<feed xmlns='http://www.w3.org/2005/Atom'>
<title>wireguard-linux/kernel/bpf, branch jd/bump-compilers</title>
<subtitle>WireGuard for the Linux kernel</subtitle>
<id>https://git.zx2c4.com/wireguard-linux/atom/kernel/bpf?h=jd%2Fbump-compilers</id>
<link rel='self' href='https://git.zx2c4.com/wireguard-linux/atom/kernel/bpf?h=jd%2Fbump-compilers'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/'/>
<updated>2024-09-13T03:22:44Z</updated>
<entry>
<title>Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2024-09-13T03:22:44Z</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2024-09-13T03:21:50Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=3b7dc7000e7ebbabc2bc5d4efa95178333844724'/>
<id>urn:sha1:3b7dc7000e7ebbabc2bc5d4efa95178333844724</id>
<content type='text'>
Daniel Borkmann says:

====================
pull-request: bpf-next 2024-09-11

We've added 12 non-merge commits during the last 16 day(s) which contain
a total of 20 files changed, 228 insertions(+), 30 deletions(-).

There's a minor merge conflict in drivers/net/netkit.c:
  00d066a4d4ed ("netdev_features: convert NETIF_F_LLTX to dev-&gt;lltx")
  d96608794889 ("netkit: Disable netpoll support")

The main changes are:

1) Enable bpf_dynptr_from_skb for tp_btf such that this can be used
   to easily parse skbs in BPF programs attached to tracepoints,
   from Philo Lu.

2) Add a cond_resched() point in BPF's sock_hash_free() as there have
   been several syzbot soft lockup reports recently, from Eric Dumazet.

3) Fix xsk_buff_can_alloc() to account for queue_empty_descs which
   got noticed when zero copy ice driver started to use it,
   from Maciej Fijalkowski.

4) Move the xdp:xdp_cpumap_kthread tracepoint before cpumap pushes skbs
   up via netif_receive_skb_list() to better measure latencies,
   from Daniel Xu.

5) Follow-up to disable netpoll support from netkit, from Daniel Borkmann.

6) Improve xsk selftests to not assume a fixed MAX_SKB_FRAGS of 17 but
   instead gather the actual value via /proc/sys/net/core/max_skb_frags,
   also from Maciej Fijalkowski.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  sock_map: Add a cond_resched() in sock_hash_free()
  selftests/bpf: Expand skb dynptr selftests for tp_btf
  bpf: Allow bpf_dynptr_from_skb() for tp_btf
  tcp: Use skb__nullable in trace_tcp_send_reset
  selftests/bpf: Add test for __nullable suffix in tp_btf
  bpf: Support __nullable argument suffix for tp_btf
  bpf, cpumap: Move xdp:xdp_cpumap_kthread tracepoint before rcv
  selftests/xsk: Read current MAX_SKB_FRAGS from sysctl knob
  xsk: Bump xsk_queue::queue_empty_descs in xp_can_alloc()
  tcp_bpf: Remove an unused parameter for bpf_tcp_ingress()
  bpf, sockmap: Correct spelling skmsg.c
  netkit: Disable netpoll support

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
====================

Link: https://patch.msgid.link/20240911211525.13834-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: Support __nullable argument suffix for tp_btf</title>
<updated>2024-09-11T15:56:37Z</updated>
<author>
<name>Philo Lu</name>
<email>lulie@linux.alibaba.com</email>
</author>
<published>2024-09-11T03:37:15Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=8aeaed21befc90f27f4fca6dd190850d97d2e9e3'/>
<id>urn:sha1:8aeaed21befc90f27f4fca6dd190850d97d2e9e3</id>
<content type='text'>
Pointers passed to tp_btf were trusted to be valid, but some tracepoints
do take NULL pointer as input, such as trace_tcp_send_reset(). Then the
invalid memory access cannot be detected by verifier.

This patch fix it by add a suffix "__nullable" to the unreliable
argument. The suffix is shown in btf, and PTR_MAYBE_NULL will be added
to nullable arguments. Then users must check the pointer before use it.

A problem here is that we use "btf_trace_##call" to search func_proto.
As it is a typedef, argument names as well as the suffix are not
recorded. To solve this, I use bpf_raw_event_map to find
"__bpf_trace##template" from "btf_trace_##call", and then we can see the
suffix.

Suggested-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Philo Lu &lt;lulie@linux.alibaba.com&gt;
Link: https://lore.kernel.org/r/20240911033719.91468-2-lulie@linux.alibaba.com
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf, cpumap: Move xdp:xdp_cpumap_kthread tracepoint before rcv</title>
<updated>2024-09-11T14:32:11Z</updated>
<author>
<name>Daniel Xu</name>
<email>dxu@dxuuu.xyz</email>
</author>
<published>2024-09-06T01:22:44Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=23dc9867329c72b48e5039ac93fbf50d9099cdb3'/>
<id>urn:sha1:23dc9867329c72b48e5039ac93fbf50d9099cdb3</id>
<content type='text'>
cpumap takes RX processing out of softirq and onto a separate kthread.
Since the kthread needs to be scheduled in order to run (versus softirq
which does not), we can theoretically experience extra latency if the
system is under load and the scheduler is being unfair to us.

Moving the tracepoint to before passing the skb list up the stack allows
users to more accurately measure enqueue/dequeue latency introduced by
cpumap via xdp:xdp_cpumap_enqueue and xdp:xdp_cpumap_kthread tracepoints.

f9419f7bd7a5 ("bpf: cpumap add tracepoints") which added the tracepoints
states that the intent behind them was for general observability and for
a feedback loop to see if the queues are being overwhelmed. This change
does not mess with either of those use cases but rather adds a third
one.

Signed-off-by: Daniel Xu &lt;dxu@dxuuu.xyz&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Jesper Dangaard Brouer &lt;hawk@kernel.org&gt;
Link: https://lore.kernel.org/bpf/47615d5b5e302e4bd30220473779e98b492d47cd.1725585718.git.dxu@dxuuu.xyz
</content>
</entry>
<entry>
<title>bpf: add check for invalid name in btf_name_valid_section()</title>
<updated>2024-09-04T18:56:34Z</updated>
<author>
<name>Jeongjun Park</name>
<email>aha310510@gmail.com</email>
</author>
<published>2024-08-31T05:47:02Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=bb6705c3f93bed2af03d43691743d4c43e3c8e6f'/>
<id>urn:sha1:bb6705c3f93bed2af03d43691743d4c43e3c8e6f</id>
<content type='text'>
If the length of the name string is 1 and the value of name[0] is NULL
byte, an OOB vulnerability occurs in btf_name_valid_section() and the
return value is true, so the invalid name passes the check.

To solve this, you need to check if the first position is NULL byte and
if the first character is printable.

Suggested-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Fixes: bd70a8fb7ca4 ("bpf: Allow all printable characters in BTF DATASEC names")
Signed-off-by: Jeongjun Park &lt;aha310510@gmail.com&gt;
Link: https://lore.kernel.org/r/20240831054702.364455-1-aha310510@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
</content>
</entry>
<entry>
<title>bpf: Fix a crash when btf_parse_base() returns an error pointer</title>
<updated>2024-08-30T17:34:47Z</updated>
<author>
<name>Martin KaFai Lau</name>
<email>martin.lau@kernel.org</email>
</author>
<published>2024-08-30T01:22:14Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=b408473ea01b2e499d23503e2bf898416da9d7ac'/>
<id>urn:sha1:b408473ea01b2e499d23503e2bf898416da9d7ac</id>
<content type='text'>
The pointer returned by btf_parse_base could be an error pointer.
IS_ERR() check is needed before calling btf_free(base_btf).

Fixes: 8646db238997 ("libbpf,bpf: Share BTF relocate-related code with kernel")
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Reviewed-by: Alan Maguire &lt;alan.maguire@oracle.com&gt;
Acked-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20240830012214.1646005-1-martin.lau@linux.dev
</content>
</entry>
<entry>
<title>bpf: Fix a kernel verifier crash in stacksafe()</title>
<updated>2024-08-13T01:09:48Z</updated>
<author>
<name>Yonghong Song</name>
<email>yonghong.song@linux.dev</email>
</author>
<published>2024-08-12T21:48:47Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=bed2eb964c70b780fb55925892a74f26cb590b25'/>
<id>urn:sha1:bed2eb964c70b780fb55925892a74f26cb590b25</id>
<content type='text'>
Daniel Hodges reported a kernel verifier crash when playing with sched-ext.
Further investigation shows that the crash is due to invalid memory access
in stacksafe(). More specifically, it is the following code:

    if (exact != NOT_EXACT &amp;&amp;
        old-&gt;stack[spi].slot_type[i % BPF_REG_SIZE] !=
        cur-&gt;stack[spi].slot_type[i % BPF_REG_SIZE])
            return false;

The 'i' iterates old-&gt;allocated_stack.
If cur-&gt;allocated_stack &lt; old-&gt;allocated_stack the out-of-bound
access will happen.

To fix the issue add 'i &gt;= cur-&gt;allocated_stack' check such that if
the condition is true, stacksafe() should fail. Otherwise,
cur-&gt;stack[spi].slot_type[i % BPF_REG_SIZE] memory access is legal.

Fixes: 2793a8b015f7 ("bpf: exact states comparison for iterator convergence checks")
Cc: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Reported-by: Daniel Hodges &lt;hodgesd@meta.com&gt;
Acked-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Signed-off-by: Yonghong Song &lt;yonghong.song@linux.dev&gt;
Link: https://lore.kernel.org/r/20240812214847.213612-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
</entry>
<entry>
<title>sysctl: treewide: constify the ctl_table argument of proc_handlers</title>
<updated>2024-07-24T18:59:29Z</updated>
<author>
<name>Joel Granados</name>
<email>j.granados@samsung.com</email>
</author>
<published>2024-07-24T18:59:29Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=78eb4ea25cd5fdbdae7eb9fdf87b99195ff67508'/>
<id>urn:sha1:78eb4ea25cd5fdbdae7eb9fdf87b99195ff67508</id>
<content type='text'>
const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.

This patch has been generated by the following coccinelle script:

```
  virtual patch

  @r1@
  identifier ctl, write, buffer, lenp, ppos;
  identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

  @r2@
  identifier func, ctl, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos)
  { ... }

  @r3@
  identifier func;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int , void *, size_t *, loff_t *);

  @r4@
  identifier func, ctl;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int , void *, size_t *, loff_t *);

  @r5@
  identifier func, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

```

* Code formatting was adjusted in xfs_sysctl.c to comply with code
  conventions. The xfs_stats_clear_proc_handler,
  xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
  adjusted.

* The ctl_table argument in proc_watchdog_common was const qualified.
  This is called from a proc_handler itself and is calling back into
  another proc_handler, making it necessary to change it as part of the
  proc_handler migration.

Co-developed-by: Thomas Weißschuh &lt;linux@weissschuh.net&gt;
Signed-off-by: Thomas Weißschuh &lt;linux@weissschuh.net&gt;
Co-developed-by: Joel Granados &lt;j.granados@samsung.com&gt;
Signed-off-by: Joel Granados &lt;j.granados@samsung.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2024-07-22T00:15:46Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-07-22T00:15:46Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=fbc90c042cd1dc7258ebfebe6d226017e5b5ac8c'/>
<id>urn:sha1:fbc90c042cd1dc7258ebfebe6d226017e5b5ac8c</id>
<content type='text'>
Pull MM updates from Andrew Morton:

 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.

 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that. This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches. My
   bad.

 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"

 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability
   of cgroup writeback"

 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache
   index".

 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of
   the zeropage in MAP_SHARED mappings. I don't see any runtime effects
   here - more a cleanup/understandability/maintainablity thing.

 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
   of higher addresses, for aarch64. The (poorly named) series is
   "Restructure va_high_addr_switch".

 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".

 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
   the series "Enhance soft hwpoison handling and injection".

 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything. Some landed in this pull.

 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
   has simplified migration's use of hardware-offload memory copying.

 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".

 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code. This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.

 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.

 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP. By default this
   is a no-op - users must opt in vis sysfs controls. Dramatic
   improvements in pagefault latency are realized.

 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".

 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".

 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".

 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".

 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances. A 10x speedup is seen in a microbenchmark.

   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.

 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".

 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.

 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.

 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".

 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.

 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".

 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.

 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.

 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large
   folio userspace copying.

 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers. From SeongJae Park.

 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.

 - David Hildenbrand sends along more cleanups, this time against the
   migration code. The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".

 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code. He addresses this in the series "mm: Fix various
   readahead quirks".

 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's
   self testing code.

 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code. The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this. The series is marked cc:stable.

 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.

 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion. The series (which also makes the memcg-v1 code
   Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
   under config option" and "mm: memcg: put cgroup v1-specific memcg
   data under CONFIG_MEMCG_V1"

 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.

 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of
   excessive correctable memory errors. In order to permit userspace to
   monitor and handle this situation.

 - Kefeng Wang's series "mm: migrate: support poison recover from
   migrate folio" teaches the kernel to appropriately handle migration
   from poisoned source folios rather than simply panicing.

 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.

 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory
   utilization.

 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than
   bare refcount increments. So these paes can first be moved aside if
   they reside in the movable zone or a CMA block.

 - Andrii Nakryiko has added a binary ioctl()-based API to
   /proc/pid/maps for much faster reading of vma information. The series
   is "query VMAs from /proc/&lt;pid&gt;/maps".

 - In the series "mm: introduce per-order mTHP split counters" Lance
   Yang improves the kernel's presentation of developer information
   related to multisize THP splitting.

 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)". This permits
   userspace to use all available huge page sizes.

 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and
   not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
  mm/mglru: fix ineffective protection calculation
  mm/zswap: fix a white space issue
  mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
  mm/hugetlb: fix possible recursive locking detected warning
  mm/gup: clear the LRU flag of a page before adding to LRU batch
  mm/numa_balancing: teach mpol_to_str about the balancing mode
  mm: memcg1: convert charge move flags to unsigned long long
  alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
  lib: reuse page_ext_data() to obtain codetag_ref
  lib: add missing newline character in the warning message
  mm/mglru: fix overshooting shrinker memory
  mm/mglru: fix div-by-zero in vmpressure_calc_level()
  mm/kmemleak: replace strncpy() with strscpy()
  mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
  mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
  mm: ignore data-race in __swap_writepage
  hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
  mm: shmem: rename mTHP shmem counters
  mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
  mm/migrate: putback split folios when numa hint migration fails
  ...
</content>
</entry>
<entry>
<title>mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC</title>
<updated>2024-07-18T04:05:18Z</updated>
<author>
<name>Vlastimil Babka</name>
<email>vbabka@suse.cz</email>
</author>
<published>2024-07-11T16:35:31Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=53dabce2652fb854eae84609ce9c37429d5d87ba'/>
<id>urn:sha1:53dabce2652fb854eae84609ce9c37429d5d87ba</id>
<content type='text'>
This mostly reverts commit af3b854492f3 ("mm/page_alloc.c: allow error
injection").  The commit made should_fail_alloc_page() a noinline function
that's always called from the page allocation hotpath, even if it's empty
because CONFIG_FAIL_PAGE_ALLOC is not enabled, and there is no option to
disable it and prevent the associated function call overhead.

As with the preceding patch "mm, slab: put should_failslab back behind
CONFIG_SHOULD_FAILSLAB" and for the same reasons, put the
should_fail_alloc_page() back behind the config option.  When enabled, the
ALLOW_ERROR_INJECTION and BTF_ID records are preserved so it's not a
complete revert.

Link: https://lkml.kernel.org/r/20240711-b4-fault-injection-reverts-v1-2-9e2651945d68@suse.cz
Signed-off-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Akinobu Mita &lt;akinobu.mita@gmail.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Cc: Hao Luo &lt;haoluo@google.com&gt;
Cc: Hyeonggon Yoo &lt;42.hyeyoo@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Fastabend &lt;john.fastabend@gmail.com&gt;
Cc: KP Singh &lt;kpsingh@kernel.org&gt;
Cc: Martin KaFai Lau &lt;martin.lau@linux.dev&gt;
Cc: Mateusz Guzik &lt;mjguzik@gmail.com&gt;
Cc: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Cc: Song Liu &lt;song@kernel.org&gt;
Cc: Stanislav Fomichev &lt;sdf@fomichev.me&gt;
Cc: Yonghong Song &lt;yonghong.song@linux.dev&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB</title>
<updated>2024-07-18T04:05:18Z</updated>
<author>
<name>Vlastimil Babka</name>
<email>vbabka@suse.cz</email>
</author>
<published>2024-07-11T16:35:30Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=a7526fe8b94eced7d82aa00b2bcca44e39ae0769'/>
<id>urn:sha1:a7526fe8b94eced7d82aa00b2bcca44e39ae0769</id>
<content type='text'>
Patch series "revert unconditional slab and page allocator fault injection
calls".

These two patches largely revert commits that added function call overhead
into slab and page allocation hotpaths and that cannot be currently
disabled even though related CONFIG_ options do exist.

A much more involved solution that can keep the callsites always existing
but hidden behind a static key if unused, is possible [1] and can be
pursued by anyone who believes it's necessary.  Meanwhile the fact the
should_failslab() error injection is already not functional on kernels
built with current gcc without anyone noticing [2], and lukewarm response
to [1] suggests the need is not there.  I believe it will be more fair to
have the state after this series as a baseline for possible further
optimisation, instead of the unconditional overhead.

For example a possible compromise for anyone who's fine with an empty
function call overhead but not the full CONFIG_FAILSLAB /
CONFIG_FAIL_PAGE_ALLOC overhead is to reuse patch 1 from [1] but insert a
static key check only inside should_failslab() and
should_fail_alloc_page() before performing the more expensive checks.

[1] https://lore.kernel.org/all/20240620-fault-injection-statickeys-v2-0-e23947d3d84b@suse.cz/#t
[2] https://github.com/bpftrace/bpftrace/issues/3258


This patch (of 2):

This mostly reverts commit 4f6923fbb352 ("mm: make should_failslab always
available for fault injection").  The commit made should_failslab() a
noinline function that's always called from the slab allocation hotpath,
even if it's empty because CONFIG_SHOULD_FAILSLAB is not enabled, and
there is no option to disable that call.  This is visible in profiles and
the function call overhead can be noticeable especially with cpu
mitigations.

Meanwhile the bpftrace program example in the commit silently does not
work without CONFIG_SHOULD_FAILSLAB anyway with a recent gcc, because the
empty function gets a .constprop clone that is actually being called
(uselessly) from the slab hotpath, while the error injection is hooked to
the original function that's not being called at all [1].

Thus put the whole should_failslab() function back behind
CONFIG_SHOULD_FAILSLAB.  It's not a complete revert of 4f6923fbb352 - the
int return type that returns -ENOMEM on failure is preserved, as well
ALLOW_ERROR_INJECTION annotation.  The BTF_ID() record that was meanwhile
added is also guarded by CONFIG_SHOULD_FAILSLAB.

[1] https://github.com/bpftrace/bpftrace/issues/3258

Link: https://lkml.kernel.org/r/20240711-b4-fault-injection-reverts-v1-0-9e2651945d68@suse.cz
Link: https://lkml.kernel.org/r/20240711-b4-fault-injection-reverts-v1-1-9e2651945d68@suse.cz
Signed-off-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Akinobu Mita &lt;akinobu.mita@gmail.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Cc: Hao Luo &lt;haoluo@google.com&gt;
Cc: Hyeonggon Yoo &lt;42.hyeyoo@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Fastabend &lt;john.fastabend@gmail.com&gt;
Cc: KP Singh &lt;kpsingh@kernel.org&gt;
Cc: Martin KaFai Lau &lt;martin.lau@linux.dev&gt;
Cc: Mateusz Guzik &lt;mjguzik@gmail.com&gt;
Cc: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Cc: Song Liu &lt;song@kernel.org&gt;
Cc: Stanislav Fomichev &lt;sdf@fomichev.me&gt;
Cc: Yonghong Song &lt;yonghong.song@linux.dev&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
</feed>
