1452 | u8 *its_static_thunk(int reg)
| ^~~~~~~~~~~~~~~~
Fix it by moving its_static_thunk() under CONFIG_MITIGATION_ITS.
Fixes: e52c1dc745 ("x86/its: FineIBT-paranoid vs ITS")
Reported-by: Natanael Copa <ncopa@alpinelinux.org>
Link: https://lore.kernel.org/all/20250519164717.18738b4e@ncopa-desktop/
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 12614f7942 upstream.
arch_uprobe_skip_sstep() returns true if instruction was emulated, that
is to say, there is no need to single step for the emulated instructions.
regs->csr_era will point to the destination address directly after the
exception, so the resume_era related code is redundant, just remove them.
Cc: stable@vger.kernel.org
Fixes: 19bc6cb640 ("LoongArch: Add uprobes support")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0b326b2371 upstream.
When executing the "perf probe" and "perf stat" test cases about some
cryptographic algorithm, the output shows that "Trace/breakpoint trap".
This is because it uses the software singlestep breakpoint for uprobes
on LoongArch, and no need to use the hardware singlestep. So just remove
the related function call to user_{en,dis}able_single_step() for uprobes
on LoongArch.
How to reproduce:
Please make sure CONFIG_UPROBE_EVENTS is set and openssl supports sm2
algorithm, then execute the following command.
cd tools/perf && make
./perf probe -x /usr/lib64/libcrypto.so BN_mod_mul_montgomery
./perf stat -e probe_libcrypto:BN_mod_mul_montgomery openssl speed sm2
Cc: stable@vger.kernel.org
Fixes: 19bc6cb640 ("LoongArch: Add uprobes support")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 90436d2342 upstream.
Fix MAX_REG_OFFSET calculation, make it point to the last register
in 'struct pt_regs' and not to the marker itself, which could allow
regs_get_register() to return an invalid offset.
Cc: stable@vger.kernel.org
Fixes: 803b0fc5c3 ("LoongArch: Add process management")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ceb9155d05 upstream.
Save and restore CSR.CNTC for hibernation which is similar to suspend.
For host this is unnecessary because sched clock is ensured continuous,
but for kvm guest sched clock isn't enough because rdtime.d should also
be continuous.
Host::rdtime.d = Host::CSR.CNTC + counter
Guest::rdtime.d = Host::CSR.CNTC + Host::CSR.GCNTC + Guest::CSR.CNTC + counter
so,
Guest::rdtime.d = Host::rdtime.d + Host::CSR.GCNTC + Guest::CSR.CNTC
To ensure Guest::rdtime.d continuous, Host::rdtime.d should be at first
continuous, while Host::CSR.GCNTC / Guest::CSR.CNTC is maintained by KVM.
Cc: stable@vger.kernel.org
Signed-off-by: Xianglai Li <lixianglai@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2468b0e3d5 upstream.
When CONFIG_PREEMPT_COUNT is not configured (i.e. CONFIG_PREEMPT_NONE/
CONFIG_PREEMPT_VOLUNTARY), preempt_disable() / preempt_enable() merely
acts as a barrier(). However, in these cases cond_resched() can still
trigger a context switch and modify the CSR.EUEN, resulting in do_fpu()
exception being activated within the kernel-fpu critical sections, as
demonstrated in the following path:
dcn32_calculate_wm_and_dlg()
DC_FP_START()
dcn32_calculate_wm_and_dlg_fpu()
dcn32_find_dummy_latency_index_for_fw_based_mclk_switch()
dcn32_internal_validate_bw()
dcn32_enable_phantom_stream()
dc_create_stream_for_sink()
kzalloc(GFP_KERNEL)
__kmem_cache_alloc_node()
__cond_resched()
DC_FP_END()
This patch is similar to commit d021985504 (x86/fpu: Improve crypto
performance by making kernel-mode FPU reliably usable in softirqs). It
uses local_bh_disable() instead of preempt_disable() for non-RT kernels
so it can avoid the cond_resched() issue, and also extend the kernel-fpu
application scenarios to the softirq context.
Cc: stable@vger.kernel.org
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a2620f8932 ]
Previously, commit ed129ec905 ("KVM: x86: forcibly leave nested mode
on vCPU reset") addressed an issue where a triple fault occurring in
nested mode could lead to use-after-free scenarios. However, the commit
did not handle the analogous situation for System Management Mode (SMM).
This omission results in triggering a WARN when KVM forces a vCPU INIT
after SHUTDOWN interception while the vCPU is in SMM. This situation was
reprodused using Syzkaller by:
1) Creating a KVM VM and vCPU
2) Sending a KVM_SMI ioctl to explicitly enter SMM
3) Executing invalid instructions causing consecutive exceptions and
eventually a triple fault
The issue manifests as follows:
WARNING: CPU: 0 PID: 25506 at arch/x86/kvm/x86.c:12112
kvm_vcpu_reset+0x1d2/0x1530 arch/x86/kvm/x86.c:12112
Modules linked in:
CPU: 0 PID: 25506 Comm: syz-executor.0 Not tainted
6.1.130-syzkaller-00157-g164fe5dde9b6 #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.12.0-1 04/01/2014
RIP: 0010:kvm_vcpu_reset+0x1d2/0x1530 arch/x86/kvm/x86.c:12112
Call Trace:
<TASK>
shutdown_interception+0x66/0xb0 arch/x86/kvm/svm/svm.c:2136
svm_invoke_exit_handler+0x110/0x530 arch/x86/kvm/svm/svm.c:3395
svm_handle_exit+0x424/0x920 arch/x86/kvm/svm/svm.c:3457
vcpu_enter_guest arch/x86/kvm/x86.c:10959 [inline]
vcpu_run+0x2c43/0x5a90 arch/x86/kvm/x86.c:11062
kvm_arch_vcpu_ioctl_run+0x50f/0x1cf0 arch/x86/kvm/x86.c:11283
kvm_vcpu_ioctl+0x570/0xf00 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4122
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Architecturally, INIT is blocked when the CPU is in SMM, hence KVM's WARN()
in kvm_vcpu_reset() to guard against KVM bugs, e.g. to detect improper
emulation of INIT. SHUTDOWN on SVM is a weird edge case where KVM needs to
do _something_ sane with the VMCB, since it's technically undefined, and
INIT is the least awful choice given KVM's ABI.
So, double down on stuffing INIT on SHUTDOWN, and force the vCPU out of
SMM to avoid any weirdness (and the WARN).
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: ed129ec905 ("KVM: x86: forcibly leave nested mode on vCPU reset")
Cc: stable@vger.kernel.org
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Mikhail Lobanov <m.lobanov@rosa.ru>
Link: https://lore.kernel.org/r/20250414171207.155121-1-m.lobanov@rosa.ru
[sean: massage changelog, make it clear this isn't architectural behavior]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bc3d7c5570 ]
Currently if an SEV-ES VM shuts down userspace sees KVM_RUN struct with
only errno=EINVAL. This is a very limited amount of information to debug
the situation. Instead return KVM_EXIT_SHUTDOWN to alert userspace the VM
is shutting down and is not usable any further.
Signed-off-by: Peter Gonda <pgonda@google.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Suggested-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20230907162449.1739785-1-pgonda@google.com
[sean: tweak changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Stable-dep-of: a2620f8932 ("KVM: SVM: Forcibly leave SMM mode on SHUTDOWN interception")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e52c1dc745 upstream.
FineIBT-paranoid was using the retpoline bytes for the paranoid check,
disabling retpolines, because all parts that have IBT also have eIBRS
and thus don't need no stinking retpolines.
Except... ITS needs the retpolines for indirect calls must not be in
the first half of a cacheline :-/
So what was the paranoid call sequence:
<fineibt_paranoid_start>:
0: 41 ba 78 56 34 12 mov $0x12345678, %r10d
6: 45 3b 53 f7 cmp -0x9(%r11), %r10d
a: 4d 8d 5b <f0> lea -0x10(%r11), %r11
e: 75 fd jne d <fineibt_paranoid_start+0xd>
10: 41 ff d3 call *%r11
13: 90 nop
Now becomes:
<fineibt_paranoid_start>:
0: 41 ba 78 56 34 12 mov $0x12345678, %r10d
6: 45 3b 53 f7 cmp -0x9(%r11), %r10d
a: 4d 8d 5b f0 lea -0x10(%r11), %r11
e: 2e e8 XX XX XX XX cs call __x86_indirect_paranoid_thunk_r11
Where the paranoid_thunk looks like:
1d: <ea> (bad)
__x86_indirect_paranoid_thunk_r11:
1e: 75 fd jne 1d
__x86_indirect_its_thunk_r11:
20: 41 ff eb jmp *%r11
23: cc int3
[ dhansen: remove initialization to false ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
[ Just a portion of the original commit, in order to fix a build issue
in stable kernels due to backports ]
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Link: https://lore.kernel.org/r/20250514113952.GB16434@noisy.programming.kicks-ass.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 872df34d7c upstream.
ITS mitigation moves the unsafe indirect branches to a safe thunk. This
could degrade the prediction accuracy as the source address of indirect
branches becomes same for different execution paths.
To improve the predictions, and hence the performance, assign a separate
thunk for each indirect callsite. This is also a defense-in-depth measure
to avoid indirect branches aliasing with each other.
As an example, 5000 dynamic thunks would utilize around 16 bits of the
address space, thereby gaining entropy. For a BTB that uses
32 bits for indexing, dynamic thunks could provide better prediction
accuracy over fixed thunks.
Have ITS thunks be variable sized and use EXECMEM_MODULE_TEXT such that
they are both more flexible (got to extend them later) and live in 2M TLBs,
just like kernel code, avoiding undue TLB pressure.
[ pawan: CONFIG_EXECMEM and CONFIG_EXECMEM_ROX are not supported on
backport kernel, made changes to use module_alloc() and
set_memory_*() for dynamic thunks. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
