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Author SHA1 Message Date
Paolo Bonzini
3c7a8e190b uapi: introduce uapi-friendly macros for GENMASK 
Move __GENMASK and __GENMASK_ULL from include/ to include/uapi/ so that they can
be used to define masks in userspace API headers.  Compared to what is already
in include/linux/bits.h, the definitions need to use the uglified versions of
UL(), ULL(), BITS_PER_LONG and BITS_PER_LONG_LONG (which did not even exist),
but otherwise expand to the same content.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
 2024-02-08 08:41:03 -05:00
Linus Torvalds
063a7ce32d Merge tag 'lsm-pr-20240105' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm 
Pull security module updates from Paul Moore:

 - Add three new syscalls: lsm_list_modules(), lsm_get_self_attr(), and
   lsm_set_self_attr().

   The first syscall simply lists the LSMs enabled, while the second and
   third get and set the current process' LSM attributes. Yes, these
   syscalls may provide similar functionality to what can be found under
   /proc or /sys, but they were designed to support multiple,
   simultaneaous (stacked) LSMs from the start as opposed to the current
   /proc based solutions which were created at a time when only one LSM
   was allowed to be active at a given time.

   We have spent considerable time discussing ways to extend the
   existing /proc interfaces to support multiple, simultaneaous LSMs and
   even our best ideas have been far too ugly to support as a kernel
   API; after +20 years in the kernel, I felt the LSM layer had
   established itself enough to justify a handful of syscalls.

   Support amongst the individual LSM developers has been nearly
   unanimous, with a single objection coming from Tetsuo (TOMOYO) as he
   is worried that the LSM_ID_XXX token concept will make it more
   difficult for out-of-tree LSMs to survive. Several members of the LSM
   community have demonstrated the ability for out-of-tree LSMs to
   continue to exist by picking high/unused LSM_ID values as well as
   pointing out that many kernel APIs rely on integer identifiers, e.g.
   syscalls (!), but unfortunately Tetsuo's objections remain.

   My personal opinion is that while I have no interest in penalizing
   out-of-tree LSMs, I'm not going to penalize in-tree development to
   support out-of-tree development, and I view this as a necessary step
   forward to support the push for expanded LSM stacking and reduce our
   reliance on /proc and /sys which has occassionally been problematic
   for some container users. Finally, we have included the linux-api
   folks on (all?) recent revisions of the patchset and addressed all of
   their concerns.

 - Add a new security_file_ioctl_compat() LSM hook to handle the 32-bit
   ioctls on 64-bit systems problem.

   This patch includes support for all of the existing LSMs which
   provide ioctl hooks, although it turns out only SELinux actually
   cares about the individual ioctls. It is worth noting that while
   Casey (Smack) and Tetsuo (TOMOYO) did not give explicit ACKs to this
   patch, they did both indicate they are okay with the changes.

 - Fix a potential memory leak in the CALIPSO code when IPv6 is disabled
   at boot.

   While it's good that we are fixing this, I doubt this is something
   users are seeing in the wild as you need to both disable IPv6 and
   then attempt to configure IPv6 labeled networking via
   NetLabel/CALIPSO; that just doesn't make much sense.

   Normally this would go through netdev, but Jakub asked me to take
   this patch and of all the trees I maintain, the LSM tree seemed like
   the best fit.

 - Update the LSM MAINTAINERS entry with additional information about
   our process docs, patchwork, bug reporting, etc.

   I also noticed that the Lockdown LSM is missing a dedicated
   MAINTAINERS entry so I've added that to the pull request. I've been
   working with one of the major Lockdown authors/contributors to see if
   they are willing to step up and assume a Lockdown maintainer role;
   hopefully that will happen soon, but in the meantime I'll continue to
   look after it.

 - Add a handful of mailmap entries for Serge Hallyn and myself.

* tag 'lsm-pr-20240105' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (27 commits)
  lsm: new security_file_ioctl_compat() hook
  lsm: Add a __counted_by() annotation to lsm_ctx.ctx
  calipso: fix memory leak in netlbl_calipso_add_pass()
  selftests: remove the LSM_ID_IMA check in lsm/lsm_list_modules_test
  MAINTAINERS: add an entry for the lockdown LSM
  MAINTAINERS: update the LSM entry
  mailmap: add entries for Serge Hallyn's dead accounts
  mailmap: update/replace my old email addresses
  lsm: mark the lsm_id variables are marked as static
  lsm: convert security_setselfattr() to use memdup_user()
  lsm: align based on pointer length in lsm_fill_user_ctx()
  lsm: consolidate buffer size handling into lsm_fill_user_ctx()
  lsm: correct error codes in security_getselfattr()
  lsm: cleanup the size counters in security_getselfattr()
  lsm: don't yet account for IMA in LSM_CONFIG_COUNT calculation
  lsm: drop LSM_ID_IMA
  LSM: selftests for Linux Security Module syscalls
  SELinux: Add selfattr hooks
  AppArmor: Add selfattr hooks
  Smack: implement setselfattr and getselfattr hooks
  ...
 2024-01-09 12:57:46 -08:00
Miklos Szeredi
d8b0f54650 wire up syscalls for statmount/listmount 
Wire up all archs.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Link: https://lore.kernel.org/r/20231025140205.3586473-7-mszeredi@redhat.com
Reviewed-by: Ian Kent <raven@themaw.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>
 2023-12-14 11:49:17 +01:00
Casey Schaufler
5f42375904 LSM: wireup Linux Security Module syscalls 
Wireup lsm_get_self_attr, lsm_set_self_attr and lsm_list_modules
system calls.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: linux-api@vger.kernel.org
Reviewed-by: Mickaël Salaün <mic@digikod.net>
[PM: forward ported beyond v6.6 due merge window changes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
 2023-11-12 22:54:42 -05:00
Linus Torvalds
1e0c505e13 Merge tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic 
Pull ia64 removal and asm-generic updates from Arnd Bergmann:

 - The ia64 architecture gets its well-earned retirement as planned,
   now that there is one last (mostly) working release that will be
   maintained as an LTS kernel.

 - The architecture specific system call tables are updated for the
   added map_shadow_stack() syscall and to remove references to the
   long-gone sys_lookup_dcookie() syscall.

* tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  hexagon: Remove unusable symbols from the ptrace.h uapi
  asm-generic: Fix spelling of architecture
  arch: Reserve map_shadow_stack() syscall number for all architectures
  syscalls: Cleanup references to sys_lookup_dcookie()
  Documentation: Drop or replace remaining mentions of IA64
  lib/raid6: Drop IA64 support
  Documentation: Drop IA64 from feature descriptions
  kernel: Drop IA64 support from sig_fault handlers
  arch: Remove Itanium (IA-64) architecture
 2023-11-01 15:28:33 -10:00
Sohil Mehta
2fd0ebad27 arch: Reserve map_shadow_stack() syscall number for all architectures 
commit c35559f94e ("x86/shstk: Introduce map_shadow_stack syscall")
recently added support for map_shadow_stack() but it is limited to x86
only for now. There is a possibility that other architectures (namely,
arm64 and RISC-V), that are implementing equivalent support for shadow
stacks, might need to add support for it.

Independent of that, reserving arch-specific syscall numbers in the
syscall tables of all architectures is good practice and would help
avoid future conflicts. map_shadow_stack() is marked as a conditional
syscall in sys_ni.c. Adding it to the syscall tables of other
architectures is harmless and would return ENOSYS when exercised.

Note, map_shadow_stack() was assigned #453 during the merge process
since #452 was taken by fchmodat2().

For Powerpc, map it to sys_ni_syscall() as is the norm for Powerpc
syscall tables.

For Alpha, map_shadow_stack() takes up #563 as Alpha still diverges from
the common syscall numbering system in the other architectures.

Link: https://lore.kernel.org/lkml/20230515212255.GA562920@debug.ba.rivosinc.com/
Link: https://lore.kernel.org/lkml/b402b80b-a7c6-4ef0-b977-c0f5f582b78a@sirena.org.uk/

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
 2023-10-06 22:26:51 +02:00
Sohil Mehta
ccab211af3 syscalls: Cleanup references to sys_lookup_dcookie() 
commit 'be65de6b03aa ("fs: Remove dcookies support")' removed the
syscall definition for lookup_dcookie.  However, syscall tables still
point to the old sys_lookup_dcookie() definition. Update syscall tables
of all architectures to directly point to sys_ni_syscall() instead.

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org> # for perf
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
 2023-10-03 19:51:37 +02:00
peterz@infradead.org
0f4b5f9722 futex: Add sys_futex_requeue() 
Finish off the 'simple' futex2 syscall group by adding
sys_futex_requeue(). Unlike sys_futex_{wait,wake}() its arguments are
too numerous to fit into a regular syscall. As such, use struct
futex_waitv to pass the 'source' and 'destination' futexes to the
syscall.

This syscall implements what was previously known as FUTEX_CMP_REQUEUE
and uses {val, uaddr, flags} for source and {uaddr, flags} for
destination.

This design explicitly allows requeueing between different types of
futex by having a different flags word per uaddr.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20230921105248.511860556@noisy.programming.kicks-ass.net
 2023-09-21 19:22:10 +02:00
peterz@infradead.org
cb8c4312af futex: Add sys_futex_wait() 
To complement sys_futex_waitv()/wake(), add sys_futex_wait(). This
syscall implements what was previously known as FUTEX_WAIT_BITSET
except it uses 'unsigned long' for the value and bitmask arguments,
takes timespec and clockid_t arguments for the absolute timeout and
uses FUTEX2 flags.

The 'unsigned long' allows FUTEX2_SIZE_U64 on 64bit platforms.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20230921105248.164324363@noisy.programming.kicks-ass.net
 2023-09-21 19:22:08 +02:00
peterz@infradead.org
9f6c532f59 futex: Add sys_futex_wake() 
To complement sys_futex_waitv() add sys_futex_wake(). This syscall
implements what was previously known as FUTEX_WAKE_BITSET except it
uses 'unsigned long' for the bitmask and takes FUTEX2 flags.

The 'unsigned long' allows FUTEX2_SIZE_U64 on 64bit platforms.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20230921105247.936205525@noisy.programming.kicks-ass.net
 2023-09-21 19:22:07 +02:00
Ard Biesheuvel
f5e836884d kernel: Drop IA64 support from sig_fault handlers 
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
 2023-09-11 08:13:18 +00:00
Linus Torvalds
df57721f9a Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 
Pull x86 shadow stack support from Dave Hansen:
 "This is the long awaited x86 shadow stack support, part of Intel's
  Control-flow Enforcement Technology (CET).

  CET consists of two related security features: shadow stacks and
  indirect branch tracking. This series implements just the shadow stack
  part of this feature, and just for userspace.

  The main use case for shadow stack is providing protection against
  return oriented programming attacks. It works by maintaining a
  secondary (shadow) stack using a special memory type that has
  protections against modification. When executing a CALL instruction,
  the processor pushes the return address to both the normal stack and
  to the special permission shadow stack. Upon RET, the processor pops
  the shadow stack copy and compares it to the normal stack copy.

  For more information, refer to the links below for the earlier
  versions of this patch set"

Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/
Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/

* tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/shstk: Change order of __user in type
  x86/ibt: Convert IBT selftest to asm
  x86/shstk: Don't retry vm_munmap() on -EINTR
  x86/kbuild: Fix Documentation/ reference
  x86/shstk: Move arch detail comment out of core mm
  x86/shstk: Add ARCH_SHSTK_STATUS
  x86/shstk: Add ARCH_SHSTK_UNLOCK
  x86: Add PTRACE interface for shadow stack
  selftests/x86: Add shadow stack test
  x86/cpufeatures: Enable CET CR4 bit for shadow stack
  x86/shstk: Wire in shadow stack interface
  x86: Expose thread features in /proc/$PID/status
  x86/shstk: Support WRSS for userspace
  x86/shstk: Introduce map_shadow_stack syscall
  x86/shstk: Check that signal frame is shadow stack mem
  x86/shstk: Check that SSP is aligned on sigreturn
  x86/shstk: Handle signals for shadow stack
  x86/shstk: Introduce routines modifying shstk
  x86/shstk: Handle thread shadow stack
  x86/shstk: Add user-mode shadow stack support
  ...
 2023-08-31 12:20:12 -07:00
Rick Edgecombe
a5f6c2ace9 x86/shstk: Add user control-protection fault handler 
A control-protection fault is triggered when a control-flow transfer
attempt violates Shadow Stack or Indirect Branch Tracking constraints.
For example, the return address for a RET instruction differs from the copy
on the shadow stack.

There already exists a control-protection fault handler for handling kernel
IBT faults. Refactor this fault handler into separate user and kernel
handlers, like the page fault handler. Add a control-protection handler
for usermode. To avoid ifdeffery, put them both in a new file cet.c, which
is compiled in the case of either of the two CET features supported in the
kernel: kernel IBT or user mode shadow stack. Move some static inline
functions from traps.c into a header so they can be used in cet.c.

Opportunistically fix a comment in the kernel IBT part of the fault
handler that is on the end of the line instead of preceding it.

Keep the same behavior for the kernel side of the fault handler, except for
converting a BUG to a WARN in the case of a #CP happening when the feature
is missing. This unifies the behavior with the new shadow stack code, and
also prevents the kernel from crashing under this situation which is
potentially recoverable.

The control-protection fault handler works in a similar way as the general
protection fault handler. It provides the si_code SEGV_CPERR to the signal
handler.

Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-28-rick.p.edgecombe%40intel.com
 2023-08-02 15:01:50 -07:00
Palmer Dabbelt
78252deb02 arch: Register fchmodat2, usually as syscall 452 
This registers the new fchmodat2 syscall in most places as nuber 452,
with alpha being the exception where it's 562.  I found all these sites
by grepping for fspick, which I assume has found me everything.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Message-Id: <a677d521f048e4ca439e7080a5328f21eb8e960e.1689092120.git.legion@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
 2023-07-27 12:25:35 +02:00
Linus Torvalds
7b82e90411 Merge tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic 
Pull asm-generic updates from Arnd Bergmann:
 "These are cleanups for architecture specific header files:

   - the comments in include/linux/syscalls.h have gone out of sync and
     are really pointless, so these get removed

   - The asm/bitsperlong.h header no longer needs to be architecture
     specific on modern compilers, so use a generic version for newer
     architectures that use new enough userspace compilers

   - A cleanup for virt_to_pfn/virt_to_bus to have proper type checking,
     forcing the use of pointers"

* tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  syscalls: Remove file path comments from headers
  tools arch: Remove uapi bitsperlong.h of hexagon and microblaze
  asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch
  m68k/mm: Make pfn accessors static inlines
  arm64: memory: Make virt_to_pfn() a static inline
  ARM: mm: Make virt_to_pfn() a static inline
  asm-generic/page.h: Make pfn accessors static inlines
  xen/netback: Pass (void *) to virt_to_page()
  netfs: Pass a pointer to virt_to_page()
  cifs: Pass a pointer to virt_to_page() in cifsglob
  cifs: Pass a pointer to virt_to_page()
  riscv: mm: init: Pass a pointer to virt_to_page()
  ARC: init: Pass a pointer to virt_to_pfn() in init
  m68k: Pass a pointer to virt_to_pfn() virt_to_page()
  fs/proc/kcore.c: Pass a pointer to virt_addr_valid()
 2023-07-06 10:06:04 -07:00
Linus Torvalds
3a8a670eee Merge tag 'net-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 
Pull networking changes from Jakub Kicinski:
 "WiFi 7 and sendpage changes are the biggest pieces of work for this
  release. The latter will definitely require fixes but I think that we
  got it to a reasonable point.

  Core:

   - Rework the sendpage & splice implementations

     Instead of feeding data into sockets page by page extend sendmsg
     handlers to support taking a reference on the data, controlled by a
     new flag called MSG_SPLICE_PAGES

     Rework the handling of unexpected-end-of-file to invoke an
     additional callback instead of trying to predict what the right
     combination of MORE/NOTLAST flags is

     Remove the MSG_SENDPAGE_NOTLAST flag completely

   - Implement SCM_PIDFD, a new type of CMSG type analogous to
     SCM_CREDENTIALS, but it contains pidfd instead of plain pid

   - Enable socket busy polling with CONFIG_RT

   - Improve reliability and efficiency of reporting for ref_tracker

   - Auto-generate a user space C library for various Netlink families

  Protocols:

   - Allow TCP to shrink the advertised window when necessary, prevent
     sk_rcvbuf auto-tuning from growing the window all the way up to
     tcp_rmem[2]

   - Use per-VMA locking for "page-flipping" TCP receive zerocopy

   - Prepare TCP for device-to-device data transfers, by making sure
     that payloads are always attached to skbs as page frags

   - Make the backoff time for the first N TCP SYN retransmissions
     linear. Exponential backoff is unnecessarily conservative

   - Create a new MPTCP getsockopt to retrieve all info
     (MPTCP_FULL_INFO)

   - Avoid waking up applications using TLS sockets until we have a full
     record

   - Allow using kernel memory for protocol ioctl callbacks, paving the
     way to issuing ioctls over io_uring

   - Add nolocalbypass option to VxLAN, forcing packets to be fully
     encapsulated even if they are destined for a local IP address

   - Make TCPv4 use consistent hash in TIME_WAIT and SYN_RECV. Ensure
     in-kernel ECMP implementation (e.g. Open vSwitch) select the same
     link for all packets. Support L4 symmetric hashing in Open vSwitch

   - PPPoE: make number of hash bits configurable

   - Allow DNS to be overwritten by DHCPACK in the in-kernel DHCP client
     (ipconfig)

   - Add layer 2 miss indication and filtering, allowing higher layers
     (e.g. ACL filters) to make forwarding decisions based on whether
     packet matched forwarding state in lower devices (bridge)

   - Support matching on Connectivity Fault Management (CFM) packets

   - Hide the "link becomes ready" IPv6 messages by demoting their
     printk level to debug

   - HSR: don't enable promiscuous mode if device offloads the proto

   - Support active scanning in IEEE 802.15.4

   - Continue work on Multi-Link Operation for WiFi 7

  BPF:

   - Add precision propagation for subprogs and callbacks. This allows
     maintaining verification efficiency when subprograms are used, or
     in fact passing the verifier at all for complex programs,
     especially those using open-coded iterators

   - Improve BPF's {g,s}setsockopt() length handling. Previously BPF
     assumed the length is always equal to the amount of written data.
     But some protos allow passing a NULL buffer to discover what the
     output buffer *should* be, without writing anything

   - Accept dynptr memory as memory arguments passed to helpers

   - Add routing table ID to bpf_fib_lookup BPF helper

   - Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands

   - Drop bpf_capable() check in BPF_MAP_FREEZE command (used to mark
     maps as read-only)

   - Show target_{obj,btf}_id in tracing link fdinfo

   - Addition of several new kfuncs (most of the names are
     self-explanatory):
      - Add a set of new dynptr kfuncs: bpf_dynptr_adjust(),
        bpf_dynptr_is_null(), bpf_dynptr_is_rdonly(), bpf_dynptr_size()
        and bpf_dynptr_clone().
      - bpf_task_under_cgroup()
      - bpf_sock_destroy() - force closing sockets
      - bpf_cpumask_first_and(), rework bpf_cpumask_any*() kfuncs

  Netfilter:

   - Relax set/map validation checks in nf_tables. Allow checking
     presence of an entry in a map without using the value

   - Increase ip_vs_conn_tab_bits range for 64BIT builds

   - Allow updating size of a set

   - Improve NAT tuple selection when connection is closing

  Driver API:

   - Integrate netdev with LED subsystem, to allow configuring HW
     "offloaded" blinking of LEDs based on link state and activity
     (i.e. packets coming in and out)

   - Support configuring rate selection pins of SFP modules

   - Factor Clause 73 auto-negotiation code out of the drivers, provide
     common helper routines

   - Add more fool-proof helpers for managing lifetime of MDIO devices
     associated with the PCS layer

   - Allow drivers to report advanced statistics related to Time Aware
     scheduler offload (taprio)

   - Allow opting out of VF statistics in link dump, to allow more VFs
     to fit into the message

   - Split devlink instance and devlink port operations

  New hardware / drivers:

   - Ethernet:
      - Synopsys EMAC4 IP support (stmmac)
      - Marvell 88E6361 8 port (5x1GE + 3x2.5GE) switches
      - Marvell 88E6250 7 port switches
      - Microchip LAN8650/1 Rev.B0 PHYs
      - MediaTek MT7981/MT7988 built-in 1GE PHY driver

   - WiFi:
      - Realtek RTL8192FU, 2.4 GHz, b/g/n mode, 2T2R, 300 Mbps
      - Realtek RTL8723DS (SDIO variant)
      - Realtek RTL8851BE

   - CAN:
      - Fintek F81604

  Drivers:

   - Ethernet NICs:
      - Intel (100G, ice):
         - support dynamic interrupt allocation
         - use meta data match instead of VF MAC addr on slow-path
      - nVidia/Mellanox:
         - extend link aggregation to handle 4, rather than just 2 ports
         - spawn sub-functions without any features by default
      - OcteonTX2:
         - support HTB (Tx scheduling/QoS) offload
         - make RSS hash generation configurable
         - support selecting Rx queue using TC filters
      - Wangxun (ngbe/txgbe):
         - add basic Tx/Rx packet offloads
         - add phylink support (SFP/PCS control)
      - Freescale/NXP (enetc):
         - report TAPRIO packet statistics
      - Solarflare/AMD:
         - support matching on IP ToS and UDP source port of outer
           header
         - VxLAN and GENEVE tunnel encapsulation over IPv4 or IPv6
         - add devlink dev info support for EF10

   - Virtual NICs:
      - Microsoft vNIC:
         - size the Rx indirection table based on requested
           configuration
         - support VLAN tagging
      - Amazon vNIC:
         - try to reuse Rx buffers if not fully consumed, useful for ARM
           servers running with 16kB pages
      - Google vNIC:
         - support TCP segmentation of >64kB frames

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - enable USXGMII (88E6191X)
      - Microchip:
         - lan966x: add support for Egress Stage 0 ACL engine
         - lan966x: support mapping packet priority to internal switch
           priority (based on PCP or DSCP)

   - Ethernet PHYs:
      - Broadcom PHYs:
         - support for Wake-on-LAN for BCM54210E/B50212E
         - report LPI counter
      - Microsemi PHYs: support RGMII delay configuration (VSC85xx)
      - Micrel PHYs: receive timestamp in the frame (LAN8841)
      - Realtek PHYs: support optional external PHY clock
      - Altera TSE PCS: merge the driver into Lynx PCS which it is a
        variant of

   - CAN: Kvaser PCIEcan:
      - support packet timestamping

   - WiFi:
      - Intel (iwlwifi):
         - major update for new firmware and Multi-Link Operation (MLO)
         - configuration rework to drop test devices and split the
           different families
         - support for segmented PNVM images and power tables
         - new vendor entries for PPAG (platform antenna gain) feature
      - Qualcomm 802.11ax (ath11k):
         - Multiple Basic Service Set Identifier (MBSSID) and Enhanced
           MBSSID Advertisement (EMA) support in AP mode
         - support factory test mode
      - RealTek (rtw89):
         - add RSSI based antenna diversity
         - support U-NII-4 channels on 5 GHz band
      - RealTek (rtl8xxxu):
         - AP mode support for 8188f
         - support USB RX aggregation for the newer chips"

* tag 'net-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1602 commits)
  net: scm: introduce and use scm_recv_unix helper
  af_unix: Skip SCM_PIDFD if scm->pid is NULL.
  net: lan743x: Simplify comparison
  netlink: Add __sock_i_ino() for __netlink_diag_dump().
  net: dsa: avoid suspicious RCU usage for synced VLAN-aware MAC addresses
  Revert "af_unix: Call scm_recv() only after scm_set_cred()."
  phylink: ReST-ify the phylink_pcs_neg_mode() kdoc
  libceph: Partially revert changes to support MSG_SPLICE_PAGES
  net: phy: mscc: fix packet loss due to RGMII delays
  net: mana: use vmalloc_array and vcalloc
  net: enetc: use vmalloc_array and vcalloc
  ionic: use vmalloc_array and vcalloc
  pds_core: use vmalloc_array and vcalloc
  gve: use vmalloc_array and vcalloc
  octeon_ep: use vmalloc_array and vcalloc
  net: usb: qmi_wwan: add u-blox 0x1312 composition
  perf trace: fix MSG_SPLICE_PAGES build error
  ipvlan: Fix return value of ipvlan_queue_xmit()
  netfilter: nf_tables: fix underflow in chain reference counter
  netfilter: nf_tables: unbind non-anonymous set if rule construction fails
  ...
 2023-06-28 16:43:10 -07:00
Sohil Mehta
4dd595c34c syscalls: Remove file path comments from headers 
Source file locations for syscall definitions can change over a period
of time. File paths in comments get stale and are hard to maintain long
term. Also, their usefulness is questionable since it would be easier to
locate a syscall definition using the SYSCALL_DEFINEx() macro.

Remove all source file path comments from the syscall headers. Also,
equalize the uneven line spacing (some of which is introduced due to the
deletions).

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
 2023-06-22 17:10:09 +02:00
Tiezhu Yang
8386f58f8d asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch 
Now we specify the minimal version of GCC as 5.1 and Clang/LLVM as 11.0.0
in Documentation/process/changes.rst, __CHAR_BIT__ and __SIZEOF_LONG__ are
usable, it is probably fine to unify the definition of __BITS_PER_LONG as
(__CHAR_BIT__ * __SIZEOF_LONG__) in asm-generic uapi bitsperlong.h.

In order to keep safe and avoid regression, only unify uapi bitsperlong.h
for some archs such as arm64, riscv and loongarch which are using newer
toolchains that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__.

Suggested-by: Xi Ruoyao <xry111@xry111.site>
Link: https://lore.kernel.org/all/d3e255e4746de44c9903c4433616d44ffcf18d1b.camel@xry111.site/
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-arch/a3a4f48a-07d4-4ed9-bc53-5d383428bdd2@app.fastmail.com/
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
 2023-06-22 17:04:36 +02:00
Alexander Mikhalitsyn
7b26952a91 net: core: add getsockopt SO_PEERPIDFD 
Add SO_PEERPIDFD which allows to get pidfd of peer socket holder pidfd.
This thing is direct analog of SO_PEERCRED which allows to get plain PID.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Luca Boccassi <bluca@debian.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: bpf@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Reviewed-by: Christian Brauner <brauner@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Tested-by: Luca Boccassi <bluca@debian.org>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2023-06-12 10:45:50 +01:00
Alexander Mikhalitsyn
5e2ff6704a scm: add SO_PASSPIDFD and SCM_PIDFD 
Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS,
but it contains pidfd instead of plain pid, which allows programmers not
to care about PID reuse problem.

We mask SO_PASSPIDFD feature if CONFIG_UNIX is not builtin because
it depends on a pidfd_prepare() API which is not exported to the kernel
modules.

Idea comes from UAPI kernel group:
https://uapi-group.org/kernel-features/

Big thanks to Christian Brauner and Lennart Poettering for productive
discussions about this.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Luca Boccassi <bluca@debian.org>
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Tested-by: Luca Boccassi <bluca@debian.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2023-06-12 10:45:49 +01:00
Nhat Pham
cf264e1329 cachestat: implement cachestat syscall 
There is currently no good way to query the page cache state of large file
sets and directory trees.  There is mincore(), but it scales poorly: the
kernel writes out a lot of bitmap data that userspace has to aggregate,
when the user really doesn not care about per-page information in that
case.  The user also needs to mmap and unmap each file as it goes along,
which can be quite slow as well.

Some use cases where this information could come in handy:
  * Allowing database to decide whether to perform an index scan or
    direct table queries based on the in-memory cache state of the
    index.
  * Visibility into the writeback algorithm, for performance issues
    diagnostic.
  * Workload-aware writeback pacing: estimating IO fulfilled by page
    cache (and IO to be done) within a range of a file, allowing for
    more frequent syncing when and where there is IO capacity, and
    batching when there is not.
  * Computing memory usage of large files/directory trees, analogous to
    the du tool for disk usage.

More information about these use cases could be found in the following
thread:

https://lore.kernel.org/lkml/20230315170934.GA97793@cmpxchg.org/

This patch implements a new syscall that queries cache state of a file and
summarizes the number of cached pages, number of dirty pages, number of
pages marked for writeback, number of (recently) evicted pages, etc.  in a
given range.  Currently, the syscall is only wired in for x86
architecture.

NAME
    cachestat - query the page cache statistics of a file.

SYNOPSIS
    #include <sys/mman.h>

    struct cachestat_range {
        __u64 off;
        __u64 len;
    };

    struct cachestat {
        __u64 nr_cache;
        __u64 nr_dirty;
        __u64 nr_writeback;
        __u64 nr_evicted;
        __u64 nr_recently_evicted;
    };

    int cachestat(unsigned int fd, struct cachestat_range *cstat_range,
        struct cachestat *cstat, unsigned int flags);

DESCRIPTION
    cachestat() queries the number of cached pages, number of dirty
    pages, number of pages marked for writeback, number of evicted
    pages, number of recently evicted pages, in the bytes range given by
    `off` and `len`.

    An evicted page is a page that is previously in the page cache but
    has been evicted since. A page is recently evicted if its last
    eviction was recent enough that its reentry to the cache would
    indicate that it is actively being used by the system, and that
    there is memory pressure on the system.

    These values are returned in a cachestat struct, whose address is
    given by the `cstat` argument.

    The `off` and `len` arguments must be non-negative integers. If
    `len` > 0, the queried range is [`off`, `off` + `len`]. If `len` ==
    0, we will query in the range from `off` to the end of the file.

    The `flags` argument is unused for now, but is included for future
    extensibility. User should pass 0 (i.e no flag specified).

    Currently, hugetlbfs is not supported.

    Because the status of a page can change after cachestat() checks it
    but before it returns to the application, the returned values may
    contain stale information.

RETURN VALUE
    On success, cachestat returns 0. On error, -1 is returned, and errno
    is set to indicate the error.

ERRORS
    EFAULT cstat or cstat_args points to an invalid address.

    EINVAL invalid flags.

    EBADF  invalid file descriptor.

    EOPNOTSUPP file descriptor is of a hugetlbfs file

[nphamcs@gmail.com: replace rounddown logic with the existing helper]
  Link: https://lkml.kernel.org/r/20230504022044.3675469-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20230503013608.2431726-3-nphamcs@gmail.com
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2023-06-09 16:25:16 -07:00
Christian Brauner
43b4506326 open: return EINVAL for O_DIRECTORY | O_CREAT 
After a couple of years and multiple LTS releases we received a report
that the behavior of O_DIRECTORY | O_CREAT changed starting with v5.7.

On kernels prior to v5.7 combinations of O_DIRECTORY, O_CREAT, O_EXCL
had the following semantics:

(1) open("/tmp/d", O_DIRECTORY | O_CREAT)
    * d doesn't exist:                create regular file
    * d exists and is a regular file: ENOTDIR
    * d exists and is a directory:    EISDIR

(2) open("/tmp/d", O_DIRECTORY | O_CREAT | O_EXCL)
    * d doesn't exist:                create regular file
    * d exists and is a regular file: EEXIST
    * d exists and is a directory:    EEXIST

(3) open("/tmp/d", O_DIRECTORY | O_EXCL)
    * d doesn't exist:                ENOENT
    * d exists and is a regular file: ENOTDIR
    * d exists and is a directory:    open directory

On kernels since to v5.7 combinations of O_DIRECTORY, O_CREAT, O_EXCL
have the following semantics:

(1) open("/tmp/d", O_DIRECTORY | O_CREAT)
    * d doesn't exist:                ENOTDIR (create regular file)
    * d exists and is a regular file: ENOTDIR
    * d exists and is a directory:    EISDIR

(2) open("/tmp/d", O_DIRECTORY | O_CREAT | O_EXCL)
    * d doesn't exist:                ENOTDIR (create regular file)
    * d exists and is a regular file: EEXIST
    * d exists and is a directory:    EEXIST

(3) open("/tmp/d", O_DIRECTORY | O_EXCL)
    * d doesn't exist:                ENOENT
    * d exists and is a regular file: ENOTDIR
    * d exists and is a directory:    open directory

This is a fairly substantial semantic change that userspace didn't
notice until Pedro took the time to deliberately figure out corner
cases. Since no one noticed this breakage we can somewhat safely assume
that O_DIRECTORY | O_CREAT combinations are likely unused.

The v5.7 breakage is especially weird because while ENOTDIR is returned
indicating failure a regular file is actually created. This doesn't make
a lot of sense.

Time was spent finding potential users of this combination. Searching on
codesearch.debian.net showed that codebases often express semantical
expectations about O_DIRECTORY | O_CREAT which are completely contrary
to what our code has done and currently does.

The expectation often is that this particular combination would create
and open a directory. This suggests users who tried to use that
combination would stumble upon the counterintuitive behavior no matter
if pre-v5.7 or post v5.7 and quickly realize neither semantics give them
what they want. For some examples see the code examples in [1] to [3]
and the discussion in [4].

There are various ways to address this issue. The lazy/simple option
would be to restore the pre-v5.7 behavior and to just live with that bug
forever. But since there's a real chance that the O_DIRECTORY | O_CREAT
quirk isn't relied upon we should try to get away with murder(ing bad
semantics) first. If we need to Frankenstein pre-v5.7 behavior later so
be it.

So let's simply return EINVAL categorically for O_DIRECTORY | O_CREAT
combinations. In addition to cleaning up the old bug this also opens up
the possiblity to make that flag combination do something more intuitive
in the future.

Starting with this commit the following semantics apply:

(1) open("/tmp/d", O_DIRECTORY | O_CREAT)
    * d doesn't exist:                EINVAL
    * d exists and is a regular file: EINVAL
    * d exists and is a directory:    EINVAL

(2) open("/tmp/d", O_DIRECTORY | O_CREAT | O_EXCL)
    * d doesn't exist:                EINVAL
    * d exists and is a regular file: EINVAL
    * d exists and is a directory:    EINVAL

(3) open("/tmp/d", O_DIRECTORY | O_EXCL)
    * d doesn't exist:                ENOENT
    * d exists and is a regular file: ENOTDIR
    * d exists and is a directory:    open directory

One additional note, O_TMPFILE is implemented as:

    #define __O_TMPFILE    020000000
    #define O_TMPFILE      (__O_TMPFILE | O_DIRECTORY)
    #define O_TMPFILE_MASK (__O_TMPFILE | O_DIRECTORY | O_CREAT)

For older kernels it was important to return an explicit error when
O_TMPFILE wasn't supported. So O_TMPFILE requires that O_DIRECTORY is
raised alongside __O_TMPFILE. It also enforced that O_CREAT wasn't
specified. Since O_DIRECTORY | O_CREAT could be used to create a regular
allowing that combination together with __O_TMPFILE would've meant that
false positives were possible, i.e., that a regular file was created
instead of a O_TMPFILE. This could've been used to trick userspace into
thinking it operated on a O_TMPFILE when it wasn't.

Now that we block O_DIRECTORY | O_CREAT completely the check for O_CREAT
in the __O_TMPFILE branch via if ((flags & O_TMPFILE_MASK) != O_TMPFILE)
can be dropped. Instead we can simply check verify that O_DIRECTORY is
raised via if (!(flags & O_DIRECTORY)) and explain this in two comments.

As Aleksa pointed out O_PATH is unaffected by this change since it
always returned EINVAL if O_CREAT was specified - with or without
O_DIRECTORY.

Link: https://lore.kernel.org/lkml/20230320071442.172228-1-pedro.falcato@gmail.com
Link: https://sources.debian.org/src/flatpak/1.14.4-1/subprojects/libglnx/glnx-dirfd.c/?hl=324#L324 [1]
Link: https://sources.debian.org/src/flatpak-builder/1.2.3-1/subprojects/libglnx/glnx-shutil.c/?hl=251#L251 [2]
Link: https://sources.debian.org/src/ostree/2022.7-2/libglnx/glnx-dirfd.c/?hl=324#L324 [3]
Link: https://www.openwall.com/lists/oss-security/2014/11/26/14 [4]
Reported-by: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
 2023-03-22 11:06:55 +01:00
Geert Uytterhoeven
32975c491e uapi: Add missing _UAPI prefix to <asm-generic/types.h> include guard 
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
 2022-12-01 16:22:06 +01:00
Matthias Goergens
710bb68c2e hugetlb_encode.h: fix undefined behaviour (34 << 26) 
Left-shifting past the size of your datatype is undefined behaviour in C. 
The literal 34 gets the type `int`, and that one is not big enough to be
left shifted by 26 bits.

An `unsigned` is long enough (on any machine that has at least 32 bits for
their ints.)

For uniformity, we mark all the literals as unsigned.  But it's only
really needed for HUGETLB_FLAG_ENCODE_16GB.

Thanks to Randy Dunlap for an initial review and suggestion.

Link: https://lkml.kernel.org/r/20220905031904.150925-1-matthias.goergens@gmail.com
Signed-off-by: Matthias Goergens <matthias.goergens@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2022-10-03 14:02:55 -07:00
Zach O'Keefe
7d8faaf155 mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse 
This idea was introduced by David Rientjes[1].

Introduce a new madvise mode, MADV_COLLAPSE, that allows users to request
a synchronous collapse of memory at their own expense.

The benefits of this approach are:

* CPU is charged to the process that wants to spend the cycles for the
  THP
* Avoid unpredictable timing of khugepaged collapse

Semantics

This call is independent of the system-wide THP sysfs settings, but will
fail for memory marked VM_NOHUGEPAGE.  If the ranges provided span
multiple VMAs, the semantics of the collapse over each VMA is independent
from the others.  This implies a hugepage cannot cross a VMA boundary.  If
collapse of a given hugepage-aligned/sized region fails, the operation may
continue to attempt collapsing the remainder of memory specified.

The memory ranges provided must be page-aligned, but are not required to
be hugepage-aligned.  If the memory ranges are not hugepage-aligned, the
start/end of the range will be clamped to the first/last hugepage-aligned
address covered by said range.  The memory ranges must span at least one
hugepage-sized region.

All non-resident pages covered by the range will first be
swapped/faulted-in, before being internally copied onto a freshly
allocated hugepage.  Unmapped pages will have their data directly
initialized to 0 in the new hugepage.  However, for every eligible
hugepage aligned/sized region to-be collapsed, at least one page must
currently be backed by memory (a PMD covering the address range must
already exist).

Allocation for the new hugepage may enter direct reclaim and/or
compaction, regardless of VMA flags.  When the system has multiple NUMA
nodes, the hugepage will be allocated from the node providing the most
native pages.  This operation operates on the current state of the
specified process and makes no persistent changes or guarantees on how
pages will be mapped, constructed, or faulted in the future

Return Value

If all hugepage-sized/aligned regions covered by the provided range were
either successfully collapsed, or were already PMD-mapped THPs, this
operation will be deemed successful.  On success, process_madvise(2)
returns the number of bytes advised, and madvise(2) returns 0.  Else, -1
is returned and errno is set to indicate the error for the most-recently
attempted hugepage collapse.  Note that many failures might have occurred,
since the operation may continue to collapse in the event a single
hugepage-sized/aligned region fails.

	ENOMEM	Memory allocation failed or VMA not found
	EBUSY	Memcg charging failed
	EAGAIN	Required resource temporarily unavailable.  Try again
		might succeed.
	EINVAL	Other error: No PMD found, subpage doesn't have Present
		bit set, "Special" page no backed by struct page, VMA
		incorrectly sized, address not page-aligned, ...

Most notable here is ENOMEM and EBUSY (new to madvise) which are intended
to provide the caller with actionable feedback so they may take an
appropriate fallback measure.

Use Cases

An immediate user of this new functionality are malloc() implementations
that manage memory in hugepage-sized chunks, but sometimes subrelease
memory back to the system in native-sized chunks via MADV_DONTNEED;
zapping the pmd.  Later, when the memory is hot, the implementation could
madvise(MADV_COLLAPSE) to re-back the memory by THPs to regain hugepage
coverage and dTLB performance.  TCMalloc is such an implementation that
could benefit from this[2].

Only privately-mapped anon memory is supported for now, but additional
support for file, shmem, and HugeTLB high-granularity mappings[2] is
expected.  File and tmpfs/shmem support would permit:

* Backing executable text by THPs.  Current support provided by
  CONFIG_READ_ONLY_THP_FOR_FS may take a long time on a large system which
  might impair services from serving at their full rated load after
  (re)starting.  Tricks like mremap(2)'ing text onto anonymous memory to
  immediately realize iTLB performance prevents page sharing and demand
  paging, both of which increase steady state memory footprint.  With
  MADV_COLLAPSE, we get the best of both worlds: Peak upfront performance
  and lower RAM footprints.
* Backing guest memory by hugapages after the memory contents have been
  migrated in native-page-sized chunks to a new host, in a
  userfaultfd-based live-migration stack.

[1] https://lore.kernel.org/linux-mm/d098c392-273a-36a4-1a29-59731cdf5d3d@google.com/
[2] https://github.com/google/tcmalloc/tree/master/tcmalloc

[jrdr.linux@gmail.com: avoid possible memory leak in failure path]
  Link: https://lkml.kernel.org/r/20220713024109.62810-1-jrdr.linux@gmail.com
[zokeefe@google.com add missing kfree() to madvise_collapse()]
  Link: https://lore.kernel.org/linux-mm/20220713024109.62810-1-jrdr.linux@gmail.com/
  Link: https://lkml.kernel.org/r/20220713161851.1879439-1-zokeefe@google.com
[zokeefe@google.com: delay computation of hpage boundaries until use]]
  Link: https://lkml.kernel.org/r/20220720140603.1958773-4-zokeefe@google.com
Link: https://lkml.kernel.org/r/20220706235936.2197195-10-zokeefe@google.com
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: "Souptick Joarder (HPE)" <jrdr.linux@gmail.com>
Suggested-by: David Rientjes <rientjes@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2022-09-11 20:25:46 -07:00