Jeff Layton [Mon, 13 Oct 2025 13:54:53 +0000 (09:54 -0400)]
sunrpc: allocate a separate bvec array for socket sends
svc_tcp_sendmsg() calls xdr_buf_to_bvec() with the second slot of
rq_bvec as the start, but doesn't reduce the array length by one, which
could lead to an array overrun. Also, rq_bvec is always rq_maxpages in
length, which can be too short in some cases, since the TCP record
marker consumes a slot.
Fix both problems by adding a separate bvec array to the svc_sock that
is specifically for sending. For TCP, make this array one slot longer
than rq_maxpages, to account for the record marker. For UDP, only
allocate as large an array as we need since it's limited to 64k of
payload.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Chuck Lever [Wed, 8 Oct 2025 13:52:30 +0000 (09:52 -0400)]
NFSD: Implement NFSD_IO_DIRECT for NFS READ
Add an experimental option that forces NFS READ operations to use
direct I/O instead of reading through the NFS server's page cache.
There is already at least one other layer of read caching: the page
cache on NFS clients.
The server's page cache, in many cases, is unlikely to provide
additional benefit. Some benchmarks have demonstrated that the
server's page cache is actively detrimental for workloads whose
working set is larger than the server's available physical memory.
For instance, on small NFS servers, cached NFS file content can
squeeze out local memory consumers. For large sequential workloads,
an enormous amount of data flows into and out of the page cache
and is consumed by NFS clients exactly once -- caching that data
is expensive to do and totally valueless.
For now this is a hidden option that can be enabled on test
systems for benchmarking. In the longer term, this option might
be enabled persistently or per-export. When the exported file
system does not support direct I/O, NFSD falls back to using
either DONTCACHE or buffered I/O to fulfill NFS READ requests.
Suggested-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Chuck Lever [Wed, 8 Oct 2025 13:52:29 +0000 (09:52 -0400)]
NFSD: Relocate the xdr_reserve_space_vec() call site
In order to detect when a direct READ is possible, we need the send
buffer's .page_len to be zero when there is nothing in the buffer's
.pages array yet.
However, when xdr_reserve_space_vec() extends the size of the
xdr_stream to accommodate a READ payload, it adds to the send
buffer's .page_len.
It should be safe to reserve the stream space /after/ the VFS read
operation completes. This is, for example, how an NFSv3 READ works:
the VFS read goes into the rq_bvec, and is then added to the send
xdr_stream later by svcxdr_encode_opaque_pages().
Now that xdr_reserve_space_vec() uses the number of bytes actually
read, the xdr_truncate_encode() call is no longer necessary.
Reviewed-by: NeilBrown <neil@brown.name> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Mike Snitzer [Wed, 8 Oct 2025 13:52:28 +0000 (09:52 -0400)]
NFSD: pass nfsd_file to nfsd_iter_read()
Prepare for nfsd_iter_read() to use the DIO alignment stored in
nfsd_file by passing the nfsd_file to nfsd_iter_read() rather than
just the file which is associaed with the nfsd_file.
This means nfsd4_encode_readv() now also needs the nfsd_file rather
than the file. Instead of changing the file arg to be the nfsd_file,
we discard the file arg as the nfsd_file (and indeed the file) is
already available via the "read" argument.
Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neil@brown.name> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Sergey Bashirov [Fri, 3 Oct 2025 09:11:06 +0000 (12:11 +0300)]
NFSD/blocklayout: Support multiple extents per LAYOUTGET
Allow the pNFS server to respond with multiple extents to a LAYOUTGET
request, thereby avoiding unnecessary load on the server and improving
performance for the client. The number of LAYOUTGET requests is
significantly reduced for various file access patterns, including
random and parallel writes.
Additionally, this change allows the client to request layouts with the
loga_minlength value greater than the minimum possible length of a single
extent in XFS. We use this functionality to fix a livelock in the client.
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Add a layout content structure instead of a single extent. The ability
to store and encode an array of extents is then used to implement support
for multiple extents per LAYOUTGET.
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Sergey Bashirov [Fri, 3 Oct 2025 09:11:04 +0000 (12:11 +0300)]
NFSD/blocklayout: Extract extent mapping from proc_layoutget
No changes in functionality. Split the proc_layoutget function to
create a helper function that maps single extent to the requested
range. This helper function is then used to implement support for
multiple extents per LAYOUTGET.
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Sergey Bashirov [Fri, 3 Oct 2025 09:11:03 +0000 (12:11 +0300)]
NFSD/blocklayout: Fix minlength check in proc_layoutget
The extent returned by the file system may have a smaller offset than
the segment offset requested by the client. In this case, the minimum
segment length must be checked against the requested range. Otherwise,
the client may not be able to continue the read/write operation.
Fixes: 8650b8a05850 ("nfsd: pNFS block layout driver") Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Chuck Lever [Thu, 2 Oct 2025 14:00:52 +0000 (10:00 -0400)]
svcrdma: Increase the server's default RPC/RDMA credit grant
The range of commits from commit e3274026e2ec ("SUNRPC: move all of
xprt handling into svc_xprt_handle()") to commit 15d39883ee7d
("SUNRPC: change the back-channel queue to lwq") enabled NFSD
performance to scale better as the number of nfsd threads is
increased. These commits were merged in v6.7.
Now that the nfsd thread count can scale to more threads, permit
individual clients to make more use of those threads. Increase the
RPC/RDMA per-connection credit grant from 64 to 128 -- same as the
Linux NFS client.
Simple single client fio-based benchmarking so far shows only
improvement, no regression.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd: delete unreachable confusing code in nfs4_open_delegation()
op_delegate_type is assigned OPEN_DELEGATE_NONE just before the if-block
where condition specifies it not be equal to OPEN_DELEGATE_NONE. Compiler
treats the block as unreachable and optimizes it out from the resulting
executable.
In that aspect commit d08d32e6e5c0 ("nfsd4: return delegation immediately
if lease fails") notably makes no difference.
Seems it's better to just drop this code instead of fiddling with memory
barriers or atomics.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Matvey Kovalev <matvey.kovalev@ispras.ru> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Chuck Lever [Wed, 17 Sep 2025 14:31:40 +0000 (10:31 -0400)]
NFSD: Add array bounds-checking in nfsd_iter_read()
The *count parameter does not appear to be explicitly restricted
to being smaller than rsize, so it might be possible to overrun
the rq_bvec or rq_pages arrays.
Rather than overrunning these arrays (damage done!) and then WARNING
once, let's harden the loop so that it terminates before the end of
the arrays are reached. This should result in a short read, which is
OK -- clients recover by sending additional READ requests for the
remaining unread bytes.
Reported-by: NeilBrown <neil@brown.name> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd: change nfs4_client_to_reclaim() to allocate data
The calling convention for nfs4_client_to_reclaim() is clumsy in that
the caller needs to free memory if the function fails. It is much
cleaner if the function frees its own memory.
This patch changes nfs4_client_to_reclaim() to re-allocate the .data
fields to be stored in the newly allocated struct nfs4_client_reclaim,
and to free everything on failure.
__cld_pipe_inprogress_downcall() needs to allocate the data anyway to
copy it from user-space, so now that data is allocated twice. I think
that is a small price to pay for a cleaner interface.
Signed-off-by: NeilBrown <neil@brown.name> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd: move name lookup out of nfsd4_list_rec_dir()
nfsd4_list_rec_dir() is called with two different callbacks.
One of the callbacks uses vfs_rmdir() to remove the directory.
The other doesn't use the dentry at all, just the name.
As only one callback needs the dentry, this patch moves the lookup into
that callback. This prepares of changes to how directory operations
are locked.
Signed-off-by: NeilBrown <neil@brown.name> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Chuck Lever [Wed, 3 Sep 2025 15:53:35 +0000 (11:53 -0400)]
svcrdma: Release transport resources synchronously
NFSD has always supported added network listeners. The new netlink
protocol now enables the removal of listeners.
Olga noticed that if an RDMA listener is removed and immediately
re-added, the deferred __svc_rdma_free() function might not have
run yet, so some or all of the old listener's RDMA resources
linger, which prevents a new listener on the same address from
being created.
Also, svc_xprt_free() does a module_put() just after calling
->xpo_free(). That means if there is deferred work going on, the
module could be unloaded before that work is even started,
resulting in a UAF.
Neil asks:
> What particular part of __svc_rdma_free() needs to run in order for a
> subsequent registration to succeed?
> Can that bit be run directory from svc_rdma_free() rather than be
> delayed?
> (I know almost nothing about rdma so forgive me if the answers to these
> questions seems obvious)
The reasons I can recall are:
- Some of the transport tear-down work can sleep
- Releasing a cm_id is tricky and can deadlock
We might be able to mitigate the second issue with judicious
application of transport reference counting.
Reported-by: Olga Kornievskaia <okorniev@redhat.com> Closes: https://lore.kernel.org/linux-nfs/20250821204328.89218-1-okorniev@redhat.com/ Suggested-by: NeilBrown <neil@brown.name> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Linus Torvalds [Sun, 16 Nov 2025 21:45:03 +0000 (13:45 -0800)]
Merge tag 'perf-tools-fixes-for-v6.18-2-2025-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools
Pull perf tools fixes from Arnaldo Carvalho de Melo:
- Fix writing bpf_prog (infos|btfs)_cnt to data file, to not generate
invalid perf.data files in some corner cases.
- Fix 'perf top' segfault by ensuring libbfd is initialized. This is an
opt-in feature due to license incompatibilities.
- Fix segfault in 'perf lock' due to missing kernel map.
- Fix 'perf lock contention' test.
- Don't fail fast path detection if binutils-devel isn't available.
- Sync KVM's vmx.h with the kernel to pick SEAMCALL exit reason.
* tag 'perf-tools-fixes-for-v6.18-2-2025-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
perf libbfd: Ensure libbfd is initialized prior to use
perf test: Fix lock contention test
perf lock: Fix segfault due to missing kernel map
tools headers UAPI: Sync KVM's vmx.h with the kernel to pick SEAMCALL exit reason
perf build: Don't fail fast path feature detection when binutils-devel is not available
perf header: Write bpf_prog (infos|btfs)_cnt to data file
Linus Torvalds [Sun, 16 Nov 2025 21:31:14 +0000 (13:31 -0800)]
Merge tag 'mm-hotfixes-stable-2025-11-16-10-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"7 hotfixes. 5 are cc:stable, 4 are against mm/
All are singletons - please see the respective changelogs for details"
* tag 'mm-hotfixes-stable-2025-11-16-10-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm, swap: fix potential UAF issue for VMA readahead
selftests/user_events: fix type cast for write_index packed member in perf_test
lib/test_kho: check if KHO is enabled
mm/huge_memory: fix folio split check for anon folios in swapcache
MAINTAINERS: update David Hildenbrand's email address
crash: fix crashkernel resource shrink
mm: fix MAX_FOLIO_ORDER on powerpc configs with hugetlb
Linus Torvalds [Sun, 16 Nov 2025 15:08:28 +0000 (07:08 -0800)]
Merge tag 'firewire-fixes-6.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394
Pull firewire fixes from Takashi Sakamoto:
"This includes some fixes for the topology map, newly introduced in
v6.18 kernel"
* tag 'firewire-fixes-6.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
firewire: core: fix to update generation field in topology map
firewire: core: Initialize topology_map.lock
Linus Torvalds [Sun, 16 Nov 2025 15:05:24 +0000 (07:05 -0800)]
Merge tag 'edac_urgent_for_v6.18_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras
Pull EDAC fixes from Borislav Petkov:
- In Versalnet, handle the reporting of non-standard hw errors whose
information can come in more than one remote processor message.
- Explicitly reenable ECC checking after a warm reset in Altera OCRAM
as those registers are reset to default otherwise
- Fix single-bit error injection in Altera EDAC to not inject errors
directly in ECC RAM and thus lead to false double-bit errors due to
same ECC RAM being in concurrent use
* tag 'edac_urgent_for_v6.18_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
EDAC/altera: Use INTTEST register for Ethernet and USB SBE injection
EDAC/altera: Handle OCRAM ECC enable after warm reset
EDAC/versalnet: Handle split messages for non-standard errors
Takashi Sakamoto [Fri, 14 Nov 2025 14:44:21 +0000 (23:44 +0900)]
firewire: core: fix to update generation field in topology map
The generation field of topology map is updated after initialized by zero.
The updated value of generation field is always zero, and is against
specification.
Kairui Song [Tue, 11 Nov 2025 13:36:08 +0000 (21:36 +0800)]
mm, swap: fix potential UAF issue for VMA readahead
Since commit 78524b05f1a3 ("mm, swap: avoid redundant swap device
pinning"), the common helper for allocating and preparing a folio in the
swap cache layer no longer tries to get a swap device reference
internally, because all callers of __read_swap_cache_async are already
holding a swap entry reference. The repeated swap device pinning isn't
needed on the same swap device.
Caller of VMA readahead is also holding a reference to the target entry's
swap device, but VMA readahead walks the page table, so it might encounter
swap entries from other devices, and call __read_swap_cache_async on
another device without holding a reference to it.
So it is possible to cause a UAF when swapoff of device A raced with
swapin on device B, and VMA readahead tries to read swap entries from
device A. It's not easy to trigger, but in theory, it could cause real
issues.
Make VMA readahead try to get the device reference first if the swap
device is a different one from the target entry.
Link: https://lkml.kernel.org/r/20251111-swap-fix-vma-uaf-v1-1-41c660e58562@tencent.com Fixes: 78524b05f1a3 ("mm, swap: avoid redundant swap device pinning") Suggested-by: Huang Ying <ying.huang@linux.alibaba.com> Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Chris Li <chrisl@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Ankit Khushwaha [Thu, 6 Nov 2025 09:55:32 +0000 (15:25 +0530)]
selftests/user_events: fix type cast for write_index packed member in perf_test
Accessing 'reg.write_index' directly triggers a -Waddress-of-packed-member
warning due to potential unaligned pointer access:
perf_test.c:239:38: warning: taking address of packed member 'write_index'
of class or structure 'user_reg' may result in an unaligned pointer value
[-Waddress-of-packed-member]
239 | ASSERT_NE(-1, write(self->data_fd, ®.write_index,
| ^~~~~~~~~~~~~~~
Since write(2) works with any alignment. Casting '®.write_index'
explicitly to 'void *' to suppress this warning.
Zi Yan [Wed, 5 Nov 2025 16:29:10 +0000 (11:29 -0500)]
mm/huge_memory: fix folio split check for anon folios in swapcache
Both uniform and non uniform split check missed the check to prevent
splitting anon folios in swapcache to non-zero order.
Splitting anon folios in swapcache to non-zero order can cause data
corruption since swapcache only support PMD order and order-0 entries.
This can happen when one use split_huge_pages under debugfs to split
anon folios in swapcache.
In-tree callers do not perform such an illegal operation. Only debugfs
interface could trigger it. I will put adding a test case on my TODO
list.
Fix the check.
Link: https://lkml.kernel.org/r/20251105162910.752266-1-ziy@nvidia.com Fixes: 58729c04cf10 ("mm/huge_memory: add buddy allocator like (non-uniform) folio_split()") Signed-off-by: Zi Yan <ziy@nvidia.com> Reported-by: "David Hildenbrand (Red Hat)" <david@kernel.org> Closes: https://lore.kernel.org/all/dc0ecc2c-4089-484f-917f-920fdca4c898@kernel.org/ Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
MAINTAINERS: update David Hildenbrand's email address
Switch to kernel.org email address as I will be leaving Red Hat. The old
address will remain active until end of January 2026, so performing the
change now should make sure that most mails will reach me.
If crashkernel is then shrunk to 50MB (echo 52428800 >
/sys/kernel/kexec_crash_size), /proc/iomem still shows 256MB reserved: af000000-beffffff : Crash kernel
This happens because __crash_shrink_memory()/kernel/crash_core.c
incorrectly updates the crashk_res resource object even when
crashk_low_res should be updated.
Fix this by ensuring the correct crashkernel resource object is updated
when shrinking crashkernel memory.
Link: https://lkml.kernel.org/r/20251101193741.289252-1-sourabhjain@linux.ibm.com Fixes: 16c6006af4d4 ("kexec: enable kexec_crash_size to support two crash kernel regions") Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Zhen Lei <thunder.leizhen@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: fix MAX_FOLIO_ORDER on powerpc configs with hugetlb
In the past, CONFIG_ARCH_HAS_GIGANTIC_PAGE indicated that we support
runtime allocation of gigantic hugetlb folios. In the meantime it evolved
into a generic way for the architecture to state that it supports gigantic
hugetlb folios.
In commit fae7d834c43c ("mm: add __dump_folio()") we started using
CONFIG_ARCH_HAS_GIGANTIC_PAGE to decide MAX_FOLIO_ORDER: whether we could
have folios larger than what the buddy can handle. In the context of that
commit, we started using MAX_FOLIO_ORDER to detect page corruptions when
dumping tail pages of folios. Before that commit, we assumed that we
cannot have folios larger than the highest buddy order, which was
obviously wrong.
In commit 7b4f21f5e038 ("mm/hugetlb: check for unreasonable folio sizes
when registering hstate"), we used MAX_FOLIO_ORDER to detect
inconsistencies, and in fact, we found some now.
Powerpc allows for configs that can allocate gigantic folio during boot
(not at runtime), that do not set CONFIG_ARCH_HAS_GIGANTIC_PAGE and can
exceed PUD_ORDER.
To fix it, let's make powerpc select CONFIG_ARCH_HAS_GIGANTIC_PAGE with
hugetlb on powerpc, and increase the maximum folio size with hugetlb to 16
GiB on 64bit (possible on arm64 and powerpc) and 1 GiB on 32 bit
(powerpc). Note that on some powerpc configurations, whether we actually
have gigantic pages depends on the setting of CONFIG_ARCH_FORCE_MAX_ORDER,
but there is nothing really problematic about setting it unconditionally:
we just try to keep the value small so we can better detect problems in
__dump_folio() and inconsistencies around the expected largest folio in
the system.
Ideally, we'd have a better way to obtain the maximum hugetlb folio size
and detect ourselves whether we really end up with gigantic folios. Let's
defer bigger changes and fix the warnings first.
While at it, handle gigantic DAX folios more clearly: DAX can only end up
creating gigantic folios with HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD.
Add a new Kconfig option HAVE_GIGANTIC_FOLIOS to make both cases clearer.
In particular, worry about ARCH_HAS_GIGANTIC_PAGE only with HUGETLB_PAGE.
Note: with enabling CONFIG_ARCH_HAS_GIGANTIC_PAGE on powerpc, we will now
also allow for runtime allocations of folios in some more powerpc configs.
I don't think this is a problem, but if it is we could handle it through
__HAVE_ARCH_GIGANTIC_PAGE_RUNTIME_SUPPORTED.
While __dump_page()/__dump_folio was also problematic (not handling
dumping of tail pages of such gigantic folios correctly), it doesn't seem
critical enough to mark it as a fix.
Link: https://lkml.kernel.org/r/20251114214920.2550676-1-david@kernel.org Fixes: 7b4f21f5e038 ("mm/hugetlb: check for unreasonable folio sizes when registering hstate") Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> Closes: https://lore.kernel.org/r/3e043453-3f27-48ad-b987-cc39f523060a@csgroup.eu/ Reported-by: Sourabh Jain <sourabhjain@linux.ibm.com> Closes: https://lore.kernel.org/r/94377f5c-d4f0-4c0f-b0f6-5bf1cd7305b1@linux.ibm.com/ Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Ian Rogers [Wed, 12 Nov 2025 07:43:11 +0000 (23:43 -0800)]
perf libbfd: Ensure libbfd is initialized prior to use
Multiple threads may be creating and destroying BFD objects in
situations like `perf top`.
Without appropriate initialization crashes may occur during libbfd's
cache management.
BFD's locks require recursive mutexes, add support for these.
Committer testing:
This happens only when building with 'make BUILD_NONDISTRO=1' and having
the binutils-devel package (or equivalent) installed, i.e. linking with
binutils devel files, an opt-in perf build.
Before:
root@x1:~# perf top
perf: Segmentation fault
-------- backtrace --------
<SNIP multiple failed attempts at printing a backtrace>
root@x1:~#
After this patch it works as before.
Closes: https://lore.kernel.org/lkml/aQt66zhfxSA80xwt@gentoo.org/ Fixes: 95931d9a594dd0b5 ("perf libbfd: Move libbfd functionality to its own file") Reported-by: Guilherme Amadio <amadio@gentoo.org> Signed-off-by: Ian Rogers <irogers@google.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ravi Bangoria [Thu, 13 Nov 2025 16:01:24 +0000 (16:01 +0000)]
perf test: Fix lock contention test
Couple of independent fixes:
1. Wire in SIGSEGV handler that terminates the test with a failure code.
2. Use "--lock-cgroup" instead of "-g"; "-g" was proposed but never
merged. See commit 4d1792d0a2564caf ("perf lock contention: Add
--lock-cgroup option")
3. Call cleanup() on every normal exit so trap_cleanup() doesn't mistake
it for an unexpected signal and emit a false-negative "Unexpected
signal in main" message.
Before patch:
# ./perf test -vv "lock contention"
85: kernel lock contention analysis test:
--- start ---
test child forked, pid 610711
Testing perf lock record and perf lock contention
Testing perf lock contention --use-bpf
Testing perf lock record and perf lock contention at the same time
Testing perf lock contention --threads
Testing perf lock contention --lock-addr
Testing perf lock contention --lock-cgroup
Unexpected signal in test_aggr_cgroup
---- end(0) ----
85: kernel lock contention analysis test : Ok
After patch:
# ./perf test -vv "lock contention"
85: kernel lock contention analysis test:
--- start ---
test child forked, pid 602637
Testing perf lock record and perf lock contention
Testing perf lock contention --use-bpf
Testing perf lock record and perf lock contention at the same time
Testing perf lock contention --threads
Testing perf lock contention --lock-addr
Testing perf lock contention --lock-cgroup
Testing perf lock contention --type-filter (w/ spinlock)
Testing perf lock contention --lock-filter (w/ tasklist_lock)
Testing perf lock contention --callstack-filter (w/ unix_stream)
[Skip] Could not find 'unix_stream'
Testing perf lock contention --callstack-filter with task aggregation
[Skip] Could not find 'unix_stream'
Testing perf lock contention --cgroup-filter
Testing perf lock contention CSV output
---- end(0) ----
85: kernel lock contention analysis test : Ok
Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ananth Narayan <ananth.narayan@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sandipan Das <sandipan.das@amd.com> Cc: Santosh Shukla <santosh.shukla@amd.com> Cc: Tycho Andersen <tycho@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools headers UAPI: Sync KVM's vmx.h with the kernel to pick SEAMCALL exit reason
To pick the changes in:
9d7dfb95da2cb5c1 ("KVM: VMX: Inject #UD if guest tries to execute SEAMCALL or TDCALL")
The 'perf kvm-stat' tool uses the exit reasons that are included in the
VMX_EXIT_REASONS define, this new SEAMCALL isn't included there (TDCALL
is), so shouldn't be causing any change in behaviour, this patch ends up
being just addressess the following perf build warning:
Warning: Kernel ABI header differences:
diff -u tools/arch/x86/include/uapi/asm/vmx.h arch/x86/include/uapi/asm/vmx.h
Please see tools/include/uapi/README for further details.
Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf build: Don't fail fast path feature detection when binutils-devel is not available
This is one more remnant of the BUILD_NONDISTRO series to make building
with binutils-devel opt-in due to license incompatibility.
In this case just the references at link time were still in place, which
make building the test-all.bin file fail, which wasn't detected before
probably because the last test was done with binutils-devel available,
doh.
Now:
$ rpm -q binutils-devel
package binutils-devel is not installed
$ file /tmp/build/perf-tools/feature/test-all.bin
/tmp/build/perf-tools/feature/test-all.bin: ELF 64-bit LSB executable, x86-64, version 1 (SYSV),
dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2,
BuildID[sha1]=4b5388a346b51f1b993f0b0dbd49f4570769b03c, for GNU/Linux 3.2.0, not stripped
$
Fixes: 970ae86307718c34 ("perf build: The bfd features are opt-in, stop testing for them by default") Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Thomas Falcon [Fri, 7 Nov 2025 17:31:50 +0000 (11:31 -0600)]
perf header: Write bpf_prog (infos|btfs)_cnt to data file
With commit f0d0f978f3f5830a ("perf header: Don't write empty BPF/BTF
info"), the write_bpf_( prog_info() | btf() ) functions exit without
writing anything if env->bpf_prog.(infos| btfs)_cnt is zero.
process_bpf_( prog_info() | btf() ), however, still expect a "count"
value to exist in the data file. If btf information is empty, for
example, process_bpf_btf will read garbage or some other data as the
number of btf nodes in the data file. As a result, the data file will
not be processed correctly.
Instead, write the count to the data file and exit if it is zero.
Fixes: f0d0f978f3f5830a ("perf header: Don't write empty BPF/BTF info") Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Thomas Falcon <thomas.falcon@intel.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linus Torvalds [Thu, 13 Nov 2025 19:37:40 +0000 (11:37 -0800)]
Merge tag 'linux_kselftest-fixes-6.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull kselftest fix from Shuah Khan:
"Fixes event-filter-function.tc tracing test failure caused when a
first run to sample events triggers kmem_cache_free which interferes
with the rest of the test.
Fix this by calling sample_events twice to eliminate the
kmem_cache_free related noise from the sampling"
* tag 'linux_kselftest-fixes-6.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests/tracing: Run sample events to clear page cache events
Harry Yoo [Tue, 11 Nov 2025 12:53:31 +0000 (21:53 +0900)]
mm/slub: fix memory leak in free_to_pcs_bulk()
The commit 989b09b73978 ("slab: skip percpu sheaves for remote object
freeing") introduced the remote_objects array in free_to_pcs_bulk() to
skip sheaves when objects from a remote node are freed.
However, the array is flushed only when:
1) the array becomes full (++remote_nr >= PCS_BATCH_MAX), or
2) slab_free_hook() returns false and size becomes zero.
When neither of the conditions is met, objects in the array are leaked.
This resulted in a memory leak [1], where 82 GiB of memory was allocated
for the maple_node cache.
Flush the array after successfully freeing objects to sheaves
in the do_free: path.
In the meantime, move the snippet if (!size) goto flush_remote; outside
the while loop for readability. Let's say all objects in the array are
from a remote node: then we acquire s->cpu_sheaves->lock and try to free
an object even when size is zero. This doesn't appear to be harmful,
but isn't really readable.
Reported-by: Tytus Rogalewski <admin@simplepod.ai> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220765 [1] Closes: https://lore.kernel.org/linux-mm/20251107094809.12e9d705b7bf4815783eb184@linux-foundation.org Closes: https://lore.kernel.org/all/aRGDTwbt2EIz2CYn@hyeyoo Fixes: 989b09b73978 ("slab: skip percpu sheaves for remote object freeing") Signed-off-by: Harry Yoo <harry.yoo@oracle.com> Link: https://patch.msgid.link/20251111125331.12246-1-harry.yoo@oracle.com Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Tested-by: Darrick J. Wong <djwong@kernel.org> Tested-by: Tytus Rogalewski <admin@simplepod.ai> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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