Commit Graph

44007 Commits

Author SHA1 Message Date
Linus Torvalds
88afbb21d4 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.
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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
2023-06-26 14:45:53 -07:00
Linus Torvalds
9244724fbf 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.
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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
  ...
2023-06-26 13:59:56 -07:00
Linus Torvalds
7cffdbe360 Updates for the x86 boot process:
- 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()
2023-06-26 13:39:10 -07:00
Linus Torvalds
64bf6ae93e v6.5/vfs.misc
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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
  ...
2023-06-26 09:50:21 -07:00
Linus Torvalds
547cc9be86 - 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
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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
2023-06-25 10:13:17 -07:00
Linus Torvalds
300edd751b - 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
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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
2023-06-25 10:00:17 -07:00
Linus Torvalds
661e723b6f - 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
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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
2023-06-25 09:47:04 -07:00
Linus Torvalds
8a28a0b6f1 Networking fixes for 6.4-rc8, 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
 
 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
  ...
2023-06-22 17:59:51 -07:00
Jakub Kicinski
59bb14bda2 bpf-for-netdev
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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>
2023-06-21 13:59:46 -07:00
Thomas Gleixner
45e34c8af5 x86/smp: Put CPUs into INIT on shutdown if possible
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
2023-06-20 14:51:47 +02:00
Thomas Gleixner
6087dd5e86 x86/smp: Split sending INIT IPI out into a helper function
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
2023-06-20 14:51:47 +02:00
Thomas Gleixner
d7893093a7 x86/smp: Cure kexec() vs. mwait_play_dead() breakage
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: ea53069231 ("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
2023-06-20 14:51:47 +02:00
Thomas Gleixner
f9c9987bf5 x86/smp: Use dedicated cache-line for mwait_play_dead()
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
2023-06-20 14:51:47 +02:00
Thomas Gleixner
2affa6d6db x86/smp: Remove pointless wmb()s from native_stop_other_cpus()
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
2023-06-20 14:51:46 +02:00
Tony Battersby
9b040453d4 x86/smp: Dont access non-existing CPUID leaf
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: 08f253ec37 ("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
2023-06-20 14:51:46 +02:00
Thomas Gleixner
1f5e7eb786 x86/smp: Make stop_other_cpus() more robust
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: 08f253ec37 ("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
2023-06-20 14:51:46 +02:00
Linus Torvalds
692b7dc87c hyperv-fixes for 6.4-rc8
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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
2023-06-19 17:05:43 -07:00
Dheeraj Kumar Srivastava
85d38d5810 x86/apic: Fix kernel panic when booting with intremap=off and x2apic_phys
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: 9ebd680bd0 ("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
2023-06-19 20:59:40 +02:00
Michael Kelley
9636be85cc x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline
These commits

a494aef23d ("PCI: hv: Replace retarget_msi_interrupt_params with hyperv_pcpu_input_arg")
2c6ba42168 ("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>
2023-06-17 23:09:47 +00:00
Thomas Gleixner
0a9567ac5e x86/mem_encrypt: Unbreak the AMD_MEM_ENCRYPT=n build
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 20f07a044a ("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: 439e17576e ("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/
2023-06-16 22:23:27 +02:00
Lee Jones
d082d48737 x86/mm: Avoid using set_pgd() outside of real PGD pages
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: 0925dda596 ("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
2023-06-16 11:46:42 -07:00
Omar Sandoval
b9f174c811 x86/unwind/orc: Add ELF section with ORC version identifier
Commits ffb1b4a410 ("x86/unwind/orc: Add 'signal' field to ORC
metadata") and fb799447ae ("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: ffb1b4a410 ("x86/unwind/orc: Add 'signal' field to ORC metadata")
Fixes: fb799447ae ("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
2023-06-16 17:17:42 +02:00
Kan Liang
a6742cb90b perf/x86/intel: Fix the FRONTEND encoding on GNR and MTL
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: bc4000fdb0 ("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
2023-06-16 16:46:33 +02:00
Thomas Gleixner
b81fac906a x86/fpu: Move FPU initialization into arch_cpu_finalize_init()
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
2023-06-16 10:16:01 +02:00
Thomas Gleixner
1703db2b90 x86/fpu: Mark init functions __init
No point in keeping them around.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.841685728@linutronix.de
2023-06-16 10:16:01 +02:00
Thomas Gleixner
1f34bb2a24 x86/fpu: Remove cpuinfo argument from init functions
Nothing in the call chain requires it

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.783704297@linutronix.de
2023-06-16 10:16:01 +02:00
Thomas Gleixner
54d9a91a3d x86/init: Initialize signal frame size late
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
2023-06-16 10:16:00 +02:00
Thomas Gleixner
439e17576e init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()
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
2023-06-16 10:16:00 +02:00
Thomas Gleixner
7c7077a726 x86/cpu: Switch to arch_cpu_finalize_init()
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
2023-06-16 10:15:59 +02:00
Linus Torvalds
fb054096ae 19 hotfixes. 14 are cc:stable and the remainder address issues which were
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()
2023-06-12 16:14:34 -07:00
Ricardo Ribalda
97b6b9cbba x86/purgatory: remove PGO flags
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: 930457057a ("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>
2023-06-12 11:31:50 -07:00
Yonghong Song
ad96f1c913 bpf: Fix a bpf_jit_dump issue for x86_64 with sysctl bpf_jit_enable.
The sysctl net/core/bpf_jit_enable does not work now due to commit
1022a5498f ("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: 1022a5498f ("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
2023-06-12 16:47:18 +02:00
Linus Torvalds
4c605260bc - 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
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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
2023-06-11 10:14:02 -07:00
Linus Torvalds
b066935bf8 ARM:
* Address some fallout of the locking rework, this time affecting
   the way the vgic is configured
 
 * Fix an issue where the page table walker frees a subtree and
   then proceeds with walking what it has just freed...
 
 * Check that a given PA donated to the guest is actually memory
   (only affecting pKVM)
 
 * Correctly handle MTE CMOs by Set/Way
 
 * Fix the reported address of a watchpoint forwarded to userspace
 
 * Fix the freeing of the root of stage-2 page tables
 
 * Stop creating spurious PMU events to perform detection of the
   default PMU and use the existing PMU list instead.
 
 x86:
 
 * Fix a memslot lookup bug in the NX recovery thread that could
    theoretically let userspace bypass the NX hugepage mitigation
 
 * Fix a s/BLOCKING/PENDING bug in SVM's vNMI support
 
 * Account exit stats for fastpath VM-Exits that never leave the super
   tight run-loop
 
 * Fix an out-of-bounds bug in the optimized APIC map code, and add a
   regression test for the race.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Address some fallout of the locking rework, this time affecting the
     way the vgic is configured

   - Fix an issue where the page table walker frees a subtree and then
     proceeds with walking what it has just freed...

   - Check that a given PA donated to the guest is actually memory (only
     affecting pKVM)

   - Correctly handle MTE CMOs by Set/Way

   - Fix the reported address of a watchpoint forwarded to userspace

   - Fix the freeing of the root of stage-2 page tables

   - Stop creating spurious PMU events to perform detection of the
     default PMU and use the existing PMU list instead

  x86:

   - Fix a memslot lookup bug in the NX recovery thread that could
     theoretically let userspace bypass the NX hugepage mitigation

   - Fix a s/BLOCKING/PENDING bug in SVM's vNMI support

   - Account exit stats for fastpath VM-Exits that never leave the super
     tight run-loop

   - Fix an out-of-bounds bug in the optimized APIC map code, and add a
     regression test for the race"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: selftests: Add test for race in kvm_recalculate_apic_map()
  KVM: x86: Bail from kvm_recalculate_phys_map() if x2APIC ID is out-of-bounds
  KVM: x86: Account fastpath-only VM-Exits in vCPU stats
  KVM: SVM: vNMI pending bit is V_NMI_PENDING_MASK not V_NMI_BLOCKING_MASK
  KVM: x86/mmu: Grab memslot for correct address space in NX recovery worker
  KVM: arm64: Document default vPMU behavior on heterogeneous systems
  KVM: arm64: Iterate arm_pmus list to probe for default PMU
  KVM: arm64: Drop last page ref in kvm_pgtable_stage2_free_removed()
  KVM: arm64: Populate fault info for watchpoint
  KVM: arm64: Reload PTE after invoking walker callback on preorder traversal
  KVM: arm64: Handle trap of tagged Set/Way CMOs
  arm64: Add missing Set/Way CMO encodings
  KVM: arm64: Prevent unconditional donation of unmapped regions from the host
  KVM: arm64: vgic: Fix a comment
  KVM: arm64: vgic: Fix locking comment
  KVM: arm64: vgic: Wrap vgic_its_create() with config_lock
  KVM: arm64: vgic: Fix a circular locking issue
2023-06-04 07:16:53 -04:00
Sean Christopherson
4364b28798 KVM: x86: Bail from kvm_recalculate_phys_map() if x2APIC ID is out-of-bounds
Bail from kvm_recalculate_phys_map() and disable the optimized map if the
target vCPU's x2APIC ID is out-of-bounds, i.e. if the vCPU was added
and/or enabled its local APIC after the map was allocated.  This fixes an
out-of-bounds access bug in the !x2apic_format path where KVM would write
beyond the end of phys_map.

Check the x2APIC ID regardless of whether or not x2APIC is enabled,
as KVM's hardcodes x2APIC ID to be the vCPU ID, i.e. it can't change, and
the map allocation in kvm_recalculate_apic_map() doesn't check for x2APIC
being enabled, i.e. the check won't get false postivies.

Note, this also affects the x2apic_format path, which previously just
ignored the "x2apic_id > new->max_apic_id" case.  That too is arguably a
bug fix, as ignoring the vCPU meant that KVM would not send interrupts to
the vCPU until the next map recalculation.  In practice, that "bug" is
likely benign as a newly present vCPU/APIC would immediately trigger a
recalc.  But, there's no functional downside to disabling the map, and
a future patch will gracefully handle the -E2BIG case by retrying instead
of simply disabling the optimized map.

Opportunistically add a sanity check on the xAPIC ID size, along with a
comment explaining why the xAPIC ID is guaranteed to be "good".

Reported-by: Michal Luczaj <mhal@rbox.co>
Fixes: 5b84b02917 ("KVM: x86: Honor architectural behavior for aliased 8-bit APIC IDs")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230602233250.1014316-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-06-02 17:20:50 -07:00
Tom Lendacky
a37f2699c3 x86/head/64: Switch to KERNEL_CS as soon as new GDT is installed
The call to startup_64_setup_env() will install a new GDT but does not
actually switch to using the KERNEL_CS entry until returning from the
function call.

Commit bcce829083 ("x86/sev: Detect/setup SEV/SME features earlier in
boot") moved the call to sme_enable() earlier in the boot process and in
between the call to startup_64_setup_env() and the switch to KERNEL_CS.
An SEV-ES or an SEV-SNP guest will trigger #VC exceptions during the call
to sme_enable() and if the CS pushed on the stack as part of the exception
and used by IRETQ is not mapped by the new GDT, then problems occur.
Today, the current CS when entering startup_64 is the kernel CS value
because it was set up by the decompressor code, so no issue is seen.

However, a recent patchset that looked to avoid using the legacy
decompressor during an EFI boot exposed this bug. At entry to startup_64,
the CS value is that of EFI and is not mapped in the new kernel GDT. So
when a #VC exception occurs, the CS value used by IRETQ is not valid and
the guest boot crashes.

Fix this issue by moving the block that switches to the KERNEL_CS value to
be done immediately after returning from startup_64_setup_env().

Fixes: bcce829083 ("x86/sev: Detect/setup SEV/SME features earlier in boot")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/all/6ff1f28af2829cc9aea357ebee285825f90a431f.1684340801.git.thomas.lendacky%40amd.com
2023-06-02 16:59:57 -07:00
Sean Christopherson
8b703a49c9 KVM: x86: Account fastpath-only VM-Exits in vCPU stats
Increment vcpu->stat.exits when handling a fastpath VM-Exit without
going through any part of the "slow" path.  Not bumping the exits stat
can result in wildly misleading exit counts, e.g. if the primary reason
the guest is exiting is to program the TSC deadline timer.

Fixes: 404d5d7bff ("KVM: X86: Introduce more exit_fastpath_completion enum values")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230602011920.787844-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-06-02 16:37:49 -07:00
Maciej S. Szmigiero
b2ce899788 KVM: SVM: vNMI pending bit is V_NMI_PENDING_MASK not V_NMI_BLOCKING_MASK
While testing Hyper-V enabled Windows Server 2019 guests on Zen4 hardware
I noticed that with vCPU count large enough (> 16) they sometimes froze at
boot.
With vCPU count of 64 they never booted successfully - suggesting some kind
of a race condition.

Since adding "vnmi=0" module parameter made these guests boot successfully
it was clear that the problem is most likely (v)NMI-related.

Running kvm-unit-tests quickly showed failing NMI-related tests cases, like
"multiple nmi" and "pending nmi" from apic-split, x2apic and xapic tests
and the NMI parts of eventinj test.

The issue was that once one NMI was being serviced no other NMI was allowed
to be set pending (NMI limit = 0), which was traced to
svm_is_vnmi_pending() wrongly testing for the "NMI blocked" flag rather
than for the "NMI pending" flag.

Fix this by testing for the right flag in svm_is_vnmi_pending().
Once this is done, the NMI-related kvm-unit-tests pass successfully and
the Windows guest no longer freezes at boot.

Fixes: fa4c027a79 ("KVM: x86: Add support for SVM's Virtual NMI")
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/be4ca192eb0c1e69a210db3009ca984e6a54ae69.1684495380.git.maciej.szmigiero@oracle.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-06-02 16:34:20 -07:00
Sean Christopherson
817fa99836 KVM: x86/mmu: Grab memslot for correct address space in NX recovery worker
Factor in the address space (non-SMM vs. SMM) of the target shadow page
when recovering potential NX huge pages, otherwise KVM will retrieve the
wrong memslot when zapping shadow pages that were created for SMM.  The
bug most visibly manifests as a WARN on the memslot being non-NULL, but
the worst case scenario is that KVM could unaccount the shadow page
without ensuring KVM won't install a huge page, i.e. if the non-SMM slot
is being dirty logged, but the SMM slot is not.

 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 3911 at arch/x86/kvm/mmu/mmu.c:7015
 kvm_nx_huge_page_recovery_worker+0x38c/0x3d0 [kvm]
 CPU: 1 PID: 3911 Comm: kvm-nx-lpage-re
 RIP: 0010:kvm_nx_huge_page_recovery_worker+0x38c/0x3d0 [kvm]
 RSP: 0018:ffff99b284f0be68 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffff99b284edd000 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
 RBP: ffff9271397024e0 R08: 0000000000000000 R09: ffff927139702450
 R10: 0000000000000000 R11: 0000000000000001 R12: ffff99b284f0be98
 R13: 0000000000000000 R14: ffff9270991fcd80 R15: 0000000000000003
 FS:  0000000000000000(0000) GS:ffff927f9f640000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f0aacad3ae0 CR3: 000000088fc2c005 CR4: 00000000003726e0
 Call Trace:
  <TASK>
__pfx_kvm_nx_huge_page_recovery_worker+0x10/0x10 [kvm]
  kvm_vm_worker_thread+0x106/0x1c0 [kvm]
  kthread+0xd9/0x100
  ret_from_fork+0x2c/0x50
  </TASK>
 ---[ end trace 0000000000000000 ]---

This bug was exposed by commit edbdb43fc9 ("KVM: x86: Preserve TDP MMU
roots until they are explicitly invalidated"), which allowed KVM to retain
SMM TDP MMU roots effectively indefinitely.  Before commit edbdb43fc9,
KVM would zap all SMM TDP MMU roots and thus all SMM TDP MMU shadow pages
once all vCPUs exited SMM, which made the window where this bug (recovering
an SMM NX huge page) could be encountered quite tiny.  To hit the bug, the
NX recovery thread would have to run while at least one vCPU was in SMM.
Most VMs typically only use SMM during boot, and so the problematic shadow
pages were gone by the time the NX recovery thread ran.

Now that KVM preserves TDP MMU roots until they are explicitly invalidated
(e.g. by a memslot deletion), the window to trigger the bug is effectively
never closed because most VMMs don't delete memslots after boot (except
for a handful of special scenarios).

Fixes: eb29860570 ("KVM: x86/mmu: Do not recover dirty-tracked NX Huge Pages")
Reported-by: Fabio Coatti <fabio.coatti@gmail.com>
Closes: https://lore.kernel.org/all/CADpTngX9LESCdHVu_2mQkNGena_Ng2CphWNwsRGSMxzDsTjU2A@mail.gmail.com
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230602010137.784664-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-06-02 16:34:10 -07:00
Mike Christie
f9010dbdce fork, vhost: Use CLONE_THREAD to fix freezer/ps regression
When switching from kthreads to vhost_tasks two bugs were added:
1. The vhost worker tasks's now show up as processes so scripts doing
ps or ps a would not incorrectly detect the vhost task as another
process.  2. kthreads disabled freeze by setting PF_NOFREEZE, but
vhost tasks's didn't disable or add support for them.

To fix both bugs, this switches the vhost task to be thread in the
process that does the VHOST_SET_OWNER ioctl, and has vhost_worker call
get_signal to support SIGKILL/SIGSTOP and freeze signals. Note that
SIGKILL/STOP support is required because CLONE_THREAD requires
CLONE_SIGHAND which requires those 2 signals to be supported.

This is a modified version of the patch written by Mike Christie
<michael.christie@oracle.com> which was a modified version of patch
originally written by Linus.

Much of what depended upon PF_IO_WORKER now depends on PF_USER_WORKER.
Including ignoring signals, setting up the register state, and having
get_signal return instead of calling do_group_exit.

Tidied up the vhost_task abstraction so that the definition of
vhost_task only needs to be visible inside of vhost_task.c.  Making
it easier to review the code and tell what needs to be done where.
As part of this the main loop has been moved from vhost_worker into
vhost_task_fn.  vhost_worker now returns true if work was done.

The main loop has been updated to call get_signal which handles
SIGSTOP, freezing, and collects the message that tells the thread to
exit as part of process exit.  This collection clears
__fatal_signal_pending.  This collection is not guaranteed to
clear signal_pending() so clear that explicitly so the schedule()
sleeps.

For now the vhost thread continues to exist and run work until the
last file descriptor is closed and the release function is called as
part of freeing struct file.  To avoid hangs in the coredump
rendezvous and when killing threads in a multi-threaded exec.  The
coredump code and de_thread have been modified to ignore vhost threads.

Remvoing the special case for exec appears to require teaching
vhost_dev_flush how to directly complete transactions in case
the vhost thread is no longer running.

Removing the special case for coredump rendezvous requires either the
above fix needed for exec or moving the coredump rendezvous into
get_signal.

Fixes: 6e890c5d50 ("vhost: use vhost_tasks for worker threads")
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Co-developed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-01 17:15:33 -04:00
Thomas Gleixner
ff3cfcb0d4 x86/smpboot: Fix the parallel bringup decision
The decision to allow parallel bringup of secondary CPUs checks
CC_ATTR_GUEST_STATE_ENCRYPT to detect encrypted guests. Those cannot use
parallel bootup because accessing the local APIC is intercepted and raises
a #VC or #VE, which cannot be handled at that point.

The check works correctly, but only for AMD encrypted guests. TDX does not
set that flag.

As there is no real connection between CC attributes and the inability to
support parallel bringup, replace this with a generic control flag in
x86_cpuinit and let SEV-ES and TDX init code disable it.

Fixes: 0c7ffa32db ("x86/smpboot/64: Implement arch_cpuhp_init_parallel_bringup() and enable it")
Reported-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/87ilc9gd2d.ffs@tglx
2023-05-31 16:49:34 +02:00
Thomas Gleixner
33e20b07be x86/realmode: Make stack lock work in trampoline_compat()
The stack locking and stack assignment macro LOAD_REALMODE_ESP fails to
work when invoked from the 64bit trampoline entry point:

trampoline_start64
  trampoline_compat
    LOAD_REALMODE_ESP <- lock

Accessing tr_lock is only possible from 16bit mode. For the compat entry
point this needs to be pa_tr_lock so that the required relocation entry is
generated. Otherwise it locks the non-relocated address which is
aside of being wrong never cleared in secondary_startup_64() causing all
but the first CPU to get stuck on the lock.

Make the macro take an argument lock_pa which defaults to 0 and rename it
to LOCK_AND_LOAD_REALMODE_ESP to make it clear what this is about.

Fixes: f6f1ae9128 ("x86/smpboot: Implement a bit spinlock to protect the realmode stack")
Reported-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/87h6rujdvl.ffs@tglx
2023-05-30 14:11:47 +02:00
Thomas Gleixner
5da80b28bf x86/smp: Initialize cpu_primary_thread_mask late
Marking primary threads in the cpumask during early boot is only correct in
certain configurations, but broken e.g. for the legacy hyperthreading
detection.

This is due to the complete mess in the CPUID evaluation code which
initializes smp_num_siblings only half during early init and fixes it up
later when identify_boot_cpu() is invoked.

So using smp_num_siblings before identify_boot_cpu() leads to incorrect
results.

Fixing the early CPU init code to provide the proper data is a larger scale
surgery as the code has dependencies on data structures which are not
initialized during early boot.

Move the initialization of cpu_primary_thread_mask wich depends on
smp_num_siblings being correct to an early initcall so that it is set up
correctly before SMP bringup.

Fixes: f54d4434c2 ("x86/apic: Provide cpu_primary_thread mask")
Reported-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/87sfbhlwp9.ffs@tglx
2023-05-29 21:31:23 +02:00
Linus Torvalds
7a6c8e512f This push fixes an alignment crash in x86/aria.
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Merge tag 'v6.4-p3' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Pull crypto fix from Herbert Xu:
 "Fix an alignment crash in x86/aria"

* tag 'v6.4-p3' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: x86/aria - Use 16 byte alignment for GFNI constant vectors
2023-05-29 07:05:49 -04:00
Linus Torvalds
f8b2507c26 A single fix for x86:
- Prevent a bogus setting for the number of HT siblings, which is caused
    by the CPUID evaluation trainwreck of X86. That recomputes the value
    for each CPU, so the last CPU "wins". That can cause completely bogus
    sibling values.
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Merge tag 'x86-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpu fix from Thomas Gleixner:
 "A single fix for x86:

   - Prevent a bogus setting for the number of HT siblings, which is
     caused by the CPUID evaluation trainwreck of X86. That recomputes
     the value for each CPU, so the last CPU "wins". That can cause
     completely bogus sibling values"

* tag 'x86-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/topology: Fix erroneous smp_num_siblings on Intel Hybrid platforms
2023-05-28 07:42:05 -04:00
Linus Torvalds
2d5438f4c6 A small set of perf fixes:
- Make the CHA discovery based on MSR readout to work around broken
    discovery tables in some SPR firmwares.
 
  - Prevent saving PEBS configuration which has software bits set that
    cause a crash when restored into the relevant MSR.
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Merge tag 'perf-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Thomas Gleixner:
 "A small set of perf fixes:

   - Make the MSR-readout based CHA discovery work around broken
     discovery tables in some SPR firmwares.

   - Prevent saving PEBS configuration which has software bits set that
     cause a crash when restored into the relevant MSR"

* tag 'perf-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/uncore: Correct the number of CHAs on SPR
  perf/x86/intel: Save/restore cpuc->active_pebs_data_cfg when using guest PEBS
2023-05-28 07:37:23 -04:00
Linus Torvalds
abbf7fa15b A set of unwinder and tooling fixes:
- Ensure that the stack pointer on x86 is aligned again so that the
     unwinder does not read past the end of the stack
 
   - Discard .note.gnu.property section which has a pointlessly different
     alignment than the other note sections. That confuses tooling of all
     sorts including readelf, libbpf and pahole.
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Merge tag 'objtool-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull unwinder fixes from Thomas Gleixner:
 "A set of unwinder and tooling fixes:

   - Ensure that the stack pointer on x86 is aligned again so that the
     unwinder does not read past the end of the stack

   - Discard .note.gnu.property section which has a pointlessly
     different alignment than the other note sections. That confuses
     tooling of all sorts including readelf, libbpf and pahole"

* tag 'objtool-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/show_trace_log_lvl: Ensure stack pointer is aligned, again
  vmlinux.lds.h: Discard .note.gnu.property section
2023-05-28 07:33:29 -04:00
Linus Torvalds
4e893b5aa4 xen: branch for v6.4-rc4
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Merge tag 'for-linus-6.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:

 - a double free fix in the Xen pvcalls backend driver

 - a fix for a regression causing the MSI related sysfs entries to not
   being created in Xen PV guests

 - a fix in the Xen blkfront driver for handling insane input data
   better

* tag 'for-linus-6.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/pci/xen: populate MSI sysfs entries
  xen/pvcalls-back: fix double frees with pvcalls_new_active_socket()
  xen/blkfront: Only check REQ_FUA for writes
2023-05-27 09:42:56 -07:00
Linus Torvalds
47ee3f1dd9 x86: re-introduce support for ERMS copies for user space accesses
I tried to streamline our user memory copy code fairly aggressively in
commit adfcf4231b ("x86: don't use REP_GOOD or ERMS for user memory
copies"), in order to then be able to clean up the code and inline the
modern FSRM case in commit 577e6a7fd5 ("x86: inline the 'rep movs' in
user copies for the FSRM case").

We had reports [1] of that causing regressions earlier with blogbench,
but that turned out to be a horrible benchmark for that case, and not a
sufficient reason for re-instating "rep movsb" on older machines.

However, now Eric Dumazet reported [2] a regression in performance that
seems to be a rather more real benchmark, where due to the removal of
"rep movs" a TCP stream over a 100Gbps network no longer reaches line
speed.

And it turns out that with the simplified the calling convention for the
non-FSRM case in commit 427fda2c8a ("x86: improve on the non-rep
'copy_user' function"), re-introducing the ERMS case is actually fairly
simple.

Of course, that "fairly simple" is glossing over several missteps due to
having to fight our assembler alternative code.  This code really wanted
to rewrite a conditional branch to have two different targets, but that
made objtool sufficiently unhappy that this instead just ended up doing
a choice between "jump to the unrolled loop, or use 'rep movsb'
directly".

Let's see if somebody finds a case where the kernel memory copies also
care (see commit 68674f94ff: "x86: don't use REP_GOOD or ERMS for
small memory copies").  But Eric does argue that the user copies are
special because networking tries to copy up to 32KB at a time, if
order-3 pages allocations are possible.

In-kernel memory copies are typically small, unless they are the special
"copy pages at a time" kind that still use "rep movs".

Link: https://lore.kernel.org/lkml/202305041446.71d46724-yujie.liu@intel.com/ [1]
Link: https://lore.kernel.org/lkml/CANn89iKUbyrJ=r2+_kK+sb2ZSSHifFZ7QkPLDpAtkJ8v4WUumA@mail.gmail.com/ [2]
Reported-and-tested-by: Eric Dumazet <edumazet@google.com>
Fixes: adfcf4231b ("x86: don't use REP_GOOD or ERMS for user memory copies")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-05-26 12:34:20 -07:00
Zhang Rui
edc0a2b595 x86/topology: Fix erroneous smp_num_siblings on Intel Hybrid platforms
Traditionally, all CPUs in a system have identical numbers of SMT
siblings.  That changes with hybrid processors where some logical CPUs
have a sibling and others have none.

Today, the CPU boot code sets the global variable smp_num_siblings when
every CPU thread is brought up. The last thread to boot will overwrite
it with the number of siblings of *that* thread. That last thread to
boot will "win". If the thread is a Pcore, smp_num_siblings == 2.  If it
is an Ecore, smp_num_siblings == 1.

smp_num_siblings describes if the *system* supports SMT.  It should
specify the maximum number of SMT threads among all cores.

Ensure that smp_num_siblings represents the system-wide maximum number
of siblings by always increasing its value. Never allow it to decrease.

On MeteorLake-P platform, this fixes a problem that the Ecore CPUs are
not updated in any cpu sibling map because the system is treated as an
UP system when probing Ecore CPUs.

Below shows part of the CPU topology information before and after the
fix, for both Pcore and Ecore CPU (cpu0 is Pcore, cpu 12 is Ecore).
...
-/sys/devices/system/cpu/cpu0/topology/package_cpus:000fff
-/sys/devices/system/cpu/cpu0/topology/package_cpus_list:0-11
+/sys/devices/system/cpu/cpu0/topology/package_cpus:3fffff
+/sys/devices/system/cpu/cpu0/topology/package_cpus_list:0-21
...
-/sys/devices/system/cpu/cpu12/topology/package_cpus:001000
-/sys/devices/system/cpu/cpu12/topology/package_cpus_list:12
+/sys/devices/system/cpu/cpu12/topology/package_cpus:3fffff
+/sys/devices/system/cpu/cpu12/topology/package_cpus_list:0-21

Notice that the "before" 'package_cpus_list' has only one CPU.  This
means that userspace tools like lscpu will see a little laptop like
an 11-socket system:

-Core(s) per socket:  1
-Socket(s):           11
+Core(s) per socket:  16
+Socket(s):           1

This is also expected to make the scheduler do rather wonky things
too.

[ dhansen: remove CPUID detail from changelog, add end user effects ]

CC: stable@kernel.org
Fixes: bbb65d2d36 ("x86: use cpuid vector 0xb when available for detecting cpu topology")
Fixes: 95f3d39ccf ("x86/cpu/topology: Provide detect_extended_topology_early()")
Suggested-by: Len Brown <len.brown@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230323015640.27906-1-rui.zhang%40intel.com
2023-05-25 10:48:42 -07:00