Commit Graph

45240 Commits

Author SHA1 Message Date
Huang Ying
99185c10d5 resource, kunit: add test case for region_intersects()
Patch series "resource: Fix region_intersects() vs
add_memory_driver_managed()", v3.

The patchset fixes a bug of region_intersects() for systems with CXL
memory.  The details of the bug can be found in [1/3].  To avoid similar
bugs in the future.  A kunit test case for region_intersects() is added in
[3/3].  [2/3] is a preparation patch for [3/3].


This patch (of 3):

region_intersects() is important because it's used for /dev/mem permission
checking.  To avoid possible bug of region_intersects() in the future, a
kunit test case for region_intersects() is added.

Link: https://lkml.kernel.org/r/20240906030713.204292-1-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20240906030713.204292-4-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-17 01:07:00 -07:00
Huang Ying
bacf9c3cbb resource: make alloc_free_mem_region() works for iomem_resource
During developing a kunit test case for region_intersects(), some fake
resources need to be inserted into iomem_resource.  To do that, a resource
hole needs to be found first in iomem_resource.

However, alloc_free_mem_region() cannot work for iomem_resource now. 
Because the start address to check cannot be 0 to detect address wrapping
0 in gfr_continue(), while iomem_resource.start == 0.  To make
alloc_free_mem_region() works for iomem_resource, gfr_start() is changed
to avoid to return 0 even if base->start == 0.  We don't need to check 0
as start address.

Link: https://lkml.kernel.org/r/20240906030713.204292-3-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-17 01:07:00 -07:00
Kinsey Ho
0e40cf2a8b cgroup: clarify css sibling linkage is protected by cgroup_mutex or RCU
Patch series "Improve mem_cgroup_iter()", v4.

Incremental cgroup iteration is being used again [1]. This patchset
improves the reliability of mem_cgroup_iter(). It also improves
simplicity and code readability.

[1] https://lore.kernel.org/20240514202641.2821494-1-hannes@cmpxchg.org/


This patch (of 5):

Explicitly document that css sibling/descendant linkage is protected by
cgroup_mutex or RCU.  Also, document in css_next_descendant_pre() and
similar functions that it isn't necessary to hold a ref on @pos.

The following changes in this patchset rely on this clarification for
simplification in memcg iteration code.

Link: https://lkml.kernel.org/r/20240905003058.1859929-1-kinseyho@google.com
Link: https://lkml.kernel.org/r/20240905003058.1859929-2-kinseyho@google.com
Suggested-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:15 -07:00
Sven Schnelle
08e28de116 uprobes: use vm_special_mapping close() functionality
The following KASAN splat was shown:

[   44.505448] ==================================================================                                                                      20:37:27 [3421/145075]
[   44.505455] BUG: KASAN: slab-use-after-free in special_mapping_close+0x9c/0xc8
[   44.505471] Read of size 8 at addr 00000000868dac48 by task sh/1384
[   44.505479]
[   44.505486] CPU: 51 UID: 0 PID: 1384 Comm: sh Not tainted 6.11.0-rc6-next-20240902-dirty #1496
[   44.505503] Hardware name: IBM 3931 A01 704 (z/VM 7.3.0)
[   44.505508] Call Trace:
[   44.505511]  [<000b0324d2f78080>] dump_stack_lvl+0xd0/0x108
[   44.505521]  [<000b0324d2f5435c>] print_address_description.constprop.0+0x34/0x2e0
[   44.505529]  [<000b0324d2f5464c>] print_report+0x44/0x138
[   44.505536]  [<000b0324d1383192>] kasan_report+0xc2/0x140
[   44.505543]  [<000b0324d2f52904>] special_mapping_close+0x9c/0xc8
[   44.505550]  [<000b0324d12c7978>] remove_vma+0x78/0x120
[   44.505557]  [<000b0324d128a2c6>] exit_mmap+0x326/0x750
[   44.505563]  [<000b0324d0ba655a>] __mmput+0x9a/0x370
[   44.505570]  [<000b0324d0bbfbe0>] exit_mm+0x240/0x340
[   44.505575]  [<000b0324d0bc0228>] do_exit+0x548/0xd70
[   44.505580]  [<000b0324d0bc1102>] do_group_exit+0x132/0x390
[   44.505586]  [<000b0324d0bc13b6>] __s390x_sys_exit_group+0x56/0x60
[   44.505592]  [<000b0324d0adcbd6>] do_syscall+0x2f6/0x430
[   44.505599]  [<000b0324d2f78434>] __do_syscall+0xa4/0x170
[   44.505606]  [<000b0324d2f9454c>] system_call+0x74/0x98
[   44.505614]
[   44.505616] Allocated by task 1384:
[   44.505621]  kasan_save_stack+0x40/0x70
[   44.505630]  kasan_save_track+0x28/0x40
[   44.505636]  __kasan_kmalloc+0xa0/0xc0
[   44.505642]  __create_xol_area+0xfa/0x410
[   44.505648]  get_xol_area+0xb0/0xf0
[   44.505652]  uprobe_notify_resume+0x27a/0x470
[   44.505657]  irqentry_exit_to_user_mode+0x15e/0x1d0
[   44.505664]  pgm_check_handler+0x122/0x170
[   44.505670]
[   44.505672] Freed by task 1384:
[   44.505676]  kasan_save_stack+0x40/0x70
[   44.505682]  kasan_save_track+0x28/0x40
[   44.505687]  kasan_save_free_info+0x4a/0x70
[   44.505693]  __kasan_slab_free+0x5a/0x70
[   44.505698]  kfree+0xe8/0x3f0
[   44.505704]  __mmput+0x20/0x370
[   44.505709]  exit_mm+0x240/0x340
[   44.505713]  do_exit+0x548/0xd70
[   44.505718]  do_group_exit+0x132/0x390
[   44.505722]  __s390x_sys_exit_group+0x56/0x60
[   44.505727]  do_syscall+0x2f6/0x430
[   44.505732]  __do_syscall+0xa4/0x170
[   44.505738]  system_call+0x74/0x98

The problem is that uprobe_clear_state() kfree's struct xol_area, which
contains struct vm_special_mapping *xol_mapping. This one is passed to
_install_special_mapping() in xol_add_vma().
__mput reads:

static inline void __mmput(struct mm_struct *mm)
{
        VM_BUG_ON(atomic_read(&mm->mm_users));

        uprobe_clear_state(mm);
        exit_aio(mm);
        ksm_exit(mm);
        khugepaged_exit(mm); /* must run before exit_mmap */
        exit_mmap(mm);
        ...
}

So uprobe_clear_state() in the beginning free's the memory area
containing the vm_special_mapping data, but exit_mmap() uses this
address later via vma->vm_private_data (which was set in
_install_special_mapping().

Fix this by moving uprobe_clear_state() to uprobes.c and use it as
close() callback.

[usama.anjum@collabora.com: remove unneeded condition]
  Link: https://lkml.kernel.org/r/20240906101825.177490-1-usama.anjum@collabora.com
Link: https://lkml.kernel.org/r/20240903073629.2442754-1-svens@linux.ibm.com
Fixes: 223febc6e5 ("mm: add optional close() to struct vm_special_mapping")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:14 -07:00
Yujie Liu
f22cde4371 sched/numa: Fix the vma scan starving issue
Problem statement:
Since commit fc137c0dda ("sched/numa: enhance vma scanning logic"), the
Numa vma scan overhead has been reduced a lot.  Meanwhile, the reducing of
the vma scan might create less Numa page fault information.  The
insufficient information makes it harder for the Numa balancer to make
decision.  Later, commit b7a5b537c5 ("sched/numa: Complete scanning of
partial VMAs regardless of PID activity") and commit 84db47ca71
("sched/numa: Fix mm numa_scan_seq based unconditional scan") are found to
bring back part of the performance.

Recently when running SPECcpu omnetpp_r on a 320 CPUs/2 Sockets system, a
long duration of remote Numa node read was observed by PMU events: A few
cores having ~500MB/s remote memory access for ~20 seconds.  It causes
high core-to-core variance and performance penalty.  After the
investigation, it is found that many vmas are skipped due to the active
PID check.  According to the trace events, in most cases,
vma_is_accessed() returns false because the history access info stored in
pids_active array has been cleared.

Proposal:
The main idea is to adjust vma_is_accessed() to let it return true easier.
Thus compare the diff between mm->numa_scan_seq and
vma->numab_state->prev_scan_seq.  If the diff has exceeded the threshold,
scan the vma.

This patch especially helps the cases where there are small number of
threads, like the process-based SPECcpu.  Without this patch, if the
SPECcpu process access the vma at the beginning, then sleeps for a long
time, the pid_active array will be cleared.  A a result, if this process
is woken up again, it never has a chance to set prot_none anymore. 
Because only the first 2 times of access is granted for vma scan:
(current->mm->numa_scan_seq) - vma->numab_state->start_scan_seq) < 2 to be
worse, no other threads within the task can help set the prot_none.  This
causes information lost.

Raghavendra helped test current patch and got the positive result
on the AMD platform:

autonumabench NUMA01
                            base                  patched
Amean     syst-NUMA01      194.05 (   0.00%)      165.11 *  14.92%*
Amean     elsp-NUMA01      324.86 (   0.00%)      315.58 *   2.86%*

Duration User      380345.36   368252.04
Duration System      1358.89     1156.23
Duration Elapsed     2277.45     2213.25

autonumabench NUMA02

Amean     syst-NUMA02        1.12 (   0.00%)        1.09 *   2.93%*
Amean     elsp-NUMA02        3.50 (   0.00%)        3.56 *  -1.84%*

Duration User        1513.23     1575.48
Duration System         8.33        8.13
Duration Elapsed       28.59       29.71

kernbench

Amean     user-256    22935.42 (   0.00%)    22535.19 *   1.75%*
Amean     syst-256     7284.16 (   0.00%)     7608.72 *  -4.46%*
Amean     elsp-256      159.01 (   0.00%)      158.17 *   0.53%*

Duration User       68816.41    67615.74
Duration System     21873.94    22848.08
Duration Elapsed      506.66      504.55

Intel 256 CPUs/2 Sockets:
autonuma benchmark also shows improvements:

                                               v6.10-rc5              v6.10-rc5
                                                                         +patch
Amean     syst-NUMA01                  245.85 (   0.00%)      230.84 *   6.11%*
Amean     syst-NUMA01_THREADLOCAL      205.27 (   0.00%)      191.86 *   6.53%*
Amean     syst-NUMA02                   18.57 (   0.00%)       18.09 *   2.58%*
Amean     syst-NUMA02_SMT                2.63 (   0.00%)        2.54 *   3.47%*
Amean     elsp-NUMA01                  517.17 (   0.00%)      526.34 *  -1.77%*
Amean     elsp-NUMA01_THREADLOCAL       99.92 (   0.00%)      100.59 *  -0.67%*
Amean     elsp-NUMA02                   15.81 (   0.00%)       15.72 *   0.59%*
Amean     elsp-NUMA02_SMT               13.23 (   0.00%)       12.89 *   2.53%*

                   v6.10-rc5   v6.10-rc5
                                  +patch
Duration User     1064010.16  1075416.23
Duration System      3307.64     3104.66
Duration Elapsed     4537.54     4604.73

The SPECcpu remote node access issue disappears with the patch applied.

Link: https://lkml.kernel.org/r/20240827112958.181388-1-yu.c.chen@intel.com
Fixes: fc137c0dda ("sched/numa: enhance vma scanning logic")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Yujie Liu <yujie.liu@intel.com>
Reported-by: Xiaoping Zhou <xiaoping.zhou@intel.com>
Reviewed-and-tested-by: Raghavendra K T <raghavendra.kt@amd.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: "Chen, Tim C" <tim.c.chen@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:56 -07:00
Matthew Wilcox (Oracle)
4ffca5a966 mm: support only one page_type per page
By using a few values in the top byte, users of page_type can store up to
24 bits of additional data in page_type.  It also reduces the code size as
(with replacement of READ_ONCE() with data_race()), the kernel can check
just a single byte.  eg:

ffffffff811e3a79:       8b 47 30                mov    0x30(%rdi),%eax
ffffffff811e3a7c:       55                      push   %rbp
ffffffff811e3a7d:       48 89 e5                mov    %rsp,%rbp
ffffffff811e3a80:       25 00 00 00 82          and    $0x82000000,%eax
ffffffff811e3a85:       3d 00 00 00 80          cmp    $0x80000000,%eax
ffffffff811e3a8a:       74 4d                   je     ffffffff811e3ad9 <folio_mapping+0x69>

becomes:

ffffffff811e3a69:       80 7f 33 f5             cmpb   $0xf5,0x33(%rdi)
ffffffff811e3a6d:       55                      push   %rbp
ffffffff811e3a6e:       48 89 e5                mov    %rsp,%rbp
ffffffff811e3a71:       74 4d                   je     ffffffff811e3ac0 <folio_mapping+0x60>

replacing three instructions with one.

[wangkefeng.wang@huawei.com: fix ubsan warnings]
  Link: https://lkml.kernel.org/r/2d19c48a-c550-4345-bf36-d05cd303c5de@huawei.com
Link: https://lkml.kernel.org/r/20240821173914.2270383-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:43 -07:00
Mike Rapoport (Microsoft)
0e8b67982b mm: move kernel/numa.c to mm/
Patch series "mm: introduce numa_memblks", v4.

Following the discussion about handling of CXL fixed memory windows on
arm64 [1] I decided to bite the bullet and move numa_memblks from x86 to
the generic code so they will be available on arm64/riscv and maybe on
loongarch sometime later.

While it could be possible to use memblock to describe CXL memory windows,
it currently lacks notion of unpopulated memory ranges and numa_memblks
does implement this.

Another reason to make numa_memblks generic is that both arch_numa (arm64
and riscv) and loongarch use trimmed copy of x86 code although there is no
fundamental reason why the same code cannot be used on all these
platforms.  Having numa_memblks in mm/ will make it's interaction with
ACPI and FDT more consistent and I believe will reduce maintenance burden.

And with generic numa_memblks it is (almost) straightforward to enable
NUMA emulation on arm64 and riscv.

The first 9 commits in this series are cleanups that are not strictly
related to numa_memblks.
Commits 10-16 slightly reorder code in x86 to allow extracting numa_memblks
and NUMA emulation to the generic code.
Commits 17-19 actually move the code from arch/x86/ to mm/ and commits 20-22
does some aftermath cleanups.
Commit 23 updates of_numa_init() to return error of no NUMA nodes were
found in the device tree.
Commit 24 switches arch_numa to numa_memblks.
Commit 25 enables usage of phys_to_target_node() and
memory_add_physaddr_to_nid() with numa_memblks.
Commit 26 moves the description for numa=fake from x86 to admin-guide.

[1] https://lore.kernel.org/all/20240529171236.32002-1-Jonathan.Cameron@huawei.com/


This patch (of 26):

The stub functions in kernel/numa.c belong to mm/ rather than to kernel/

Link: https://lkml.kernel.org/r/20240807064110.1003856-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20240807064110.1003856-2-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Zi Yan <ziy@nvidia.com> # for x86_64 and arm64
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> [arm64 + CXL via QEMU]
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Rob Herring (Arm) <robh@kernel.org>
Cc: Samuel Holland <samuel.holland@sifive.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:26 -07:00
Kaiyang Zhao
03790c51a4 mm: create promo_wmark_pages and clean up open-coded sites
Patch series "mm: print the promo watermark in zoneinfo", v2.


This patch (of 2):

Define promo_wmark_pages and convert current call sites of wmark_pages
with fixed WMARK_PROMO to using it instead.

Link: https://lkml.kernel.org/r/20240801232548.36604-1-kaiyang2@cs.cmu.edu
Link: https://lkml.kernel.org/r/20240801232548.36604-2-kaiyang2@cs.cmu.edu
Signed-off-by: Kaiyang Zhao <kaiyang2@cs.cmu.edu>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:58 -07:00
David Finkel
c6f53ed8f2 mm, memcg: cg2 memory{.swap,}.peak write handlers
Patch series "mm, memcg: cg2 memory{.swap,}.peak write handlers", v7.


This patch (of 2):

Other mechanisms for querying the peak memory usage of either a process or
v1 memory cgroup allow for resetting the high watermark.  Restore parity
with those mechanisms, but with a less racy API.

For example:
 - Any write to memory.max_usage_in_bytes in a cgroup v1 mount resets
   the high watermark.
 - writing "5" to the clear_refs pseudo-file in a processes's proc
   directory resets the peak RSS.

This change is an evolution of a previous patch, which mostly copied the
cgroup v1 behavior, however, there were concerns about races/ownership
issues with a global reset, so instead this change makes the reset
filedescriptor-local.

Writing any non-empty string to the memory.peak and memory.swap.peak
pseudo-files reset the high watermark to the current usage for subsequent
reads through that same FD.

Notably, following Johannes's suggestion, this implementation moves the
O(FDs that have written) behavior onto the FD write(2) path.  Instead, on
the page-allocation path, we simply add one additional watermark to
conditionally bump per-hierarchy level in the page-counter.

Additionally, this takes Longman's suggestion of nesting the
page-charging-path checks for the two watermarks to reduce the number of
common-case comparisons.

This behavior is particularly useful for work scheduling systems that need
to track memory usage of worker processes/cgroups per-work-item.  Since
memory can't be squeezed like CPU can (the OOM-killer has opinions), these
systems need to track the peak memory usage to compute system/container
fullness when binpacking workitems.

Most notably, Vimeo's use-case involves a system that's doing global
binpacking across many Kubernetes pods/containers, and while we can use
PSI for some local decisions about overload, we strive to avoid packing
workloads too tightly in the first place.  To facilitate this, we track
the peak memory usage.  However, since we run with long-lived workers (to
amortize startup costs) we need a way to track the high watermark while a
work-item is executing.  Polling runs the risk of missing short spikes
that last for timescales below the polling interval, and peak memory
tracking at the cgroup level is otherwise perfect for this use-case.

As this data is used to ensure that binpacked work ends up with sufficient
headroom, this use-case mostly avoids the inaccuracies surrounding
reclaimable memory.

Link: https://lkml.kernel.org/r/20240730231304.761942-1-davidf@vimeo.com
Link: https://lkml.kernel.org/r/20240729143743.34236-1-davidf@vimeo.com
Link: https://lkml.kernel.org/r/20240729143743.34236-2-davidf@vimeo.com
Signed-off-by: David Finkel <davidf@vimeo.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Waiman Long <longman@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:53 -07:00
David Hildenbrand
394290cba9 mm: turn USE_SPLIT_PTE_PTLOCKS / USE_SPLIT_PTE_PTLOCKS into Kconfig options
Patch series "mm: split PTE/PMD PT table Kconfig cleanups+clarifications".

This series is a follow up to the fixes:
	"[PATCH v1 0/2] mm/hugetlb: fix hugetlb vs. core-mm PT locking"

When working on the fixes, I wondered why 8xx is fine (-> never uses split
PT locks) and how PT locking even works properly with PMD page table
sharing (-> always requires split PMD PT locks).

Let's improve the split PT lock detection, make hugetlb properly depend on
it and make 8xx bail out if it would ever get enabled by accident.

As an alternative to patch #3 we could extend the Kconfig
SPLIT_PTE_PTLOCKS option from patch #2 -- but enforcing it closer to the
code that actually implements it feels a bit nicer for documentation
purposes, and there is no need to actually disable it because it should
always be disabled (!SMP).

Did a bunch of cross-compilations to make sure that split PTE/PMD PT locks
are still getting used where we would expect them.

[1] https://lkml.kernel.org/r/20240725183955.2268884-1-david@redhat.com


This patch (of 3):

Let's clean that up a bit and prepare for depending on
CONFIG_SPLIT_PMD_PTLOCKS in other Kconfig options.

More cleanups would be reasonable (like the arch-specific "depends on" for
CONFIG_SPLIT_PTE_PTLOCKS), but we'll leave that for another day.

Link: https://lkml.kernel.org/r/20240726150728.3159964-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240726150728.3159964-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:51 -07:00
Pasha Tatashin
fbe76a6557 task_stack: uninline stack_not_used
Given that stack_not_used() is not performance critical function
uninline it.

Link: https://lkml.kernel.org/r/20240730150158.832783-4-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240724203322.2765486-4-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:49 -07:00
Pasha Tatashin
c4a6fce856 vmstat: kernel stack usage histogram
As part of the dynamic kernel stack project, we need to know the amount of
data that can be saved by reducing the default kernel stack size [1].

Provide a kernel stack usage histogram to aid in optimizing kernel stack
sizes and minimizing memory waste in large-scale environments.  The
histogram divides stack usage into power-of-two buckets and reports the
results in /proc/vmstat.  This information is especially valuable in
environments with millions of machines, where even small optimizations can
have a significant impact.

The histogram data is presented in /proc/vmstat with entries like
"kstack_1k", "kstack_2k", and so on, indicating the number of threads that
exited with stack usage falling within each respective bucket.

Example outputs:
Intel:
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0

ARM with 64K page_size:
$ grep kstack /proc/vmstat
kstack_1k 1
kstack_2k 340
kstack_4k 25212
kstack_8k 1659
kstack_16k 0
kstack_32k 0
kstack_64k 0

Note: once the dynamic kernel stack is implemented it will depend on the
implementation the usability of this feature: On hardware that supports
faults on kernel stacks, we will have other metrics that show the total
number of pages allocated for stacks.  On hardware where faults are not
supported, we will most likely have some optimization where only some
threads are extended, and for those, these metrics will still be very
useful.

[1] https://lwn.net/Articles/974367

Link: https://lkml.kernel.org/r/20240730150158.832783-3-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240724203322.2765486-3-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:49 -07:00
Zi Yan
2a28713a67 memory tiering: introduce folio_use_access_time() check
If memory tiering mode is on and a folio is not in the top tier memory,
folio's cpupid field is repurposed to store page access time.  Instead of
an open coded check, use a function to encapsulate the check.

Link: https://lkml.kernel.org/r/20240724130115.793641-3-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:47 -07:00
Danilo Krummrich
590b9d576c mm: kvmalloc: align kvrealloc() with krealloc()
Besides the obvious (and desired) difference between krealloc() and
kvrealloc(), there is some inconsistency in their function signatures and
behavior:

 - krealloc() frees the memory when the requested size is zero, whereas
   kvrealloc() simply returns a pointer to the existing allocation.

 - krealloc() behaves like kmalloc() if a NULL pointer is passed, whereas
   kvrealloc() does not accept a NULL pointer at all and, if passed,
   would fault instead.

 - krealloc() is self-contained, whereas kvrealloc() relies on the caller
   to provide the size of the previous allocation.

Inconsistent behavior throughout allocation APIs is error prone, hence
make kvrealloc() behave like krealloc(), which seems superior in all
mentioned aspects.

Besides that, implementing kvrealloc() by making use of krealloc() and
vrealloc() provides oppertunities to grow (and shrink) allocations more
efficiently.  For instance, vrealloc() can be optimized to allocate and
map additional pages to grow the allocation or unmap and free unused pages
to shrink the allocation.

[dakr@kernel.org: document concurrency restrictions]
  Link: https://lkml.kernel.org/r/20240725125442.4957-1-dakr@kernel.org
[dakr@kernel.org: disable KASAN when switching to vmalloc]
  Link: https://lkml.kernel.org/r/20240730185049.6244-2-dakr@kernel.org
[dakr@kernel.org: properly document __GFP_ZERO behavior]
  Link: https://lkml.kernel.org/r/20240730185049.6244-5-dakr@kernel.org
Link: https://lkml.kernel.org/r/20240722163111.4766-3-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:44 -07:00
Linus Torvalds
3e9bff3bbe vfs-6.11-rc6.fixes
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Merge tag 'vfs-6.11-rc6.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:
 "VFS:

   - Ensure that backing files uses file->f_ops->splice_write() for
     splice

  netfs:

   - Revert the removal of PG_private_2 from netfs_release_folio() as
     cephfs still relies on this

   - When AS_RELEASE_ALWAYS is set on a mapping the folio needs to
     always be invalidated during truncation

   - Fix losing untruncated data in a folio by making letting
     netfs_release_folio() return false if the folio is dirty

   - Fix trimming of streaming-write folios in netfs_inval_folio()

   - Reset iterator before retrying a short read

   - Fix interaction of streaming writes with zero-point tracker

  afs:

   - During truncation afs currently calls truncate_setsize() which sets
     i_size, expands the pagecache and truncates it. The first two
     operations aren't needed because they will have already been done.
     So call truncate_pagecache() instead and skip the redundant parts

  overlayfs:

   - Fix checking of the number of allowed lower layers so 500 layers
     can actually be used instead of just 499

   - Add missing '\n' to pr_err() output

   - Pass string to ovl_parse_layer() and thus allow it to be used for
     Opt_lowerdir as well

  pidfd:

   - Revert blocking the creation of pidfds for kthread as apparently
     userspace relies on this. Specifically, it breaks systemd during
     shutdown

  romfs:

   - Fix romfs_read_folio() to use the correct offset with
     folio_zero_tail()"

* tag 'vfs-6.11-rc6.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
  netfs: Fix interaction of streaming writes with zero-point tracker
  netfs: Fix missing iterator reset on retry of short read
  netfs: Fix trimming of streaming-write folios in netfs_inval_folio()
  netfs: Fix netfs_release_folio() to say no if folio dirty
  afs: Fix post-setattr file edit to do truncation correctly
  mm: Fix missing folio invalidation calls during truncation
  ovl: ovl_parse_param_lowerdir: Add missed '\n' for pr_err
  ovl: fix wrong lowerdir number check for parameter Opt_lowerdir
  ovl: pass string to ovl_parse_layer()
  backing-file: convert to using fops->splice_write
  Revert "pidfd: prevent creation of pidfds for kthreads"
  romfs: fix romfs_read_folio()
  netfs, ceph: Partially revert "netfs: Replace PG_fscache by setting folio->private and marking dirty"
2024-08-27 16:57:35 +12:00
Linus Torvalds
d2bafcf224 cgroup: Fixes for v6.11-rc4
Three patches addressing cpuset corner cases.
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Merge tag 'cgroup-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:
 "Three patches addressing cpuset corner cases"

* tag 'cgroup-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/cpuset: Eliminate unncessary sched domains rebuilds in hotplug
  cgroup/cpuset: Clear effective_xcpus on cpus_allowed clearing only if cpus.exclusive not set
  cgroup/cpuset: fix panic caused by partcmd_update
2024-08-24 10:39:18 +08:00
Linus Torvalds
cb2c84b380 workqueue: Fixes for v6.11-rc4
Nothing too interesting. One patch to remove spurious warning and others to
 address static checker warnings.
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Merge tag 'wq-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue fixes from Tejun Heo:
 "Nothing too interesting. One patch to remove spurious warning and
  others to address static checker warnings"

* tag 'wq-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Correct declaration of cpu_pwq in struct workqueue_struct
  workqueue: Fix spruious data race in __flush_work()
  workqueue: Remove incorrect "WARN_ON_ONCE(!list_empty(&worker->entry));" from dying worker
  workqueue: Fix UBSAN 'subtraction overflow' error in shift_and_mask()
  workqueue: doc: Fix function name, remove markers
2024-08-24 10:35:57 +08:00
Christian Brauner
232590ea7f
Revert "pidfd: prevent creation of pidfds for kthreads"
This reverts commit 3b5bbe798b.

Eric reported that systemd-shutdown gets broken by blocking the creating
of pidfds for kthreads as older versions seems to rely on being able to
create a pidfd for any process in /proc.

Reported-by: Eric Biggers <ebiggers@kernel.org>
Link: https://lore.kernel.org/r/20240818035818.GA1929@sol.localdomain
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-21 22:32:58 +02:00
Linus Torvalds
b0da640826 printk fixup for 6.11-rc5
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Merge tag 'printk-for-6.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fix from Petr Mladek:

 - Do not block printk on non-panic CPUs when they are dumping
   backtraces

* tag 'printk-for-6.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk/panic: Allow cpu backtraces to be written into ringbuffer during panic
2024-08-19 09:26:35 -07:00
Linus Torvalds
c3f2d783a4 16 hotfixes. All except one are for MM. 10 of these are cc:stable and
the others pertain to post-6.10 issues.
 
 As usual with these merges, singletons and doubletons all over the place,
 no identifiable-by-me theme.  Please see the lovingly curated changelogs
 to get the skinny.
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Merge tag 'mm-hotfixes-stable-2024-08-17-19-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "16 hotfixes. All except one are for MM. 10 of these are cc:stable and
  the others pertain to post-6.10 issues.

  As usual with these merges, singletons and doubletons all over the
  place, no identifiable-by-me theme. Please see the lovingly curated
  changelogs to get the skinny"

* tag 'mm-hotfixes-stable-2024-08-17-19-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/migrate: fix deadlock in migrate_pages_batch() on large folios
  alloc_tag: mark pages reserved during CMA activation as not tagged
  alloc_tag: introduce clear_page_tag_ref() helper function
  crash: fix riscv64 crash memory reserve dead loop
  selftests: memfd_secret: don't build memfd_secret test on unsupported arches
  mm: fix endless reclaim on machines with unaccepted memory
  selftests/mm: compaction_test: fix off by one in check_compaction()
  mm/numa: no task_numa_fault() call if PMD is changed
  mm/numa: no task_numa_fault() call if PTE is changed
  mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0
  mm/memory-failure: use raw_spinlock_t in struct memory_failure_cpu
  mm: don't account memmap per-node
  mm: add system wide stats items category
  mm: don't account memmap on failure
  mm/hugetlb: fix hugetlb vs. core-mm PT locking
  mseal: fix is_madv_discard()
2024-08-17 19:50:16 -07:00
Linus Torvalds
810996a363 powerpc fixes for 6.11 #2
- Fix crashes on 85xx with some configs since the recent hugepd rework.
 
  - Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUAL on some platforms.
 
  - Don't enable offline cores when changing SMT modes, to match existing
    userspace behaviour.
 
 Thanks to: Christophe Leroy, Dr. David Alan Gilbert, Guenter Roeck, Nysal Jan
 K.A, Shrikanth Hegde, Thomas Gleixner, Tyrel Datwyler.
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Merge tag 'powerpc-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - Fix crashes on 85xx with some configs since the recent hugepd rework.

 - Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUAL on some
   platforms.

 - Don't enable offline cores when changing SMT modes, to match existing
   userspace behaviour.

Thanks to Christophe Leroy, Dr. David Alan Gilbert, Guenter Roeck, Nysal
Jan K.A, Shrikanth Hegde, Thomas Gleixner, and Tyrel Datwyler.

* tag 'powerpc-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/topology: Check if a core is online
  cpu/SMT: Enable SMT only if a core is online
  powerpc/mm: Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUAL
  powerpc/mm: Fix size of allocated PGDIR
  soc: fsl: qbman: remove unused struct 'cgr_comp'
2024-08-17 19:23:02 -07:00
Linus Torvalds
4a621e2910 A couple of fixes for tracing:
- Prevent a NULL pointer dereference in the error path of RTLA tool
 
 - Fix an infinite loop bug when reading from the ring buffer when closed.
   If there's a thread trying to read the ring buffer and it gets closed
   by another thread, the one reading will go into an infinite loop
   when the buffer is empty instead of exiting back to user space.
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Merge tag 'trace-v6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:
 "A couple of fixes for tracing:

   - Prevent a NULL pointer dereference in the error path of RTLA tool

   - Fix an infinite loop bug when reading from the ring buffer when
     closed. If there's a thread trying to read the ring buffer and it
     gets closed by another thread, the one reading will go into an
     infinite loop when the buffer is empty instead of exiting back to
     user space"

* tag 'trace-v6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  rtla/osnoise: Prevent NULL dereference in error handling
  tracing: Return from tracing_buffers_read() if the file has been closed
2024-08-16 11:12:29 -07:00
Jinjie Ruan
edb907a613 crash: fix riscv64 crash memory reserve dead loop
On RISCV64 Qemu machine with 512MB memory, cmdline "crashkernel=500M,high"
will cause system stall as below:

	 Zone ranges:
	   DMA32    [mem 0x0000000080000000-0x000000009fffffff]
	   Normal   empty
	 Movable zone start for each node
	 Early memory node ranges
	   node   0: [mem 0x0000000080000000-0x000000008005ffff]
	   node   0: [mem 0x0000000080060000-0x000000009fffffff]
	 Initmem setup node 0 [mem 0x0000000080000000-0x000000009fffffff]
	(stall here)

commit 5d99cadf1568 ("crash: fix x86_32 crash memory reserve dead loop
bug") fix this on 32-bit architecture.  However, the problem is not
completely solved.  If `CRASH_ADDR_LOW_MAX = CRASH_ADDR_HIGH_MAX` on
64-bit architecture, for example, when system memory is equal to
CRASH_ADDR_LOW_MAX on RISCV64, the following infinite loop will also
occur:

	-> reserve_crashkernel_generic() and high is true
	   -> alloc at [CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX] fail
	      -> alloc at [0, CRASH_ADDR_LOW_MAX] fail and repeatedly
	         (because CRASH_ADDR_LOW_MAX = CRASH_ADDR_HIGH_MAX).

As Catalin suggested, do not remove the ",high" reservation fallback to
",low" logic which will change arm64's kdump behavior, but fix it by
skipping the above situation similar to commit d2f32f23190b ("crash: fix
x86_32 crash memory reserve dead loop").

After this patch, it print:
	cannot allocate crashkernel (size:0x1f400000)

Link: https://lkml.kernel.org/r/20240812062017.2674441-1-ruanjinjie@huawei.com
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Dave Young <dyoung@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-15 22:16:16 -07:00
Linus Torvalds
e724918b37 hardening fixes for v6.11-rc4
- gcc-plugins: randstruct: Remove GCC 4.7 or newer requirement
   (Thorsten Blum)
 
 - kallsyms: Clean up interaction with LTO suffixes (Song Liu)
 
 - refcount: Report UAF for refcount_sub_and_test(0) when counter==0
   (Petr Pavlu)
 
 - kunit/overflow: Avoid misallocation of driver name (Ivan Orlov)
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Merge tag 'hardening-v6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening fixes from Kees Cook:

 - gcc-plugins: randstruct: Remove GCC 4.7 or newer requirement
   (Thorsten Blum)

 - kallsyms: Clean up interaction with LTO suffixes (Song Liu)

 - refcount: Report UAF for refcount_sub_and_test(0) when counter==0
   (Petr Pavlu)

 - kunit/overflow: Avoid misallocation of driver name (Ivan Orlov)

* tag 'hardening-v6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kallsyms: Match symbols exactly with CONFIG_LTO_CLANG
  kallsyms: Do not cleanup .llvm.<hash> suffix before sorting symbols
  kunit/overflow: Fix UB in overflow_allocation_test
  gcc-plugins: randstruct: Remove GCC 4.7 or newer requirement
  refcount: Report UAF for refcount_sub_and_test(0) when counter==0
2024-08-15 11:50:07 -07:00
Song Liu
fb6a421fb6 kallsyms: Match symbols exactly with CONFIG_LTO_CLANG
With CONFIG_LTO_CLANG=y, the compiler may add .llvm.<hash> suffix to
function names to avoid duplication. APIs like kallsyms_lookup_name()
and kallsyms_on_each_match_symbol() tries to match these symbol names
without the .llvm.<hash> suffix, e.g., match "c_stop" with symbol
c_stop.llvm.17132674095431275852. This turned out to be problematic
for use cases that require exact match, for example, livepatch.

Fix this by making the APIs to match symbols exactly.

Also cleanup kallsyms_selftests accordingly.

Signed-off-by: Song Liu <song@kernel.org>
Fixes: 8cc32a9bbf ("kallsyms: strip LTO-only suffixes from promoted global functions")
Tested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240807220513.3100483-3-song@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
2024-08-15 09:33:35 -07:00
Linus Torvalds
4ac0f08f44 vfs-6.11-rc4.fixes
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Merge tag 'vfs-6.11-rc4.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:
 "VFS:

   - Fix the name of file lease slab cache. When file leases were split
     out of file locks the name of the file lock slab cache was used for
     the file leases slab cache as well.

   - Fix a type in take_fd() helper.

   - Fix infinite directory iteration for stable offsets in tmpfs.

   - When the icache is pruned all reclaimable inodes are marked with
     I_FREEING and other processes that try to lookup such inodes will
     block.

     But some filesystems like ext4 can trigger lookups in their inode
     evict callback causing deadlocks. Ext4 does such lookups if the
     ea_inode feature is used whereby a separate inode may be used to
     store xattrs.

     Introduce I_LRU_ISOLATING which pins the inode while its pages are
     reclaimed. This avoids inode deletion during inode_lru_isolate()
     avoiding the deadlock and evict is made to wait until
     I_LRU_ISOLATING is done.

  netfs:

   - Fault in smaller chunks for non-large folio mappings for
     filesystems that haven't been converted to large folios yet.

   - Fix the CONFIG_NETFS_DEBUG config option. The config option was
     renamed a short while ago and that introduced two minor issues.
     First, it depended on CONFIG_NETFS whereas it wants to depend on
     CONFIG_NETFS_SUPPORT. The former doesn't exist, while the latter
     does. Second, the documentation for the config option wasn't fixed
     up.

   - Revert the removal of the PG_private_2 writeback flag as ceph is
     using it and fix how that flag is handled in netfs.

   - Fix DIO reads on 9p. A program watching a file on a 9p mount
     wouldn't see any changes in the size of the file being exported by
     the server if the file was changed directly in the source
     filesystem. Fix this by attempting to read the full size specified
     when a DIO read is requested.

   - Fix a NULL pointer dereference bug due to a data race where a
     cachefiles cookies was retired even though it was still in use.
     Check the cookie's n_accesses counter before discarding it.

  nsfs:

   - Fix ioctl declaration for NS_GET_MNTNS_ID from _IO() to _IOR() as
     the kernel is writing to userspace.

  pidfs:

   - Prevent the creation of pidfds for kthreads until we have a
     use-case for it and we know the semantics we want. It also confuses
     userspace why they can get pidfds for kthreads.

  squashfs:

   - Fix an unitialized value bug reported by KMSAN caused by a
     corrupted symbolic link size read from disk. Check that the
     symbolic link size is not larger than expected"

* tag 'vfs-6.11-rc4.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  Squashfs: sanity check symbolic link size
  9p: Fix DIO read through netfs
  vfs: Don't evict inode under the inode lru traversing context
  netfs: Fix handling of USE_PGPRIV2 and WRITE_TO_CACHE flags
  netfs, ceph: Revert "netfs: Remove deprecated use of PG_private_2 as a second writeback flag"
  file: fix typo in take_fd() comment
  pidfd: prevent creation of pidfds for kthreads
  netfs: clean up after renaming FSCACHE_DEBUG config
  libfs: fix infinite directory reads for offset dir
  nsfs: fix ioctl declaration
  fs/netfs/fscache_cookie: add missing "n_accesses" check
  filelock: fix name of file_lease slab cache
  netfs: Fault in smaller chunks for non-large folio mappings
2024-08-14 09:06:28 -07:00
Kyle Huey
100bff2381 perf/bpf: Don't call bpf_overflow_handler() for tracing events
The regressing commit is new in 6.10. It assumed that anytime event->prog
is set bpf_overflow_handler() should be invoked to execute the attached bpf
program. This assumption is false for tracing events, and as a result the
regressing commit broke bpftrace by invoking the bpf handler with garbage
inputs on overflow.

Prior to the regression the overflow handlers formed a chain (of length 0,
1, or 2) and perf_event_set_bpf_handler() (the !tracing case) added
bpf_overflow_handler() to that chain, while perf_event_attach_bpf_prog()
(the tracing case) did not. Both set event->prog. The chain of overflow
handlers was replaced by a single overflow handler slot and a fixed call to
bpf_overflow_handler() when appropriate. This modifies the condition there
to check event->prog->type == BPF_PROG_TYPE_PERF_EVENT, restoring the
previous behavior and fixing bpftrace.

Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Reported-by: Joe Damato <jdamato@fastly.com>
Closes: https://lore.kernel.org/lkml/ZpFfocvyF3KHaSzF@LQ3V64L9R2/
Fixes: f11f10bfa1 ("perf/bpf: Call BPF handler directly, not through overflow machinery")
Cc: stable@vger.kernel.org
Tested-by: Joe Damato <jdamato@fastly.com> # bpftrace
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240813151727.28797-1-jdamato@fastly.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-13 10:25:28 -07:00
Ryo Takakura
bcc954c6ca printk/panic: Allow cpu backtraces to be written into ringbuffer during panic
commit 779dbc2e78 ("printk: Avoid non-panic CPUs writing
to ringbuffer") disabled non-panic CPUs to further write messages to
ringbuffer after panicked.

Since the commit, non-panicked CPU's are not allowed to write to
ring buffer after panicked and CPU backtrace which is triggered
after panicked to sample non-panicked CPUs' backtrace no longer
serves its function as it has nothing to print.

Fix the issue by allowing non-panicked CPUs to write into ringbuffer
while CPU backtrace is in flight.

Fixes: 779dbc2e78 ("printk: Avoid non-panic CPUs writing to ringbuffer")
Signed-off-by: Ryo Takakura <takakura@valinux.co.jp>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240812072703.339690-1-takakura@valinux.co.jp
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-13 14:16:22 +02:00
Yonghong Song
bed2eb964c bpf: Fix a kernel verifier crash in stacksafe()
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 &&
        old->stack[spi].slot_type[i % BPF_REG_SIZE] !=
        cur->stack[spi].slot_type[i % BPF_REG_SIZE])
            return false;

The 'i' iterates old->allocated_stack.
If cur->allocated_stack < old->allocated_stack the out-of-bound
access will happen.

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

Fixes: 2793a8b015 ("bpf: exact states comparison for iterator convergence checks")
Cc: Eduard Zingerman <eddyz87@gmail.com>
Reported-by: Daniel Hodges <hodgesd@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240812214847.213612-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-12 18:09:48 -07:00
Nysal Jan K.A
6c17ea1f3e cpu/SMT: Enable SMT only if a core is online
If a core is offline then enabling SMT should not online CPUs of
this core. By enabling SMT, what is intended is either changing the SMT
value from "off" to "on" or setting the SMT level (threads per core) from a
lower to higher value.

On PowerPC the ppc64_cpu utility can be used, among other things, to
perform the following functions:

ppc64_cpu --cores-on                # Get the number of online cores
ppc64_cpu --cores-on=X              # Put exactly X cores online
ppc64_cpu --offline-cores=X[,Y,...] # Put specified cores offline
ppc64_cpu --smt={on|off|value}      # Enable, disable or change SMT level

If the user has decided to offline certain cores, enabling SMT should
not online CPUs in those cores. This patch fixes the issue and changes
the behaviour as described, by introducing an arch specific function
topology_is_core_online(). It is currently implemented only for PowerPC.

Fixes: 73c58e7e14 ("powerpc: Add HOTPLUG_SMT support")
Reported-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Closes: https://groups.google.com/g/powerpc-utils-devel/c/wrwVzAAnRlI/m/5KJSoqP4BAAJ
Signed-off-by: Nysal Jan K.A <nysal@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240731030126.956210-2-nysal@linux.ibm.com
2024-08-13 10:31:24 +10:00
Christian Brauner
3b5bbe798b
pidfd: prevent creation of pidfds for kthreads
It's currently possible to create pidfds for kthreads but it is unclear
what that is supposed to mean. Until we have use-cases for it and we
figured out what behavior we want block the creation of pidfds for
kthreads.

Link: https://lore.kernel.org/r/20240731-gleis-mehreinnahmen-6bbadd128383@brauner
Fixes: 32fcb426ec ("pid: add pidfd_open()")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-12 22:03:26 +02:00
Linus Torvalds
7270e931b5 Updates for time keeping:
- Fix a couple of issues in the NTP code where user supplied values are
     neither sanity checked nor clamped to the operating range. This results
     in integer overflows and eventualy NTP getting out of sync.
 
     According to the history the sanity checks had been removed in favor of
     clamping the values, but the clamping never worked correctly under all
     circumstances. The NTP people asked to not bring the sanity checks back
     as it might break existing applications.
 
     Make the clamping work correctly and add it where it's missing
 
   - If adjtimex() sets the clock it has to trigger the hrtimer subsystem so
     it can adjust and if the clock was set into the future expire timers if
     needed. The caller should provide a bitmask to tell hrtimers which
     clocks have been adjusted. adjtimex() uses not the proper constant and
     uses CLOCK_REALTIME instead, which is 0. So hrtimers adjusts only the
     clocks, but does not check for expired timers, which might make them
     expire really late. Use the proper bitmask constant instead.
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Merge tag 'timers-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull time keeping fixes from Thomas Gleixner:

 - Fix a couple of issues in the NTP code where user supplied values are
   neither sanity checked nor clamped to the operating range. This
   results in integer overflows and eventualy NTP getting out of sync.

   According to the history the sanity checks had been removed in favor
   of clamping the values, but the clamping never worked correctly under
   all circumstances. The NTP people asked to not bring the sanity
   checks back as it might break existing applications.

   Make the clamping work correctly and add it where it's missing

 - If adjtimex() sets the clock it has to trigger the hrtimer subsystem
   so it can adjust and if the clock was set into the future expire
   timers if needed. The caller should provide a bitmask to tell
   hrtimers which clocks have been adjusted.

   adjtimex() uses not the proper constant and uses CLOCK_REALTIME
   instead, which is 0. So hrtimers adjusts only the clocks, but does
   not check for expired timers, which might make them expire really
   late. Use the proper bitmask constant instead.

* tag 'timers-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Fix bogus clock_was_set() invocation in do_adjtimex()
  ntp: Safeguard against time_constant overflow
  ntp: Clamp maxerror and esterror to operating range
2024-08-11 10:15:34 -07:00
Linus Torvalds
56fe0a6a9f Three small fixes for interrupt core and drivers:
- The interrupt core fails to honor caller supplied affinity hints for
       non-managed interrupts and uses the system default affinity on
       startup instead. Set the missing flag in the descriptor to tell the
       core to use the provided affinity.
 
     - Fix a shift out of bounds error in the Xilinx driver
 
     - Handle switching to level trigger correctly in the RISCV APLIC
       driver. It failed to retrigger the interrupt which causes it to
       become stale.
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Merge tag 'irq-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Thomas Gleixner:
 "Three small fixes for interrupt core and drivers:

   - The interrupt core fails to honor caller supplied affinity hints
     for non-managed interrupts and uses the system default affinity on
     startup instead. Set the missing flag in the descriptor to tell the
     core to use the provided affinity.

   - Fix a shift out of bounds error in the Xilinx driver

   - Handle switching to level trigger correctly in the RISCV APLIC
     driver. It failed to retrigger the interrupt which causes it to
     become stale"

* tag 'irq-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/riscv-aplic: Retrigger MSI interrupt on source configuration
  irqchip/xilinx: Fix shift out of bounds
  genirq/irqdesc: Honor caller provided affinity in alloc_desc()
2024-08-11 10:07:52 -07:00
Linus Torvalds
0409cc53c4 dma-mapping fix for Linux 6.11
- avoid a deadlock with dma-debug and netconsole (Rik van Riel)
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Merge tag 'dma-mapping-6.11-2024-08-10' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fix from Christoph Hellwig:

 - avoid a deadlock with dma-debug and netconsole (Rik van Riel)

* tag 'dma-mapping-6.11-2024-08-10' of git://git.infradead.org/users/hch/dma-mapping:
  dma-debug: avoid deadlock between dma debug vs printk and netconsole
2024-08-10 10:19:05 -07:00
Steven Rostedt
d0949cd44a tracing: Return from tracing_buffers_read() if the file has been closed
When running the following:

 # cd /sys/kernel/tracing/
 # echo 1 > events/sched/sched_waking/enable
 # echo 1 > events/sched/sched_switch/enable
 # echo 0 > tracing_on
 # dd if=per_cpu/cpu0/trace_pipe_raw of=/tmp/raw0.dat

The dd task would get stuck in an infinite loop in the kernel. What would
happen is the following:

When ring_buffer_read_page() returns -1 (no data) then a check is made to
see if the buffer is empty (as happens when the page is not full), it will
call wait_on_pipe() to wait until the ring buffer has data. When it is it
will try again to read data (unless O_NONBLOCK is set).

The issue happens when there's a reader and the file descriptor is closed.
The wait_on_pipe() will return when that is the case. But this loop will
continue to try again and wait_on_pipe() will again return immediately and
the loop will continue and never stop.

Simply check if the file was closed before looping and exit out if it is.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240808235730.78bf63e5@rorschach.local.home
Fixes: 2aa043a55b ("tracing/ring-buffer: Fix wait_on_pipe() race")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-09 12:59:35 -04:00
Linus Torvalds
146430a0c2 Probes fixes for v6.11-rc2:
- kprobes: Fix misusing str_has_prefix() parameter order to check symbol
   prefix correctly.
 - bpf: kprobe: remove unused declaring of bpf_kprobe_override.
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Merge tag 'probes-fixes-v6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull kprobe fixes from Masami Hiramatsu:

 - Fix misusing str_has_prefix() parameter order to check symbol prefix
   correctly

 - bpf: remove unused declaring of bpf_kprobe_override

* tag 'probes-fixes-v6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kprobes: Fix to check symbol prefixes correctly
  bpf: kprobe: remove unused declaring of bpf_kprobe_override
2024-08-09 09:43:46 -07:00
Linus Torvalds
2124d84db2 module: make waiting for a concurrent module loader interruptible
The recursive aes-arm-bs module load situation reported by Russell King
is getting fixed in the crypto layer, but this in the meantime fixes the
"recursive load hangs forever" by just making the waiting for the first
module load be interruptible.

This should now match the old behavior before commit 9b9879fc03
("modules: catch concurrent module loads, treat them as idempotent"),
which used the different "wait for module to be ready" code in
module_patient_check_exists().

End result: a recursive module load will still block, but now a signal
will interrupt it and fail the second module load, at which point the
first module will successfully complete loading.

Fixes: 9b9879fc03 ("modules: catch concurrent module loads, treat them as idempotent")
Cc: Russell King <linux@armlinux.org.uk>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-08-09 08:33:28 -07:00
Linus Torvalds
9466b6ae6b tracing fixes for v6.11:
- Have reading of event format files test if the meta data still exists.
   When a event is freed, a flag (EVENT_FILE_FL_FREED) in the meta data is
   set to state that it is to prevent any new references to it from happening
   while waiting for existing references to close. When the last reference
   closes, the meta data is freed. But the "format" was missing a check to
   this flag (along with some other files) that allowed new references to
   happen, and a use-after-free bug to occur.
 
 - Have the trace event meta data use the refcount infrastructure instead
   of relying on its own atomic counters.
 
 - Have tracefs inodes use alloc_inode_sb() for allocation instead of
   using kmem_cache_alloc() directly.
 
 - Have eventfs_create_dir() return an ERR_PTR instead of NULL as
   the callers expect a real object or an ERR_PTR.
 
 - Have release_ei() use call_srcu() and not call_rcu() as all the
   protection is on SRCU and not RCU.
 
 - Fix ftrace_graph_ret_addr() to use the task passed in and not current.
 
 - Fix overflow bug in get_free_elt() where the counter can overflow
   the integer and cause an infinite loop.
 
 - Remove unused function ring_buffer_nr_pages()
 
 - Have tracefs freeing use the inode RCU infrastructure instead of
   creating its own. When the kernel had randomize structure fields
   enabled, the rcu field of the tracefs_inode was overlapping the
   rcu field of the inode structure, and corrupting it. Instead,
   use the destroy_inode() callback to do the initial cleanup of
   the code, and then have free_inode() free it.
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Merge tag 'trace-v6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Have reading of event format files test if the metadata still exists.

   When a event is freed, a flag (EVENT_FILE_FL_FREED) in the metadata
   is set to state that it is to prevent any new references to it from
   happening while waiting for existing references to close. When the
   last reference closes, the metadata is freed. But the "format" was
   missing a check to this flag (along with some other files) that
   allowed new references to happen, and a use-after-free bug to occur.

 - Have the trace event meta data use the refcount infrastructure
   instead of relying on its own atomic counters.

 - Have tracefs inodes use alloc_inode_sb() for allocation instead of
   using kmem_cache_alloc() directly.

 - Have eventfs_create_dir() return an ERR_PTR instead of NULL as the
   callers expect a real object or an ERR_PTR.

 - Have release_ei() use call_srcu() and not call_rcu() as all the
   protection is on SRCU and not RCU.

 - Fix ftrace_graph_ret_addr() to use the task passed in and not
   current.

 - Fix overflow bug in get_free_elt() where the counter can overflow the
   integer and cause an infinite loop.

 - Remove unused function ring_buffer_nr_pages()

 - Have tracefs freeing use the inode RCU infrastructure instead of
   creating its own.

   When the kernel had randomize structure fields enabled, the rcu field
   of the tracefs_inode was overlapping the rcu field of the inode
   structure, and corrupting it. Instead, use the destroy_inode()
   callback to do the initial cleanup of the code, and then have
   free_inode() free it.

* tag 'trace-v6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracefs: Use generic inode RCU for synchronizing freeing
  ring-buffer: Remove unused function ring_buffer_nr_pages()
  tracing: Fix overflow in get_free_elt()
  function_graph: Fix the ret_stack used by ftrace_graph_ret_addr()
  eventfs: Use SRCU for freeing eventfs_inodes
  eventfs: Don't return NULL in eventfs_create_dir()
  tracefs: Fix inode allocation
  tracing: Use refcount for trace_event_file reference counter
  tracing: Have format file honor EVENT_FILE_FL_FREED
2024-08-08 13:32:59 -07:00
Linus Torvalds
b3f5620f76 bcachefs fixes for 6.11-rc3
Assorted little stuff:
 - lockdep fixup for lockdep_set_notrack_class()
 - we can now remove a device when using erasure coding without
   deadlocking, though we still hit other issues
 - the "allocator stuck" timeout is now configurable, and messages are
   ratelimited; default timeout has been increased from 10 seconds to 30
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Merge tag 'bcachefs-2024-08-08' of git://evilpiepirate.org/bcachefs

Pull bcachefs fixes from Kent Overstreet:
 "Assorted little stuff:

   - lockdep fixup for lockdep_set_notrack_class()

   - we can now remove a device when using erasure coding without
     deadlocking, though we still hit other issues

   - the 'allocator stuck' timeout is now configurable, and messages are
     ratelimited. The default timeout has been increased from 10 seconds
     to 30"

* tag 'bcachefs-2024-08-08' of git://evilpiepirate.org/bcachefs:
  bcachefs: Use bch2_wait_on_allocator() in btree node alloc path
  bcachefs: Make allocator stuck timeout configurable, ratelimit messages
  bcachefs: Add missing path_traverse() to btree_iter_next_node()
  bcachefs: ec should not allocate from ro devs
  bcachefs: Improved allocator debugging for ec
  bcachefs: Add missing bch2_trans_begin() call
  bcachefs: Add a comment for bucket helper types
  bcachefs: Don't rely on implicit unsigned -> signed integer conversion
  lockdep: Fix lockdep_set_notrack_class() for CONFIG_LOCK_STAT
  bcachefs: Fix double free of ca->buckets_nouse
2024-08-08 13:27:31 -07:00
Linus Torvalds
cb5b81bc9a module: warn about excessively long module waits
Russell King reported that the arm cbc(aes) crypto module hangs when
loaded, and Herbert Xu bisected it to commit 9b9879fc03 ("modules:
catch concurrent module loads, treat them as idempotent"), and noted:

 "So what's happening here is that the first modprobe tries to load a
  fallback CBC implementation, in doing so it triggers a load of the
  exact same module due to module aliases.

  IOW we're loading aes-arm-bs which provides cbc(aes). However, this
  needs a fallback of cbc(aes) to operate, which is made out of the
  generic cbc module + any implementation of aes, or ecb(aes). The
  latter happens to also be provided by aes-arm-cb so that's why it
  tries to load the same module again"

So loading the aes-arm-bs module ends up wanting to recursively load
itself, and the recursive load then ends up waiting for the original
module load to complete.

This is a regression, in that it used to be that we just tried to load
the module multiple times, and then as we went on to install it the
second time we would instead just error out because the module name
already existed.

That is actually also exactly what the original "catch concurrent loads"
patch did in commit 9828ed3f69 ("module: error out early on concurrent
load of the same module file"), but it turns out that it ends up being
racy, in that erroring out before the module has been fully initialized
will cause failures in dependent module loading.

See commit ac2263b588 (which was the revert of that "error out early")
commit for details about why erroring out before the module has been
initialized is actually fundamentally racy.

Now, for the actual recursive module load (as opposed to just
concurrently loading the same module twice), the race is not an issue.

At the same time it's hard for the kernel to see that this is recursion,
because the module load is always done from a usermode helper, so the
recursion is not some simple callchain within the kernel.

End result: this is not the real fix, but this at least adds a warning
for the situation (admittedly much too late for all the debugging pain
that Russell and Herbert went through) and if we can come to a
resolution on how to detect the recursion properly, this re-organizes
the code to make that easier.

Link: https://lore.kernel.org/all/ZrFHLqvFqhzykuYw@shell.armlinux.org.uk/
Reported-by: Russell King <linux@armlinux.org.uk>
Debugged-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-08-08 12:29:40 -07:00
Linus Torvalds
660e4b18a7 9 hotfixes. 5 are cc:stable, 4 either pertain to post-6.10 material or
aren't considered necessary for earlier kernels.  5 are MM and 4 are
 non-MM.  No identifiable theme here - please see the individual changelogs.
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Merge tag 'mm-hotfixes-stable-2024-08-07-18-32' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "Nine hotfixes. Five are cc:stable, the others either pertain to
  post-6.10 material or aren't considered necessary for earlier kernels.

  Five are MM and four are non-MM. No identifiable theme here - please
  see the individual changelogs"

* tag 'mm-hotfixes-stable-2024-08-07-18-32' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  padata: Fix possible divide-by-0 panic in padata_mt_helper()
  mailmap: update entry for David Heidelberg
  memcg: protect concurrent access to mem_cgroup_idr
  mm: shmem: fix incorrect aligned index when checking conflicts
  mm: shmem: avoid allocating huge pages larger than MAX_PAGECACHE_ORDER for shmem
  mm: list_lru: fix UAF for memory cgroup
  kcov: properly check for softirq context
  MAINTAINERS: Update LTP members and web
  selftests: mm: add s390 to ARCH check
2024-08-08 07:32:20 -07:00
Waiman Long
6d45e1c948 padata: Fix possible divide-by-0 panic in padata_mt_helper()
We are hit with a not easily reproducible divide-by-0 panic in padata.c at
bootup time.

  [   10.017908] Oops: divide error: 0000 1 PREEMPT SMP NOPTI
  [   10.017908] CPU: 26 PID: 2627 Comm: kworker/u1666:1 Not tainted 6.10.0-15.el10.x86_64 #1
  [   10.017908] Hardware name: Lenovo ThinkSystem SR950 [7X12CTO1WW]/[7X12CTO1WW], BIOS [PSE140J-2.30] 07/20/2021
  [   10.017908] Workqueue: events_unbound padata_mt_helper
  [   10.017908] RIP: 0010:padata_mt_helper+0x39/0xb0
    :
  [   10.017963] Call Trace:
  [   10.017968]  <TASK>
  [   10.018004]  ? padata_mt_helper+0x39/0xb0
  [   10.018084]  process_one_work+0x174/0x330
  [   10.018093]  worker_thread+0x266/0x3a0
  [   10.018111]  kthread+0xcf/0x100
  [   10.018124]  ret_from_fork+0x31/0x50
  [   10.018138]  ret_from_fork_asm+0x1a/0x30
  [   10.018147]  </TASK>

Looking at the padata_mt_helper() function, the only way a divide-by-0
panic can happen is when ps->chunk_size is 0.  The way that chunk_size is
initialized in padata_do_multithreaded(), chunk_size can be 0 when the
min_chunk in the passed-in padata_mt_job structure is 0.

Fix this divide-by-0 panic by making sure that chunk_size will be at least
1 no matter what the input parameters are.

Link: https://lkml.kernel.org/r/20240806174647.1050398-1-longman@redhat.com
Fixes: 004ed42638 ("padata: add basic support for multithreaded jobs")
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Waiman Long <longman@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-07 18:33:56 -07:00
Andrey Konovalov
7d4df2dad3 kcov: properly check for softirq context
When collecting coverage from softirqs, KCOV uses in_serving_softirq() to
check whether the code is running in the softirq context.  Unfortunately,
in_serving_softirq() is > 0 even when the code is running in the hardirq
or NMI context for hardirqs and NMIs that happened during a softirq.

As a result, if a softirq handler contains a remote coverage collection
section and a hardirq with another remote coverage collection section
happens during handling the softirq, KCOV incorrectly detects a nested
softirq coverate collection section and prints a WARNING, as reported by
syzbot.

This issue was exposed by commit a7f3813e58 ("usb: gadget: dummy_hcd:
Switch to hrtimer transfer scheduler"), which switched dummy_hcd to using
hrtimer and made the timer's callback be executed in the hardirq context.

Change the related checks in KCOV to account for this behavior of
in_serving_softirq() and make KCOV ignore remote coverage collection
sections in the hardirq and NMI contexts.

This prevents the WARNING printed by syzbot but does not fix the inability
of KCOV to collect coverage from the __usb_hcd_giveback_urb when dummy_hcd
is in use (caused by a7f3813e58); a separate patch is required for that.

Link: https://lkml.kernel.org/r/20240729022158.92059-1-andrey.konovalov@linux.dev
Fixes: 5ff3b30ab5 ("kcov: collect coverage from interrupts")
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reported-by: syzbot+2388cdaeb6b10f0c13ac@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2388cdaeb6b10f0c13ac
Acked-by: Marco Elver <elver@google.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Marcello Sylvester Bauer <sylv@sylv.io>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-07 18:33:56 -07:00
Jianhui Zhou
58f7e4d7ba ring-buffer: Remove unused function ring_buffer_nr_pages()
Because ring_buffer_nr_pages() is not an inline function and user accesses
buffer->buffers[cpu]->nr_pages directly, the function ring_buffer_nr_pages
is removed.

Signed-off-by: Jianhui Zhou <912460177@qq.com>
Link: https://lore.kernel.org/tencent_F4A7E9AB337F44E0F4B858D07D19EF460708@qq.com
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 20:26:44 -04:00
Tze-nan Wu
bcf86c01ca tracing: Fix overflow in get_free_elt()
"tracing_map->next_elt" in get_free_elt() is at risk of overflowing.

Once it overflows, new elements can still be inserted into the tracing_map
even though the maximum number of elements (`max_elts`) has been reached.
Continuing to insert elements after the overflow could result in the
tracing_map containing "tracing_map->max_size" elements, leaving no empty
entries.
If any attempt is made to insert an element into a full tracing_map using
`__tracing_map_insert()`, it will cause an infinite loop with preemption
disabled, leading to a CPU hang problem.

Fix this by preventing any further increments to "tracing_map->next_elt"
once it reaches "tracing_map->max_elt".

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 08d43a5fa0 ("tracing: Add lock-free tracing_map")
Co-developed-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Link: https://lore.kernel.org/20240805055922.6277-1-Tze-nan.Wu@mediatek.com
Signed-off-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Signed-off-by: Tze-nan Wu <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 20:23:12 -04:00
Petr Pavlu
604b72b325 function_graph: Fix the ret_stack used by ftrace_graph_ret_addr()
When ftrace_graph_ret_addr() is invoked to convert a found stack return
address to its original value, the function can end up producing the
following crash:

[   95.442712] BUG: kernel NULL pointer dereference, address: 0000000000000028
[   95.442720] #PF: supervisor read access in kernel mode
[   95.442724] #PF: error_code(0x0000) - not-present page
[   95.442727] PGD 0 P4D 0-
[   95.442731] Oops: Oops: 0000 [#1] PREEMPT SMP PTI
[   95.442736] CPU: 1 UID: 0 PID: 2214 Comm: insmod Kdump: loaded Tainted: G           OE K    6.11.0-rc1-default #1 67c62a3b3720562f7e7db5f11c1fdb40b7a2857c
[   95.442747] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE, [K]=LIVEPATCH
[   95.442750] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
[   95.442754] RIP: 0010:ftrace_graph_ret_addr+0x42/0xc0
[   95.442766] Code: [...]
[   95.442773] RSP: 0018:ffff979b80ff7718 EFLAGS: 00010006
[   95.442776] RAX: ffffffff8ca99b10 RBX: ffff979b80ff7760 RCX: ffff979b80167dc0
[   95.442780] RDX: ffffffff8ca99b10 RSI: ffff979b80ff7790 RDI: 0000000000000005
[   95.442783] RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
[   95.442786] R10: 0000000000000005 R11: 0000000000000000 R12: ffffffff8e9491e0
[   95.442790] R13: ffffffff8d6f70f0 R14: ffff979b80167da8 R15: ffff979b80167dc8
[   95.442793] FS:  00007fbf83895740(0000) GS:ffff8a0afdd00000(0000) knlGS:0000000000000000
[   95.442797] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   95.442800] CR2: 0000000000000028 CR3: 0000000005070002 CR4: 0000000000370ef0
[   95.442806] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   95.442809] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   95.442816] Call Trace:
[   95.442823]  <TASK>
[   95.442896]  unwind_next_frame+0x20d/0x830
[   95.442905]  arch_stack_walk_reliable+0x94/0xe0
[   95.442917]  stack_trace_save_tsk_reliable+0x7d/0xe0
[   95.442922]  klp_check_and_switch_task+0x55/0x1a0
[   95.442931]  task_call_func+0xd3/0xe0
[   95.442938]  klp_try_switch_task.part.5+0x37/0x150
[   95.442942]  klp_try_complete_transition+0x79/0x2d0
[   95.442947]  klp_enable_patch+0x4db/0x890
[   95.442960]  do_one_initcall+0x41/0x2e0
[   95.442968]  do_init_module+0x60/0x220
[   95.442975]  load_module+0x1ebf/0x1fb0
[   95.443004]  init_module_from_file+0x88/0xc0
[   95.443010]  idempotent_init_module+0x190/0x240
[   95.443015]  __x64_sys_finit_module+0x5b/0xc0
[   95.443019]  do_syscall_64+0x74/0x160
[   95.443232]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   95.443236] RIP: 0033:0x7fbf82f2c709
[   95.443241] Code: [...]
[   95.443247] RSP: 002b:00007fffd5ea3b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[   95.443253] RAX: ffffffffffffffda RBX: 000056359c48e750 RCX: 00007fbf82f2c709
[   95.443257] RDX: 0000000000000000 RSI: 000056356ed4efc5 RDI: 0000000000000003
[   95.443260] RBP: 000056356ed4efc5 R08: 0000000000000000 R09: 00007fffd5ea3c10
[   95.443263] R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
[   95.443267] R13: 000056359c48e6f0 R14: 0000000000000000 R15: 0000000000000000
[   95.443272]  </TASK>
[   95.443274] Modules linked in: [...]
[   95.443385] Unloaded tainted modules: intel_uncore_frequency(E):1 isst_if_common(E):1 skx_edac(E):1
[   95.443414] CR2: 0000000000000028

The bug can be reproduced with kselftests:

 cd linux/tools/testing/selftests
 make TARGETS='ftrace livepatch'
 (cd ftrace; ./ftracetest test.d/ftrace/fgraph-filter.tc)
 (cd livepatch; ./test-livepatch.sh)

The problem is that ftrace_graph_ret_addr() is supposed to operate on the
ret_stack of a selected task but wrongly accesses the ret_stack of the
current task. Specifically, the above NULL dereference occurs when
task->curr_ret_stack is non-zero, but current->ret_stack is NULL.

Correct ftrace_graph_ret_addr() to work with the right ret_stack.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/20240803131211.17255-1-petr.pavlu@suse.com
Fixes: 7aa1eaef9f ("function_graph: Allow multiple users to attach to function graph")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 20:20:30 -04:00
Steven Rostedt
6e2fdceffd tracing: Use refcount for trace_event_file reference counter
Instead of using an atomic counter for the trace_event_file reference
counter, use the refcount interface. It has various checks to make sure
the reference counting is correct, and will warn if it detects an error
(like refcount_inc() on '0').

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240726144208.687cce24@rorschach.local.home
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 18:12:46 -04:00
Steven Rostedt
b156040869 tracing: Have format file honor EVENT_FILE_FL_FREED
When eventfs was introduced, special care had to be done to coordinate the
freeing of the file meta data with the files that are exposed to user
space. The file meta data would have a ref count that is set when the file
is created and would be decremented and freed after the last user that
opened the file closed it. When the file meta data was to be freed, it
would set a flag (EVENT_FILE_FL_FREED) to denote that the file is freed,
and any new references made (like new opens or reads) would fail as it is
marked freed. This allowed other meta data to be freed after this flag was
set (under the event_mutex).

All the files that were dynamically created in the events directory had a
pointer to the file meta data and would call event_release() when the last
reference to the user space file was closed. This would be the time that it
is safe to free the file meta data.

A shortcut was made for the "format" file. It's i_private would point to
the "call" entry directly and not point to the file's meta data. This is
because all format files are the same for the same "call", so it was
thought there was no reason to differentiate them.  The other files
maintain state (like the "enable", "trigger", etc). But this meant if the
file were to disappear, the "format" file would be unaware of it.

This caused a race that could be trigger via the user_events test (that
would create dynamic events and free them), and running a loop that would
read the user_events format files:

In one console run:

 # cd tools/testing/selftests/user_events
 # while true; do ./ftrace_test; done

And in another console run:

 # cd /sys/kernel/tracing/
 # while true; do cat events/user_events/__test_event/format; done 2>/dev/null

With KASAN memory checking, it would trigger a use-after-free bug report
(which was a real bug). This was because the format file was not checking
the file's meta data flag "EVENT_FILE_FL_FREED", so it would access the
event that the file meta data pointed to after the event was freed.

After inspection, there are other locations that were found to not check
the EVENT_FILE_FL_FREED flag when accessing the trace_event_file. Add a
new helper function: event_file_file() that will make sure that the
event_mutex is held, and will return NULL if the trace_event_file has the
EVENT_FILE_FL_FREED flag set. Have the first reference of the struct file
pointer use event_file_file() and check for NULL. Later uses can still use
the event_file_data() helper function if the event_mutex is still held and
was not released since the event_file_file() call.

Link: https://lore.kernel.org/all/20240719204701.1605950-1-minipli@grsecurity.net/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers   <mathieu.desnoyers@efficios.com>
Cc: Ajay Kaher <ajay.kaher@broadcom.com>
Cc: Ilkka Naulapää    <digirigawa@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al   Viro <viro@zeniv.linux.org.uk>
Cc: Dan Carpenter   <dan.carpenter@linaro.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Florian Fainelli  <florian.fainelli@broadcom.com>
Cc: Alexey Makhalov    <alexey.makhalov@broadcom.com>
Cc: Vasavi Sirnapalli    <vasavi.sirnapalli@broadcom.com>
Link: https://lore.kernel.org/20240730110657.3b69d3c1@gandalf.local.home
Fixes: b63db58e2f ("eventfs/tracing: Add callback for release of an eventfs_inode")
Reported-by: Mathias Krause <minipli@grsecurity.net>
Tested-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 18:12:46 -04:00
Shay Drory
edbbaae42a genirq/irqdesc: Honor caller provided affinity in alloc_desc()
Currently, whenever a caller is providing an affinity hint for an
interrupt, the allocation code uses it to calculate the node and copies the
cpumask into irq_desc::affinity.

If the affinity for the interrupt is not marked 'managed' then the startup
of the interrupt ignores irq_desc::affinity and uses the system default
affinity mask.

Prevent this by setting the IRQD_AFFINITY_SET flag for the interrupt in the
allocator, which causes irq_setup_affinity() to use irq_desc::affinity on
interrupt startup if the mask contains an online CPU.

[ tglx: Massaged changelog ]

Fixes: 45ddcecbfa ("genirq: Use affinity hint in irqdesc allocation")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/all/20240806072044.837827-1-shayd@nvidia.com
2024-08-07 17:27:00 +02:00
Kent Overstreet
ff9bf4b341 lockdep: Fix lockdep_set_notrack_class() for CONFIG_LOCK_STAT
We won't find a contended lock if it's not being tracked.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-08-07 08:31:10 -04:00