<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/alpha/kernel/syscalls/syscall.tbl, branch v5.16</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>futex: Wireup futex_waitv syscall</title>
<updated>2021-11-25T13:26:12+00:00</updated>
<author>
<name>André Almeida</name>
<email>andrealmeid@collabora.com</email>
</author>
<published>2021-11-24T13:21:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a0eb2da92b715d0c97b96b09979689ea09faefe6'/>
<id>a0eb2da92b715d0c97b96b09979689ea09faefe6</id>
<content type='text'>
Wireup futex_waitv syscall for all remaining archs.

Signed-off-by: André Almeida &lt;andrealmeid@collabora.com&gt;
Acked-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Tested-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Wireup futex_waitv syscall for all remaining archs.

Signed-off-by: André Almeida &lt;andrealmeid@collabora.com&gt;
Acked-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Tested-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2021-09-03T17:08:28+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-09-03T17:08:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=14726903c835101cd8d0a703b609305094350d61'/>
<id>14726903c835101cd8d0a703b609305094350d61</id>
<content type='text'>
Merge misc updates from Andrew Morton:
 "173 patches.

  Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
  pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
  bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure,
  hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock,
  oom-kill, migration, ksm, percpu, vmstat, and madvise)"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (173 commits)
  mm/madvise: add MADV_WILLNEED to process_madvise()
  mm/vmstat: remove unneeded return value
  mm/vmstat: simplify the array size calculation
  mm/vmstat: correct some wrong comments
  mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
  selftests: vm: add COW time test for KSM pages
  selftests: vm: add KSM merging time test
  mm: KSM: fix data type
  selftests: vm: add KSM merging across nodes test
  selftests: vm: add KSM zero page merging test
  selftests: vm: add KSM unmerge test
  selftests: vm: add KSM merge test
  mm/migrate: correct kernel-doc notation
  mm: wire up syscall process_mrelease
  mm: introduce process_mrelease system call
  memblock: make memblock_find_in_range method private
  mm/mempolicy.c: use in_task() in mempolicy_slab_node()
  mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
  mm/mempolicy: advertise new MPOL_PREFERRED_MANY
  mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge misc updates from Andrew Morton:
 "173 patches.

  Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
  pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
  bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure,
  hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock,
  oom-kill, migration, ksm, percpu, vmstat, and madvise)"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (173 commits)
  mm/madvise: add MADV_WILLNEED to process_madvise()
  mm/vmstat: remove unneeded return value
  mm/vmstat: simplify the array size calculation
  mm/vmstat: correct some wrong comments
  mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
  selftests: vm: add COW time test for KSM pages
  selftests: vm: add KSM merging time test
  mm: KSM: fix data type
  selftests: vm: add KSM merging across nodes test
  selftests: vm: add KSM zero page merging test
  selftests: vm: add KSM unmerge test
  selftests: vm: add KSM merge test
  mm/migrate: correct kernel-doc notation
  mm: wire up syscall process_mrelease
  mm: introduce process_mrelease system call
  memblock: make memblock_find_in_range method private
  mm/mempolicy.c: use in_task() in mempolicy_slab_node()
  mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
  mm/mempolicy: advertise new MPOL_PREFERRED_MANY
  mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: wire up syscall process_mrelease</title>
<updated>2021-09-03T16:58:17+00:00</updated>
<author>
<name>Suren Baghdasaryan</name>
<email>surenb@google.com</email>
</author>
<published>2021-09-02T22:00:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=dce49103962840dd61423d7627748d6c558d58c5'/>
<id>dce49103962840dd61423d7627748d6c558d58c5</id>
<content type='text'>
Split off from prev patch in the series that implements the syscall.

Link: https://lkml.kernel.org/r/20210809185259.405936-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Christian Brauner &lt;christian.brauner@ubuntu.com&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Florian Weimer &lt;fweimer@redhat.com&gt;
Cc: Jan Engelhardt &lt;jengelh@inai.de&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Roman Gushchin &lt;guro@fb.com&gt;
Cc: Shakeel Butt &lt;shakeelb@google.com&gt;
Cc: Tim Murray &lt;timmurray@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Split off from prev patch in the series that implements the syscall.

Link: https://lkml.kernel.org/r/20210809185259.405936-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Christian Brauner &lt;christian.brauner@ubuntu.com&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Florian Weimer &lt;fweimer@redhat.com&gt;
Cc: Jan Engelhardt &lt;jengelh@inai.de&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Roman Gushchin &lt;guro@fb.com&gt;
Cc: Shakeel Butt &lt;shakeelb@google.com&gt;
Cc: Tim Murray &lt;timmurray@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>exit/bdflush: Remove the deprecated bdflush system call</title>
<updated>2021-07-12T20:17:47+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2021-06-29T20:11:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b48c7236b13cb5ef1b5fdf744aa8841df0f7b43a'/>
<id>b48c7236b13cb5ef1b5fdf744aa8841df0f7b43a</id>
<content type='text'>
The bdflush system call has been deprecated for a very long time.
Recently Michael Schmitz tested[1] and found that the last known
caller of of the bdflush system call is unaffected by it's removal.

Since the code is not needed delete it.

[1] https://lkml.kernel.org/r/36123b5d-daa0-6c2b-f2d4-a942f069fd54@gmail.com
Link: https://lkml.kernel.org/r/87sg10quue.fsf_-_@disp2133
Tested-by: Michael Schmitz &lt;schmitzmic@gmail.com&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Cyril Hrubis &lt;chrubis@suse.cz&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The bdflush system call has been deprecated for a very long time.
Recently Michael Schmitz tested[1] and found that the last known
caller of of the bdflush system call is unaffected by it's removal.

Since the code is not needed delete it.

[1] https://lkml.kernel.org/r/36123b5d-daa0-6c2b-f2d4-a942f069fd54@gmail.com
Link: https://lkml.kernel.org/r/87sg10quue.fsf_-_@disp2133
Tested-by: Michael Schmitz &lt;schmitzmic@gmail.com&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Cyril Hrubis &lt;chrubis@suse.cz&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>quota: Wire up quotactl_fd syscall</title>
<updated>2021-06-07T10:11:24+00:00</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2021-05-31T16:42:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=65ffb3d69ed3da28af85b1e4b2aaacd6c13ba28b'/>
<id>65ffb3d69ed3da28af85b1e4b2aaacd6c13ba28b</id>
<content type='text'>
Wire up the quotactl_fd syscall.

Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Wire up the quotactl_fd syscall.

Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>quota: Disable quotactl_path syscall</title>
<updated>2021-05-17T12:39:56+00:00</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2021-05-17T12:39:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5b9fedb31e476693c90d8ee040e7d4c51b3e7cc4'/>
<id>5b9fedb31e476693c90d8ee040e7d4c51b3e7cc4</id>
<content type='text'>
In commit fa8b90070a80 ("quota: wire up quotactl_path") we have wired up
new quotactl_path syscall. However some people in LWN discussion have
objected that the path based syscall is missing dirfd and flags argument
which is mostly standard for contemporary path based syscalls. Indeed
they have a point and after a discussion with Christian Brauner and
Sascha Hauer I've decided to disable the syscall for now and update its
API. Since there is no userspace currently using that syscall and it
hasn't been released in any major release, we should be fine.

CC: Christian Brauner &lt;christian.brauner@ubuntu.com&gt;
CC: Sascha Hauer &lt;s.hauer@pengutronix.de&gt;
Link: https://lore.kernel.org/lkml/20210512153621.n5u43jsytbik4yze@wittgenstein
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In commit fa8b90070a80 ("quota: wire up quotactl_path") we have wired up
new quotactl_path syscall. However some people in LWN discussion have
objected that the path based syscall is missing dirfd and flags argument
which is mostly standard for contemporary path based syscalls. Indeed
they have a point and after a discussion with Christian Brauner and
Sascha Hauer I've decided to disable the syscall for now and update its
API. Since there is no userspace currently using that syscall and it
hasn't been released in any major release, we should be fine.

CC: Christian Brauner &lt;christian.brauner@ubuntu.com&gt;
CC: Sascha Hauer &lt;s.hauer@pengutronix.de&gt;
Link: https://lore.kernel.org/lkml/20210512153621.n5u43jsytbik4yze@wittgenstein
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security</title>
<updated>2021-05-02T01:50:44+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-05-02T01:50:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=17ae69aba89dbfa2139b7f8024b757ab3cc42f59'/>
<id>17ae69aba89dbfa2139b7f8024b757ab3cc42f59</id>
<content type='text'>
Pull Landlock LSM from James Morris:
 "Add Landlock, a new LSM from Mickaël Salaün.

  Briefly, Landlock provides for unprivileged application sandboxing.

  From Mickaël's cover letter:
    "The goal of Landlock is to enable to restrict ambient rights (e.g.
     global filesystem access) for a set of processes. Because Landlock
     is a stackable LSM [1], it makes possible to create safe security
     sandboxes as new security layers in addition to the existing
     system-wide access-controls. This kind of sandbox is expected to
     help mitigate the security impact of bugs or unexpected/malicious
     behaviors in user-space applications. Landlock empowers any
     process, including unprivileged ones, to securely restrict
     themselves.

     Landlock is inspired by seccomp-bpf but instead of filtering
     syscalls and their raw arguments, a Landlock rule can restrict the
     use of kernel objects like file hierarchies, according to the
     kernel semantic. Landlock also takes inspiration from other OS
     sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD
     Pledge/Unveil.

     In this current form, Landlock misses some access-control features.
     This enables to minimize this patch series and ease review. This
     series still addresses multiple use cases, especially with the
     combined use of seccomp-bpf: applications with built-in sandboxing,
     init systems, security sandbox tools and security-oriented APIs [2]"

  The cover letter and v34 posting is here:

      https://lore.kernel.org/linux-security-module/20210422154123.13086-1-mic@digikod.net/

  See also:

      https://landlock.io/

  This code has had extensive design discussion and review over several
  years"

Link: https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/ [1]
Link: https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/ [2]

* tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  landlock: Enable user space to infer supported features
  landlock: Add user and kernel documentation
  samples/landlock: Add a sandbox manager example
  selftests/landlock: Add user space tests
  landlock: Add syscall implementations
  arch: Wire up Landlock syscalls
  fs,security: Add sb_delete hook
  landlock: Support filesystem access-control
  LSM: Infrastructure management of the superblock
  landlock: Add ptrace restrictions
  landlock: Set up the security framework and manage credentials
  landlock: Add ruleset and domain management
  landlock: Add object management
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull Landlock LSM from James Morris:
 "Add Landlock, a new LSM from Mickaël Salaün.

  Briefly, Landlock provides for unprivileged application sandboxing.

  From Mickaël's cover letter:
    "The goal of Landlock is to enable to restrict ambient rights (e.g.
     global filesystem access) for a set of processes. Because Landlock
     is a stackable LSM [1], it makes possible to create safe security
     sandboxes as new security layers in addition to the existing
     system-wide access-controls. This kind of sandbox is expected to
     help mitigate the security impact of bugs or unexpected/malicious
     behaviors in user-space applications. Landlock empowers any
     process, including unprivileged ones, to securely restrict
     themselves.

     Landlock is inspired by seccomp-bpf but instead of filtering
     syscalls and their raw arguments, a Landlock rule can restrict the
     use of kernel objects like file hierarchies, according to the
     kernel semantic. Landlock also takes inspiration from other OS
     sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD
     Pledge/Unveil.

     In this current form, Landlock misses some access-control features.
     This enables to minimize this patch series and ease review. This
     series still addresses multiple use cases, especially with the
     combined use of seccomp-bpf: applications with built-in sandboxing,
     init systems, security sandbox tools and security-oriented APIs [2]"

  The cover letter and v34 posting is here:

      https://lore.kernel.org/linux-security-module/20210422154123.13086-1-mic@digikod.net/

  See also:

      https://landlock.io/

  This code has had extensive design discussion and review over several
  years"

Link: https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/ [1]
Link: https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/ [2]

* tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  landlock: Enable user space to infer supported features
  landlock: Add user and kernel documentation
  samples/landlock: Add a sandbox manager example
  selftests/landlock: Add user space tests
  landlock: Add syscall implementations
  arch: Wire up Landlock syscalls
  fs,security: Add sb_delete hook
  landlock: Support filesystem access-control
  LSM: Infrastructure management of the superblock
  landlock: Add ptrace restrictions
  landlock: Set up the security framework and manage credentials
  landlock: Add ruleset and domain management
  landlock: Add object management
</pre>
</div>
</content>
</entry>
<entry>
<title>arch: Wire up Landlock syscalls</title>
<updated>2021-04-22T19:22:11+00:00</updated>
<author>
<name>Mickaël Salaün</name>
<email>mic@linux.microsoft.com</email>
</author>
<published>2021-04-22T15:41:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a49f4f81cb48925e8d7cbd9e59068f516e984144'/>
<id>a49f4f81cb48925e8d7cbd9e59068f516e984144</id>
<content type='text'>
Wire up the following system calls for all architectures:
* landlock_create_ruleset(2)
* landlock_add_rule(2)
* landlock_restrict_self(2)

Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: James Morris &lt;jmorris@namei.org&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Serge E. Hallyn &lt;serge@hallyn.com&gt;
Signed-off-by: Mickaël Salaün &lt;mic@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20210422154123.13086-10-mic@digikod.net
Signed-off-by: James Morris &lt;jamorris@linux.microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Wire up the following system calls for all architectures:
* landlock_create_ruleset(2)
* landlock_add_rule(2)
* landlock_restrict_self(2)

Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: James Morris &lt;jmorris@namei.org&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Serge E. Hallyn &lt;serge@hallyn.com&gt;
Signed-off-by: Mickaël Salaün &lt;mic@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20210422154123.13086-10-mic@digikod.net
Signed-off-by: James Morris &lt;jamorris@linux.microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>quota: wire up quotactl_path</title>
<updated>2021-03-17T14:51:17+00:00</updated>
<author>
<name>Sascha Hauer</name>
<email>s.hauer@pengutronix.de</email>
</author>
<published>2021-03-04T12:35:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fa8b90070a80bb1a3042b4b25af4b3ee2c4c27e1'/>
<id>fa8b90070a80bb1a3042b4b25af4b3ee2c4c27e1</id>
<content type='text'>
Wire up the quotactl_path syscall added in the previous patch.

Link: https://lore.kernel.org/r/20210304123541.30749-3-s.hauer@pengutronix.de
Signed-off-by: Sascha Hauer &lt;s.hauer@pengutronix.de&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</content>
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<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Wire up the quotactl_path syscall added in the previous patch.

Link: https://lore.kernel.org/r/20210304123541.30749-3-s.hauer@pengutronix.de
Signed-off-by: Sascha Hauer &lt;s.hauer@pengutronix.de&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs: add mount_setattr()</title>
<updated>2021-01-24T13:42:45+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>christian.brauner@ubuntu.com</email>
</author>
<published>2021-01-21T13:19:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2a1867219c7b27f928e2545782b86daaf9ad50bd'/>
<id>2a1867219c7b27f928e2545782b86daaf9ad50bd</id>
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This implements the missing mount_setattr() syscall. While the new mount
api allows to change the properties of a superblock there is currently
no way to change the properties of a mount or a mount tree using file
descriptors which the new mount api is based on. In addition the old
mount api has the restriction that mount options cannot be applied
recursively. This hasn't changed since changing mount options on a
per-mount basis was implemented in [1] and has been a frequent request
not just for convenience but also for security reasons. The legacy
mount syscall is unable to accommodate this behavior without introducing
a whole new set of flags because MS_REC | MS_REMOUNT | MS_BIND |
MS_RDONLY | MS_NOEXEC | [...] only apply the mount option to the topmost
mount. Changing MS_REC to apply to the whole mount tree would mean
introducing a significant uapi change and would likely cause significant
regressions.

The new mount_setattr() syscall allows to recursively clear and set
mount options in one shot. Multiple calls to change mount options
requesting the same changes are idempotent:

int mount_setattr(int dfd, const char *path, unsigned flags,
                  struct mount_attr *uattr, size_t usize);

Flags to modify path resolution behavior are specified in the @flags
argument. Currently, AT_EMPTY_PATH, AT_RECURSIVE, AT_SYMLINK_NOFOLLOW,
and AT_NO_AUTOMOUNT are supported. If useful, additional lookup flags to
restrict path resolution as introduced with openat2() might be supported
in the future.

The mount_setattr() syscall can be expected to grow over time and is
designed with extensibility in mind. It follows the extensible syscall
pattern we have used with other syscalls such as openat2(), clone3(),
sched_{set,get}attr(), and others.
The set of mount options is passed in the uapi struct mount_attr which
currently has the following layout:

struct mount_attr {
	__u64 attr_set;
	__u64 attr_clr;
	__u64 propagation;
	__u64 userns_fd;
};

The @attr_set and @attr_clr members are used to clear and set mount
options. This way a user can e.g. request that a set of flags is to be
raised such as turning mounts readonly by raising MOUNT_ATTR_RDONLY in
@attr_set while at the same time requesting that another set of flags is
to be lowered such as removing noexec from a mount tree by specifying
MOUNT_ATTR_NOEXEC in @attr_clr.

Note, since the MOUNT_ATTR_&lt;atime&gt; values are an enum starting from 0,
not a bitmap, users wanting to transition to a different atime setting
cannot simply specify the atime setting in @attr_set, but must also
specify MOUNT_ATTR__ATIME in the @attr_clr field. So we ensure that
MOUNT_ATTR__ATIME can't be partially set in @attr_clr and that @attr_set
can't have any atime bits set if MOUNT_ATTR__ATIME isn't set in
@attr_clr.

The @propagation field lets callers specify the propagation type of a
mount tree. Propagation is a single property that has four different
settings and as such is not really a flag argument but an enum.
Specifically, it would be unclear what setting and clearing propagation
settings in combination would amount to. The legacy mount() syscall thus
forbids the combination of multiple propagation settings too. The goal
is to keep the semantics of mount propagation somewhat simple as they
are overly complex as it is.

The @userns_fd field lets user specify a user namespace whose idmapping
becomes the idmapping of the mount. This is implemented and explained in
detail in the next patch.

[1]: commit 2e4b7fcd9260 ("[PATCH] r/o bind mounts: honor mount writer counts at remount")

Link: https://lore.kernel.org/r/20210121131959.646623-35-christian.brauner@ubuntu.com
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-api@vger.kernel.org
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner &lt;christian.brauner@ubuntu.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This implements the missing mount_setattr() syscall. While the new mount
api allows to change the properties of a superblock there is currently
no way to change the properties of a mount or a mount tree using file
descriptors which the new mount api is based on. In addition the old
mount api has the restriction that mount options cannot be applied
recursively. This hasn't changed since changing mount options on a
per-mount basis was implemented in [1] and has been a frequent request
not just for convenience but also for security reasons. The legacy
mount syscall is unable to accommodate this behavior without introducing
a whole new set of flags because MS_REC | MS_REMOUNT | MS_BIND |
MS_RDONLY | MS_NOEXEC | [...] only apply the mount option to the topmost
mount. Changing MS_REC to apply to the whole mount tree would mean
introducing a significant uapi change and would likely cause significant
regressions.

The new mount_setattr() syscall allows to recursively clear and set
mount options in one shot. Multiple calls to change mount options
requesting the same changes are idempotent:

int mount_setattr(int dfd, const char *path, unsigned flags,
                  struct mount_attr *uattr, size_t usize);

Flags to modify path resolution behavior are specified in the @flags
argument. Currently, AT_EMPTY_PATH, AT_RECURSIVE, AT_SYMLINK_NOFOLLOW,
and AT_NO_AUTOMOUNT are supported. If useful, additional lookup flags to
restrict path resolution as introduced with openat2() might be supported
in the future.

The mount_setattr() syscall can be expected to grow over time and is
designed with extensibility in mind. It follows the extensible syscall
pattern we have used with other syscalls such as openat2(), clone3(),
sched_{set,get}attr(), and others.
The set of mount options is passed in the uapi struct mount_attr which
currently has the following layout:

struct mount_attr {
	__u64 attr_set;
	__u64 attr_clr;
	__u64 propagation;
	__u64 userns_fd;
};

The @attr_set and @attr_clr members are used to clear and set mount
options. This way a user can e.g. request that a set of flags is to be
raised such as turning mounts readonly by raising MOUNT_ATTR_RDONLY in
@attr_set while at the same time requesting that another set of flags is
to be lowered such as removing noexec from a mount tree by specifying
MOUNT_ATTR_NOEXEC in @attr_clr.

Note, since the MOUNT_ATTR_&lt;atime&gt; values are an enum starting from 0,
not a bitmap, users wanting to transition to a different atime setting
cannot simply specify the atime setting in @attr_set, but must also
specify MOUNT_ATTR__ATIME in the @attr_clr field. So we ensure that
MOUNT_ATTR__ATIME can't be partially set in @attr_clr and that @attr_set
can't have any atime bits set if MOUNT_ATTR__ATIME isn't set in
@attr_clr.

The @propagation field lets callers specify the propagation type of a
mount tree. Propagation is a single property that has four different
settings and as such is not really a flag argument but an enum.
Specifically, it would be unclear what setting and clearing propagation
settings in combination would amount to. The legacy mount() syscall thus
forbids the combination of multiple propagation settings too. The goal
is to keep the semantics of mount propagation somewhat simple as they
are overly complex as it is.

The @userns_fd field lets user specify a user namespace whose idmapping
becomes the idmapping of the mount. This is implemented and explained in
detail in the next patch.

[1]: commit 2e4b7fcd9260 ("[PATCH] r/o bind mounts: honor mount writer counts at remount")

Link: https://lore.kernel.org/r/20210121131959.646623-35-christian.brauner@ubuntu.com
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-api@vger.kernel.org
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner &lt;christian.brauner@ubuntu.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
