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@twilfredo twilfredo commented Aug 30, 2024

In the flags field of a GET_CAPABILITIES request, ensure we indicate that large transfers are supported by setting the CHUNK_CAP bit [1].

[1] SPDM Spec 1.3: Table 13

libspdm picked this up during testing here: https://github.com/DMTF/libspdm/blob/704d5652b2eeb451fffbd1bb1129046e377c9cf3/library/spdm_responder_lib/libspdm_rsp_capabilities.c#L221

@l1k l1k force-pushed the spdm-future branch 10 times, most recently from b048e74 to fbc92d2 Compare September 10, 2024 14:47
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@l1k This needs a rebase, but does it look right?

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l1k commented Sep 12, 2024

Sorry for the delay Wilfred! I'm underwater with Plumbers preparations and the P1363 series. I'll see to it that I come up with a solution this weekend.

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Sorry for the delay Wilfred! I'm underwater with Plumbers preparations and the P1363 series. I'll see to it that I come up with a solution this weekend.

No worries, understandable. Hope to see you there!

l1k added 16 commits September 30, 2024 11:07
Commit a7d45ba ("crypto: ecdsa - Register NIST P521 and extend test
suite") added support for ECDSA signature verification using NIST P521,
but forgot to amend the Kconfig entry.  Fix it.

Fixes: a7d45ba ("crypto: ecdsa - Register NIST P521 and extend test
suite")
Signed-off-by: Lukas Wunner <[email protected]>
Cc: Stefan Berger <[email protected]>
The ECDSA test vectors contain "params", "param_len" and "algo" elements
even though ecdsa.c doesn't make any use of them.  The only algorithm
implementation using those elements is ecrdsa.c.

Drop the unused test vector elements.

For the curious, "params" is an ASN.1 SEQUENCE of OID_id_ecPublicKey
and a second OID identifying the curve.  For example:

    "\x30\x13\x06\x07\x2a\x86\x48\xce\x3d\x02\x01\x06\x08\x2a\x86\x48"
    "\xce\x3d\x03\x01\x01"

... decodes to:

    SEQUENCE (OID_id_ecPublicKey, OID_id_prime192v1)

The curve OIDs used in those "params" elements are unsurprisingly:

    OID_id_prime192v1 (2a8648ce3d030101)
    OID_id_prime256v1 (2a8648ce3d030107)
    OID_id_ansip384r1 (2b81040022)
    OID_id_ansip521r1 (2b81040023)

Those are just different names for secp192r1, secp256r1, secp384r1 and
secp521r1, respectively, per RFC 8422 appendix A:
https://www.rfc-editor.org/rfc/rfc8422#appendix-A

The entries for secp384r1 and secp521r1 curves contain a useful code
comment calling out the curve and hash.  Add analogous code comments
to secp192r1 and secp256r1 curve entries.

Signed-off-by: Lukas Wunner <[email protected]>
Reviewed-by: Stefan Berger <[email protected]>
Commit 6cb8815 ("crypto: sig - Add interface for sign/verify")
began a transition of asymmetric sign/verify operations from
crypto_akcipher to a new crypto_sig frontend.

Internally, the crypto_sig frontend still uses akcipher_alg as backend,
however:

   "The link between sig and akcipher is meant to be temporary.  The
    plan is to create a new low-level API for sig and then migrate
    the signature code over to that from akcipher."
    https://lore.kernel.org/r/[email protected]/

   "having a separate alg for sig is definitely where we want to
    be since there is very little that the two types actually share."
    https://lore.kernel.org/r/[email protected]/

Take the next step of that migration and augment the crypto_sig frontend
with a sig_alg backend to which all algorithms can be moved.

During the migration, there will briefly be signature algorithms that
are still based on crypto_akcipher, whilst others are already based on
crypto_sig.  Allow for that by building a fork into crypto_sig_*() API
calls (i.e. crypto_sig_maxsize() and friends) such that one of the two
backends is selected based on the transform's cra_type.

Signed-off-by: Lukas Wunner <[email protected]>
A sig_alg backend has just been introduced with the intent of moving all
asymmetric sign/verify algorithms to it one by one.

Migrate ecdsa.c to the new backend.

One benefit of the new API is the use of kernel buffers instead of
sglists, which avoids the overhead of copying signature and digest
sglists back into kernel buffers.  ecdsa.c is thus simplified quite
a bit.

Signed-off-by: Lukas Wunner <[email protected]>
A sig_alg backend has just been introduced with the intent of moving all
asymmetric sign/verify algorithms to it one by one.

Migrate ecrdsa.c to the new backend.

One benefit of the new API is the use of kernel buffers instead of
sglists, which avoids the overhead of copying signature and digest
sglists back into kernel buffers.  ecrdsa.c is thus simplified quite
a bit.

Signed-off-by: Lukas Wunner <[email protected]>
pkcs1pad_set_pub_key() and pkcs1pad_set_priv_key() are almost identical.

The upcoming migration of sign/verify operations from rsa-pkcs1pad.c
into a separate crypto_template will require another copy of the exact
same functions.  When RSASSA-PSS and RSAES-OAEP are introduced, each
will need yet another copy.

Deduplicate the functions into a single one which lives in a common
header file for reuse by RSASSA-PKCS1-v1_5, RSASSA-PSS and RSAES-OAEP.

Signed-off-by: Lukas Wunner <[email protected]>
Reviewed-by: Stefan Berger <[email protected]>
A sig_alg backend has just been introduced with the intent of moving all
asymmetric sign/verify algorithms to it one by one.

Migrate the sign/verify operations from rsa-pkcs1pad.c to a separate
rsassa-pkcs1.c which uses the new backend.

Consequently there are now two templates which build on the "rsa"
akcipher_alg:

* The existing "pkcs1pad" template, which is instantiated as an
  akcipher_instance and retains the encrypt/decrypt operations of
  RSAES-PKCS1-v1_5 (RFC 8017 sec 7.2).

* The new "pkcs1" template, which is instantiated as a sig_instance
  and contains the sign/verify operations of RSASSA-PKCS1-v1_5
  (RFC 8017 sec 8.2).

In a separate step, rsa-pkcs1pad.c could optionally be renamed to
rsaes-pkcs1.c for clarity.  Additional "oaep" and "pss" templates
could be added for RSAES-OAEP and RSASSA-PSS.

Note that it's currently allowed to allocate a "pkcs1pad(rsa)" transform
without specifying a hash algorithm.  That makes sense if the transform
is only used for encrypt/decrypt and continues to be supported.  But for
sign/verify, such transforms previously did not insert the Full Hash
Prefix into the padding.  The resulting message encoding was incompliant
with EMSA-PKCS1-v1_5 (RFC 8017 sec 9.2) and therefore nonsensical.

From here on out, it's no longer allowed to allocate a transform without
specifying a hash algorithm if the transform is used for sign/verify
operations.  This simplifies the code because the insertion of the Full
Hash Prefix is no longer optional, so various "if (digest_info)" clauses
can be removed.

There has been a previous attempt to forbid transform allocation without
specifying a hash algorithm, namely by commit c0d20d2 ("crypto:
rsa-pkcs1pad - Require hash to be present").  It had to be rolled back
with commit b3a8c8a ("crypto: rsa-pkcs1pad: Allow hash to be
optional [ver l1k#2]"), presumably because it broke allocation of a
transform which was solely used for encrypt/decrypt, not sign/verify.
Avoid such breakage by allowing transform allocation for encrypt/decrypt
with and without specifying a hash algorithm (and simply ignoring the
hash algorithm in the former case).

So again, specifying a hash algorithm is now mandatory for sign/verify,
but optional and ignored for encrypt/decrypt.

The new sig_alg API uses kernel buffers instead of sglists, which
avoids the overhead of copying signature and digest from sglists back
into kernel buffers.  rsassa-pkcs1.c is thus simplified quite a bit.

sig_alg is always synchronous, whereas the underlying "rsa" akcipher_alg
may be asynchronous.  So await the result of the akcipher_alg, similar
to crypto_akcipher_sync_{en,de}crypt().

As part of the migration, rename "rsa_digest_info" to "hash_prefix" to
adhere to the spec language in RFC 9580.  Otherwise keep the code
unmodified wherever possible to ease reviewing and bisecting.  Leave
several simplification and hardening opportunities to separate commits.

rsassa-pkcs1.c uses modern __free() syntax for allocation of buffers
which need to be freed by kfree_sensitive(), hence a DEFINE_FREE()
clause for kfree_sensitive() is introduced herein as a byproduct.

Signed-off-by: Lukas Wunner <[email protected]>
The RSASSA-PKCS1-v1_5 sign operation currently only checks that the
digest length is less than "key_size - hash_prefix->size - 11".
The verify operation merely checks that it's more than zero.

Actually the precise digest length is known because the hash algorithm
is specified upon instance creation and the digest length is encoded
into the final byte of the hash algorithm's Full Hash Prefix.

So check for the exact digest length rather than solely relying on
imprecise maximum/minimum checks.

Keep the maximum length check for the sign operation as a safety net,
but drop the now unnecessary minimum check for the verify operation.

Signed-off-by: Lukas Wunner <[email protected]>
When constructing the EMSA-PKCS1-v1_5 padding for the sign operation,
a buffer for the padding is allocated and the Full Hash Prefix is copied
into it.  The padding is then passed to the RSA decrypt operation as an
sglist entry which is succeeded by a second sglist entry for the hash.

Actually copying the hash prefix around is completely unnecessary.
It can simply be referenced from a third sglist entry which sits
in-between the padding and the digest.

Signed-off-by: Lukas Wunner <[email protected]>
The virtio crypto driver exposes akcipher sign/verify operations in a
user space ABI.  This blocks removal of sign/verify from akcipher_alg.

Herbert opines:

   "I would say that this is something that we can break.  Breaking it
    is no different to running virtio on a host that does not support
    these algorithms.  After all, a software implementation must always
    be present.

    I deliberately left akcipher out of crypto_user because the API
    is still in flux.  We should not let virtio constrain ourselves."
    https://lore.kernel.org/all/[email protected]/

   "I would remove virtio akcipher support in its entirety.  This API
    was never meant to be exposed outside of the kernel."
    https://lore.kernel.org/all/[email protected]/

Drop sign/verify support from virtio crypto.  There's no strong reason
to also remove encrypt/decrypt support, so keep it.

A key selling point of virtio crypto is to allow guest access to crypto
accelerators on the host.  So far the only akcipher algorithm supported
by virtio crypto is RSA.  Dropping sign/verify merely means that the
PKCS#1 padding is now always generated or verified inside the guest,
but the actual signature generation/verification (which is an RSA
decrypt/encrypt operation) may still use an accelerator on the host.

Generating or verifying the PKCS#1 padding is cheap, so a hardware
accelerator won't be of much help there.  Which begs the question
whether virtio crypto support for sign/verify makes sense at all.

It would make sense for the sign operation if the host has a security
chip to store asymmetric private keys.  But the kernel doesn't even
have an asymmetric_key_subtype yet for hardware-based private keys.
There's at least one rudimentary driver for such chips (atmel-ecc.c for
ATECC508A), but it doesn't implement the sign operation.  The kernel
would first have to grow support for a hardware asymmetric_key_subtype
and at least one driver implementing the sign operation before exposure
to guests via virtio makes sense.

Signed-off-by: Lukas Wunner <[email protected]>
The drivers aspeed-acry.c, hpre_crypto.c and jh7110-rsa.c purport to
implement sign/verify operations for raw (unpadded) "rsa".

But there is no such thing as message digests generally need to be
padded according to a predefined scheme (such as PSS or PKCS#1) to
match the size of the usually much larger RSA keys.

The bogus sign/verify operations defined by these drivers are never
called but block removal of sign/verify from akcipher_alg.  Drop them.

Signed-off-by: Lukas Wunner <[email protected]>
A sig_alg backend has just been introduced and all asymmetric
sign/verify algorithms have been migrated to it.

The sign/verify operations can thus be dropped from akcipher_alg.
It is now purely for asymmetric encrypt/decrypt.

Move struct crypto_akcipher_sync_data from internal.h to akcipher.c and
unexport crypto_akcipher_sync_{prep,post}():  They're no longer used by
sig.c but only locally in akcipher.c.

In crypto_akcipher_sync_{prep,post}(), drop various NULL pointer checks
for data->dst as they were only necessary for the verify operation.

In the crypto_sig_*() API calls, remove the forks that were necessary
while algorithms were converted from crypto_akcipher to crypto_sig
one by one.

In struct akcipher_testvec, remove the "params", "param_len" and "algo"
elements as they were only needed for the ecrdsa verify operation.
Remove corresponding dead code from test_akcipher_one() as well.

Signed-off-by: Lukas Wunner <[email protected]>
The crypto_sig_*() API calls lived in sig.c so far because they needed
access to struct crypto_sig_type:  This was necessary to differentiate
between signature algorithms that had already been migrated from
crypto_akcipher to crypto_sig and those that hadn't yet.

Now that all algorithms have been migrated, the API calls can become
static inlines in <crypto/sig.h> to mimic what <crypto/akcipher.h> is
doing.

Signed-off-by: Lukas Wunner <[email protected]>
Reviewed-by: Stefan Berger <[email protected]>
If <linux/asn1_decoder.h> is the first header included from a .c file
(due to headers being sorted alphabetically), the compiler complains:

  include/linux/asn1_decoder.h:18:29: error: unknown type name 'size_t'

Avoid by including <linux/types.h>.

Jonathan notes that the counterpart <linux/asn1_encoder.h> already
includes <linux/types.h>, but additionally includes the unnecessary
<linux/bug.h>.  Drop it.

Signed-off-by: Lukas Wunner <[email protected]>
Reviewed-by: Stefan Berger <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
When extracting a signature component r or s from an ASN.1-encoded
integer, ecdsa_get_signature_rs() subtracts the expected length
"bufsize" from the ASN.1 length "vlen" (both of unsigned type size_t)
and stores the result in "diff" (of signed type ssize_t).

This results in a signed integer overflow if vlen > SSIZE_MAX + bufsize.

The kernel is compiled with -fno-strict-overflow, which implies -fwrapv,
meaning signed integer overflow is not undefined behavior.  And the
function does check for overflow:

       if (-diff >= bufsize)
               return -EINVAL;

So the code is fine in principle but not very obvious.  In the future it
might trigger a false-positive with CONFIG_UBSAN_SIGNED_WRAP=y.

Avoid by comparing the two unsigned variables directly and erroring out
if "vlen" is too large.

Signed-off-by: Lukas Wunner <[email protected]>
Reviewed-by: Stefan Berger <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Unlike the rsa driver, which separates signature decoding and
signature verification into two steps, the ecdsa driver does both in one.

This restricts users to the one signature format currently supported
(X9.62) and prevents addition of others such as P1363, which is needed
by the forthcoming SPDM library (Security Protocol and Data Model) for
PCI device authentication.

Per Herbert's suggestion, change ecdsa to use a "raw" signature encoding
and then implement X9.62 and P1363 as templates which convert their
respective encodings to the raw one.  One may then specify
"x962(ecdsa-nist-XXX)" or "p1363(ecdsa-nist-XXX)" to pick the encoding.

The present commit moves X9.62 decoding to a template.  A separate
commit is going to introduce another template for P1363 decoding.

The ecdsa driver internally represents a signature as two u64 arrays of
size ECC_MAX_BYTES.  This appears to be the most natural choice for the
raw format as it can directly be used for verification without having to
further decode signature data or copy it around.

Repurpose all the existing test vectors for "x962(ecdsa-nist-XXX)" and
create a duplicate of them to test the raw encoding.

Link: https://lore.kernel.org/all/[email protected]/
Tested-by: Stefan Berger <[email protected]>
Signed-off-by: Lukas Wunner <[email protected]>
In the flags field of a GET_CAPABILITIES request, ensure we indicate
that large transfers are supported by setting the CHUNK_CAP bit [1].

[1] SPDM Spec 1.3: Table 13

Signed-off-by: Wilfred Mallawa <[email protected]>
@twilfredo twilfredo force-pushed the wilfred/fixup-large-transfer-cap branch from 5fc03a9 to bc9f23e Compare October 8, 2024 01:49
l1k pushed a commit that referenced this pull request Nov 28, 2024
Patch series "Improve the copy of task comm", v8.

Using {memcpy,strncpy,strcpy,kstrdup} to copy the task comm relies on the
length of task comm.  Changes in the task comm could result in a
destination string that is overflow.  Therefore, we should explicitly
ensure the destination string is always NUL-terminated, regardless of the
task comm.  This approach will facilitate future extensions to the task
comm.

As suggested by Linus [0], we can identify all relevant code with the
following git grep command:

  git grep 'memcpy.*->comm\>'
  git grep 'kstrdup.*->comm\>'
  git grep 'strncpy.*->comm\>'
  git grep 'strcpy.*->comm\>'

PATCH #2~#4:   memcpy
PATCH #5~#6:   kstrdup
PATCH torvalds#7:      strcpy

Please note that strncpy() is not included in this series as it is being
tracked by another effort. [1]


This patch (of 7):

We want to eliminate the use of __get_task_comm() for the following
reasons:

- The task_lock() is unnecessary
  Quoted from Linus [0]:
  : Since user space can randomly change their names anyway, using locking
  : was always wrong for readers (for writers it probably does make sense
  : to have some lock - although practically speaking nobody cares there
  : either, but at least for a writer some kind of race could have
  : long-term mixed results

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/CAHk-=wivfrF0_zvf+oj6==Sh=-npJooP8chLPEfaFV0oNYTTBA@mail.gmail.com [0]
Link: https://lore.kernel.org/all/CAHk-=whWtUC-AjmGJveAETKOMeMFSTwKwu99v7+b6AyHMmaDFA@mail.gmail.com/
Link: https://lore.kernel.org/all/CAHk-=wjAmmHUg6vho1KjzQi2=psR30+CogFd4aXrThr2gsiS4g@mail.gmail.com/ [0]
Link: KSPP#90 [1]
Signed-off-by: Yafang Shao <[email protected]>
Suggested-by: Linus Torvalds <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Matus Jokay <[email protected]>
Cc: Alejandro Colomar <[email protected]>
Cc: "Serge E. Hallyn" <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Justin Stitt <[email protected]>
Cc: Steven Rostedt (Google) <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: James Morris <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Ondrej Mosnacek <[email protected]>
Cc: Paul Moore <[email protected]>
Cc: Quentin Monnet <[email protected]>
Cc: Simon Horman <[email protected]>
Cc: Stephen Smalley <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
l1k pushed a commit that referenced this pull request Nov 28, 2024
Patch series "page allocation tag compression", v4.

This patchset implements several improvements:

1. Gracefully handles module unloading while there are used
   allocations allocated from that module;

2. Provides an option to store page allocation tag references in the
   page flags, removing dependency on page extensions and eliminating the
   memory overhead from storing page allocation references (~0.2% of total
   system memory).  This also improves page allocation performance when
   CONFIG_MEM_ALLOC_PROFILING is enabled by eliminating page extension
   lookup.  Page allocation performance overhead is reduced from 41% to
   5.5%.

Patch #1 introduces mas_for_each_rev() helper function.

Patch #2 introduces shutdown_mem_profiling() helper function to be used
when disabling memory allocation profiling.

Patch #3 copies module tags into virtually contiguous memory which
serves two purposes:

- Lets us deal with the situation when module is unloaded while there
  are still live allocations from that module.  Since we are using a copy
  version of the tags we can safely unload the module.  Space and gaps in
  this contiguous memory are managed using a maple tree.

- Enables simple indexing of the tags in the later patches.

Patch #4 changes the way we allocate virtually contiguous memory for
module tags to reserve only vitrual area and populate physical pages only
as needed at module load time.

Patch #5 abstracts page allocation tag reference to simplify later
changes.

Patch #6 adds compression option to the sysctl.vm.mem_profiling boot
parameter for storing page allocation tag references inside page flags if
they fit.  If the number of available page flag bits is insufficient to
address all kernel allocations, memory allocation profiling gets disabled
with an appropriate warning.


This patch (of 6):

Add mas_for_each_rev() function to iterate maple tree nodes in reverse
order.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Suren Baghdasaryan <[email protected]>
Suggested-by: Liam R. Howlett <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Reviewed-by: Pasha Tatashin <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Daniel Gomez <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Kalesh Singh <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport (Microsoft) <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Petr Pavlu <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Sami Tolvanen <[email protected]>
Cc: Sourav Panda <[email protected]>
Cc: Steven Rostedt (Google) <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Thomas Huth <[email protected]>
Cc: Uladzislau Rezki (Sony) <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Xiongwei Song <[email protected]>
Cc: Yu Zhao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
@l1k l1k force-pushed the spdm-future branch 3 times, most recently from ffc2a74 to 72c3a69 Compare December 15, 2024 09:48
l1k pushed a commit that referenced this pull request Dec 16, 2024
Its used from trace__run(), for the 'perf trace' live mode, i.e. its
strace-like, non-perf.data file processing mode, the most common one.

The trace__run() function will set trace->host using machine__new_host()
that is supposed to give a machine instance representing the running
machine, and since we'll use perf_env__arch_strerrno() to get the right
errno -> string table, we need to use machine->env, so initialize it in
machine__new_host().

Before the patch:

  (gdb) run trace --errno-summary -a sleep 1
  <SNIP>
   Summary of events:

   gvfs-afc-volume (3187), 2 events, 0.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     pselect6               1      0     0.000     0.000     0.000     0.000      0.00%

   GUsbEventThread (3519), 2 events, 0.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     poll                   1      0     0.000     0.000     0.000     0.000      0.00%
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
  478		if (env->arch_strerrno == NULL)
  (gdb) bt
  #0  0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
  #1  0x00000000004b75d2 in thread__dump_stats (ttrace=0x14f58f0, trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4673
  #2  0x00000000004b78bf in trace__fprintf_thread (fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>, thread=0x10fa0b0, trace=0x7fffffffa5b0) at builtin-trace.c:4708
  #3  0x00000000004b7ad9 in trace__fprintf_thread_summary (trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4747
  #4  0x00000000004b656e in trace__run (trace=0x7fffffffa5b0, argc=2, argv=0x7fffffffde60) at builtin-trace.c:4456
  #5  0x00000000004ba43e in cmd_trace (argc=2, argv=0x7fffffffde60) at builtin-trace.c:5487
  #6  0x00000000004c0414 in run_builtin (p=0xec3068 <commands+648>, argc=5, argv=0x7fffffffde60) at perf.c:351
  torvalds#7  0x00000000004c06bb in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:404
  torvalds#8  0x00000000004c0814 in run_argv (argcp=0x7fffffffdc4c, argv=0x7fffffffdc40) at perf.c:448
  torvalds#9  0x00000000004c0b5d in main (argc=5, argv=0x7fffffffde60) at perf.c:560
  (gdb)

After:

  root@number:~# perf trace -a --errno-summary sleep 1
  <SNIP>
     pw-data-loop (2685), 1410 events, 16.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     epoll_wait           188      0   983.428     0.000     5.231    15.595      8.68%
     ioctl                 94      0     0.811     0.004     0.009     0.016      2.82%
     read                 188      0     0.322     0.001     0.002     0.006      5.15%
     write                141      0     0.280     0.001     0.002     0.018      8.39%
     timerfd_settime       94      0     0.138     0.001     0.001     0.007      6.47%

   gnome-control-c (179406), 1848 events, 20.9%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     poll                 222      0   959.577     0.000     4.322    21.414     11.40%
     recvmsg              150      0     0.539     0.001     0.004     0.013      5.12%
     write                300      0     0.442     0.001     0.001     0.007      3.29%
     read                 150      0     0.183     0.001     0.001     0.009      5.53%
     getpid               102      0     0.101     0.000     0.001     0.008      7.82%

  root@number:~#

Fixes: 54373b5 ("perf env: Introduce perf_env__arch_strerrno()")
Reported-by: Veronika Molnarova <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Veronika Molnarova <[email protected]>
Acked-by: Michael Petlan <[email protected]>
Tested-by: Michael Petlan <[email protected]>
Link: https://lore.kernel.org/r/Z0XffUgNSv_9OjOi@x1
Signed-off-by: Namhyung Kim <[email protected]>
@l1k l1k force-pushed the spdm-future branch 2 times, most recently from 435c3b2 to 1429a7f Compare January 23, 2025 18:32
l1k pushed a commit that referenced this pull request Jan 23, 2025
…le_direct_reclaim()

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.  

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 torvalds#7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 torvalds#8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 torvalds#9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.  

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[[email protected]: coding-style cleanups]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
l1k pushed a commit that referenced this pull request Jan 23, 2025
Nvidia's Tegra MGBE controllers require the IOMMU "Stream ID" (SID) to be
written to the MGBE_WRAP_AXI_ASID0_CTRL register.

The current driver is hard coded to use MGBE0's SID for all controllers.
This causes softirq time outs and kernel panics when using controllers
other than MGBE0.

Example dmesg errors when an ethernet cable is connected to MGBE1:

[  116.133290] tegra-mgbe 6910000.ethernet eth1: Link is Up - 1Gbps/Full - flow control rx/tx
[  121.851283] tegra-mgbe 6910000.ethernet eth1: NETDEV WATCHDOG: CPU: 5: transmit queue 0 timed out 5690 ms
[  121.851782] tegra-mgbe 6910000.ethernet eth1: Reset adapter.
[  121.892464] tegra-mgbe 6910000.ethernet eth1: Register MEM_TYPE_PAGE_POOL RxQ-0
[  121.905920] tegra-mgbe 6910000.ethernet eth1: PHY [stmmac-1:00] driver [Aquantia AQR113] (irq=171)
[  121.907356] tegra-mgbe 6910000.ethernet eth1: Enabling Safety Features
[  121.907578] tegra-mgbe 6910000.ethernet eth1: IEEE 1588-2008 Advanced Timestamp supported
[  121.908399] tegra-mgbe 6910000.ethernet eth1: registered PTP clock
[  121.908582] tegra-mgbe 6910000.ethernet eth1: configuring for phy/10gbase-r link mode
[  125.961292] tegra-mgbe 6910000.ethernet eth1: Link is Up - 1Gbps/Full - flow control rx/tx
[  181.921198] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[  181.921404] rcu: 	7-....: (1 GPs behind) idle=540c/1/0x4000000000000002 softirq=1748/1749 fqs=2337
[  181.921684] rcu: 	(detected by 4, t=6002 jiffies, g=1357, q=1254 ncpus=8)
[  181.921878] Sending NMI from CPU 4 to CPUs 7:
[  181.921886] NMI backtrace for cpu 7
[  181.922131] CPU: 7 UID: 0 PID: 0 Comm: swapper/7 Kdump: loaded Not tainted 6.13.0-rc3+ #6
[  181.922390] Hardware name: NVIDIA CTI Forge + Orin AGX/Jetson, BIOS 202402.1-Unknown 10/28/2024
[  181.922658] pstate: 40400009 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  181.922847] pc : handle_softirqs+0x98/0x368
[  181.922978] lr : __do_softirq+0x18/0x20
[  181.923095] sp : ffff80008003bf50
[  181.923189] x29: ffff80008003bf50 x28: 0000000000000008 x27: 0000000000000000
[  181.923379] x26: ffffce78ea277000 x25: 0000000000000000 x24: 0000001c61befda0
[  181.924486] x23: 0000000060400009 x22: ffffce78e99918bc x21: ffff80008018bd70
[  181.925568] x20: ffffce78e8bb00d8 x19: ffff80008018bc20 x18: 0000000000000000
[  181.926655] x17: ffff318ebe7d3000 x16: ffff800080038000 x15: 0000000000000000
[  181.931455] x14: ffff000080816680 x13: ffff318ebe7d3000 x12: 000000003464d91d
[  181.938628] x11: 0000000000000040 x10: ffff000080165a70 x9 : ffffce78e8bb0160
[  181.945804] x8 : ffff8000827b3160 x7 : f9157b241586f343 x6 : eeb6502a01c81c74
[  181.953068] x5 : a4acfcdd2e8096bb x4 : ffffce78ea277340 x3 : 00000000ffffd1e1
[  181.960329] x2 : 0000000000000101 x1 : ffffce78ea277340 x0 : ffff318ebe7d3000
[  181.967591] Call trace:
[  181.970043]  handle_softirqs+0x98/0x368 (P)
[  181.974240]  __do_softirq+0x18/0x20
[  181.977743]  ____do_softirq+0x14/0x28
[  181.981415]  call_on_irq_stack+0x24/0x30
[  181.985180]  do_softirq_own_stack+0x20/0x30
[  181.989379]  __irq_exit_rcu+0x114/0x140
[  181.993142]  irq_exit_rcu+0x14/0x28
[  181.996816]  el1_interrupt+0x44/0xb8
[  182.000316]  el1h_64_irq_handler+0x14/0x20
[  182.004343]  el1h_64_irq+0x80/0x88
[  182.007755]  cpuidle_enter_state+0xc4/0x4a8 (P)
[  182.012305]  cpuidle_enter+0x3c/0x58
[  182.015980]  cpuidle_idle_call+0x128/0x1c0
[  182.020005]  do_idle+0xe0/0xf0
[  182.023155]  cpu_startup_entry+0x3c/0x48
[  182.026917]  secondary_start_kernel+0xdc/0x120
[  182.031379]  __secondary_switched+0x74/0x78
[  212.971162] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 7-.... } 6103 jiffies s: 417 root: 0x80/.
[  212.985935] rcu: blocking rcu_node structures (internal RCU debug):
[  212.992758] Sending NMI from CPU 0 to CPUs 7:
[  212.998539] NMI backtrace for cpu 7
[  213.004304] CPU: 7 UID: 0 PID: 0 Comm: swapper/7 Kdump: loaded Not tainted 6.13.0-rc3+ #6
[  213.016116] Hardware name: NVIDIA CTI Forge + Orin AGX/Jetson, BIOS 202402.1-Unknown 10/28/2024
[  213.030817] pstate: 40400009 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  213.040528] pc : handle_softirqs+0x98/0x368
[  213.046563] lr : __do_softirq+0x18/0x20
[  213.051293] sp : ffff80008003bf50
[  213.055839] x29: ffff80008003bf50 x28: 0000000000000008 x27: 0000000000000000
[  213.067304] x26: ffffce78ea277000 x25: 0000000000000000 x24: 0000001c61befda0
[  213.077014] x23: 0000000060400009 x22: ffffce78e99918bc x21: ffff80008018bd70
[  213.087339] x20: ffffce78e8bb00d8 x19: ffff80008018bc20 x18: 0000000000000000
[  213.097313] x17: ffff318ebe7d3000 x16: ffff800080038000 x15: 0000000000000000
[  213.107201] x14: ffff000080816680 x13: ffff318ebe7d3000 x12: 000000003464d91d
[  213.116651] x11: 0000000000000040 x10: ffff000080165a70 x9 : ffffce78e8bb0160
[  213.127500] x8 : ffff8000827b3160 x7 : 0a37b344852820af x6 : 3f049caedd1ff608
[  213.138002] x5 : cff7cfdbfaf31291 x4 : ffffce78ea277340 x3 : 00000000ffffde04
[  213.150428] x2 : 0000000000000101 x1 : ffffce78ea277340 x0 : ffff318ebe7d3000
[  213.162063] Call trace:
[  213.165494]  handle_softirqs+0x98/0x368 (P)
[  213.171256]  __do_softirq+0x18/0x20
[  213.177291]  ____do_softirq+0x14/0x28
[  213.182017]  call_on_irq_stack+0x24/0x30
[  213.186565]  do_softirq_own_stack+0x20/0x30
[  213.191815]  __irq_exit_rcu+0x114/0x140
[  213.196891]  irq_exit_rcu+0x14/0x28
[  213.202401]  el1_interrupt+0x44/0xb8
[  213.207741]  el1h_64_irq_handler+0x14/0x20
[  213.213519]  el1h_64_irq+0x80/0x88
[  213.217541]  cpuidle_enter_state+0xc4/0x4a8 (P)
[  213.224364]  cpuidle_enter+0x3c/0x58
[  213.228653]  cpuidle_idle_call+0x128/0x1c0
[  213.233993]  do_idle+0xe0/0xf0
[  213.237928]  cpu_startup_entry+0x3c/0x48
[  213.243791]  secondary_start_kernel+0xdc/0x120
[  213.249830]  __secondary_switched+0x74/0x78

This bug has existed since the dwmac-tegra driver was added in Dec 2022
(See Fixes tag below for commit hash).

The Tegra234 SOC has 4 MGBE controllers, however Nvidia's Developer Kit
only uses MGBE0 which is why the bug was not found previously. Connect Tech
has many products that use 2 (or more) MGBE controllers.

The solution is to read the controller's SID from the existing "iommus"
device tree property. The 2nd field of the "iommus" device tree property
is the controller's SID.

Device tree snippet from tegra234.dtsi showing MGBE1's "iommus" property:

smmu_niso0: iommu@12000000 {
        compatible = "nvidia,tegra234-smmu", "nvidia,smmu-500";
...
}

/* MGBE1 */
ethernet@6900000 {
	compatible = "nvidia,tegra234-mgbe";
...
	iommus = <&smmu_niso0 TEGRA234_SID_MGBE_VF1>;
...
}

Nvidia's arm-smmu driver reads the "iommus" property and stores the SID in
the MGBE device's "fwspec" struct. The dwmac-tegra driver can access the
SID using the tegra_dev_iommu_get_stream_id() helper function found in
linux/iommu.h.

Calling tegra_dev_iommu_get_stream_id() should not fail unless the "iommus"
property is removed from the device tree or the IOMMU is disabled.

While the Tegra234 SOC technically supports bypassing the IOMMU, it is not
supported by the current firmware, has not been tested and not recommended.
More detailed discussion with Thierry Reding from Nvidia linked below.

Fixes: d8ca113 ("net: stmmac: tegra: Add MGBE support")
Link: https://lore.kernel.org/netdev/[email protected]
Signed-off-by: Parker Newman <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Acked-by: Thierry Reding <[email protected]>
Link: https://patch.msgid.link/6fb97f32cf4accb4f7cf92846f6b60064ba0a3bd.1736284360.git.pnewman@connecttech.com
Signed-off-by: Jakub Kicinski <[email protected]>
@l1k l1k force-pushed the spdm-future branch 5 times, most recently from 4b148e0 to 41acf53 Compare January 30, 2025 18:41
l1k pushed a commit that referenced this pull request Feb 2, 2025
This fixes the following hard lockup in isolate_lru_folios() during memory
reclaim.  If the LRU mostly contains ineligible folios this may trigger
watchdog.

watchdog: Watchdog detected hard LOCKUP on cpu 173
RIP: 0010:native_queued_spin_lock_slowpath+0x255/0x2a0
Call Trace:
	_raw_spin_lock_irqsave+0x31/0x40
	folio_lruvec_lock_irqsave+0x5f/0x90
	folio_batch_move_lru+0x91/0x150
	lru_add_drain_per_cpu+0x1c/0x40
	process_one_work+0x17d/0x350
	worker_thread+0x27b/0x3a0
	kthread+0xe8/0x120
	ret_from_fork+0x34/0x50
	ret_from_fork_asm+0x1b/0x30

lruvec->lru_lock owner:

PID: 2865     TASK: ffff888139214d40  CPU: 40   COMMAND: "kswapd0"
 #0 [fffffe0000945e60] crash_nmi_callback at ffffffffa567a555
 #1 [fffffe0000945e68] nmi_handle at ffffffffa563b171
 #2 [fffffe0000945eb0] default_do_nmi at ffffffffa6575920
 #3 [fffffe0000945ed0] exc_nmi at ffffffffa6575af4
 #4 [fffffe0000945ef0] end_repeat_nmi at ffffffffa6601dde
    [exception RIP: isolate_lru_folios+403]
    RIP: ffffffffa597df53  RSP: ffffc90006fb7c28  RFLAGS: 00000002
    RAX: 0000000000000001  RBX: ffffc90006fb7c60  RCX: ffffea04a2196f88
    RDX: ffffc90006fb7c60  RSI: ffffc90006fb7c60  RDI: ffffea04a2197048
    RBP: ffff88812cbd3010   R8: ffffea04a2197008   R9: 0000000000000001
    R10: 0000000000000000  R11: 0000000000000001  R12: ffffea04a2197008
    R13: ffffea04a2197048  R14: ffffc90006fb7de8  R15: 0000000003e3e937
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    <NMI exception stack>
 #5 [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
 #6 [ffffc90006fb7cf8] shrink_active_list at ffffffffa597f788
 torvalds#7 [ffffc90006fb7da8] balance_pgdat at ffffffffa5986db0
 torvalds#8 [ffffc90006fb7ec0] kswapd at ffffffffa5987354
 torvalds#9 [ffffc90006fb7ef8] kthread at ffffffffa5748238
crash>

Scenario:
User processe are requesting a large amount of memory and keep page active.
Then a module continuously requests memory from ZONE_DMA32 area.
Memory reclaim will be triggered due to ZONE_DMA32 watermark alarm reached.
However pages in the LRU(active_anon) list are mostly from
the ZONE_NORMAL area.

Reproduce:
Terminal 1: Construct to continuously increase pages active(anon).
mkdir /tmp/memory
mount -t tmpfs -o size=1024000M tmpfs /tmp/memory
dd if=/dev/zero of=/tmp/memory/block bs=4M
tail /tmp/memory/block

Terminal 2:
vmstat -a 1
active will increase.
procs ---memory--- ---swap-- ---io---- -system-- ---cpu--- ...
 r  b   swpd   free  inact active   si   so    bi    bo
 1  0   0 1445623076 45898836 83646008    0    0     0
 1  0   0 1445623076 43450228 86094616    0    0     0
 1  0   0 1445623076 41003480 88541364    0    0     0
 1  0   0 1445623076 38557088 90987756    0    0     0
 1  0   0 1445623076 36109688 93435156    0    0     0
 1  0   0 1445619552 33663256 95881632    0    0     0
 1  0   0 1445619804 31217140 98327792    0    0     0
 1  0   0 1445619804 28769988 100774944    0    0     0
 1  0   0 1445619804 26322348 103222584    0    0     0
 1  0   0 1445619804 23875592 105669340    0    0     0

cat /proc/meminfo | head
Active(anon) increase.
MemTotal:       1579941036 kB
MemFree:        1445618500 kB
MemAvailable:   1453013224 kB
Buffers:            6516 kB
Cached:         128653956 kB
SwapCached:            0 kB
Active:         118110812 kB
Inactive:       11436620 kB
Active(anon):   115345744 kB
Inactive(anon):   945292 kB

When the Active(anon) is 115345744 kB, insmod module triggers
the ZONE_DMA32 watermark.

perf record -e vmscan:mm_vmscan_lru_isolate -aR
perf script
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=2
nr_skipped=2 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=29
nr_skipped=29 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon

See nr_scanned=28835844.
28835844 * 4k = 115343376KB approximately equal to 115345744 kB.

If increase Active(anon) to 1000G then insmod module triggers
the ZONE_DMA32 watermark. hard lockup will occur.

In my device nr_scanned = 0000000003e3e937 when hard lockup.
Convert to memory size 0x0000000003e3e937 * 4KB = 261072092 KB.

   [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
    ffffc90006fb7c30: 0000000000000020 0000000000000000
    ffffc90006fb7c40: ffffc90006fb7d40 ffff88812cbd3000
    ffffc90006fb7c50: ffffc90006fb7d30 0000000106fb7de8
    ffffc90006fb7c60: ffffea04a2197008 ffffea0006ed4a48
    ffffc90006fb7c70: 0000000000000000 0000000000000000
    ffffc90006fb7c80: 0000000000000000 0000000000000000
    ffffc90006fb7c90: 0000000000000000 0000000000000000
    ffffc90006fb7ca0: 0000000000000000 0000000003e3e937
    ffffc90006fb7cb0: 0000000000000000 0000000000000000
    ffffc90006fb7cc0: 8d7c0b56b7874b00 ffff88812cbd3000

About the Fixes:
Why did it take eight years to be discovered?

The problem requires the following conditions to occur:
1. The device memory should be large enough.
2. Pages in the LRU(active_anon) list are mostly from the ZONE_NORMAL area.
3. The memory in ZONE_DMA32 needs to reach the watermark.

If the memory is not large enough, or if the usage design of ZONE_DMA32
area memory is reasonable, this problem is difficult to detect.

notes:
The problem is most likely to occur in ZONE_DMA32 and ZONE_NORMAL,
but other suitable scenarios may also trigger the problem.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: b2e1875 ("mm, vmscan: begin reclaiming pages on a per-node basis")
Signed-off-by: liuye <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
@l1k l1k force-pushed the spdm-future branch 2 times, most recently from 3dfd8df to 9df9c6e Compare February 4, 2025 09:40
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Feb 10, 2025
When COWing a relocation tree path, at relocation.c:replace_path(), we
can trigger a lockdep splat while we are in the btrfs_search_slot() call
against the relocation root. This happens in that callchain at
ctree.c:read_block_for_search() when we happen to find a child extent
buffer already loaded through the fs tree with a lockdep class set to
the fs tree. So when we attempt to lock that extent buffer through a
relocation tree we have to reset the lockdep class to the class for a
relocation tree, since a relocation tree has extent buffers that used
to belong to a fs tree and may currently be already loaded (we swap
extent buffers between the two trees at the end of replace_path()).

However we are missing calls to btrfs_maybe_reset_lockdep_class() to reset
the lockdep class at ctree.c:read_block_for_search() before we read lock
an extent buffer, just like we did for btrfs_search_slot() in commit
b40130b ("btrfs: fix lockdep splat with reloc root extent buffers").

So add the missing btrfs_maybe_reset_lockdep_class() calls before the
attempts to read lock an extent buffer at ctree.c:read_block_for_search().

The lockdep splat was reported by syzbot and it looks like this:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Not tainted
   ------------------------------------------------------
   syz.0.0/5335 is trying to acquire lock:
   ffff8880545dbc38 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146

   but task is already holding lock:
   ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> l1k#2 (btrfs-treloc-02/1){+.+.}-{4:4}:
          reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374
          __lock_release kernel/locking/lockdep.c:5563 [inline]
          lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870
          up_write+0x79/0x590 kernel/locking/rwsem.c:1629
          btrfs_force_cow_block+0x14b3/0x1fd0 fs/btrfs/ctree.c:660
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> l1k#1 (btrfs-tree-01/1){+.+.}-{4:4}:
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
          btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
          btrfs_init_new_buffer fs/btrfs/extent-tree.c:5052 [inline]
          btrfs_alloc_tree_block+0x41c/0x1440 fs/btrfs/extent-tree.c:5132
          btrfs_force_cow_block+0x526/0x1fd0 fs/btrfs/ctree.c:573
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4351
          btrfs_insert_empty_item fs/btrfs/ctree.h:688 [inline]
          btrfs_insert_inode_ref+0x2bb/0xf80 fs/btrfs/inode-item.c:330
          btrfs_rename_exchange fs/btrfs/inode.c:7990 [inline]
          btrfs_rename2+0xcb7/0x2b90 fs/btrfs/inode.c:8374
          vfs_rename+0xbdb/0xf00 fs/namei.c:5067
          do_renameat2+0xd94/0x13f0 fs/namei.c:5224
          __do_sys_renameat2 fs/namei.c:5258 [inline]
          __se_sys_renameat2 fs/namei.c:5255 [inline]
          __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5255
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #0 (btrfs-tree-01){++++}-{4:4}:
          check_prev_add kernel/locking/lockdep.c:3161 [inline]
          check_prevs_add kernel/locking/lockdep.c:3280 [inline]
          validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
          __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
          btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
          btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
          read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
          btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   other info that might help us debug this:

   Chain exists of:
     btrfs-tree-01 --> btrfs-tree-01/1 --> btrfs-treloc-02/1

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(btrfs-treloc-02/1);
                                  lock(btrfs-tree-01/1);
                                  lock(btrfs-treloc-02/1);
     rlock(btrfs-tree-01);

    *** DEADLOCK ***

   8 locks held by syz.0.0/5335:
    #0: ffff88801e3ae420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559
    l1k#1: ffff888052c760d0 (&fs_info->reclaim_bgs_lock){+.+.}-{4:4}, at: __btrfs_balance+0x4c2/0x26b0 fs/btrfs/volumes.c:4183
    l1k#2: ffff888052c74850 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: btrfs_relocate_block_group+0x775/0xd90 fs/btrfs/relocation.c:4086
    l1k#3: ffff88801e3ae610 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xf11/0x1ad0 fs/btrfs/relocation.c:1659
    l1k#4: ffff888052c76470 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    l1k#5: ffff888052c76498 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    l1k#6: ffff8880545db878 (btrfs-tree-01/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
    torvalds#7: ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   stack backtrace:
   CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
    check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
    check_prev_add kernel/locking/lockdep.c:3161 [inline]
    check_prevs_add kernel/locking/lockdep.c:3280 [inline]
    validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
    __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
    down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
    btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
    btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
    read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
    btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
    replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
    merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
    merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
    relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:906 [inline]
    __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f1ac6985d29
   Code: ff ff c3 (...)
   RSP: 002b:00007f1ac63fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007f1ac6b76160 RCX: 00007f1ac6985d29
   RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000007
   RBP: 00007f1ac6a01b08 R08: 0000000000000000 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000001 R14: 00007f1ac6b76160 R15: 00007fffda145a88
    </TASK>

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: 9978599 ("btrfs: reduce lock contention when eb cache miss for btree search")
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Feb 26, 2025
We have several places across the kernel where we want to access another
task's syscall arguments, such as ptrace(2), seccomp(2), etc., by making
a call to syscall_get_arguments().

This works for register arguments right away by accessing the task's
`regs' member of `struct pt_regs', however for stack arguments seen with
32-bit/o32 kernels things are more complicated.  Technically they ought
to be obtained from the user stack with calls to an access_remote_vm(),
but we have an easier way available already.

So as to be able to access syscall stack arguments as regular function
arguments following the MIPS calling convention we copy them over from
the user stack to the kernel stack in arch/mips/kernel/scall32-o32.S, in
handle_sys(), to the current stack frame's outgoing argument space at
the top of the stack, which is where the handler called expects to see
its incoming arguments.  This area is also pointed at by the `pt_regs'
pointer obtained by task_pt_regs().

Make the o32 stack argument space a proper member of `struct pt_regs'
then, by renaming the existing member from `pad0' to `args' and using
generated offsets to access the space.  No functional change though.

With the change in place the o32 kernel stack frame layout at the entry
to a syscall handler invoked by handle_sys() is therefore as follows:

$sp + 68 -> |         ...         | <- pt_regs.regs[9]
            +---------------------+
$sp + 64 -> |         $t0         | <- pt_regs.regs[8]
            +---------------------+
$sp + 60 -> |   $a3/argument l1k#4   | <- pt_regs.regs[7]
            +---------------------+
$sp + 56 -> |   $a2/argument l1k#3   | <- pt_regs.regs[6]
            +---------------------+
$sp + 52 -> |   $a1/argument l1k#2   | <- pt_regs.regs[5]
            +---------------------+
$sp + 48 -> |   $a0/argument l1k#1   | <- pt_regs.regs[4]
            +---------------------+
$sp + 44 -> |         $v1         | <- pt_regs.regs[3]
            +---------------------+
$sp + 40 -> |         $v0         | <- pt_regs.regs[2]
            +---------------------+
$sp + 36 -> |         $at         | <- pt_regs.regs[1]
            +---------------------+
$sp + 32 -> |        $zero        | <- pt_regs.regs[0]
            +---------------------+
$sp + 28 -> |  stack argument torvalds#8  | <- pt_regs.args[7]
            +---------------------+
$sp + 24 -> |  stack argument torvalds#7  | <- pt_regs.args[6]
            +---------------------+
$sp + 20 -> |  stack argument l1k#6  | <- pt_regs.args[5]
            +---------------------+
$sp + 16 -> |  stack argument l1k#5  | <- pt_regs.args[4]
            +---------------------+
$sp + 12 -> | psABI space for $a3 | <- pt_regs.args[3]
            +---------------------+
$sp +  8 -> | psABI space for $a2 | <- pt_regs.args[2]
            +---------------------+
$sp +  4 -> | psABI space for $a1 | <- pt_regs.args[1]
            +---------------------+
$sp +  0 -> | psABI space for $a0 | <- pt_regs.args[0]
            +---------------------+

holding user data received and with the first 4 frame slots reserved by
the psABI for the compiler to spill the incoming arguments from $a0-$a3
registers (which it sometimes does according to its needs) and the next
4 frame slots designated by the psABI for any stack function arguments
that follow.  This data is also available for other tasks to peek/poke
at as reqired and where permitted.

Signed-off-by: Maciej W. Rozycki <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Feb 26, 2025
This makes ptrace/get_syscall_info selftest pass on mips o32 and
mips64 o32 by fixing the following two test assertions:

1. get_syscall_info test assertion on mips o32:
  # get_syscall_info.c:218:get_syscall_info:Expected exp_args[5] (3134521044) == info.entry.args[4] (4911432)
  # get_syscall_info.c:219:get_syscall_info:wait l1k#1: entry stop mismatch

2. get_syscall_info test assertion on mips64 o32:
  # get_syscall_info.c:209:get_syscall_info:Expected exp_args[2] (3134324433) == info.entry.args[1] (18446744072548908753)
  # get_syscall_info.c:210:get_syscall_info:wait l1k#1: entry stop mismatch

The first assertion happens due to mips_get_syscall_arg() trying to access
another task's context but failing to do it properly because get_user() it
calls just peeks at the current task's context.  It usually does not crash
because the default user stack always gets assigned the same VMA, but it
is pure luck which mips_get_syscall_arg() wouldn't have if e.g. the stack
was switched (via setcontext(3) or however) or a non-default process's
thread peeked at, and in any case irrelevant data is obtained just as
observed with the test case.

mips_get_syscall_arg() ought to be using access_remote_vm() instead to
retrieve the other task's stack contents, but given that the data has been
already obtained and saved in `struct pt_regs' it would be an overkill.

The first assertion is fixed for mips o32 by using struct pt_regs.args
instead of get_user() to obtain syscall arguments.  This approach works
due to this piece in arch/mips/kernel/scall32-o32.S:

        /*
         * Ok, copy the args from the luser stack to the kernel stack.
         */

        .set    push
        .set    noreorder
        .set    nomacro

    load_a4: user_lw(t5, 16(t0))		# argument l1k#5 from usp
    load_a5: user_lw(t6, 20(t0))		# argument l1k#6 from usp
    load_a6: user_lw(t7, 24(t0))		# argument torvalds#7 from usp
    load_a7: user_lw(t8, 28(t0))		# argument torvalds#8 from usp
    loads_done:

        sw	t5, PT_ARG4(sp)		# argument l1k#5 to ksp
        sw	t6, PT_ARG5(sp)		# argument l1k#6 to ksp
        sw	t7, PT_ARG6(sp)		# argument torvalds#7 to ksp
        sw	t8, PT_ARG7(sp)		# argument torvalds#8 to ksp
        .set	pop

        .section __ex_table,"a"
        PTR_WD	load_a4, bad_stack_a4
        PTR_WD	load_a5, bad_stack_a5
        PTR_WD	load_a6, bad_stack_a6
        PTR_WD	load_a7, bad_stack_a7
        .previous

arch/mips/kernel/scall64-o32.S has analogous code for mips64 o32 that
allows fixing the issue by obtaining syscall arguments from struct
pt_regs.regs[4..11] instead of the erroneous use of get_user().

The second assertion is fixed by truncating 64-bit values to 32-bit
syscall arguments.

Fixes: c0ff3c5 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.")
Signed-off-by: Dmitry V. Levin <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>
l1k pushed a commit that referenced this pull request Apr 3, 2025
When a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush()
generates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,
which causes the flush_bio to be throttled by wbt_wait().

An example from v5.4, similar problem also exists in upstream:

    crash> bt 2091206
    PID: 2091206  TASK: ffff2050df92a300  CPU: 109  COMMAND: "kworker/u260:0"
     #0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8
     #1 [ffff800084a2f820] __schedule at ffff800040bfa0c4
     #2 [ffff800084a2f880] schedule at ffff800040bfa4b4
     #3 [ffff800084a2f8a0] io_schedule at ffff800040bfa9c4
     #4 [ffff800084a2f8c0] rq_qos_wait at ffff8000405925bc
     #5 [ffff800084a2f940] wbt_wait at ffff8000405bb3a0
     #6 [ffff800084a2f9a0] __rq_qos_throttle at ffff800040592254
     torvalds#7 [ffff800084a2f9c0] blk_mq_make_request at ffff80004057cf38
     torvalds#8 [ffff800084a2fa60] generic_make_request at ffff800040570138
     torvalds#9 [ffff800084a2fae0] submit_bio at ffff8000405703b4
    torvalds#10 [ffff800084a2fb50] xlog_write_iclog at ffff800001280834 [xfs]
    torvalds#11 [ffff800084a2fbb0] xlog_sync at ffff800001280c3c [xfs]
    torvalds#12 [ffff800084a2fbf0] xlog_state_release_iclog at ffff800001280df4 [xfs]
    torvalds#13 [ffff800084a2fc10] xlog_write at ffff80000128203c [xfs]
    torvalds#14 [ffff800084a2fcd0] xlog_cil_push at ffff8000012846dc [xfs]
    torvalds#15 [ffff800084a2fda0] xlog_cil_push_work at ffff800001284a2c [xfs]
    torvalds#16 [ffff800084a2fdb0] process_one_work at ffff800040111d08
    torvalds#17 [ffff800084a2fe00] worker_thread at ffff8000401121cc
    torvalds#18 [ffff800084a2fe70] kthread at ffff800040118de4

After commit 2def284 ("xfs: don't allow log IO to be throttled"),
the metadata submitted by xlog_write_iclog() should not be throttled.
But due to the existence of the dm layer, throttling flush_bio indirectly
causes the metadata bio to be throttled.

Fix this by conditionally adding REQ_IDLE to flush_bio.bi_opf, which makes
wbt_should_throttle() return false to avoid wbt_wait().

Signed-off-by: Jinliang Zheng <[email protected]>
Reviewed-by: Tianxiang Peng <[email protected]>
Reviewed-by: Hao Peng <[email protected]>
Signed-off-by: Mikulas Patocka <[email protected]>
l1k pushed a commit that referenced this pull request Apr 6, 2025
In ThinPro, we use the convention <upstream_ver>+hp<patchlevel> for
the kernel package. This does not have a dash in the name or version.
This is built by editing ".version" before a build, and setting
EXTRAVERSION="+hp" and KDEB_PKGVERSION make variables:

    echo 68 > .version
    make -j<n> EXTRAVERSION="+hp" bindeb-pkg KDEB_PKGVERSION=6.12.2+hp69

    .deb name: linux-image-6.12.2+hp_6.12.2+hp69_amd64.deb

Since commit 7d4f07d ("kbuild: deb-pkg: squash
scripts/package/deb-build-option to debian/rules"), this no longer
works. The deb build logic changed, even though, the commit message
implies that the logic should be unmodified.

Before, KBUILD_BUILD_VERSION was not set if the KDEB_PKGVERSION did
not contain a dash. After the change KBUILD_BUILD_VERSION is always
set to KDEB_PKGVERSION. Since this determines UTS_VERSION, the uname
output to look off:

    (now)      uname -a: version 6.12.2+hp ... #6.12.2+hp69
    (expected) uname -a: version 6.12.2+hp ... torvalds#69

Update the debian/rules logic to restore the original behavior.

Fixes: 7d4f07d ("kbuild: deb-pkg: squash scripts/package/deb-build-option to debian/rules")
Signed-off-by: Alexandru Gagniuc <[email protected]>
Reviewed-by: Nicolas Schier <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>
l1k pushed a commit that referenced this pull request Apr 17, 2025
syzkaller triggered an oversized kvmalloc() warning.
Silence it by adding __GFP_NOWARN.

syzkaller log:
 WARNING: CPU: 7 PID: 518 at mm/util.c:665 __kvmalloc_node_noprof+0x175/0x180
 CPU: 7 UID: 0 PID: 518 Comm: c_repro Not tainted 6.11.0-rc6+ #6
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 RIP: 0010:__kvmalloc_node_noprof+0x175/0x180
 RSP: 0018:ffffc90001e67c10 EFLAGS: 00010246
 RAX: 0000000000000100 RBX: 0000000000000400 RCX: ffffffff8149d46b
 RDX: 0000000000000000 RSI: ffff8881030fae80 RDI: 0000000000000002
 RBP: 000000712c800000 R08: 0000000000000100 R09: 0000000000000000
 R10: ffffc90001e67c10 R11: 0030ae0601000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000
 FS:  00007fde79159740(0000) GS:ffff88813bdc0000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000020000180 CR3: 0000000105eb4005 CR4: 00000000003706b0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <TASK>
  ib_umem_odp_get+0x1f6/0x390
  mlx5_ib_reg_user_mr+0x1e8/0x450
  ib_uverbs_reg_mr+0x28b/0x440
  ib_uverbs_write+0x7d3/0xa30
  vfs_write+0x1ac/0x6c0
  ksys_write+0x134/0x170
  ? __sanitizer_cov_trace_pc+0x1c/0x50
  do_syscall_64+0x50/0x110
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fixes: 3782495 ("RDMA/odp: Use kvcalloc for the dma_list and page_list")
Signed-off-by: Shay Drory <[email protected]>
Link: https://patch.msgid.link/c6cb92379de668be94894f49c2cfa40e73f94d56.1742388096.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <[email protected]>
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3 participants