Commit Graph

130 Commits

Author SHA1 Message Date
Linus Torvalds
5b0ed59649 for-6.3/block-2023-02-16
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmPvfncQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpob2EADXJxcr2jjYHm/7cjKkyuVX8fr80dNdMeuY
 JFdsjG1k6Uj73BVhQQWYTcs/PsrWBHWRsv6uz4WgOELj55eXmf5Q0kJszyUeJW33
 /DjqLvtoppVcYf80xE13wKvCfn73BjwQo6xkGM0qAYn15eaXiD/Ax3xC6eJlsBeK
 PEw7EJyhacbSxZa/1D2B6+mqII1jUQWProTCc3udZ4JHi3WvdWa3Rda0qCqHl4a1
 +K2aP2YTFIRPxBzfMNa/CafWVIFubTdht+4Ds6R60RImzB9e0VUBfcsiUyW5Zg7L
 Fwv7ptXuWrALwVNdW56Oz1QikBxn2pdRR2HMLwKJW1MD8kP9r8LMm2jV5Rhiwe0B
 OQsGRYkOzBvw+bxeP5fvk0iPGVMz6ActH4gkraA5QdLqayDaFYOadlhqz0uRo5SH
 Fb42Vl658K/MHDSIk8U58TNkmrsIJsBGohXI9DOGINPPvv3XOPi4Q1HmXkGRmii0
 y+lNU/QEGh7xXXew29SPP76uQpQaYfC7NxXCMw/OpOMwehzjsjshmM2lpxi8zsgt
 PJUmfHv5qxCplNmTJXmUpmX7sS7550HUdu9FJb13DM+gzKg8bk9jWVuLrzqrVlG5
 1hKWEl1+heg1heRfaIuJVLbPI0au6Sb4uqhih/PHyrP9TWIoAruDbDJM65GKTxyE
 2uEgcHzHQw==
 =poRc
 -----END PGP SIGNATURE-----

Merge tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe updates via Christoph:
      - Small improvements to the logging functionality (Amit Engel)
      - Authentication cleanups (Hannes Reinecke)
      - Cleanup and optimize the DMA mapping cod in the PCIe driver
        (Keith Busch)
      - Work around the command effects for Format NVM (Keith Busch)
      - Misc cleanups (Keith Busch, Christoph Hellwig)
      - Fix and cleanup freeing single sgl (Keith Busch)

 - MD updates via Song:
      - Fix a rare crash during the takeover process
      - Don't update recovery_cp when curr_resync is ACTIVE
      - Free writes_pending in md_stop
      - Change active_io to percpu

 - Updates to drbd, inching us closer to unifying the out-of-tree driver
   with the in-tree one (Andreas, Christoph, Lars, Robert)

 - BFQ update adding support for multi-actuator drives (Paolo, Federico,
   Davide)

 - Make brd compliant with REQ_NOWAIT (me)

 - Fix for IOPOLL and queue entering, fixing stalled IO waiting on
   timeouts (me)

 - Fix for REQ_NOWAIT with multiple bios (me)

 - Fix memory leak in blktrace cleanup (Greg)

 - Clean up sbitmap and fix a potential hang (Kemeng)

 - Clean up some bits in BFQ, and fix a bug in the request injection
   (Kemeng)

 - Clean up the request allocation and issue code, and fix some bugs
   related to that (Kemeng)

 - ublk updates and fixes:
      - Add support for unprivileged ublk (Ming)
      - Improve device deletion handling (Ming)
      - Misc (Liu, Ziyang)

 - s390 dasd fixes (Alexander, Qiheng)

 - Improve utility of request caching and fixes (Anuj, Xiao)

 - zoned cleanups (Pankaj)

 - More constification for kobjs (Thomas)

 - blk-iocost cleanups (Yu)

 - Remove bio splitting from drivers that don't need it (Christoph)

 - Switch blk-cgroups to use struct gendisk. Some of this is now
   incomplete as select late reverts were done. (Christoph)

 - Add bvec initialization helpers, and convert callers to use that
   rather than open-coding it (Christoph)

 - Misc fixes and cleanups (Jinke, Keith, Arnd, Bart, Li, Martin,
   Matthew, Ulf, Zhong)

* tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux: (169 commits)
  brd: use radix_tree_maybe_preload instead of radix_tree_preload
  block: use proper return value from bio_failfast()
  block: bio-integrity: Copy flags when bio_integrity_payload is cloned
  block: Fix io statistics for cgroup in throttle path
  brd: mark as nowait compatible
  brd: check for REQ_NOWAIT and set correct page allocation mask
  brd: return 0/-error from brd_insert_page()
  block: sync mixed merged request's failfast with 1st bio's
  Revert "blk-cgroup: pin the gendisk in struct blkcg_gq"
  Revert "blk-cgroup: pass a gendisk to blkg_lookup"
  Revert "blk-cgroup: delay blk-cgroup initialization until add_disk"
  Revert "blk-cgroup: delay calling blkcg_exit_disk until disk_release"
  Revert "blk-cgroup: move the cgroup information to struct gendisk"
  nvme-pci: remove iod use_sgls
  nvme-pci: fix freeing single sgl
  block: ublk: check IO buffer based on flag need_get_data
  s390/dasd: Fix potential memleak in dasd_eckd_init()
  s390/dasd: sort out physical vs virtual pointers usage
  block: Remove the ALLOC_CACHE_SLACK constant
  block: make kobj_type structures constant
  ...
2023-02-20 14:27:21 -08:00
Linus Torvalds
05e6295f7b fs.idmapped.v6.3
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCY+5NlQAKCRCRxhvAZXjc
 orOaAP9i2h3OJy95nO2Fpde0Bt2UT+oulKCCcGlvXJ8/+TQpyQD/ZQq47gFQ0EAz
 Br5NxeyGeecAb0lHpFz+CpLGsxMrMwQ=
 =+BG5
 -----END PGP SIGNATURE-----

Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull vfs idmapping updates from Christian Brauner:

 - Last cycle we introduced the dedicated struct mnt_idmap type for
   mount idmapping and the required infrastucture in 256c8aed2b ("fs:
   introduce dedicated idmap type for mounts"). As promised in last
   cycle's pull request message this converts everything to rely on
   struct mnt_idmap.

   Currently we still pass around the plain namespace that was attached
   to a mount. This is in general pretty convenient but it makes it easy
   to conflate namespaces that are relevant on the filesystem with
   namespaces that are relevant on the mount level. Especially for
   non-vfs developers without detailed knowledge in this area this was a
   potential source for bugs.

   This finishes the conversion. Instead of passing the plain namespace
   around this updates all places that currently take a pointer to a
   mnt_userns with a pointer to struct mnt_idmap.

   Now that the conversion is done all helpers down to the really
   low-level helpers only accept a struct mnt_idmap argument instead of
   two namespace arguments.

   Conflating mount and other idmappings will now cause the compiler to
   complain loudly thus eliminating the possibility of any bugs. This
   makes it impossible for filesystem developers to mix up mount and
   filesystem idmappings as they are two distinct types and require
   distinct helpers that cannot be used interchangeably.

   Everything associated with struct mnt_idmap is moved into a single
   separate file. With that change no code can poke around in struct
   mnt_idmap. It can only be interacted with through dedicated helpers.
   That means all filesystems are and all of the vfs is completely
   oblivious to the actual implementation of idmappings.

   We are now also able to extend struct mnt_idmap as we see fit. For
   example, we can decouple it completely from namespaces for users that
   don't require or don't want to use them at all. We can also extend
   the concept of idmappings so we can cover filesystem specific
   requirements.

   In combination with the vfs{g,u}id_t work we finished in v6.2 this
   makes this feature substantially more robust and thus difficult to
   implement wrong by a given filesystem and also protects the vfs.

 - Enable idmapped mounts for tmpfs and fulfill a longstanding request.

   A long-standing request from users had been to make it possible to
   create idmapped mounts for tmpfs. For example, to share the host's
   tmpfs mount between multiple sandboxes. This is a prerequisite for
   some advanced Kubernetes cases. Systemd also has a range of use-cases
   to increase service isolation. And there are more users of this.

   However, with all of the other work going on this was way down on the
   priority list but luckily someone other than ourselves picked this
   up.

   As usual the patch is tiny as all the infrastructure work had been
   done multiple kernel releases ago. In addition to all the tests that
   we already have I requested that Rodrigo add a dedicated tmpfs
   testsuite for idmapped mounts to xfstests. It is to be included into
   xfstests during the v6.3 development cycle. This should add a slew of
   additional tests.

* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
  shmem: support idmapped mounts for tmpfs
  fs: move mnt_idmap
  fs: port vfs{g,u}id helpers to mnt_idmap
  fs: port fs{g,u}id helpers to mnt_idmap
  fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
  fs: port i_{g,u}id_{needs_}update() to mnt_idmap
  quota: port to mnt_idmap
  fs: port privilege checking helpers to mnt_idmap
  fs: port inode_owner_or_capable() to mnt_idmap
  fs: port inode_init_owner() to mnt_idmap
  fs: port acl to mnt_idmap
  fs: port xattr to mnt_idmap
  fs: port ->permission() to pass mnt_idmap
  fs: port ->fileattr_set() to pass mnt_idmap
  fs: port ->set_acl() to pass mnt_idmap
  fs: port ->get_acl() to pass mnt_idmap
  fs: port ->tmpfile() to pass mnt_idmap
  fs: port ->rename() to pass mnt_idmap
  fs: port ->mknod() to pass mnt_idmap
  fs: port ->mkdir() to pass mnt_idmap
  ...
2023-02-20 11:53:11 -08:00
Christoph Hellwig
cd59800320 coredump: use bvec_set_page to initialize a bvec
Use the bvec_set_page helper to initialize a bvec.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230203150634.3199647-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-03 10:17:42 -07:00
Christian Brauner
e67fe63341
fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
Convert to struct mnt_idmap.
Remove legacy file_mnt_user_ns() and mnt_user_ns().

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:29 +01:00
Christian Brauner
abf08576af
fs: port vfs_*() helpers to struct mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-18 17:51:45 +01:00
Geert Uytterhoeven
9c7417b5ec coredump: Move dump_emit_page() to kill unused warning
If CONFIG_ELF_CORE is not set:

    fs/coredump.c:835:12: error: ‘dump_emit_page’ defined but not used [-Werror=unused-function]
      835 | static int dump_emit_page(struct coredump_params *cprm, struct page *page)
          |            ^~~~~~~~~~~~~~

Fix this by moving dump_emit_page() inside the existing section
protected by #ifdef CONFIG_ELF_CORE.

Fixes: 06bbaa6dc5 ("[coredump] don't use __kernel_write() on kmap_local_page()")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-01-10 21:03:01 -05:00
Linus Torvalds
48ea09cdda hardening updates for v6.2-rc1
- Convert flexible array members, fix -Wstringop-overflow warnings,
   and fix KCFI function type mismatches that went ignored by
   maintainers (Gustavo A. R. Silva, Nathan Chancellor, Kees Cook).
 
 - Remove the remaining side-effect users of ksize() by converting
   dma-buf, btrfs, and coredump to using kmalloc_size_roundup(),
   add more __alloc_size attributes, and introduce full testing
   of all allocator functions. Finally remove the ksize() side-effect
   so that each allocation-aware checker can finally behave without
   exceptions.
 
 - Introduce oops_limit (default 10,000) and warn_limit (default off)
   to provide greater granularity of control for panic_on_oops and
   panic_on_warn (Jann Horn, Kees Cook).
 
 - Introduce overflows_type() and castable_to_type() helpers for
   cleaner overflow checking.
 
 - Improve code generation for strscpy() and update str*() kern-doc.
 
 - Convert strscpy and sigphash tests to KUnit, and expand memcpy
   tests.
 
 - Always use a non-NULL argument for prepare_kernel_cred().
 
 - Disable structleak plugin in FORTIFY KUnit test (Anders Roxell).
 
 - Adjust orphan linker section checking to respect CONFIG_WERROR
   (Xin Li).
 
 - Make sure siginfo is cleared for forced SIGKILL (haifeng.xu).
 
 - Fix um vs FORTIFY warnings for always-NULL arguments.
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmOZSOoWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJjAAD/0YkvpU7f03f8hcQMJK6wv//24K
 AW41hEaBikq9RcmkuvkLLrJRibGgZ5O2xUkUkxRs/HxhkhrZ0kEw8sbwZe8MoWls
 F4Y9+TDjsrdHmjhfcBZdLnVxwcKK5wlaEcpjZXtbsfcdhx3TbgcDA23YELl5t0K+
 I11j4kYmf9SLl4CwIrSP5iACml8CBHARDh8oIMF7FT/LrjNbM8XkvBcVVT6hTbOV
 yjgA8WP2e9GXvj9GzKgqvd0uE/kwPkVAeXLNFWopPi4FQ8AWjlxbBZR0gamA6/EB
 d7TIs0ifpVU2JGQaTav4xO6SsFMj3ntoUI0qIrFaTxZAvV4KYGrPT/Kwz1O4SFaG
 rN5lcxseQbPQSBTFNG4zFjpywTkVCgD2tZqDwz5Rrmiraz0RyIokCN+i4CD9S0Ds
 oEd8JSyLBk1sRALczkuEKo0an5AyC9YWRcBXuRdIHpLo08PsbeUUSe//4pe303cw
 0ApQxYOXnrIk26MLElTzSMImlSvlzW6/5XXzL9ME16leSHOIfDeerPnc9FU9Eb3z
 ODv22z6tJZ9H/apSUIHZbMciMbbVTZ8zgpkfydr08o87b342N/ncYHZ5cSvQ6DWb
 jS5YOIuvl46/IhMPT16qWC8p0bP5YhxoPv5l6Xr0zq0ooEj0E7keiD/SzoLvW+Qs
 AHXcibguPRQBPAdiPQ==
 =yaaN
 -----END PGP SIGNATURE-----

Merge tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull kernel hardening updates from Kees Cook:

 - Convert flexible array members, fix -Wstringop-overflow warnings, and
   fix KCFI function type mismatches that went ignored by maintainers
   (Gustavo A. R. Silva, Nathan Chancellor, Kees Cook)

 - Remove the remaining side-effect users of ksize() by converting
   dma-buf, btrfs, and coredump to using kmalloc_size_roundup(), add
   more __alloc_size attributes, and introduce full testing of all
   allocator functions. Finally remove the ksize() side-effect so that
   each allocation-aware checker can finally behave without exceptions

 - Introduce oops_limit (default 10,000) and warn_limit (default off) to
   provide greater granularity of control for panic_on_oops and
   panic_on_warn (Jann Horn, Kees Cook)

 - Introduce overflows_type() and castable_to_type() helpers for cleaner
   overflow checking

 - Improve code generation for strscpy() and update str*() kern-doc

 - Convert strscpy and sigphash tests to KUnit, and expand memcpy tests

 - Always use a non-NULL argument for prepare_kernel_cred()

 - Disable structleak plugin in FORTIFY KUnit test (Anders Roxell)

 - Adjust orphan linker section checking to respect CONFIG_WERROR (Xin
   Li)

 - Make sure siginfo is cleared for forced SIGKILL (haifeng.xu)

 - Fix um vs FORTIFY warnings for always-NULL arguments

* tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (31 commits)
  ksmbd: replace one-element arrays with flexible-array members
  hpet: Replace one-element array with flexible-array member
  um: virt-pci: Avoid GCC non-NULL warning
  signal: Initialize the info in ksignal
  lib: fortify_kunit: build without structleak plugin
  panic: Expose "warn_count" to sysfs
  panic: Introduce warn_limit
  panic: Consolidate open-coded panic_on_warn checks
  exit: Allow oops_limit to be disabled
  exit: Expose "oops_count" to sysfs
  exit: Put an upper limit on how often we can oops
  panic: Separate sysctl logic from CONFIG_SMP
  mm/pgtable: Fix multiple -Wstringop-overflow warnings
  mm: Make ksize() a reporting-only function
  kunit/fortify: Validate __alloc_size attribute results
  drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid()
  drm/fsl-dcu: Fix return type of fsl_dcu_drm_connector_mode_valid()
  driver core: Add __alloc_size hint to devm allocators
  overflow: Introduce overflows_type() and castable_to_type()
  coredump: Proactively round up to kmalloc bucket size
  ...
2022-12-14 12:20:00 -08:00
Linus Torvalds
e1212e9b6f fs.vfsuid.conversion.v6.2
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCY5bspgAKCRCRxhvAZXjc
 opEWAQDpF5rnZn1vv4/uOTij9ztcA4yLxu/Q19CdqBaoHlWZ9AD/d3eecee3bh5h
 iPHtlUK5/VspfD9LPpdc5ZbPCdZ2pA4=
 =t6NN
 -----END PGP SIGNATURE-----

Merge tag 'fs.vfsuid.conversion.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull vfsuid updates from Christian Brauner:
 "Last cycle we introduced the vfs{g,u}id_t types and associated helpers
  to gain type safety when dealing with idmapped mounts. That initial
  work already converted a lot of places over but there were still some
  left,

  This converts all remaining places that still make use of non-type
  safe idmapping helpers to rely on the new type safe vfs{g,u}id based
  helpers.

  Afterwards it removes all the old non-type safe helpers"

* tag 'fs.vfsuid.conversion.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping:
  fs: remove unused idmapping helpers
  ovl: port to vfs{g,u}id_t and associated helpers
  fuse: port to vfs{g,u}id_t and associated helpers
  ima: use type safe idmapping helpers
  apparmor: use type safe idmapping helpers
  caps: use type safe idmapping helpers
  fs: use type safe idmapping helpers
  mnt_idmapping: add missing helpers
2022-12-12 19:20:05 -08:00
Linus Torvalds
75f4d9af8b iov_iter work; most of that is about getting rid of
direction misannotations and (hopefully) preventing
 more of the same for the future.
 
 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
 -----BEGIN PGP SIGNATURE-----
 
 iHQEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCY5ZzQAAKCRBZ7Krx/gZQ
 65RZAP4nTkvOn0NZLVFkuGOx8pgJelXAvrteyAuecVL8V6CR4AD40qCVY51PJp8N
 MzwiRTeqnGDxTTF7mgd//IB6hoatAA==
 =bcvF
 -----END PGP SIGNATURE-----

Merge tag 'pull-iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull iov_iter updates from Al Viro:
 "iov_iter work; most of that is about getting rid of direction
  misannotations and (hopefully) preventing more of the same for the
  future"

* tag 'pull-iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  use less confusing names for iov_iter direction initializers
  iov_iter: saner checks for attempt to copy to/from iterator
  [xen] fix "direction" argument of iov_iter_kvec()
  [vhost] fix 'direction' argument of iov_iter_{init,bvec}()
  [target] fix iov_iter_bvec() "direction" argument
  [s390] memcpy_real(): WRITE is "data source", not destination...
  [s390] zcore: WRITE is "data source", not destination...
  [infiniband] READ is "data destination", not source...
  [fsi] WRITE is "data source", not destination...
  [s390] copy_oldmem_kernel() - WRITE is "data source", not destination
  csum_and_copy_to_iter(): handle ITER_DISCARD
  get rid of unlikely() on page_copy_sane() calls
2022-12-12 18:29:54 -08:00
Linus Torvalds
405b2fc663 Unification of regset and non-regset sides of ELF coredump
handling.  Collecting per-thread register values is the
 only thing that needs to be ifdefed there...
 
 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCY5ZyNgAKCRBZ7Krx/gZQ
 63MZAQDZDE9Pk9EQ/3qOPNb2cuz8KSB3THUyotvustUUGPTUVAD/Ut1xD03jpWCY
 oQ6tM8dNyh3+Vsx6/XKNd1+pj6IgNQE=
 =XYkZ
 -----END PGP SIGNATURE-----

Merge tag 'pull-elfcore' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull elf coredumping updates from Al Viro:
 "Unification of regset and non-regset sides of ELF coredump handling.

  Collecting per-thread register values is the only thing that needs to
  be ifdefed there..."

* tag 'pull-elfcore' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  [elf] get rid of get_note_info_size()
  [elf] unify regset and non-regset cases
  [elf][non-regset] use elf_core_copy_task_regs() for dumper as well
  [elf][non-regset] uninline elf_core_copy_task_fpregs() (and lose pt_regs argument)
  elf_core_copy_task_regs(): task_pt_regs is defined everywhere
  [elf][regset] simplify thread list handling in fill_note_info()
  [elf][regset] clean fill_note_info() a bit
  kill extern of vsyscall32_sysctl
  kill coredump_params->regs
  kill signal_pt_regs()
2022-12-12 18:18:34 -08:00
Al Viro
de4eda9de2 use less confusing names for iov_iter direction initializers
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-11-25 13:01:55 -05:00
Oleksandr Natalenko
8603b6f586 core_pattern: add CPU specifier
Statistically, in a large deployment regular segfaults may indicate a CPU
issue.

Currently, it is not possible to find out what CPU the segfault happened
on.  There are at least two attempts to improve segfault logging with this
regard, but they do not help in case the logs rotate.

Hence, lets make sure it is possible to permanently record a CPU the task
ran on using a new core_pattern specifier.

Link: https://lkml.kernel.org/r/20220903064330.20772-1-oleksandr@redhat.com
Signed-off-by: Oleksandr Natalenko <oleksandr@redhat.com>
Suggested-by: Renaud Métrich <rmetrich@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Grzegorz Halat <ghalat@redhat.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Joel Savitz <jsavitz@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Will Deacon <will@kernel.org>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-18 13:55:06 -08:00
Kees Cook
6dd142d901 coredump: Proactively round up to kmalloc bucket size
Instead of discovering the kmalloc bucket size _after_ allocation, round
up proactively so the allocation is explicitly made for the full size,
allowing the compiler to correctly reason about the resulting size of
the buffer through the existing __alloc_size() hint.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-11-01 10:04:52 -07:00
Christian Brauner
a2bd096fb2
fs: use type safe idmapping helpers
We already ported most parts and filesystems over for v6.0 to the new
vfs{g,u}id_t type and associated helpers for v6.0. Convert the remaining
places so we can remove all the old helpers.
This is a non-functional change.

Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-26 10:02:34 +02:00
Al Viro
9a938eba8d kill coredump_params->regs
it's always task_pt_regs(current)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-10-23 18:06:55 -04:00
Al Viro
6a542d1d5f kill signal_pt_regs()
Once upon at it was used on hot paths, but that had not been
true since 2013.  IOW, there's no point for arch-optimized
equivalent of task_pt_regs(current) - remaining two users are
not worth bothering with.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-10-23 18:06:54 -04:00
Linus Torvalds
27bc50fc90 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative
   reports (or any positive ones, come to that).
 
 - Also the Maple Tree from Liam R.  Howlett.  An overlapping range-based
   tree for vmas.  It it apparently slight more efficient in its own right,
   but is mainly targeted at enabling work to reduce mmap_lock contention.
 
   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.
 
   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
   This has yet to be addressed due to Liam's unfortunately timed
   vacation.  He is now back and we'll get this fixed up.
 
 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer.  It uses
   clang-generated instrumentation to detect used-unintialized bugs down to
   the single bit level.
 
   KMSAN keeps finding bugs.  New ones, as well as the legacy ones.
 
 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.
 
 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
   file/shmem-backed pages.
 
 - userfaultfd updates from Axel Rasmussen
 
 - zsmalloc cleanups from Alexey Romanov
 
 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
 
 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.
 
 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.
 
 - memcg cleanups from Kairui Song.
 
 - memcg fixes and cleanups from Johannes Weiner.
 
 - Vishal Moola provides more folio conversions
 
 - Zhang Yi removed ll_rw_block() :(
 
 - migration enhancements from Peter Xu
 
 - migration error-path bugfixes from Huang Ying
 
 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths.  For optimizations by PMEM drivers, DRM
   drivers, etc.
 
 - vma merging improvements from Jakub Matěn.
 
 - NUMA hinting cleanups from David Hildenbrand.
 
 - xu xin added aditional userspace visibility into KSM merging activity.
 
 - THP & KSM code consolidation from Qi Zheng.
 
 - more folio work from Matthew Wilcox.
 
 - KASAN updates from Andrey Konovalov.
 
 - DAMON cleanups from Kaixu Xia.
 
 - DAMON work from SeongJae Park: fixes, cleanups.
 
 - hugetlb sysfs cleanups from Muchun Song.
 
 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY0HaPgAKCRDdBJ7gKXxA
 joPjAQDZ5LlRCMWZ1oxLP2NOTp6nm63q9PWcGnmY50FjD/dNlwEAnx7OejCLWGWf
 bbTuk6U2+TKgJa4X7+pbbejeoqnt5QU=
 =xfWx
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
2022-10-10 17:53:04 -07:00
Linus Torvalds
30c999937f Scheduler changes for v6.1:
- Debuggability:
 
      - Change most occurances of BUG_ON() to WARN_ON_ONCE()
 
      - Reorganize & fix TASK_ state comparisons, turn it into a bitmap
 
      - Update/fix misc scheduler debugging facilities
 
  - Load-balancing & regular scheduling:
 
      - Improve the behavior of the scheduler in presence of lot of
        SCHED_IDLE tasks - in particular they should not impact other
        scheduling classes.
 
      - Optimize task load tracking, cleanups & fixes
 
      - Clean up & simplify misc load-balancing code
 
  - Freezer:
 
      - Rewrite the core freezer to behave better wrt thawing and be simpler
        in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting
        all the fallout.
 
  - Deadline scheduler:
 
      - Fix the DL capacity-aware code
 
      - Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period()
 
      - Relax/optimize locking in task_non_contending()
 
  - Cleanups:
 
      - Factor out the update_current_exec_runtime() helper
 
      - Various cleanups, simplifications
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmM/01cRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1geZA/+PB4KC1T9aVxzaTHI36R03YgJYZmIdtxw
 wTf02MixePmz+gQCbepJbempGOh5ST28aOcI0xhdYOql5B63MaUBBMlB0HvGUyDG
 IU3zETqLMRtAbnSTdQFv8m++ECUtZYp8/x1FCel4WO7ya4ETkRu1NRfCoUepEhpZ
 aVAlae9LH3NBaF9t7s0PT2lTjf3pIzMFRkddJ0ywJhbFR3VnWat05fAK+J6fGY8+
 LS54coefNlJD4oDh5TY8uniL1j5SmWmmwbk9Cdj7bLU5P3dFSS0/+5FJNHJPVGDE
 srGT7wstRUcDrN0CnZo48VIUBiApJCCDqTfJYi9wNYd0NAHvwY6MIJJgEIY8mKsI
 L/qH26H81Wt+ezSZ/5JIlGlZ/LIeNaa6OO/fbWEYABBQogvvx3nxsRNUYKSQzumH
 CnSBasBjLnjWyLlK4qARM9cI7NFSEK6NUigrEx/7h8JFu/8T4DlSy6LsF1HUyKgq
 4+FJLAqG6cL0tcwB/fHYd0oRESN8dStnQhGxSojgufwLc7dlFULvCYF5JM/dX+/V
 IKwbOfIOeOn6ViMtSOXAEGdII+IQ2/ZFPwr+8Z5JC7NzvTVL6xlu/3JXkLZR3L7o
 yaXTSaz06h1vil7Z+GRf7RHc+wUeGkEpXh5vnarGZKXivhFdWsBdROIJANK+xR0i
 TeSLCxQxXlU=
 =KjMD
 -----END PGP SIGNATURE-----

Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Debuggability:

   - Change most occurances of BUG_ON() to WARN_ON_ONCE()

   - Reorganize & fix TASK_ state comparisons, turn it into a bitmap

   - Update/fix misc scheduler debugging facilities

  Load-balancing & regular scheduling:

   - Improve the behavior of the scheduler in presence of lot of
     SCHED_IDLE tasks - in particular they should not impact other
     scheduling classes.

   - Optimize task load tracking, cleanups & fixes

   - Clean up & simplify misc load-balancing code

  Freezer:

   - Rewrite the core freezer to behave better wrt thawing and be
     simpler in general, by replacing PF_FROZEN with TASK_FROZEN &
     fixing/adjusting all the fallout.

  Deadline scheduler:

   - Fix the DL capacity-aware code

   - Factor out dl_task_is_earliest_deadline() &
     replenish_dl_new_period()

   - Relax/optimize locking in task_non_contending()

  Cleanups:

   - Factor out the update_current_exec_runtime() helper

   - Various cleanups, simplifications"

* tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  sched: Fix more TASK_state comparisons
  sched: Fix TASK_state comparisons
  sched/fair: Move call to list_last_entry() in detach_tasks
  sched/fair: Cleanup loop_max and loop_break
  sched/fair: Make sure to try to detach at least one movable task
  sched: Show PF_flag holes
  freezer,sched: Rewrite core freezer logic
  sched: Widen TAKS_state literals
  sched/wait: Add wait_event_state()
  sched/completion: Add wait_for_completion_state()
  sched: Add TASK_ANY for wait_task_inactive()
  sched: Change wait_task_inactive()s match_state
  freezer,umh: Clean up freezer/initrd interaction
  freezer: Have {,un}lock_system_sleep() save/restore flags
  sched: Rename task_running() to task_on_cpu()
  sched/fair: Cleanup for SIS_PROP
  sched/fair: Default to false in test_idle_cores()
  sched/fair: Remove useless check in select_idle_core()
  sched/fair: Avoid double search on same cpu
  sched/fair: Remove redundant check in select_idle_smt()
  ...
2022-10-10 09:10:28 -07:00
Linus Torvalds
e572410e47 ptrace: Stop supporting SIGKILL for PTRACE_EVENT_EXIT
Recently I had a conversation where it was pointed out to me that
 SIGKILL sent to a tracee stropped in PTRACE_EVENT_EXIT is quite
 difficult for a tracer to handle.
 
 Keeping SIGKILL working after the process has been killed is pain
 from an implementation point of view.
 
 So since the debuggers don't want this behavior let's see if we can
 remove this wart for the userspace API
 
 If a regression is detected it should only need to be the last change
 that is the reverted.  The other two are just general cleanups that
 make the last patch simpler.
 
 Eric W. Biederman (3):
       signal: Ensure SIGNAL_GROUP_EXIT gets set in do_group_exit
       signal: Guarantee that SIGNAL_GROUP_EXIT is set on process exit
       signal: Drop signals received after a fatal signal has been processed
 
  fs/coredump.c                |  2 +-
  include/linux/sched/signal.h |  1 +
  kernel/exit.c                | 20 +++++++++++++++++++-
  kernel/fork.c                |  2 ++
  kernel/signal.c              |  3 ++-
  5 files changed, 25 insertions(+), 3 deletions(-)
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEgjlraLDcwBA2B+6cC/v6Eiajj0AFAmM7U40ACgkQC/v6Eiaj
 j0B7eRAAst6EW4nkxiDBN/PRo43Kz7tkYCZGLAq73vZAaKkyTFSwghT85cZwTsuc
 px/iDPWZpSGdIeHhdt1giJeuFG0FuoMR9prQVx3z/fM6KLXEJb86OtW1c1uW00Bh
 TkhVPQiF/9bc+Eb/nRKF61NA4sP0OXwO1+t/zBL4clekO9vFLP1DpRBE9OrNlHq2
 NlDqoPqq6SsKYG8f+J2LJKKzRWLICvHCtz4uUt6O11Wt/PH2TZYdYnXf/2vvZyzS
 SOs8kQjw4QPSptcNH/LIZz0WNHagn1uU/2/T106LOgPgcr515T4MhqOK+Wp95BjA
 0RrhsfdMD+7HArqLmt9VKgKO9Gs+T/M6jQZgpUyzlw3qPorKUGu4s9UnUgS7l4uz
 oNV9no1Ei2fQ+YR6RBR74579a45FWkqRBsaia59KFCzZxRsQz8VB1cqcIgl9dFUA
 f81qt9FiX8duVYZIcoT79BvV1bQ3LGwyygrH+X3sDTQSdN/aeZ24JdGP2MNtYO/c
 jWN/mMVHc1xOsYmACVGETWhZf0Y7lGGBYSIJ92jT2HxIuEiqmFE4kngRjKcYgL/G
 1/o9z8VntMq5t+ZcQY5WfK/WpSeSPXa6TsP80PEm/hvdMwZLEO4IzCR+gPJB6oJS
 KPQ3EZfRCB2Jb1qBmcpbleA/RBA0iJUZtBvtIPI7QmMTR+VRdhc=
 =gX4y
 -----END PGP SIGNATURE-----

Merge tag 'signal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull ptrace update from Eric Biederman:
 "ptrace: Stop supporting SIGKILL for PTRACE_EVENT_EXIT

  Recently I had a conversation where it was pointed out to me that
  SIGKILL sent to a tracee stropped in PTRACE_EVENT_EXIT is quite
  difficult for a tracer to handle.

  Keeping SIGKILL working after the process has been killed is pain from
  an implementation point of view.

  So since the debuggers don't want this behavior let's see if we can
  remove this wart for the userspace API

  If a regression is detected it should only need to be the last change
  that is the reverted. The other two are just general cleanups that
  make the last patch simpler"

* tag 'signal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Drop signals received after a fatal signal has been processed
  signal: Guarantee that SIGNAL_GROUP_EXIT is set on process exit
  signal: Ensure SIGNAL_GROUP_EXIT gets set in do_group_exit
2022-10-09 16:14:15 -07:00
Al Viro
4f526fef91 [brown paperbag] fix coredump breakage
Let me count the ways in which I'd screwed up:

* when emitting a page, handling of gaps in coredump should happen
before fetching the current file position.
* fix for a problem that occurs on rather uncommon setups (and hadn't
been observed in the wild) had been sent very late in the cycle.
* ... with badly insufficient testing, introducing an easily
reproducible breakage.  Without giving it time to soak in -next.

Fucked-up-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: "J. R. Okajima" <hooanon05g@gmail.com>
Tested-by: "J. R. Okajima" <hooanon05g@gmail.com>
Fixes: 06bbaa6dc5 "[coredump] don't use __kernel_write() on kmap_local_page()"
Cc: stable@kernel.org	# v6.0-only
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-10-03 20:28:38 -04:00
Al Viro
06bbaa6dc5 [coredump] don't use __kernel_write() on kmap_local_page()
passing kmap_local_page() result to __kernel_write() is unsafe -
random ->write_iter() might (and 9p one does) get unhappy when
passed ITER_KVEC with pointer that came from kmap_local_page().

Fix by providing a variant of __kernel_write() that takes an iov_iter
from caller (__kernel_write() becomes a trivial wrapper) and adding
dump_emit_page() that parallels dump_emit(), except that instead of
__kernel_write() it uses __kernel_write_iter() with ITER_BVEC source.

Fixes: 3159ed5779 "fs/coredump: use kmap_local_page()"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-09-28 14:28:40 -04:00
Matthew Wilcox (Oracle)
182ea1d717 coredump: remove vma linked list walk
Use the Maple Tree iterator instead.  This is too complicated for the VMA
iterator to handle, so let's open-code it for now.  If this turns out to
be a common pattern, we can migrate it to common code.

Link: https://lkml.kernel.org/r/20220906194824.2110408-41-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:20 -07:00
Peter Zijlstra
f5d39b0208 freezer,sched: Rewrite core freezer logic
Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.

As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).

Specifically; the current scheme works a little like:

	freezer_do_not_count();
	schedule();
	freezer_count();

And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.

However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.

That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.

This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.

As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:

	TASK_FREEZABLE	-> TASK_FROZEN
	__TASK_STOPPED	-> TASK_FROZEN
	__TASK_TRACED	-> TASK_FROZEN

The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).

The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.

With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
2022-09-07 21:53:50 +02:00
Peter Zijlstra
f9fc8cad97 sched: Add TASK_ANY for wait_task_inactive()
Now that wait_task_inactive()'s @match_state argument is a mask (like
ttwu()) it is possible to replace the special !match_state case with
an 'all-states' value such that any blocked state will match.

Suggested-by: Ingo Molnar (mingo@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YxhkzfuFTvRnpUaH@hirez.programming.kicks-ass.net
2022-09-07 21:53:49 +02:00
Eric W. Biederman
9a95f78eab signal: Drop signals received after a fatal signal has been processed
In 403bad72b6 ("coredump: only SIGKILL should interrupt the
coredumping task") Oleg modified the kernel to drop all signals that
come in during a coredump except SIGKILL, and suggested that it might
be a good idea to generalize that to other cases after the process has
received a fatal signal.

Semantically it does not make sense to perform any signal delivery
after the process has already been killed.

When a signal is sent while a process is dying today the signal is
placed in the signal queue by __send_signal and a single task of the
process is woken up with signal_wake_up, if there are any tasks that
have not set PF_EXITING.

Take things one step farther and have prepare_signal report that all
signals that come after a process has been killed should be ignored.
While retaining the historical exception of allowing SIGKILL to
interrupt coredumps.

Update the comment in fs/coredump.c to make it clear coredumps are
special in being able to receive SIGKILL.

This changes things so that a process stopped in PTRACE_EVENT_EXIT can
not be made to escape it's ptracer and finish exiting by sending it
SIGKILL.  That a process can be made to leave PTRACE_EVENT_EXIT and
escape it's tracer by sending the process a SIGKILL has been
complicating tracer's for no apparent advantage.  If the process needs
to be made to leave PTRACE_EVENT_EXIT all that needs to happen is to
kill the proceses's tracer.  This differs from the coredump code where
there is no other mechanism besides honoring SIGKILL to expedite the
end of coredumping.

Link: https://lkml.kernel.org/r/875yksd4s9.fsf_-_@email.froward.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-07-20 10:24:17 -05:00
Jason A. Donenfeld
4e3299eadd fs: do not compare against ->llseek
Now vfs_llseek() can simply check for FMODE_LSEEK; if it's set,
we know that ->llseek() won't be NULL and if it's not we should
just fail with -ESPIPE.

A couple of other places where we used to check for special
values of ->llseek() (somewhat inconsistently) switched to
checking FMODE_LSEEK.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-07-16 09:19:15 -04:00
Linus Torvalds
1930a6e739 ptrace: Cleanups for v5.18
This set of changes removes tracehook.h, moves modification of all of
 the ptrace fields inside of siglock to remove races, adds a missing
 permission check to ptrace.c
 
 The removal of tracehook.h is quite significant as it has been a major
 source of confusion in recent years.  Much of that confusion was
 around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled
 making the semantics clearer).
 
 For people who don't know tracehook.h is a vestiage of an attempt to
 implement uprobes like functionality that was never fully merged, and
 was later superseeded by uprobes when uprobes was merged.  For many
 years now we have been removing what tracehook functionaly a little
 bit at a time.  To the point where now anything left in tracehook.h is
 some weird strange thing that is difficult to understand.
 
 Eric W. Biederman (15):
       ptrace: Move ptrace_report_syscall into ptrace.h
       ptrace/arm: Rename tracehook_report_syscall report_syscall
       ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
       ptrace: Remove arch_syscall_{enter,exit}_tracehook
       ptrace: Remove tracehook_signal_handler
       task_work: Remove unnecessary include from posix_timers.h
       task_work: Introduce task_work_pending
       task_work: Call tracehook_notify_signal from get_signal on all architectures
       task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
       signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
       resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
       resume_user_mode: Move to resume_user_mode.h
       tracehook: Remove tracehook.h
       ptrace: Move setting/clearing ptrace_message into ptrace_stop
       ptrace: Return the signal to continue with from ptrace_stop
 
 Jann Horn (1):
       ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
 
 Yang Li (1):
       ptrace: Remove duplicated include in ptrace.c
 
  MAINTAINERS                          |   1 -
  arch/Kconfig                         |   5 +-
  arch/alpha/kernel/ptrace.c           |   5 +-
  arch/alpha/kernel/signal.c           |   4 +-
  arch/arc/kernel/ptrace.c             |   5 +-
  arch/arc/kernel/signal.c             |   4 +-
  arch/arm/kernel/ptrace.c             |  12 +-
  arch/arm/kernel/signal.c             |   4 +-
  arch/arm64/kernel/ptrace.c           |  14 +--
  arch/arm64/kernel/signal.c           |   4 +-
  arch/csky/kernel/ptrace.c            |   5 +-
  arch/csky/kernel/signal.c            |   4 +-
  arch/h8300/kernel/ptrace.c           |   5 +-
  arch/h8300/kernel/signal.c           |   4 +-
  arch/hexagon/kernel/process.c        |   4 +-
  arch/hexagon/kernel/signal.c         |   1 -
  arch/hexagon/kernel/traps.c          |   6 +-
  arch/ia64/kernel/process.c           |   4 +-
  arch/ia64/kernel/ptrace.c            |   6 +-
  arch/ia64/kernel/signal.c            |   1 -
  arch/m68k/kernel/ptrace.c            |   5 +-
  arch/m68k/kernel/signal.c            |   4 +-
  arch/microblaze/kernel/ptrace.c      |   5 +-
  arch/microblaze/kernel/signal.c      |   4 +-
  arch/mips/kernel/ptrace.c            |   5 +-
  arch/mips/kernel/signal.c            |   4 +-
  arch/nds32/include/asm/syscall.h     |   2 +-
  arch/nds32/kernel/ptrace.c           |   5 +-
  arch/nds32/kernel/signal.c           |   4 +-
  arch/nios2/kernel/ptrace.c           |   5 +-
  arch/nios2/kernel/signal.c           |   4 +-
  arch/openrisc/kernel/ptrace.c        |   5 +-
  arch/openrisc/kernel/signal.c        |   4 +-
  arch/parisc/kernel/ptrace.c          |   7 +-
  arch/parisc/kernel/signal.c          |   4 +-
  arch/powerpc/kernel/ptrace/ptrace.c  |   8 +-
  arch/powerpc/kernel/signal.c         |   4 +-
  arch/riscv/kernel/ptrace.c           |   5 +-
  arch/riscv/kernel/signal.c           |   4 +-
  arch/s390/include/asm/entry-common.h |   1 -
  arch/s390/kernel/ptrace.c            |   1 -
  arch/s390/kernel/signal.c            |   5 +-
  arch/sh/kernel/ptrace_32.c           |   5 +-
  arch/sh/kernel/signal_32.c           |   4 +-
  arch/sparc/kernel/ptrace_32.c        |   5 +-
  arch/sparc/kernel/ptrace_64.c        |   5 +-
  arch/sparc/kernel/signal32.c         |   1 -
  arch/sparc/kernel/signal_32.c        |   4 +-
  arch/sparc/kernel/signal_64.c        |   4 +-
  arch/um/kernel/process.c             |   4 +-
  arch/um/kernel/ptrace.c              |   5 +-
  arch/x86/kernel/ptrace.c             |   1 -
  arch/x86/kernel/signal.c             |   5 +-
  arch/x86/mm/tlb.c                    |   1 +
  arch/xtensa/kernel/ptrace.c          |   5 +-
  arch/xtensa/kernel/signal.c          |   4 +-
  block/blk-cgroup.c                   |   2 +-
  fs/coredump.c                        |   1 -
  fs/exec.c                            |   1 -
  fs/io-wq.c                           |   6 +-
  fs/io_uring.c                        |  11 +-
  fs/proc/array.c                      |   1 -
  fs/proc/base.c                       |   1 -
  include/asm-generic/syscall.h        |   2 +-
  include/linux/entry-common.h         |  47 +-------
  include/linux/entry-kvm.h            |   2 +-
  include/linux/posix-timers.h         |   1 -
  include/linux/ptrace.h               |  81 ++++++++++++-
  include/linux/resume_user_mode.h     |  64 ++++++++++
  include/linux/sched/signal.h         |  17 +++
  include/linux/task_work.h            |   5 +
  include/linux/tracehook.h            | 226 -----------------------------------
  include/uapi/linux/ptrace.h          |   2 +-
  kernel/entry/common.c                |  19 +--
  kernel/entry/kvm.c                   |   9 +-
  kernel/exit.c                        |   3 +-
  kernel/livepatch/transition.c        |   1 -
  kernel/ptrace.c                      |  47 +++++---
  kernel/seccomp.c                     |   1 -
  kernel/signal.c                      |  62 +++++-----
  kernel/task_work.c                   |   4 +-
  kernel/time/posix-cpu-timers.c       |   1 +
  mm/memcontrol.c                      |   2 +-
  security/apparmor/domain.c           |   1 -
  security/selinux/hooks.c             |   1 -
  85 files changed, 372 insertions(+), 495 deletions(-)
 
 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEgjlraLDcwBA2B+6cC/v6Eiajj0AFAmJCQkoACgkQC/v6Eiaj
 j0DCWQ/5AZVFU+hX32obUNCLackHTwgcCtSOs3JNBmNA/zL/htPiYYG0ghkvtlDR
 Dw5J5DnxC6P7PVAdAqrpvx2uX2FebHYU0bRlyLx8LYUEP5dhyNicxX9jA882Z+vw
 Ud0Ue9EojwGWS76dC9YoKUj3slThMATbhA2r4GVEoof8fSNJaBxQIqath44t0FwU
 DinWa+tIOvZANGBZr6CUUINNIgqBIZCH/R4h6ArBhMlJpuQ5Ufk2kAaiWFwZCkX4
 0LuuAwbKsCKkF8eap5I2KrIg/7zZVgxAg9O3cHOzzm8OPbKzRnNnQClcDe8perqp
 S6e/f3MgpE+eavd1EiLxevZ660cJChnmikXVVh8ZYYoefaMKGqBaBSsB38bNcLjY
 3+f2dB+TNBFRnZs1aCujK3tWBT9QyjZDKtCBfzxDNWBpXGLhHH6j6lA5Lj+Cef5K
 /HNHFb+FuqedlFZh5m1Y+piFQ70hTgCa2u8b+FSOubI2hW9Zd+WzINV0ANaZ2LvZ
 4YGtcyDNk1q1+c87lxP9xMRl/xi6rNg+B9T2MCo4IUnHgpSVP6VEB3osgUmrrrN0
 eQlUI154G/AaDlqXLgmn1xhRmlPGfmenkxpok1AuzxvNJsfLKnpEwQSc13g3oiZr
 disZQxNY0kBO2Nv3G323Z6PLinhbiIIFez6cJzK5v0YJ2WtO3pY=
 =uEro
 -----END PGP SIGNATURE-----

Merge tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull ptrace cleanups from Eric Biederman:
 "This set of changes removes tracehook.h, moves modification of all of
  the ptrace fields inside of siglock to remove races, adds a missing
  permission check to ptrace.c

  The removal of tracehook.h is quite significant as it has been a major
  source of confusion in recent years. Much of that confusion was around
  task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the
  semantics clearer).

  For people who don't know tracehook.h is a vestiage of an attempt to
  implement uprobes like functionality that was never fully merged, and
  was later superseeded by uprobes when uprobes was merged. For many
  years now we have been removing what tracehook functionaly a little
  bit at a time. To the point where anything left in tracehook.h was
  some weird strange thing that was difficult to understand"

* tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ptrace: Remove duplicated include in ptrace.c
  ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
  ptrace: Return the signal to continue with from ptrace_stop
  ptrace: Move setting/clearing ptrace_message into ptrace_stop
  tracehook: Remove tracehook.h
  resume_user_mode: Move to resume_user_mode.h
  resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
  signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
  task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
  task_work: Call tracehook_notify_signal from get_signal on all architectures
  task_work: Introduce task_work_pending
  task_work: Remove unnecessary include from posix_timers.h
  ptrace: Remove tracehook_signal_handler
  ptrace: Remove arch_syscall_{enter,exit}_tracehook
  ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
  ptrace/arm: Rename tracehook_report_syscall report_syscall
  ptrace: Move ptrace_report_syscall into ptrace.h
2022-03-28 17:29:53 -07:00
Eric W. Biederman
355f841a3f tracehook: Remove tracehook.h
Now that all of the definitions have moved out of tracehook.h into
ptrace.h, sched/signal.h, resume_user_mode.h there is nothing left in
tracehook.h so remove it.

Update the few files that were depending upon tracehook.h to bring in
definitions to use the headers they need directly.

Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20220309162454.123006-13-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10 16:51:51 -06:00
Eric W. Biederman
390031c942 coredump: Use the vma snapshot in fill_files_note
Matthew Wilcox reported that there is a missing mmap_lock in
file_files_note that could possibly lead to a user after free.

Solve this by using the existing vma snapshot for consistency
and to avoid the need to take the mmap_lock anywhere in the
coredump code except for dump_vma_snapshot.

Update the dump_vma_snapshot to capture vm_pgoff and vm_file
that are neeeded by fill_files_note.

Add free_vma_snapshot to free the captured values of vm_file.

Reported-by: Matthew Wilcox <willy@infradead.org>
Link: https://lkml.kernel.org/r/20220131153740.2396974-1-willy@infradead.org
Cc: stable@vger.kernel.org
Fixes: a07279c9a8 ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot")
Fixes: 2aa362c49c ("coredump: extend core dump note section to contain file names of mapped files")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-08 13:04:19 -06:00
Eric W. Biederman
49c1866348 coredump: Remove the WARN_ON in dump_vma_snapshot
The condition is impossible and to the best of my knowledge has never
triggered.

We are in deep trouble if that conditions happens and we walk past
the end of our allocated array.

So delete the WARN_ON and the code that makes it look like the kernel
can handle the case of walking past the end of it's vma_meta array.

Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-08 13:01:19 -06:00
Eric W. Biederman
95c5436a48 coredump: Snapshot the vmas in do_coredump
Move the call of dump_vma_snapshot and kvfree(vma_meta) out of the
individual coredump routines into do_coredump itself.  This makes
the code less error prone and easier to maintain.

Make the vma snapshot available to the coredump routines
in struct coredump_params.  This makes it easier to
change and update what is captures in the vma snapshot
and will be needed for fixing fill_file_notes.

Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-08 12:55:29 -06:00
Jann Horn
84158b7f6a coredump: Also dump first pages of non-executable ELF libraries
When I rewrote the VMA dumping logic for coredumps, I changed it to
recognize ELF library mappings based on the file being executable instead
of the mapping having an ELF header. But turns out, distros ship many ELF
libraries as non-executable, so the heuristic goes wrong...

Restore the old behavior where FILTER(ELF_HEADERS) dumps the first page of
any offset-0 readable mapping that starts with the ELF magic.

This fix is technically layer-breaking a bit, because it checks for
something ELF-specific in fs/coredump.c; but since we probably want to
share this between standard ELF and FDPIC ELF anyway, I guess it's fine?
And this also keeps the change small for backporting.

Cc: stable@vger.kernel.org
Fixes: 429a22e776 ("coredump: rework elf/elf_fdpic vma_dump_size() into common helper")
Reported-by: Bill Messmer <wmessmer@microsoft.com>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220126025739.2014888-1-jannh@google.com
2022-03-01 16:16:26 -08:00
Xiaoming Ni
f0bc21b268 fs/coredump: move coredump sysctls into its own file
This moves the fs/coredump.c respective sysctls to its own file.

Link: https://lkml.kernel.org/r/20211129211943.640266-6-mcgrof@kernel.org
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Stephen Kitt <steve@sk2.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-22 08:33:36 +02:00
Eric W. Biederman
49697335e0 signal: Remove the helper signal_group_exit
This helper is misleading.  It tests for an ongoing exec as well as
the process having received a fatal signal.

Sometimes it is appropriate to treat an on-going exec differently than
a process that is shutting down due to a fatal signal.  In particular
taking the fast path out of exit_signals instead of retargeting
signals is not appropriate during exec, and not changing the the exit
code in do_group_exit during exec.

Removing the helper makes it more obvious what is going on as both
cases must be coded for explicitly.

While removing the helper fix the two cases where I have observed
using signal_group_exit resulted in the wrong result.

In exit_signals only test for SIGNAL_GROUP_EXIT so that signals are
retargetted during an exec.

In do_group_exit use 0 as the exit code during an exec as de_thread
does not set group_exit_code.  As best as I can determine
group_exit_code has been is set to 0 most of the time during
de_thread.  During a thread group stop group_exit_code is set to the
stop signal and when the thread group receives SIGCONT group_exit_code
is reset to 0.

Link: https://lkml.kernel.org/r/20211213225350.27481-8-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman
6ac79ec537 coredump: Stop setting signal->group_exit_task
Currently the coredump code sets group_exit_task so that
signal_group_exit() will return true during a coredump.  Now that the
coredump code always sets SIGNAL_GROUP_EXIT there is no longer a need
to set signal->group_exit_task.

Link: https://lkml.kernel.org/r/20211213225350.27481-6-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman
2f824d4d19 signal: Remove SIGNAL_GROUP_COREDUMP
After the previous cleanups "signal->core_state" is set whenever
SIGNAL_GROUP_COREDUMP is set and "signal->core_state" is tested
whenver the code wants to know if a coredump is in progress.  The
remaining tests of SIGNAL_GROUP_COREDUMP also test to see if
SIGNAL_GROUP_EXIT is set.  Similarly the only place that sets
SIGNAL_GROUP_COREDUMP also sets SIGNAL_GROUP_EXIT.

Which makes SIGNAL_GROUP_COREDUMP unecessary and redundant. So stop
setting SIGNAL_GROUP_COREDUMP, stop testing SIGNAL_GROUP_COREDUMP, and
remove it's definition.

With the setting of SIGNAL_GROUP_COREDUMP gone, coredump_finish no
longer needs to clear SIGNAL_GROUP_COREDUMP out of signal->flags
by setting SIGNAL_GROUP_EXIT.

Link: https://lkml.kernel.org/r/20211213225350.27481-5-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman
752dc97075 signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process
There are only a few places that test SIGNAL_GROUP_EXIT and
are not also already testing SIGNAL_GROUP_COREDUMP.

This will not affect the callers of signal_group_exit as zap_process
also sets group_exit_task so signal_group_exit will continue to return
true at the same times.

This does not affect wait_task_zombie as the none of the threads
wind up in EXIT_ZOMBIE state during a coredump.

This does not affect oom_kill.c:__task_will_free_mem as
sig->core_state is tested and handled before SIGNAL_GROUP_EXIT is
tested for.

This does not affect complete_signal as signal->core_state is tested
for to ensure the coredump case is handled appropriately.

Link: https://lkml.kernel.org/r/20211213225350.27481-4-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:56 -06:00
Eric W. Biederman
0258b5fd7c coredump: Limit coredumps to a single thread group
Today when a signal is delivered with a handler of SIG_DFL whose
default behavior is to generate a core dump not only that process but
every process that shares the mm is killed.

In the case of vfork this looks like a real world problem.  Consider
the following well defined sequence.

	if (vfork() == 0) {
		execve(...);
		_exit(EXIT_FAILURE);
	}

If a signal that generates a core dump is received after vfork but
before the execve changes the mm the process that called vfork will
also be killed (as the mm is shared).

Similarly if the execve fails after the point of no return the kernel
delivers SIGSEGV which will kill both the exec'ing process and because
the mm is shared the process that called vfork as well.

As far as I can tell this behavior is a violation of people's
reasonable expectations, POSIX, and is unnecessarily fragile when the
system is low on memory.

Solve this by making a userspace visible change to only kill a single
process/thread group.  This is possible because Jann Horn recently
modified[1] the coredump code so that the mm can safely be modified
while the coredump is happening.  With LinuxThreads long gone I don't
expect anyone to have a notice this behavior change in practice.

To accomplish this move the core_state pointer from mm_struct to
signal_struct, which allows different thread groups to coredump
simultatenously.

In zap_threads remove the work to kill anything except for the current
thread group.

v2: Remove core_state from the VM_BUG_ON_MM print to fix
    compile failure when CONFIG_DEBUG_VM is enabled.
    Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>

[1] a07279c9a8 ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot")
Fixes: d89f3847def4 ("[PATCH] thread-aware coredumps, 2.5.43-C3")
History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Link: https://lkml.kernel.org/r/87y27mvnke.fsf@disp2133
Link: https://lkml.kernel.org/r/20211007144701.67592574@canb.auug.org.au
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-10-08 12:06:02 -05:00
Eric W. Biederman
9230738308 coredump: Don't perform any cleanups before dumping core
Rename coredump_exit_mm to coredump_task_exit and call it from do_exit
before PTRACE_EVENT_EXIT, and before any cleanup work for a task
happens.  This ensures that an accurate copy of the process can be
captured in the coredump as no cleanup for the process happens before
the coredump completes.  This also ensures that PTRACE_EVENT_EXIT
will not be visited by any thread until the coredump is complete.

Add a new flag PF_POSTCOREDUMP so that tasks that have passed through
coredump_task_exit can be recognized and ignored in zap_process.

Now that all of the coredumping happens before exit_mm remove code to
test for a coredump in progress from mm_release.

Replace "may_ptrace_stop()" with a simple test of "current->ptrace".
The other tests in may_ptrace_stop all concern avoiding stopping
during a coredump.  These tests are no longer necessary as it is now
guaranteed that fatal_signal_pending will be set if the code enters
ptrace_stop during a coredump.  The code in ptrace_stop is guaranteed
not to stop if fatal_signal_pending returns true.

Until this change "ptrace_event(PTRACE_EVENT_EXIT)" could call
ptrace_stop without fatal_signal_pending being true, as signals are
dequeued in get_signal before calling do_exit.  This is no longer
an issue as "ptrace_event(PTRACE_EVENT_EXIT)" is no longer reached
until after the coredump completes.

Link: https://lkml.kernel.org/r/874kaax26c.fsf@disp2133
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-10-06 11:28:39 -05:00
Eric W. Biederman
d67e03e361 exit: Factor coredump_exit_mm out of exit_mm
Separate the coredump logic from the ordinary exit_mm logic
by moving the coredump logic out of exit_mm into it's own
function coredump_exit_mm.

Link: https://lkml.kernel.org/r/87a6k2x277.fsf@disp2133
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-10-06 11:28:21 -05:00
QiuXi
6fcac87e1f coredump: fix memleak in dump_vma_snapshot()
dump_vma_snapshot() allocs memory for *vma_meta, when dump_vma_snapshot()
returns -EFAULT, the memory will be leaked, so we free it correctly.

Link: https://lkml.kernel.org/r/20210810020441.62806-1-qiuxi1@huawei.com
Fixes: a07279c9a8 ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot")
Signed-off-by: QiuXi <qiuxi1@huawei.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jann Horn <jannh@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-08 11:50:27 -07:00
David Oberhollenzer
dbd9d6f8fa fs/coredump.c: log if a core dump is aborted due to changed file permissions
For obvious security reasons, a core dump is aborted if the filesystem
cannot preserve ownership or permissions of the dump file.

This affects filesystems like e.g.  vfat, but also something like a 9pfs
share in a Qemu test setup, running as a regular user, depending on the
security model used.  In those cases, the result is an empty core file and
a confused user.

To hopefully save other people a lot of time figuring out the cause, this
patch adds a simple log message for those specific cases.

[akpm@linux-foundation.org: s/|%s/%s/ in printk text]

Link: https://lkml.kernel.org/r/20210701233151.102720-1-david.oberhollenzer@sigma-star.at
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-08 11:50:27 -07:00
Linus Torvalds
58ec9059b3 Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs name lookup updates from Al Viro:
 "Small namei.c patch series, mostly to simplify the rules for nameidata
  state. It's actually from the previous cycle - but I didn't post it
  for review in time...

  Changes visible outside of fs/namei.c: file_open_root() calling
  conventions change, some freed bits in LOOKUP_... space"

* 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  namei: make sure nd->depth is always valid
  teach set_nameidata() to handle setting the root as well
  take LOOKUP_{ROOT,ROOT_GRABBED,JUMPED} out of LOOKUP_... space
  switch file_open_root() to struct path
2021-07-03 11:41:14 -07:00
Eric W. Biederman
06af867944 coredump: Limit what can interrupt coredumps
Olivier Langlois has been struggling with coredumps being incompletely written in
processes using io_uring.

Olivier Langlois <olivier@trillion01.com> writes:
> io_uring is a big user of task_work and any event that io_uring made a
> task waiting for that occurs during the core dump generation will
> generate a TIF_NOTIFY_SIGNAL.
>
> Here are the detailed steps of the problem:
> 1. io_uring calls vfs_poll() to install a task to a file wait queue
>    with io_async_wake() as the wakeup function cb from io_arm_poll_handler()
> 2. wakeup function ends up calling task_work_add() with TWA_SIGNAL
> 3. task_work_add() sets the TIF_NOTIFY_SIGNAL bit by calling
>    set_notify_signal()

The coredump code deliberately supports being interrupted by SIGKILL,
and depends upon prepare_signal to filter out all other signals.   Now
that signal_pending includes wake ups for TIF_NOTIFY_SIGNAL this hack
in dump_emitted by the coredump code no longer works.

Make the coredump code more robust by explicitly testing for all of
the wakeup conditions the coredump code supports.  This prevents
new wakeup conditions from breaking the coredump code, as well
as fixing the current issue.

The filesystem code that the coredump code uses already limits
itself to only aborting on fatal_signal_pending.  So it should
not develop surprising wake-up reasons either.

v2: Don't remove the now unnecessary code in prepare_signal.

Cc: stable@vger.kernel.org
Fixes: 12db8b6900 ("entry: Add support for TIF_NOTIFY_SIGNAL")
Reported-by: Olivier Langlois <olivier@trillion01.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-10 14:02:29 -07:00
Al Viro
ffb37ca3bd switch file_open_root() to struct path
... and provide file_open_root_mnt(), using the root of given mount.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-04-07 13:56:43 -04:00
Al Viro
d0f1088b31 coredump: don't bother with do_truncate()
have dump_skip() just remember how much needs to be skipped,
leave actual seeks/writing zeroes to the next dump_emit()
or the end of coredump output, whichever comes first.
And instead of playing with do_truncate() in the end, just
write one NUL at the end of the last gap (if any).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-03-08 10:21:11 -05:00
Ira Weiny
3159ed5779 fs/coredump: use kmap_local_page()
In dump_user_range() there is no reason for the mapping to be global.  Use
kmap_local_page() rather than kmap.

Link: https://lkml.kernel.org/r/20210203223328.558945-1-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:41:05 -08:00
Christian Brauner
643fe55a06
open: handle idmapped mounts in do_truncate()
When truncating files the vfs will verify that the caller is privileged
over the inode. Extend it to handle idmapped mounts. If the inode is
accessed through an idmapped mount it is mapped according to the mount's
user namespace. Afterwards the permissions checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-16-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:18 +01:00
Linus Torvalds
faf145d6f3 Merge branch 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull execve updates from Eric Biederman:
 "This set of changes ultimately fixes the interaction of posix file
  lock and exec. Fundamentally most of the change is just moving where
  unshare_files is called during exec, and tweaking the users of
  files_struct so that the count of files_struct is not unnecessarily
  played with.

  Along the way fcheck and related helpers were renamed to more
  accurately reflect what they do.

  There were also many other small changes that fell out, as this is the
  first time in a long time much of this code has been touched.

  Benchmarks haven't turned up any practical issues but Al Viro has
  observed a possibility for a lot of pounding on task_lock. So I have
  some changes in progress to convert put_files_struct to always rcu
  free files_struct. That wasn't ready for the merge window so that will
  have to wait until next time"

* 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  exec: Move io_uring_task_cancel after the point of no return
  coredump: Document coredump code exclusively used by cell spufs
  file: Remove get_files_struct
  file: Rename __close_fd_get_file close_fd_get_file
  file: Replace ksys_close with close_fd
  file: Rename __close_fd to close_fd and remove the files parameter
  file: Merge __alloc_fd into alloc_fd
  file: In f_dupfd read RLIMIT_NOFILE once.
  file: Merge __fd_install into fd_install
  proc/fd: In fdinfo seq_show don't use get_files_struct
  bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu
  proc/fd: In proc_readfd_common use task_lookup_next_fd_rcu
  file: Implement task_lookup_next_fd_rcu
  kcmp: In get_file_raw_ptr use task_lookup_fd_rcu
  proc/fd: In tid_fd_mode use task_lookup_fd_rcu
  file: Implement task_lookup_fd_rcu
  file: Rename fcheck lookup_fd_rcu
  file: Replace fcheck_files with files_lookup_fd_rcu
  file: Factor files_lookup_fd_locked out of fcheck_files
  file: Rename __fcheck_files to files_lookup_fd_raw
  ...
2020-12-15 19:29:43 -08:00
Eric W. Biederman
c39ab6de22 coredump: Document coredump code exclusively used by cell spufs
Oleg Nesterov recently asked[1] why is there an unshare_files in
do_coredump.  After digging through all of the callers of lookup_fd it
turns out that it is
arch/powerpc/platforms/cell/spufs/coredump.c:coredump_next_context
that needs the unshare_files in do_coredump.

Looking at the history[2] this code was also the only piece of coredump code
that required the unshare_files when the unshare_files was added.

Looking at that code it turns out that cell is also the only
architecture that implements elf_coredump_extra_notes_size and
elf_coredump_extra_notes_write.

I looked at the gdb repo[3] support for cell has been removed[4] in binutils
2.34.  Geoff Levand reports he is still getting questions on how to
run modern kernels on the PS3, from people using 3rd party firmware so
this code is not dead.  According to Wikipedia the last PS3 shipped in
Japan sometime in 2017.  So it will probably be a little while before
everyone's hardware dies.

Add some comments briefly documenting the coredump code that exists
only to support cell spufs to make it easier to understand the
coredump code.  Eventually the hardware will be dead, or their won't
be userspace tools, or the coredump code will be refactored and it
will be too difficult to update a dead architecture and these comments
make it easy to tell where to pull to remove cell spufs support.

[1] https://lkml.kernel.org/r/20201123175052.GA20279@redhat.com
[2] 179e037fc1 ("do_coredump(): make sure that descriptor table isn't shared")
[3] git://sourceware.org/git/binutils-gdb.git
[4] abf516c6931a ("Remove Cell Broadband Engine debugging support").
Link: https://lkml.kernel.org/r/87h7pdnlzv.fsf_-_@x220.int.ebiederm.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-12-10 12:57:08 -06:00