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and assert __x86_return_thunk's alignment so that future changes to
the symbol macros do not accidentally break them.
- Remove CONFIG_X86_FEATURE_NAMES Kconfig option as its existence is
pointless
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Merge tag 'x86_cpu_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu updates from Borislav Petkov:
- Compute the purposeful misalignment of zen_untrain_ret automatically
and assert __x86_return_thunk's alignment so that future changes to
the symbol macros do not accidentally break them.
- Remove CONFIG_X86_FEATURE_NAMES Kconfig option as its existence is
pointless
* tag 'x86_cpu_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/retbleed: Add __x86_return_thunk alignment checks
x86/cpu: Remove X86_FEATURE_NAMES
x86/Kconfig: Make X86_FEATURE_NAMES non-configurable in prompt
The gist of it all is that Intel TDX and AMD SEV-SNP confidential
computing guests define the notion of accepting memory before using it
and thus preventing a whole set of attacks against such guests like
memory replay and the like.
There are a couple of strategies of how memory should be accepted
- the current implementation does an on-demand way of accepting.
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Merge tag 'x86_cc_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 confidential computing update from Borislav Petkov:
- Add support for unaccepted memory as specified in the UEFI spec v2.9.
The gist of it all is that Intel TDX and AMD SEV-SNP confidential
computing guests define the notion of accepting memory before using
it and thus preventing a whole set of attacks against such guests
like memory replay and the like.
There are a couple of strategies of how memory should be accepted -
the current implementation does an on-demand way of accepting.
* tag 'x86_cc_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
virt: sevguest: Add CONFIG_CRYPTO dependency
x86/efi: Safely enable unaccepted memory in UEFI
x86/sev: Add SNP-specific unaccepted memory support
x86/sev: Use large PSC requests if applicable
x86/sev: Allow for use of the early boot GHCB for PSC requests
x86/sev: Put PSC struct on the stack in prep for unaccepted memory support
x86/sev: Fix calculation of end address based on number of pages
x86/tdx: Add unaccepted memory support
x86/tdx: Refactor try_accept_one()
x86/tdx: Make _tdx_hypercall() and __tdx_module_call() available in boot stub
efi/unaccepted: Avoid load_unaligned_zeropad() stepping into unaccepted memory
efi: Add unaccepted memory support
x86/boot/compressed: Handle unaccepted memory
efi/libstub: Implement support for unaccepted memory
efi/x86: Get full memory map in allocate_e820()
mm: Add support for unaccepted memory
of application containers with dynamically changing task lists
- When reading the tasks file, show the tasks' pid which are only in
the current namespace as opposed to showing the pids from the init
namespace too
- Other fixes and improvements
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Merge tag 'x86_cache_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 resource control updates from Borislav Petkov:
- Implement a rename operation in resctrlfs to facilitate handling of
application containers with dynamically changing task lists
- When reading the tasks file, show the tasks' pid which are only in
the current namespace as opposed to showing the pids from the init
namespace too
- Other fixes and improvements
* tag 'x86_cache_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Documentation/x86: Documentation for MON group move feature
x86/resctrl: Implement rename op for mon groups
x86/resctrl: Factor rdtgroup lock for multi-file ops
x86/resctrl: Only show tasks' pid in current pid namespace
other tooling and thus a slimmer binary is generated. This is
important for distros who have to distribute vmlinux blobs with their
kernel packages too and that extraneous unnecessary data bloats them
for no good reason
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Merge tag 'x86_build_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 build update from Borislav Petkov:
- Remove relocation information from vmlinux as it is not needed by
other tooling and thus a slimmer binary is generated.
This is important for distros who have to distribute vmlinux blobs
with their kernel packages too and that extraneous unnecessary data
bloats them for no good reason
* tag 'x86_build_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/build: Avoid relocation information in final vmlinux
of the ERMS CPUID flag. AMD decoupled them with a BIOS setting so decouple
that dependency in the kernel code too
- Teach the alternatives machinery to handle relocations
- Make debug_alternative accept flags in order to see only that set of
patching done one is interested in
- Other fixes, cleanups and optimizations to the patching code
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Merge tag 'x86_alternatives_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 instruction alternatives updates from Borislav Petkov:
- Up until now the Fast Short Rep Mov optimizations implied the
presence of the ERMS CPUID flag. AMD decoupled them with a BIOS
setting so decouple that dependency in the kernel code too
- Teach the alternatives machinery to handle relocations
- Make debug_alternative accept flags in order to see only that set of
patching done one is interested in
- Other fixes, cleanups and optimizations to the patching code
* tag 'x86_alternatives_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/alternative: PAUSE is not a NOP
x86/alternatives: Add cond_resched() to text_poke_bp_batch()
x86/nospec: Shorten RESET_CALL_DEPTH
x86/alternatives: Add longer 64-bit NOPs
x86/alternatives: Fix section mismatch warnings
x86/alternative: Optimize returns patching
x86/alternative: Complicate optimize_nops() some more
x86/alternative: Rewrite optimize_nops() some
x86/lib/memmove: Decouple ERMS from FSRM
x86/alternative: Support relocations in alternatives
x86/alternative: Make debug-alternative selective
Those GPUs and CPUs are connected together through the coherent fabric
and the GPU memory controllers report errors through x86's MCA so EDAC
needs to support them. The amd64_edac driver supports now HBM (High
Bandwidth Memory) and thus such heterogeneous memory controller
systems
- Other small cleanups and improvements
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Merge tag 'ras_core_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS updates from Borislav Petkov:
- Add initial support for RAS hardware found on AMD server GPUs (MI200).
Those GPUs and CPUs are connected together through the coherent
fabric and the GPU memory controllers report errors through x86's MCA
so EDAC needs to support them. The amd64_edac driver supports now HBM
(High Bandwidth Memory) and thus such heterogeneous memory controller
systems
- Other small cleanups and improvements
* tag 'ras_core_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
EDAC/amd64: Cache and use GPU node map
EDAC/amd64: Add support for AMD heterogeneous Family 19h Model 30h-3Fh
EDAC/amd64: Document heterogeneous system enumeration
x86/MCE/AMD, EDAC/mce_amd: Decode UMC_V2 ECC errors
x86/amd_nb: Re-sort and re-indent PCI defines
x86/amd_nb: Add MI200 PCI IDs
ras/debugfs: Fix error checking for debugfs_create_dir()
x86/MCE: Check a hw error's address to determine proper recovery action
- Ensure that the WBINVD in stop_this_cpu() has been completed before the
control CPU proceedes.
stop_this_cpu() is used for kexec(), reboot and shutdown to park the APs
in a HLT loop.
The control CPU sends an IPI to the APs and waits for their CPU online bits
to be cleared. Once they all are marked "offline" it proceeds.
But stop_this_cpu() clears the CPU online bit before issuing WBINVD,
which means there is no guarantee that the AP has reached the HLT loop.
This was reported to cause intermittent reboot/shutdown failures due to
some dubious interaction with the firmware.
This is not only a problem of WBINVD. The code to actually "stop" the
CPU which runs between clearing the online bit and reaching the HLT loop
can cause large enough delays on its own (think virtualization). That's
especially dangerous for kexec() as kexec() expects that all APs are in
a safe state and not executing code while the boot CPU jumps to the new
kernel. There are more issues vs. kexec() which are addressed separately.
Cure this by implementing an explicit synchronization point right before
the AP reaches HLT. This guarantees that the AP has completed the full
stop proceedure.
- Fix the condition for WBINVD in stop_this_cpu().
The WBINVD in stop_this_cpu() is required for ensuring that when
switching to or from memory encryption no dirty data is left in the
cache lines which might cause a write back in the wrong more later.
This checks CPUID directly because the feature bit might have been
cleared due to a command line option.
But that CPUID check accesses leaf 0x8000001f::EAX unconditionally. Intel
CPUs return the content of the highest supported leaf when a non-existing
leaf is read, while AMD CPUs return all zeros for unsupported leafs.
So the result of the test on Intel CPUs is lottery and on AMD its just
correct by chance.
While harmless it's incorrect and causes the conditional wbinvd() to be
issued where not required, which caused the above issue to be unearthed.
- Make kexec() robust against AP code execution
Ashok observed triple faults when doing kexec() on a system which had
been booted with "nosmt".
It turned out that the SMT siblings which had been brought up partially
are parked in mwait_play_dead() to enable power savings.
mwait_play_dead() is monitoring the thread flags of the AP's idle task,
which has been chosen as it's unlikely to be written to.
But kexec() can overwrite the previous kernel text and data including
page tables etc. When it overwrites the cache lines monitored by an AP
that AP resumes execution after the MWAIT on eventually overwritten
text, stack and page tables, which obviously might end up in a triple
fault easily.
Make this more robust in several steps:
1) Use an explicit per CPU cache line for monitoring.
2) Write a command to these cache lines to kick APs out of MWAIT before
proceeding with kexec(), shutdown or reboot.
The APs confirm the wakeup by writing status back and then enter a
HLT loop.
3) If the system uses INIT/INIT/STARTUP for AP bringup, park the APs
in INIT state.
HLT is not a guarantee that an AP won't wake up and resume
execution. HLT is woken up by NMI and SMI. SMI puts the CPU back
into HLT (+/- firmware bugs), but NMI is delivered to the CPU which
executes the NMI handler. Same issue as the MWAIT scenario described
above.
Sending an INIT/INIT sequence to the APs puts them into wait for
STARTUP state, which is safe against NMI.
There is still an issue remaining which can't be fixed: #MCE
If the AP sits in HLT and receives a broadcast #MCE it will try to
handle it with the obvious consequences.
INIT/INIT clears CR4.MCE in the AP which will cause a broadcast #MCE to
shut down the machine.
So there is a choice between fire (HLT) and frying pan (INIT). Frying
pan has been chosen as it's at least preventing the NMI issue.
On systems which are not using INIT/INIT/STARTUP there is not much
which can be done right now, but at least the obvious and easy to
trigger MWAIT issue has been addressed.
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Merge tag 'x86-core-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Thomas Gleixner:
"A set of fixes for kexec(), reboot and shutdown issues:
- Ensure that the WBINVD in stop_this_cpu() has been completed before
the control CPU proceedes.
stop_this_cpu() is used for kexec(), reboot and shutdown to park
the APs in a HLT loop.
The control CPU sends an IPI to the APs and waits for their CPU
online bits to be cleared. Once they all are marked "offline" it
proceeds.
But stop_this_cpu() clears the CPU online bit before issuing
WBINVD, which means there is no guarantee that the AP has reached
the HLT loop.
This was reported to cause intermittent reboot/shutdown failures
due to some dubious interaction with the firmware.
This is not only a problem of WBINVD. The code to actually "stop"
the CPU which runs between clearing the online bit and reaching the
HLT loop can cause large enough delays on its own (think
virtualization). That's especially dangerous for kexec() as kexec()
expects that all APs are in a safe state and not executing code
while the boot CPU jumps to the new kernel. There are more issues
vs kexec() which are addressed separately.
Cure this by implementing an explicit synchronization point right
before the AP reaches HLT. This guarantees that the AP has
completed the full stop proceedure.
- Fix the condition for WBINVD in stop_this_cpu().
The WBINVD in stop_this_cpu() is required for ensuring that when
switching to or from memory encryption no dirty data is left in the
cache lines which might cause a write back in the wrong more later.
This checks CPUID directly because the feature bit might have been
cleared due to a command line option.
But that CPUID check accesses leaf 0x8000001f::EAX unconditionally.
Intel CPUs return the content of the highest supported leaf when a
non-existing leaf is read, while AMD CPUs return all zeros for
unsupported leafs.
So the result of the test on Intel CPUs is lottery and on AMD its
just correct by chance.
While harmless it's incorrect and causes the conditional wbinvd()
to be issued where not required, which caused the above issue to be
unearthed.
- Make kexec() robust against AP code execution
Ashok observed triple faults when doing kexec() on a system which
had been booted with "nosmt".
It turned out that the SMT siblings which had been brought up
partially are parked in mwait_play_dead() to enable power savings.
mwait_play_dead() is monitoring the thread flags of the AP's idle
task, which has been chosen as it's unlikely to be written to.
But kexec() can overwrite the previous kernel text and data
including page tables etc. When it overwrites the cache lines
monitored by an AP that AP resumes execution after the MWAIT on
eventually overwritten text, stack and page tables, which obviously
might end up in a triple fault easily.
Make this more robust in several steps:
1) Use an explicit per CPU cache line for monitoring.
2) Write a command to these cache lines to kick APs out of MWAIT
before proceeding with kexec(), shutdown or reboot.
The APs confirm the wakeup by writing status back and then
enter a HLT loop.
3) If the system uses INIT/INIT/STARTUP for AP bringup, park the
APs in INIT state.
HLT is not a guarantee that an AP won't wake up and resume
execution. HLT is woken up by NMI and SMI. SMI puts the CPU
back into HLT (+/- firmware bugs), but NMI is delivered to the
CPU which executes the NMI handler. Same issue as the MWAIT
scenario described above.
Sending an INIT/INIT sequence to the APs puts them into wait
for STARTUP state, which is safe against NMI.
There is still an issue remaining which can't be fixed: #MCE
If the AP sits in HLT and receives a broadcast #MCE it will try to
handle it with the obvious consequences.
INIT/INIT clears CR4.MCE in the AP which will cause a broadcast
#MCE to shut down the machine.
So there is a choice between fire (HLT) and frying pan (INIT).
Frying pan has been chosen as it's at least preventing the NMI
issue.
On systems which are not using INIT/INIT/STARTUP there is not much
which can be done right now, but at least the obvious and easy to
trigger MWAIT issue has been addressed"
* tag 'x86-core-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/smp: Put CPUs into INIT on shutdown if possible
x86/smp: Split sending INIT IPI out into a helper function
x86/smp: Cure kexec() vs. mwait_play_dead() breakage
x86/smp: Use dedicated cache-line for mwait_play_dead()
x86/smp: Remove pointless wmb()s from native_stop_other_cpus()
x86/smp: Dont access non-existing CPUID leaf
x86/smp: Make stop_other_cpus() more robust
- Parallel CPU bringup
The reason why people are interested in parallel bringup is to shorten
the (kexec) reboot time of cloud servers to reduce the downtime of the
VM tenants.
The current fully serialized bringup does the following per AP:
1) Prepare callbacks (allocate, intialize, create threads)
2) Kick the AP alive (e.g. INIT/SIPI on x86)
3) Wait for the AP to report alive state
4) Let the AP continue through the atomic bringup
5) Let the AP run the threaded bringup to full online state
There are two significant delays:
#3 The time for an AP to report alive state in start_secondary() on
x86 has been measured in the range between 350us and 3.5ms
depending on vendor and CPU type, BIOS microcode size etc.
#4 The atomic bringup does the microcode update. This has been
measured to take up to ~8ms on the primary threads depending on
the microcode patch size to apply.
On a two socket SKL server with 56 cores (112 threads) the boot CPU
spends on current mainline about 800ms busy waiting for the APs to come
up and apply microcode. That's more than 80% of the actual onlining
procedure.
This can be reduced significantly by splitting the bringup mechanism
into two parts:
1) Run the prepare callbacks and kick the AP alive for each AP which
needs to be brought up.
The APs wake up, do their firmware initialization and run the low
level kernel startup code including microcode loading in parallel
up to the first synchronization point. (#1 and #2 above)
2) Run the rest of the bringup code strictly serialized per CPU
(#3 - #5 above) as it's done today.
Parallelizing that stage of the CPU bringup might be possible in
theory, but it's questionable whether required surgery would be
justified for a pretty small gain.
If the system is large enough the first AP is already waiting at the
first synchronization point when the boot CPU finished the wake-up of
the last AP. That reduces the AP bringup time on that SKL from ~800ms
to ~80ms, i.e. by a factor ~10x.
The actual gain varies wildly depending on the system, CPU, microcode
patch size and other factors. There are some opportunities to reduce
the overhead further, but that needs some deep surgery in the x86 CPU
bringup code.
For now this is only enabled on x86, but the core functionality
obviously works for all SMP capable architectures.
- Enhancements for SMP function call tracing so it is possible to locate
the scheduling and the actual execution points. That allows to measure
IPI delivery time precisely.
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Merge tag 'smp-core-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP updates from Thomas Gleixner:
"A large update for SMP management:
- Parallel CPU bringup
The reason why people are interested in parallel bringup is to
shorten the (kexec) reboot time of cloud servers to reduce the
downtime of the VM tenants.
The current fully serialized bringup does the following per AP:
1) Prepare callbacks (allocate, intialize, create threads)
2) Kick the AP alive (e.g. INIT/SIPI on x86)
3) Wait for the AP to report alive state
4) Let the AP continue through the atomic bringup
5) Let the AP run the threaded bringup to full online state
There are two significant delays:
#3 The time for an AP to report alive state in start_secondary()
on x86 has been measured in the range between 350us and 3.5ms
depending on vendor and CPU type, BIOS microcode size etc.
#4 The atomic bringup does the microcode update. This has been
measured to take up to ~8ms on the primary threads depending
on the microcode patch size to apply.
On a two socket SKL server with 56 cores (112 threads) the boot CPU
spends on current mainline about 800ms busy waiting for the APs to
come up and apply microcode. That's more than 80% of the actual
onlining procedure.
This can be reduced significantly by splitting the bringup
mechanism into two parts:
1) Run the prepare callbacks and kick the AP alive for each AP
which needs to be brought up.
The APs wake up, do their firmware initialization and run the
low level kernel startup code including microcode loading in
parallel up to the first synchronization point. (#1 and #2
above)
2) Run the rest of the bringup code strictly serialized per CPU
(#3 - #5 above) as it's done today.
Parallelizing that stage of the CPU bringup might be possible
in theory, but it's questionable whether required surgery
would be justified for a pretty small gain.
If the system is large enough the first AP is already waiting at
the first synchronization point when the boot CPU finished the
wake-up of the last AP. That reduces the AP bringup time on that
SKL from ~800ms to ~80ms, i.e. by a factor ~10x.
The actual gain varies wildly depending on the system, CPU,
microcode patch size and other factors. There are some
opportunities to reduce the overhead further, but that needs some
deep surgery in the x86 CPU bringup code.
For now this is only enabled on x86, but the core functionality
obviously works for all SMP capable architectures.
- Enhancements for SMP function call tracing so it is possible to
locate the scheduling and the actual execution points. That allows
to measure IPI delivery time precisely"
* tag 'smp-core-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
trace,smp: Add tracepoints for scheduling remotelly called functions
trace,smp: Add tracepoints around remotelly called functions
MAINTAINERS: Add CPU HOTPLUG entry
x86/smpboot: Fix the parallel bringup decision
x86/realmode: Make stack lock work in trampoline_compat()
x86/smp: Initialize cpu_primary_thread_mask late
cpu/hotplug: Fix off by one in cpuhp_bringup_mask()
x86/apic: Fix use of X{,2}APIC_ENABLE in asm with older binutils
x86/smpboot/64: Implement arch_cpuhp_init_parallel_bringup() and enable it
x86/smpboot: Support parallel startup of secondary CPUs
x86/smpboot: Implement a bit spinlock to protect the realmode stack
x86/apic: Save the APIC virtual base address
cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE
x86/apic: Provide cpu_primary_thread mask
x86/smpboot: Enable split CPU startup
cpu/hotplug: Provide a split up CPUHP_BRINGUP mechanism
cpu/hotplug: Reset task stack state in _cpu_up()
cpu/hotplug: Remove unused state functions
riscv: Switch to hotplug core state synchronization
parisc: Switch to hotplug core state synchronization
...
- Initialize FPU late.
Right now FPU is initialized very early during boot. There is no real
requirement to do so. The only requirement is to have it done before
alternatives are patched.
That's done in check_bugs() which does way more than what the function
name suggests.
So first rename check_bugs() to arch_cpu_finalize_init() which makes it
clear what this is about.
Move the invocation of arch_cpu_finalize_init() earlier in
start_kernel() as it has to be done before fork_init() which needs to
know the FPU register buffer size.
With those prerequisites the FPU initialization can be moved into
arch_cpu_finalize_init(), which removes it from the early and fragile
part of the x86 bringup.
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Merge tag 'x86-boot-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Thomas Gleixner:
"Initialize FPU late.
Right now FPU is initialized very early during boot. There is no real
requirement to do so. The only requirement is to have it done before
alternatives are patched.
That's done in check_bugs() which does way more than what the function
name suggests.
So first rename check_bugs() to arch_cpu_finalize_init() which makes
it clear what this is about.
Move the invocation of arch_cpu_finalize_init() earlier in
start_kernel() as it has to be done before fork_init() which needs to
know the FPU register buffer size.
With those prerequisites the FPU initialization can be moved into
arch_cpu_finalize_init(), which removes it from the early and fragile
part of the x86 bringup"
* tag 'x86-boot-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mem_encrypt: Unbreak the AMD_MEM_ENCRYPT=n build
x86/fpu: Move FPU initialization into arch_cpu_finalize_init()
x86/fpu: Mark init functions __init
x86/fpu: Remove cpuinfo argument from init functions
x86/init: Initialize signal frame size late
init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()
init: Invoke arch_cpu_finalize_init() earlier
init: Remove check_bugs() leftovers
um/cpu: Switch to arch_cpu_finalize_init()
sparc/cpu: Switch to arch_cpu_finalize_init()
sh/cpu: Switch to arch_cpu_finalize_init()
mips/cpu: Switch to arch_cpu_finalize_init()
m68k/cpu: Switch to arch_cpu_finalize_init()
loongarch/cpu: Switch to arch_cpu_finalize_init()
ia64/cpu: Switch to arch_cpu_finalize_init()
ARM: cpu: Switch to arch_cpu_finalize_init()
x86/cpu: Switch to arch_cpu_finalize_init()
init: Provide arch_cpu_finalize_init()
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Merge tag 'v6.5/vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Miscellaneous features, cleanups, and fixes for vfs and individual fs
Features:
- Use mode 0600 for file created by cachefilesd so it can be run by
unprivileged users. This aligns them with directories which are
already created with mode 0700 by cachefilesd
- Reorder a few members in struct file to prevent some false sharing
scenarios
- Indicate that an eventfd is used a semaphore in the eventfd's
fdinfo procfs file
- Add a missing uapi header for eventfd exposing relevant uapi
defines
- Let the VFS protect transitions of a superblock from read-only to
read-write in addition to the protection it already provides for
transitions from read-write to read-only. Protecting read-only to
read-write transitions allows filesystems such as ext4 to perform
internal writes, keeping writers away until the transition is
completed
Cleanups:
- Arnd removed the architecture specific arch_report_meminfo()
prototypes and added a generic one into procfs.h. Note, we got a
report about a warning in amdpgpu codepaths that suggested this was
bisectable to this change but we concluded it was a false positive
- Remove unused parameters from split_fs_names()
- Rename put_and_unmap_page() to unmap_and_put_page() to let the name
reflect the order of the cleanup operation that has to unmap before
the actual put
- Unexport buffer_check_dirty_writeback() as it is not used outside
of block device aops
- Stop allocating aio rings from highmem
- Protecting read-{only,write} transitions in the VFS used open-coded
barriers in various places. Replace them with proper little helpers
and document both the helpers and all barrier interactions involved
when transitioning between read-{only,write} states
- Use flexible array members in old readdir codepaths
Fixes:
- Use the correct type __poll_t for epoll and eventfd
- Replace all deprecated strlcpy() invocations, whose return value
isn't checked with an equivalent strscpy() call
- Fix some kernel-doc warnings in fs/open.c
- Reduce the stack usage in jffs2's xattr codepaths finally getting
rid of this: fs/jffs2/xattr.c:887:1: error: the frame size of 1088
bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
royally annoying compilation warning
- Use __FMODE_NONOTIFY instead of FMODE_NONOTIFY where an int and not
fmode_t is required to avoid fmode_t to integer degradation
warnings
- Create coredumps with O_WRONLY instead of O_RDWR. There's a long
explanation in that commit how O_RDWR is actually a bug which we
found out with the help of Linus and git archeology
- Fix "no previous prototype" warnings in the pipe codepaths
- Add overflow calculations for remap_verify_area() as a signed
addition overflow could be triggered in xfstests
- Fix a null pointer dereference in sysv
- Use an unsigned variable for length calculations in jfs avoiding
compilation warnings with gcc 13
- Fix a dangling pipe pointer in the watch queue codepath
- The legacy mount option parser provided as a fallback by the VFS
for filesystems not yet converted to the new mount api did prefix
the generated mount option string with a leading ',' causing issues
for some filesystems
- Fix a repeated word in a comment in fs.h
- autofs: Update the ctime when mtime is updated as mandated by
POSIX"
* tag 'v6.5/vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits)
readdir: Replace one-element arrays with flexible-array members
fs: Provide helpers for manipulating sb->s_readonly_remount
fs: Protect reconfiguration of sb read-write from racing writes
eventfd: add a uapi header for eventfd userspace APIs
autofs: set ctime as well when mtime changes on a dir
eventfd: show the EFD_SEMAPHORE flag in fdinfo
fs/aio: Stop allocating aio rings from HIGHMEM
fs: Fix comment typo
fs: unexport buffer_check_dirty_writeback
fs: avoid empty option when generating legacy mount string
watch_queue: prevent dangling pipe pointer
fs.h: Optimize file struct to prevent false sharing
highmem: Rename put_and_unmap_page() to unmap_and_put_page()
cachefiles: Allow the cache to be non-root
init: remove unused names parameter in split_fs_names()
jfs: Use unsigned variable for length calculations
fs/sysv: Null check to prevent null-ptr-deref bug
fs: use UB-safe check for signed addition overflow in remap_verify_area
procfs: consolidate arch_report_meminfo declaration
fs: pipe: reveal missing function protoypes
...
leads to the function getting replaced by a dummy stub
- Fix the umask value setup of the frontend event as former is different
on two Intel cores
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Merge tag 'perf_urgent_for_v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:
- Drop the __weak attribute from a function prototype as it otherwise
leads to the function getting replaced by a dummy stub
- Fix the umask value setup of the frontend event as former is
different on two Intel cores
* tag 'perf_urgent_for_v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Fix the FRONTEND encoding on GNR and MTL
perf/core: Drop __weak attribute from arch_perf_update_userpage() prototype
which use it, to detect changes to it and adapt accordingly
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Merge tag 'objtool_urgent_for_v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fix from Borislav Petkov:
- Add a ORC format hash to vmlinux and modules in order for other tools
which use it, to detect changes to it and adapt accordingly
* tag 'objtool_urgent_for_v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/unwind/orc: Add ELF section with ORC version identifier
because that updates the user PGD too on KPTI builds, resulting in
memory corruption
- Prevent a panic in the IO-APIC setup code due to conflicting command
line parameters
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Merge tag 'x86_urgent_for_v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Do not use set_pgd() when updating the KASLR trampoline pgd entry
because that updates the user PGD too on KPTI builds, resulting in
memory corruption
- Prevent a panic in the IO-APIC setup code due to conflicting command
line parameters
* tag 'x86_urgent_for_v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic: Fix kernel panic when booting with intremap=off and x2apic_phys
x86/mm: Avoid using set_pgd() outside of real PGD pages
mptcp and netfilter.
Current release - regressions:
- netfilter: add NFT_TRANS_PREPARE_ERROR to deal with bound set/chain
- eth: mlx5e:
- fix scheduling of IPsec ASO query while in atomic
- free IRQ rmap and notifier on kernel shutdown
Current release - new code bugs:
- phy: manual remove LEDs to ensure correct ordering
Previous releases - regressions:
- mptcp: fix possible divide by zero in recvmsg()
- dsa: revert "net: phy: dp83867: perform soft reset and retain established link"
Previous releases - always broken:
- sched: netem: acquire qdisc lock in netem_change()
- bpf:
- fix verifier id tracking of scalars on spill
- fix NULL dereference on exceptions
- accept function names that contain dots
- netfilter: disallow element updates of bound anonymous sets
- mptcp: ensure listener is unhashed before updating the sk status
- xfrm:
- add missed call to delete offloaded policies
- fix inbound ipv4/udp/esp packets to UDPv6 dualstack sockets
- selftests: fixes for FIPS mode
- dsa: mt7530: fix multiple CPU ports, BPDU and LLDP handling
- eth: sfc: use budget for TX completions
Misc:
- wifi: iwlwifi: add support for SO-F device with PCI id 0x7AF0
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.4-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from ipsec, bpf, mptcp and netfilter.
Current release - regressions:
- netfilter: add NFT_TRANS_PREPARE_ERROR to deal with bound set/chain
- eth: mlx5e:
- fix scheduling of IPsec ASO query while in atomic
- free IRQ rmap and notifier on kernel shutdown
Current release - new code bugs:
- phy: manual remove LEDs to ensure correct ordering
Previous releases - regressions:
- mptcp: fix possible divide by zero in recvmsg()
- dsa: revert "net: phy: dp83867: perform soft reset and retain
established link"
Previous releases - always broken:
- sched: netem: acquire qdisc lock in netem_change()
- bpf:
- fix verifier id tracking of scalars on spill
- fix NULL dereference on exceptions
- accept function names that contain dots
- netfilter: disallow element updates of bound anonymous sets
- mptcp: ensure listener is unhashed before updating the sk status
- xfrm:
- add missed call to delete offloaded policies
- fix inbound ipv4/udp/esp packets to UDPv6 dualstack sockets
- selftests: fixes for FIPS mode
- dsa: mt7530: fix multiple CPU ports, BPDU and LLDP handling
- eth: sfc: use budget for TX completions
Misc:
- wifi: iwlwifi: add support for SO-F device with PCI id 0x7AF0"
* tag 'net-6.4-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (74 commits)
revert "net: align SO_RCVMARK required privileges with SO_MARK"
net: wwan: iosm: Convert single instance struct member to flexible array
sch_netem: acquire qdisc lock in netem_change()
selftests: forwarding: Fix race condition in mirror installation
wifi: mac80211: report all unusable beacon frames
mptcp: ensure listener is unhashed before updating the sk status
mptcp: drop legacy code around RX EOF
mptcp: consolidate fallback and non fallback state machine
mptcp: fix possible list corruption on passive MPJ
mptcp: fix possible divide by zero in recvmsg()
mptcp: handle correctly disconnect() failures
bpf: Force kprobe multi expected_attach_type for kprobe_multi link
bpf/btf: Accept function names that contain dots
Revert "net: phy: dp83867: perform soft reset and retain established link"
net: mdio: fix the wrong parameters
netfilter: nf_tables: Fix for deleting base chains with payload
netfilter: nfnetlink_osf: fix module autoload
netfilter: nf_tables: drop module reference after updating chain
netfilter: nf_tables: disallow timeout for anonymous sets
netfilter: nf_tables: disallow updates of anonymous sets
...
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:
====================
pull-request: bpf 2023-06-21
We've added 7 non-merge commits during the last 14 day(s) which contain
a total of 7 files changed, 181 insertions(+), 15 deletions(-).
The main changes are:
1) Fix a verifier id tracking issue with scalars upon spill,
from Maxim Mikityanskiy.
2) Fix NULL dereference if an exception is generated while a BPF
subprogram is running, from Krister Johansen.
3) Fix a BTF verification failure when compiling kernel with LLVM_IAS=0,
from Florent Revest.
4) Fix expected_attach_type enforcement for kprobe_multi link,
from Jiri Olsa.
5) Fix a bpf_jit_dump issue for x86_64 to pick the correct JITed image,
from Yonghong Song.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Force kprobe multi expected_attach_type for kprobe_multi link
bpf/btf: Accept function names that contain dots
selftests/bpf: add a test for subprogram extables
bpf: ensure main program has an extable
bpf: Fix a bpf_jit_dump issue for x86_64 with sysctl bpf_jit_enable.
selftests/bpf: Add test cases to assert proper ID tracking on spill
bpf: Fix verifier id tracking of scalars on spill
====================
Link: https://lore.kernel.org/r/20230621101116.16122-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Parking CPUs in a HLT loop is not completely safe vs. kexec() as HLT can
resume execution due to NMI, SMI and MCE, which has the same issue as the
MWAIT loop.
Kicking the secondary CPUs into INIT makes this safe against NMI and SMI.
A broadcast MCE will take the machine down, but a broadcast MCE which makes
HLT resume and execute overwritten text, pagetables or data will end up in
a disaster too.
So chose the lesser of two evils and kick the secondary CPUs into INIT
unless the system has installed special wakeup mechanisms which are not
using INIT.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230615193330.608657211@linutronix.de
Putting CPUs into INIT is a safer place during kexec() to park CPUs.
Split the INIT assert/deassert sequence out so it can be reused.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Link: https://lore.kernel.org/r/20230615193330.551157083@linutronix.de
TLDR: It's a mess.
When kexec() is executed on a system with offline CPUs, which are parked in
mwait_play_dead() it can end up in a triple fault during the bootup of the
kexec kernel or cause hard to diagnose data corruption.
The reason is that kexec() eventually overwrites the previous kernel's text,
page tables, data and stack. If it writes to the cache line which is
monitored by a previously offlined CPU, MWAIT resumes execution and ends
up executing the wrong text, dereferencing overwritten page tables or
corrupting the kexec kernels data.
Cure this by bringing the offlined CPUs out of MWAIT into HLT.
Write to the monitored cache line of each offline CPU, which makes MWAIT
resume execution. The written control word tells the offlined CPUs to issue
HLT, which does not have the MWAIT problem.
That does not help, if a stray NMI, MCE or SMI hits the offlined CPUs as
those make it come out of HLT.
A follow up change will put them into INIT, which protects at least against
NMI and SMI.
Fixes: ea53069231f9 ("x86, hotplug: Use mwait to offline a processor, fix the legacy case")
Reported-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615193330.492257119@linutronix.de
Monitoring idletask::thread_info::flags in mwait_play_dead() has been an
obvious choice as all what is needed is a cache line which is not written
by other CPUs.
But there is a use case where a "dead" CPU needs to be brought out of
MWAIT: kexec().
This is required as kexec() can overwrite text, pagetables, stacks and the
monitored cacheline of the original kernel. The latter causes MWAIT to
resume execution which obviously causes havoc on the kexec kernel which
results usually in triple faults.
Use a dedicated per CPU storage to prepare for that.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615193330.434553750@linutronix.de
The wmb()s before sending the IPIs are not synchronizing anything.
If at all then the apic IPI functions have to provide or act as appropriate
barriers.
Remove these cargo cult barriers which have no explanation of what they are
synchronizing.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615193330.378358382@linutronix.de
stop_this_cpu() tests CPUID leaf 0x8000001f::EAX unconditionally. Intel
CPUs return the content of the highest supported leaf when a non-existing
leaf is read, while AMD CPUs return all zeros for unsupported leafs.
So the result of the test on Intel CPUs is lottery.
While harmless it's incorrect and causes the conditional wbinvd() to be
issued where not required.
Check whether the leaf is supported before reading it.
[ tglx: Adjusted changelog ]
Fixes: 08f253ec3767 ("x86/cpu: Clear SME feature flag when not in use")
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/3817d810-e0f1-8ef8-0bbd-663b919ca49b@cybernetics.com
Link: https://lore.kernel.org/r/20230615193330.322186388@linutronix.de
Tony reported intermittent lockups on poweroff. His analysis identified the
wbinvd() in stop_this_cpu() as the culprit. This was added to ensure that
on SME enabled machines a kexec() does not leave any stale data in the
caches when switching from encrypted to non-encrypted mode or vice versa.
That wbinvd() is conditional on the SME feature bit which is read directly
from CPUID. But that readout does not check whether the CPUID leaf is
available or not. If it's not available the CPU will return the value of
the highest supported leaf instead. Depending on the content the "SME" bit
might be set or not.
That's incorrect but harmless. Making the CPUID readout conditional makes
the observed hangs go away, but it does not fix the underlying problem:
CPU0 CPU1
stop_other_cpus()
send_IPIs(REBOOT); stop_this_cpu()
while (num_online_cpus() > 1); set_online(false);
proceed... -> hang
wbinvd()
WBINVD is an expensive operation and if multiple CPUs issue it at the same
time the resulting delays are even larger.
But CPU0 already observed num_online_cpus() going down to 1 and proceeds
which causes the system to hang.
This issue exists independent of WBINVD, but the delays caused by WBINVD
make it more prominent.
Make this more robust by adding a cpumask which is initialized to the
online CPU mask before sending the IPIs and CPUs clear their bit in
stop_this_cpu() after the WBINVD completed. Check for that cpumask to
become empty in stop_other_cpus() instead of watching num_online_cpus().
The cpumask cannot plug all holes either, but it's better than a raw
counter and allows to restrict the NMI fallback IPI to be sent only the
CPUs which have not reported within the timeout window.
Fixes: 08f253ec3767 ("x86/cpu: Clear SME feature flag when not in use")
Reported-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/3817d810-e0f1-8ef8-0bbd-663b919ca49b@cybernetics.com
Link: https://lore.kernel.org/r/87h6r770bv.ffs@tglx
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Merge tag 'hyperv-fixes-signed-20230619' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv fixes from Wei Liu:
- Fix races in Hyper-V PCI controller (Dexuan Cui)
- Fix handling of hyperv_pcpu_input_arg (Michael Kelley)
- Fix vmbus_wait_for_unload to scan present CPUs (Michael Kelley)
- Call hv_synic_free in the failure path of hv_synic_alloc (Dexuan Cui)
- Add noop for real mode handlers for virtual trust level code (Saurabh
Sengar)
* tag 'hyperv-fixes-signed-20230619' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
PCI: hv: Add a per-bus mutex state_lock
Revert "PCI: hv: Fix a timing issue which causes kdump to fail occasionally"
PCI: hv: Remove the useless hv_pcichild_state from struct hv_pci_dev
PCI: hv: Fix a race condition in hv_irq_unmask() that can cause panic
PCI: hv: Fix a race condition bug in hv_pci_query_relations()
arm64/hyperv: Use CPUHP_AP_HYPERV_ONLINE state to fix CPU online sequencing
x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline
Drivers: hv: vmbus: Fix vmbus_wait_for_unload() to scan present CPUs
Drivers: hv: vmbus: Call hv_synic_free() if hv_synic_alloc() fails
x86/hyperv/vtl: Add noop for realmode pointers
When booting with "intremap=off" and "x2apic_phys" on the kernel command
line, the physical x2APIC driver ends up being used even when x2APIC
mode is disabled ("intremap=off" disables x2APIC mode). This happens
because the first compound condition check in x2apic_phys_probe() is
false due to x2apic_mode == 0 and so the following one returns true
after default_acpi_madt_oem_check() having already selected the physical
x2APIC driver.
This results in the following panic:
kernel BUG at arch/x86/kernel/apic/io_apic.c:2409!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-rc2-ver4.1rc2 #2
Hardware name: Dell Inc. PowerEdge R6515/07PXPY, BIOS 2.3.6 07/06/2021
RIP: 0010:setup_IO_APIC+0x9c/0xaf0
Call Trace:
<TASK>
? native_read_msr
apic_intr_mode_init
x86_late_time_init
start_kernel
x86_64_start_reservations
x86_64_start_kernel
secondary_startup_64_no_verify
</TASK>
which is:
setup_IO_APIC:
apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
for_each_ioapic(ioapic)
BUG_ON(mp_irqdomain_create(ioapic));
Return 0 to denote that x2APIC has not been enabled when probing the
physical x2APIC driver.
[ bp: Massage commit message heavily. ]
Fixes: 9ebd680bd029 ("x86, apic: Use probe routines to simplify apic selection")
Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kishon Vijay Abraham I <kvijayab@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230616212236.1389-1-dheerajkumar.srivastava@amd.com
These commits
a494aef23dfc ("PCI: hv: Replace retarget_msi_interrupt_params with hyperv_pcpu_input_arg")
2c6ba4216844 ("PCI: hv: Enable PCI pass-thru devices in Confidential VMs")
update the Hyper-V virtual PCI driver to use the hyperv_pcpu_input_arg
because that memory will be correctly marked as decrypted or encrypted
for all VM types (CoCo or normal). But problems ensue when CPUs in the
VM go online or offline after virtual PCI devices have been configured.
When a CPU is brought online, the hyperv_pcpu_input_arg for that CPU is
initialized by hv_cpu_init() running under state CPUHP_AP_ONLINE_DYN.
But this state occurs after state CPUHP_AP_IRQ_AFFINITY_ONLINE, which
may call the virtual PCI driver and fault trying to use the as yet
uninitialized hyperv_pcpu_input_arg. A similar problem occurs in a CoCo
VM if the MMIO read and write hypercalls are used from state
CPUHP_AP_IRQ_AFFINITY_ONLINE.
When a CPU is taken offline, IRQs may be reassigned in state
CPUHP_TEARDOWN_CPU. Again, the virtual PCI driver may fault trying to
use the hyperv_pcpu_input_arg that has already been freed by a
higher state.
Fix the onlining problem by adding state CPUHP_AP_HYPERV_ONLINE
immediately after CPUHP_AP_ONLINE_IDLE (similar to CPUHP_AP_KVM_ONLINE)
and before CPUHP_AP_IRQ_AFFINITY_ONLINE. Use this new state for
Hyper-V initialization so that hyperv_pcpu_input_arg is allocated
early enough.
Fix the offlining problem by not freeing hyperv_pcpu_input_arg when
a CPU goes offline. Retain the allocated memory, and reuse it if
the CPU comes back online later.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Link: https://lore.kernel.org/r/1684862062-51576-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Moving mem_encrypt_init() broke the AMD_MEM_ENCRYPT=n because the
declaration of that function was under #ifdef CONFIG_AMD_MEM_ENCRYPT and
the obvious placement for the inline stub was the #else path.
This is a leftover of commit 20f07a044a76 ("x86/sev: Move common memory
encryption code to mem_encrypt.c") which made mem_encrypt_init() depend on
X86_MEM_ENCRYPT without moving the prototype. That did not fail back then
because there was no stub inline as the core init code had a weak function.
Move both the declaration and the stub out of the CONFIG_AMD_MEM_ENCRYPT
section and guard it with CONFIG_X86_MEM_ENCRYPT.
Fixes: 439e17576eb4 ("init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Closes: https://lore.kernel.org/oe-kbuild-all/202306170247.eQtCJPE8-lkp@intel.com/
KPTI keeps around two PGDs: one for userspace and another for the
kernel. Among other things, set_pgd() contains infrastructure to
ensure that updates to the kernel PGD are reflected in the user PGD
as well.
One side-effect of this is that set_pgd() expects to be passed whole
pages. Unfortunately, init_trampoline_kaslr() passes in a single entry:
'trampoline_pgd_entry'.
When KPTI is on, set_pgd() will update 'trampoline_pgd_entry' (an
8-Byte globally stored [.bss] variable) and will then proceed to
replicate that value into the non-existent neighboring user page
(located +4k away), leading to the corruption of other global [.bss]
stored variables.
Fix it by directly assigning 'trampoline_pgd_entry' and avoiding
set_pgd().
[ dhansen: tweak subject and changelog ]
Fixes: 0925dda5962e ("x86/mm/KASLR: Use only one PUD entry for real mode trampoline")
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/all/20230614163859.924309-1-lee@kernel.org/g
Commits ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC
metadata") and fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in
two") changed the ORC format. Although ORC is internal to the kernel,
it's the only way for external tools to get reliable kernel stack traces
on x86-64. In particular, the drgn debugger [1] uses ORC for stack
unwinding, and these format changes broke it [2]. As the drgn
maintainer, I don't care how often or how much the kernel changes the
ORC format as long as I have a way to detect the change.
It suffices to store a version identifier in the vmlinux and kernel
module ELF files (to use when parsing ORC sections from ELF), and in
kernel memory (to use when parsing ORC from a core dump+symbol table).
Rather than hard-coding a version number that needs to be manually
bumped, Peterz suggested hashing the definitions from orc_types.h. If
there is a format change that isn't caught by this, the hashing script
can be updated.
This patch adds an .orc_header allocated ELF section containing the
20-byte hash to vmlinux and kernel modules, along with the corresponding
__start_orc_header and __stop_orc_header symbols in vmlinux.
1: https://github.com/osandov/drgn
2: https://github.com/osandov/drgn/issues/303
Fixes: ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC metadata")
Fixes: fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in two")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lkml.kernel.org/r/aef9c8dc43915b886a8c48509a12ec1b006ca1ca.1686690801.git.osandov@osandov.com
When counting a FRONTEND event, the MSR_PEBS_FRONTEND is not correctly
set on GNR and MTL p-core.
The umask value for the FRONTEND events is changed on GNR and MTL. The
new umask is missing in the extra_regs[] table.
Add a dedicated intel_gnr_extra_regs[] for GNR and MTL p-core.
Fixes: bc4000fdb009 ("perf/x86/intel: Add Granite Rapids")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20230615173242.3726364-1-kan.liang@linux.intel.com
Initializing the FPU during the early boot process is a pointless
exercise. Early boot is convoluted and fragile enough.
Nothing requires that the FPU is set up early. It has to be initialized
before fork_init() because the task_struct size depends on the FPU register
buffer size.
Move the initialization to arch_cpu_finalize_init() which is the perfect
place to do so.
No functional change.
This allows to remove quite some of the custom early command line parsing,
but that's subject to the next installment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.902376621@linutronix.de
No point in doing this during really early boot. Move it to an early
initcall so that it is set up before possible user mode helpers are started
during device initialization.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.727330699@linutronix.de
Invoke the X86ism mem_encrypt_init() from X86 arch_cpu_finalize_init() and
remove the weak fallback from the core code.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.670360645@linutronix.de
check_bugs() is a dumping ground for finalizing the CPU bringup. Only parts of
it has to do with actual CPU bugs.
Split it apart into arch_cpu_finalize_init() and cpu_select_mitigations().
Fixup the bogus 32bit comments while at it.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230613224545.019583869@linutronix.de
The Linux build process on x86 roughly consists of compiling all input
files, statically linking them into a vmlinux ELF file, and then taking
and turning this file into an actual bzImage bootable file.
vmlinux has in this process two main purposes:
1) It is an intermediate build target on the way to produce the final
bootable image.
2) It is a file that is expected to be used by debuggers and standard
ELF tooling to work with the built kernel.
For the second purpose, a vmlinux file is typically collected by various
package build recipes, such as distribution spec files, including the
kernel's own tar-pkg target.
When building a kernel supporting KASLR with CONFIG_X86_NEED_RELOCS,
vmlinux contains also relocation information produced by using the
--emit-relocs linker option. This is utilized by subsequent build steps
to create vmlinux.relocs and produce a relocatable image. However, the
information is not needed by debuggers and other standard ELF tooling.
The issue is then that the collected vmlinux file and hence distribution
packages end up unnecessarily large because of this extra data. The
following is a size comparison of vmlinux v6.0 with and without the
relocation information:
| Configuration | With relocs | Stripped relocs |
| x86_64_defconfig | 70 MB | 43 MB |
| +CONFIG_DEBUG_INFO | 818 MB | 367 MB |
Optimize a resulting vmlinux by adding a postlink step that splits the
relocation information into vmlinux.relocs and then strips it from the
vmlinux binary.
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220927084632.14531-1-petr.pavlu@suse.com
While chasing ghosts, I did notice that optimize_nops() was replacing
'REP NOP' aka 'PAUSE' with NOP2. This is clearly not right.
Fixes: 6c480f222128 ("x86/alternative: Rewrite optimize_nops() some")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/linux-next/20230524130104.GR83892@hirez.programming.kicks-ass.net/
Debugging in the kernel has started slowing down the kernel by a
noticeable amount. The ftrace start up tests are triggering the softlockup
watchdog on some boxes. This is caused by the start up tests that enable
function and function graph tracing several times. Sprinkling
cond_resched() just in the start up test code was not enough to stop the
softlockup from triggering. It would sometimes trigger in the
text_poke_bp_batch() code.
When function tracing enables all functions, it will call
text_poke_queue() to queue the places that need to be patched. Every
256 entries will do a "flush" that calls text_poke_bp_batch() to do the
update of the 256 locations. As this is in a scheduleable context,
calling cond_resched() at the start of text_poke_bp_batch() will ensure
that other tasks could get a chance to run while the patching is
happening. This keeps the softlockup from triggering in the start up
tests.
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230531092419.4d051374@rorschach.local.home
introduced during this -rc cycle or which were considered inappropriate
for a backport.
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Merge tag 'mm-hotfixes-stable-2023-06-12-12-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"19 hotfixes. 14 are cc:stable and the remainder address issues which
were introduced during this development cycle or which were considered
inappropriate for a backport"
* tag 'mm-hotfixes-stable-2023-06-12-12-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
zswap: do not shrink if cgroup may not zswap
page cache: fix page_cache_next/prev_miss off by one
ocfs2: check new file size on fallocate call
mailmap: add entry for John Keeping
mm/damon/core: fix divide error in damon_nr_accesses_to_accesses_bp()
epoll: ep_autoremove_wake_function should use list_del_init_careful
mm/gup_test: fix ioctl fail for compat task
nilfs2: reject devices with insufficient block count
ocfs2: fix use-after-free when unmounting read-only filesystem
lib/test_vmalloc.c: avoid garbage in page array
nilfs2: fix possible out-of-bounds segment allocation in resize ioctl
riscv/purgatory: remove PGO flags
powerpc/purgatory: remove PGO flags
x86/purgatory: remove PGO flags
kexec: support purgatories with .text.hot sections
mm/uffd: allow vma to merge as much as possible
mm/uffd: fix vma operation where start addr cuts part of vma
radix-tree: move declarations to header
nilfs2: fix incomplete buffer cleanup in nilfs_btnode_abort_change_key()
If profile-guided optimization is enabled, the purgatory ends up with
multiple .text sections. This is not supported by kexec and crashes the
system.
Link: https://lkml.kernel.org/r/20230321-kexec_clang16-v7-2-b05c520b7296@chromium.org
Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Cc: <stable@vger.kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The sysctl net/core/bpf_jit_enable does not work now due to commit
1022a5498f6f ("bpf, x86_64: Use bpf_jit_binary_pack_alloc"). The
commit saved the jitted insns into 'rw_image' instead of 'image'
which caused bpf_jit_dump not dumping proper content.
With 'echo 2 > /proc/sys/net/core/bpf_jit_enable', run
'./test_progs -t fentry_test'. Without this patch, one of jitted
image for one particular prog is:
flen=17 proglen=92 pass=4 image=0000000014c64883 from=test_progs pid=1807
00000000: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
00000010: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
00000020: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
00000030: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
00000040: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
00000050: cc cc cc cc cc cc cc cc cc cc cc cc
With this patch, the jitte image for the same prog is:
flen=17 proglen=92 pass=4 image=00000000b90254b7 from=test_progs pid=1809
00000000: f3 0f 1e fa 0f 1f 44 00 00 66 90 55 48 89 e5 f3
00000010: 0f 1e fa 31 f6 48 8b 57 00 48 83 fa 07 75 2b 48
00000020: 8b 57 10 83 fa 09 75 22 48 8b 57 08 48 81 e2 ff
00000030: 00 00 00 48 83 fa 08 75 11 48 8b 7f 18 be 01 00
00000040: 00 00 48 83 ff 0a 74 02 31 f6 48 bf 18 d0 14 00
00000050: 00 c9 ff ff 48 89 77 00 31 c0 c9 c3
Fixes: 1022a5498f6f ("bpf, x86_64: Use bpf_jit_binary_pack_alloc")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20230609005439.3173569-1-yhs@fb.com
kernel after bypassing the decompressor and the CS descriptor used
ends up being the EFI one which is not mapped in the identity page
table, leading to early SEV/SNP guest communication exceptions
resulting in the guest crashing
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Merge tag 'x86_urgent_for_v6.4_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Borislav Petkov:
- Set up the kernel CS earlier in the boot process in case EFI boots
the kernel after bypassing the decompressor and the CS descriptor
used ends up being the EFI one which is not mapped in the identity
page table, leading to early SEV/SNP guest communication exceptions
resulting in the guest crashing
* tag 'x86_urgent_for_v6.4_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/head/64: Switch to KERNEL_CS as soon as new GDT is installed
Some hypervisor interrupts (such as for Hyper-V VMbus and Hyper-V timers)
have hardcoded interrupt vectors on x86 and don't have Linux IRQs assigned.
These interrupts are shown in /proc/interrupts, but are not reported in
the first field of the "intr" line in /proc/stat because the x86 version
of arch_irq_stat_cpu() doesn't include them.
Fix this by adding code to arch_irq_stat_cpu() to include these interrupts,
similar to existing interrupts that don't have Linux IRQs.
Use #if IS_ENABLED() because unlike all the other nearby #ifdefs,
CONFIG_HYPERV can be built as a module.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/1677523568-50263-1-git-send-email-mikelley%40microsoft.com
To change the resources allocated to a large group of tasks, such as an
application container, a container manager must write all of the tasks'
IDs into the tasks file interface of the new control group. This is
challenging when the container's task list is always changing.
In addition, if the container manager is using monitoring groups to
separately track the bandwidth of containers assigned to the same
control group, when moving a container, it must first move the
container's tasks to the default monitoring group of the new control
group before it can move these tasks into the container's replacement
monitoring group under the destination control group. This is
undesirable because it makes bandwidth usage during the move
unattributable to the correct tasks and resets monitoring event counters
and cache usage information for the group.
Implement the rename operation only for resctrlfs monitor groups to
enable users to move a monitoring group from one control group to
another. This effects a change in resources allocated to all the tasks
in the monitoring group while otherwise leaving the monitoring data
intact.
Signed-off-by: Peter Newman <peternewman@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20230419125015.693566-3-peternewman@google.com
rdtgroup_kn_lock_live() can only release a kernfs reference for a single
file before waiting on the rdtgroup_mutex, limiting its usefulness for
operations on multiple files, such as rename.
Factor the work needed to respectively break and unbreak active
protection on an individual file into rdtgroup_kn_{get,put}().
No functional change.
Signed-off-by: Peter Newman <peternewman@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20230419125015.693566-2-peternewman@google.com
Add SNP-specific hooks to the unaccepted memory support in the boot
path (__accept_memory()) and the core kernel (accept_memory()) in order
to support booting SNP guests when unaccepted memory is present. Without
this support, SNP guests will fail to boot and/or panic() when unaccepted
memory is present in the EFI memory map.
The process of accepting memory under SNP involves invoking the hypervisor
to perform a page state change for the page to private memory and then
issuing a PVALIDATE instruction to accept the page.
Since the boot path and the core kernel paths perform similar operations,
move the pvalidate_pages() and vmgexit_psc() functions into sev-shared.c
to avoid code duplication.
Create the new header file arch/x86/boot/compressed/sev.h because adding
the function declaration to any of the existing SEV related header files
pulls in too many other header files, causing the build to fail.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/a52fa69f460fd1876d70074b20ad68210dfc31dd.1686063086.git.thomas.lendacky@amd.com
In advance of providing support for unaccepted memory, request 2M Page
State Change (PSC) requests when the address range allows for it. By using
a 2M page size, more PSC operations can be handled in a single request to
the hypervisor. The hypervisor will determine if it can accommodate the
larger request by checking the mapping in the nested page table. If mapped
as a large page, then the 2M page request can be performed, otherwise the
2M page request will be broken down into 512 4K page requests. This is
still more efficient than having the guest perform multiple PSC requests
in order to process the 512 4K pages.
In conjunction with the 2M PSC requests, attempt to perform the associated
PVALIDATE instruction of the page using the 2M page size. If PVALIDATE
fails with a size mismatch, then fallback to validating 512 4K pages. To
do this, page validation is modified to work with the PSC structure and
not just a virtual address range.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/050d17b460dfc237b51d72082e5df4498d3513cb.1686063086.git.thomas.lendacky@amd.com
Using a GHCB for a page stage change (as opposed to the MSR protocol)
allows for multiple pages to be processed in a single request. In prep
for early PSC requests in support of unaccepted memory, update the
invocation of vmgexit_psc() to be able to use the early boot GHCB and not
just the per-CPU GHCB structure.
In order to use the proper GHCB (early boot vs per-CPU), set a flag that
indicates when the per-CPU GHCBs are available and registered. For APs,
the per-CPU GHCBs are created before they are started and registered upon
startup, so this flag can be used globally for the BSP and APs instead of
creating a per-CPU flag. This will allow for a significant reduction in
the number of MSR protocol page state change requests when accepting
memory.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/d6cbb21f87f81eb8282dd3bf6c34d9698c8a4bbc.1686063086.git.thomas.lendacky@amd.com
In advance of providing support for unaccepted memory, switch from using
kmalloc() for allocating the Page State Change (PSC) structure to using a
local variable that lives on the stack. This is needed to avoid a possible
recursive call into set_pages_state() if the kmalloc() call requires
(more) memory to be accepted, which would result in a hang.
The current size of the PSC struct is 2,032 bytes. To make the struct more
stack friendly, reduce the number of PSC entries from 253 down to 64,
resulting in a size of 520 bytes. This is a nice compromise on struct size
and total PSC requests while still allowing parallel PSC operations across
vCPUs.
If the reduction in PSC entries results in any kind of performance issue
(that is not seen at the moment), use of a larger static PSC struct, with
fallback to the smaller stack version, can be investigated.
For more background info on this decision, see the subthread in the Link:
tag below.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/lkml/658c455c40e8950cb046dd885dd19dc1c52d060a.1659103274.git.thomas.lendacky@amd.com
Linus Torvalds
Jakub Kicinski
Thomas Gleixner
Tony Battersby
Dheeraj Kumar Srivastava
Michael Kelley
Lee Jones
Omar Sandoval
Kan Liang
Petr Pavlu
Peter Zijlstra
Steven Rostedt (Google)
Ricardo Ribalda
Yonghong Song
Peter Newman
Tom Lendacky