<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel/bpf, branch v7.0-rc1</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>Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses</title>
<updated>2026-02-22T16:26:33+00:00</updated>
<author>
<name>Kees Cook</name>
<email>kees@kernel.org</email>
</author>
<published>2026-02-22T07:46:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=189f164e573e18d9f8876dbd3ad8fcbe11f93037'/>
<id>189f164e573e18d9f8876dbd3ad8fcbe11f93037</id>
<content type='text'>
Conversion performed via this Coccinelle script:

  // SPDX-License-Identifier: GPL-2.0-only
  // Options: --include-headers-for-types --all-includes --include-headers --keep-comments
  virtual patch

  @gfp depends on patch &amp;&amp; !(file in "tools") &amp;&amp; !(file in "samples")@
  identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex,
 		    kzalloc_obj,kzalloc_objs,kzalloc_flex,
		    kvmalloc_obj,kvmalloc_objs,kvmalloc_flex,
		    kvzalloc_obj,kvzalloc_objs,kvzalloc_flex};
  @@

  	ALLOC(...
  -		, GFP_KERNEL
  	)

  $ make coccicheck MODE=patch COCCI=gfp.cocci

Build and boot tested x86_64 with Fedora 42's GCC and Clang:

Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01
Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01

Signed-off-by: Kees Cook &lt;kees@kernel.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>
Conversion performed via this Coccinelle script:

  // SPDX-License-Identifier: GPL-2.0-only
  // Options: --include-headers-for-types --all-includes --include-headers --keep-comments
  virtual patch

  @gfp depends on patch &amp;&amp; !(file in "tools") &amp;&amp; !(file in "samples")@
  identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex,
 		    kzalloc_obj,kzalloc_objs,kzalloc_flex,
		    kvmalloc_obj,kvmalloc_objs,kvmalloc_flex,
		    kvzalloc_obj,kvzalloc_objs,kvzalloc_flex};
  @@

  	ALLOC(...
  -		, GFP_KERNEL
  	)

  $ make coccicheck MODE=patch COCCI=gfp.cocci

Build and boot tested x86_64 with Fedora 42's GCC and Clang:

Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01
Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Convert more 'alloc_obj' cases to default GFP_KERNEL arguments</title>
<updated>2026-02-22T04:03:00+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-22T04:03:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=32a92f8c89326985e05dce8b22d3f0aa07a3e1bd'/>
<id>32a92f8c89326985e05dce8b22d3f0aa07a3e1bd</id>
<content type='text'>
This converts some of the visually simpler cases that have been split
over multiple lines.  I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.

Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script.  I probably had made it a bit _too_ trivial.

So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.

The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This converts some of the visually simpler cases that have been split
over multiple lines.  I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.

Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script.  I probably had made it a bit _too_ trivial.

So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.

The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Convert 'alloc_flex' family to use the new default GFP_KERNEL argument</title>
<updated>2026-02-22T01:09:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-22T01:06:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=323bbfcf1ef8836d0d2ad9e2c1f1c684f0e3b5b3'/>
<id>323bbfcf1ef8836d0d2ad9e2c1f1c684f0e3b5b3</id>
<content type='text'>
This is the exact same thing as the 'alloc_obj()' version, only much
smaller because there are a lot fewer users of the *alloc_flex()
interface.

As with alloc_obj() version, this was done entirely with mindless brute
force, using the same script, except using 'flex' in the pattern rather
than 'objs*'.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is the exact same thing as the 'alloc_obj()' version, only much
smaller because there are a lot fewer users of the *alloc_flex()
interface.

As with alloc_obj() version, this was done entirely with mindless brute
force, using the same script, except using 'flex' in the pattern rather
than 'objs*'.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Convert 'alloc_obj' family to use the new default GFP_KERNEL argument</title>
<updated>2026-02-22T01:09:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-22T00:37:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43'/>
<id>bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43</id>
<content type='text'>
This was done entirely with mindless brute force, using

    git grep -l '\&lt;k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This was done entirely with mindless brute force, using

    git grep -l '\&lt;k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Replace kmalloc with kmalloc_obj for non-scalar types</title>
<updated>2026-02-21T09:02:28+00:00</updated>
<author>
<name>Kees Cook</name>
<email>kees@kernel.org</email>
</author>
<published>2026-02-21T07:49:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=69050f8d6d075dc01af7a5f2f550a8067510366f'/>
<id>69050f8d6d075dc01af7a5f2f550a8067510366f</id>
<content type='text'>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Add a map/btf from a fd array more consistently</title>
<updated>2026-02-13T22:37:02+00:00</updated>
<author>
<name>Anton Protopopov</name>
<email>a.s.protopopov@gmail.com</email>
</author>
<published>2026-02-13T21:29:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b0b1a8583d8e797114e613139e3e3318a1704690'/>
<id>b0b1a8583d8e797114e613139e3e3318a1704690</id>
<content type='text'>
The add_fd_from_fd_array() function takes a file descriptor as a
parameter and tries to add either map or btf to the corresponding
list of used objects. As was reported by Dan Carpenter, since the
commit c81e4322acf0 ("bpf: Fix a potential use-after-free of BTF
object"), the fdget() is called twice on the file descriptor, and
thus userspace, potentially, can replace the file pointed to by the
file descriptor in between the two calls. On practice, this shouldn't
break anything on the kernel side, but for consistency fix the code
such that only one fdget() is executed.

Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Closes: https://lore.kernel.org/r/aY689z7gHNv8rgVO@stanley.mountain/
Fixes: ccd2d799ed44 ("bpf: Fix a potential use-after-free of BTF object")
Signed-off-by: Anton Protopopov &lt;a.s.protopopov@gmail.com&gt;
Link: https://lore.kernel.org/r/20260213212949.759321-1-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The add_fd_from_fd_array() function takes a file descriptor as a
parameter and tries to add either map or btf to the corresponding
list of used objects. As was reported by Dan Carpenter, since the
commit c81e4322acf0 ("bpf: Fix a potential use-after-free of BTF
object"), the fdget() is called twice on the file descriptor, and
thus userspace, potentially, can replace the file pointed to by the
file descriptor in between the two calls. On practice, this shouldn't
break anything on the kernel side, but for consistency fix the code
such that only one fdget() is executed.

Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Closes: https://lore.kernel.org/r/aY689z7gHNv8rgVO@stanley.mountain/
Fixes: ccd2d799ed44 ("bpf: Fix a potential use-after-free of BTF object")
Signed-off-by: Anton Protopopov &lt;a.s.protopopov@gmail.com&gt;
Link: https://lore.kernel.org/r/20260213212949.759321-1-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Fix a potential use-after-free of BTF object</title>
<updated>2026-02-13T22:14:27+00:00</updated>
<author>
<name>Anton Protopopov</name>
<email>a.s.protopopov@gmail.com</email>
</author>
<published>2026-02-09T13:29:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ccd2d799ed4467c07f5ee18c2f5c59bcc990822c'/>
<id>ccd2d799ed4467c07f5ee18c2f5c59bcc990822c</id>
<content type='text'>
Refcounting in the check_pseudo_btf_id() function is incorrect:
the __check_pseudo_btf_id() function might get called with a zero
refcounted btf. Fix this, and patch related code accordingly.

v3: rephrase a comment (AI)
v2: fix a refcount leak introduced in v1 (AI)

Reported-by: syzbot+5a0f1995634f7c1dadbf@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=5a0f1995634f7c1dadbf
Fixes: 76145f725532 ("bpf: Refactor check_pseudo_btf_id")
Signed-off-by: Anton Protopopov &lt;a.s.protopopov@gmail.com&gt;
Link: https://lore.kernel.org/r/20260209132904.63908-1-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Refcounting in the check_pseudo_btf_id() function is incorrect:
the __check_pseudo_btf_id() function might get called with a zero
refcounted btf. Fix this, and patch related code accordingly.

v3: rephrase a comment (AI)
v2: fix a refcount leak introduced in v1 (AI)

Reported-by: syzbot+5a0f1995634f7c1dadbf@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=5a0f1995634f7c1dadbf
Fixes: 76145f725532 ("bpf: Refactor check_pseudo_btf_id")
Signed-off-by: Anton Protopopov &lt;a.s.protopopov@gmail.com&gt;
Link: https://lore.kernel.org/r/20260209132904.63908-1-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2026-02-12T20:13:01+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-12T20:13:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=136114e0abf03005e182d75761ab694648e6d388'/>
<id>136114e0abf03005e182d75761ab694648e6d388</id>
<content type='text'>
Pull non-MM updates from Andrew Morton:

 - "ocfs2: give ocfs2 the ability to reclaim suballocator free bg" saves
   disk space by teaching ocfs2 to reclaim suballocator block group
   space (Heming Zhao)

 - "Add ARRAY_END(), and use it to fix off-by-one bugs" adds the
   ARRAY_END() macro and uses it in various places (Alejandro Colomar)

 - "vmcoreinfo: support VMCOREINFO_BYTES larger than PAGE_SIZE" makes
   the vmcore code future-safe, if VMCOREINFO_BYTES ever exceeds the
   page size (Pnina Feder)

 - "kallsyms: Prevent invalid access when showing module buildid" cleans
   up kallsyms code related to module buildid and fixes an invalid
   access crash when printing backtraces (Petr Mladek)

 - "Address page fault in ima_restore_measurement_list()" fixes a
   kexec-related crash that can occur when booting the second-stage
   kernel on x86 (Harshit Mogalapalli)

 - "kho: ABI headers and Documentation updates" updates the kexec
   handover ABI documentation (Mike Rapoport)

 - "Align atomic storage" adds the __aligned attribute to atomic_t and
   atomic64_t definitions to get natural alignment of both types on
   csky, m68k, microblaze, nios2, openrisc and sh (Finn Thain)

 - "kho: clean up page initialization logic" simplifies the page
   initialization logic in kho_restore_page() (Pratyush Yadav)

 - "Unload linux/kernel.h" moves several things out of kernel.h and into
   more appropriate places (Yury Norov)

 - "don't abuse task_struct.group_leader" removes the usage of
   -&gt;group_leader when it is "obviously unnecessary" (Oleg Nesterov)

 - "list private v2 &amp; luo flb" adds some infrastructure improvements to
   the live update orchestrator (Pasha Tatashin)

* tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (107 commits)
  watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency
  procfs: fix missing RCU protection when reading real_parent in do_task_stat()
  watchdog/softlockup: fix sample ring index wrap in need_counting_irqs()
  kcsan, compiler_types: avoid duplicate type issues in BPF Type Format
  kho: fix doc for kho_restore_pages()
  tests/liveupdate: add in-kernel liveupdate test
  liveupdate: luo_flb: introduce File-Lifecycle-Bound global state
  liveupdate: luo_file: Use private list
  list: add kunit test for private list primitives
  list: add primitives for private list manipulations
  delayacct: fix uapi timespec64 definition
  panic: add panic_force_cpu= parameter to redirect panic to a specific CPU
  netclassid: use thread_group_leader(p) in update_classid_task()
  RDMA/umem: don't abuse current-&gt;group_leader
  drm/pan*: don't abuse current-&gt;group_leader
  drm/amd: kill the outdated "Only the pthreads threading model is supported" checks
  drm/amdgpu: don't abuse current-&gt;group_leader
  android/binder: use same_thread_group(proc-&gt;tsk, current) in binder_mmap()
  android/binder: don't abuse current-&gt;group_leader
  kho: skip memoryless NUMA nodes when reserving scratch areas
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull non-MM updates from Andrew Morton:

 - "ocfs2: give ocfs2 the ability to reclaim suballocator free bg" saves
   disk space by teaching ocfs2 to reclaim suballocator block group
   space (Heming Zhao)

 - "Add ARRAY_END(), and use it to fix off-by-one bugs" adds the
   ARRAY_END() macro and uses it in various places (Alejandro Colomar)

 - "vmcoreinfo: support VMCOREINFO_BYTES larger than PAGE_SIZE" makes
   the vmcore code future-safe, if VMCOREINFO_BYTES ever exceeds the
   page size (Pnina Feder)

 - "kallsyms: Prevent invalid access when showing module buildid" cleans
   up kallsyms code related to module buildid and fixes an invalid
   access crash when printing backtraces (Petr Mladek)

 - "Address page fault in ima_restore_measurement_list()" fixes a
   kexec-related crash that can occur when booting the second-stage
   kernel on x86 (Harshit Mogalapalli)

 - "kho: ABI headers and Documentation updates" updates the kexec
   handover ABI documentation (Mike Rapoport)

 - "Align atomic storage" adds the __aligned attribute to atomic_t and
   atomic64_t definitions to get natural alignment of both types on
   csky, m68k, microblaze, nios2, openrisc and sh (Finn Thain)

 - "kho: clean up page initialization logic" simplifies the page
   initialization logic in kho_restore_page() (Pratyush Yadav)

 - "Unload linux/kernel.h" moves several things out of kernel.h and into
   more appropriate places (Yury Norov)

 - "don't abuse task_struct.group_leader" removes the usage of
   -&gt;group_leader when it is "obviously unnecessary" (Oleg Nesterov)

 - "list private v2 &amp; luo flb" adds some infrastructure improvements to
   the live update orchestrator (Pasha Tatashin)

* tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (107 commits)
  watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency
  procfs: fix missing RCU protection when reading real_parent in do_task_stat()
  watchdog/softlockup: fix sample ring index wrap in need_counting_irqs()
  kcsan, compiler_types: avoid duplicate type issues in BPF Type Format
  kho: fix doc for kho_restore_pages()
  tests/liveupdate: add in-kernel liveupdate test
  liveupdate: luo_flb: introduce File-Lifecycle-Bound global state
  liveupdate: luo_file: Use private list
  list: add kunit test for private list primitives
  list: add primitives for private list manipulations
  delayacct: fix uapi timespec64 definition
  panic: add panic_force_cpu= parameter to redirect panic to a specific CPU
  netclassid: use thread_group_leader(p) in update_classid_task()
  RDMA/umem: don't abuse current-&gt;group_leader
  drm/pan*: don't abuse current-&gt;group_leader
  drm/amd: kill the outdated "Only the pthreads threading model is supported" checks
  drm/amdgpu: don't abuse current-&gt;group_leader
  android/binder: use same_thread_group(proc-&gt;tsk, current) in binder_mmap()
  android/binder: don't abuse current-&gt;group_leader
  kho: skip memoryless NUMA nodes when reserving scratch areas
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Switch to bpf_selem_unlink_nofail in bpf_local_storage_{map_free, destroy}</title>
<updated>2026-02-06T22:47:59+00:00</updated>
<author>
<name>Amery Hung</name>
<email>ameryhung@gmail.com</email>
</author>
<published>2026-02-05T22:29:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0be08389c7f2f9db0194ee666d2e4870886e6ffb'/>
<id>0be08389c7f2f9db0194ee666d2e4870886e6ffb</id>
<content type='text'>
Take care of rqspinlock error in bpf_local_storage_{map_free, destroy}()
properly by switching to bpf_selem_unlink_nofail().

Both functions iterate their own RCU-protected list of selems and call
bpf_selem_unlink_nofail(). In map_free(), to prevent infinite loop when
both map_free() and destroy() fail to remove a selem from b-&gt;list
(extremely unlikely), switch to hlist_for_each_entry_rcu(). In destroy(),
also switch to hlist_for_each_entry_rcu() since we no longer iterate
local_storage-&gt;list under local_storage-&gt;lock.

bpf_selem_unlink() now becomes dedicated to helpers and syscalls paths
so reuse_now should always be false. Remove it from the argument and
hardcode it.

Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Co-developed-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Signed-off-by: Amery Hung &lt;ameryhung@gmail.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Link: https://patch.msgid.link/20260205222916.1788211-12-ameryhung@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Take care of rqspinlock error in bpf_local_storage_{map_free, destroy}()
properly by switching to bpf_selem_unlink_nofail().

Both functions iterate their own RCU-protected list of selems and call
bpf_selem_unlink_nofail(). In map_free(), to prevent infinite loop when
both map_free() and destroy() fail to remove a selem from b-&gt;list
(extremely unlikely), switch to hlist_for_each_entry_rcu(). In destroy(),
also switch to hlist_for_each_entry_rcu() since we no longer iterate
local_storage-&gt;list under local_storage-&gt;lock.

bpf_selem_unlink() now becomes dedicated to helpers and syscalls paths
so reuse_now should always be false. Remove it from the argument and
hardcode it.

Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Co-developed-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Signed-off-by: Amery Hung &lt;ameryhung@gmail.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Link: https://patch.msgid.link/20260205222916.1788211-12-ameryhung@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Support lockless unlink when freeing map or local storage</title>
<updated>2026-02-06T22:47:47+00:00</updated>
<author>
<name>Amery Hung</name>
<email>ameryhung@gmail.com</email>
</author>
<published>2026-02-05T22:29:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5d800f87d0a5ea1b156c47a4b9fd128479335153'/>
<id>5d800f87d0a5ea1b156c47a4b9fd128479335153</id>
<content type='text'>
Introduce bpf_selem_unlink_nofail() to properly handle errors returned
from rqspinlock in bpf_local_storage_map_free() and
bpf_local_storage_destroy() where the operation must succeeds.

The idea of bpf_selem_unlink_nofail() is to allow an selem to be
partially linked and use atomic operation on a bit field, selem-&gt;state,
to determine when and who can free the selem if any unlink under lock
fails. An selem initially is fully linked to a map and a local storage.
Under normal circumstances, bpf_selem_unlink_nofail() will be able to
grab locks and unlink a selem from map and local storage in sequeunce,
just like bpf_selem_unlink(), and then free it after an RCU grace period.
However, if any of the lock attempts fails, it will only clear
SDATA(selem)-&gt;smap or selem-&gt;local_storage depending on the caller and
set SELEM_MAP_UNLINKED or SELEM_STORAGE_UNLINKED according to the
caller. Then, after both map_free() and destroy() see the selem and the
state becomes SELEM_UNLINKED, one of two racing caller can succeed in
cmpxchg the state from SELEM_UNLINKED to SELEM_TOFREE, ensuring no
double free or memory leak.

To make sure bpf_obj_free_fields() is done only once and when map is
still present, it is called when unlinking an selem from b-&gt;list under
b-&gt;lock.

To make sure uncharging memory is done only when the owner is still
present in map_free(), block destroy() from returning until there is no
pending map_free().

Since smap may not be valid in destroy(), bpf_selem_unlink_nofail()
skips bpf_selem_unlink_storage_nolock_misc() when called from destroy().
This is okay as bpf_local_storage_destroy() will return the remaining
amount of memory charge tracked by mem_charge to the owner to uncharge.
It is also safe to skip clearing local_storage-&gt;owner and owner_storage
as the owner is being freed and no users or bpf programs should be able
to reference the owner and using local_storage.

Finally, access of selem, SDATA(selem)-&gt;smap and selem-&gt;local_storage
are racy. Callers will protect these fields with RCU.

Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Co-developed-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Signed-off-by: Amery Hung &lt;ameryhung@gmail.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Link: https://patch.msgid.link/20260205222916.1788211-11-ameryhung@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce bpf_selem_unlink_nofail() to properly handle errors returned
from rqspinlock in bpf_local_storage_map_free() and
bpf_local_storage_destroy() where the operation must succeeds.

The idea of bpf_selem_unlink_nofail() is to allow an selem to be
partially linked and use atomic operation on a bit field, selem-&gt;state,
to determine when and who can free the selem if any unlink under lock
fails. An selem initially is fully linked to a map and a local storage.
Under normal circumstances, bpf_selem_unlink_nofail() will be able to
grab locks and unlink a selem from map and local storage in sequeunce,
just like bpf_selem_unlink(), and then free it after an RCU grace period.
However, if any of the lock attempts fails, it will only clear
SDATA(selem)-&gt;smap or selem-&gt;local_storage depending on the caller and
set SELEM_MAP_UNLINKED or SELEM_STORAGE_UNLINKED according to the
caller. Then, after both map_free() and destroy() see the selem and the
state becomes SELEM_UNLINKED, one of two racing caller can succeed in
cmpxchg the state from SELEM_UNLINKED to SELEM_TOFREE, ensuring no
double free or memory leak.

To make sure bpf_obj_free_fields() is done only once and when map is
still present, it is called when unlinking an selem from b-&gt;list under
b-&gt;lock.

To make sure uncharging memory is done only when the owner is still
present in map_free(), block destroy() from returning until there is no
pending map_free().

Since smap may not be valid in destroy(), bpf_selem_unlink_nofail()
skips bpf_selem_unlink_storage_nolock_misc() when called from destroy().
This is okay as bpf_local_storage_destroy() will return the remaining
amount of memory charge tracked by mem_charge to the owner to uncharge.
It is also safe to skip clearing local_storage-&gt;owner and owner_storage
as the owner is being freed and no users or bpf programs should be able
to reference the owner and using local_storage.

Finally, access of selem, SDATA(selem)-&gt;smap and selem-&gt;local_storage
are racy. Callers will protect these fields with RCU.

Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Co-developed-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Signed-off-by: Amery Hung &lt;ameryhung@gmail.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Link: https://patch.msgid.link/20260205222916.1788211-11-ameryhung@gmail.com
</pre>
</div>
</content>
</entry>
</feed>
