New CPU #defines encode vendor and family as well as model.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Link: https://lore.kernel.org/r/20240520224620.9480-2-tony.luck@intel.com
Remove a redundant expansion of the AES key, and use rodata for zeroes.
Also rename rfc4106_set_hash_subkey() to aes_gcm_derive_hash_subkey()
because it's used for both versions of AES-GCM, not just RFC4106.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Delete aesni_gcm_enc() and aesni_gcm_dec() because they are unused.
Only the incremental AES-GCM functions (aesni_gcm_init(),
aesni_gcm_enc_update(), aesni_gcm_finalize()) are actually used.
This saves 17 KB of object code.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since the total length processed by the loop in xts_crypt_slowpath() is
a multiple of AES_BLOCK_SIZE, just round the length down to
AES_BLOCK_SIZE even on the last step. This doesn't change behavior, as
the last step will process a multiple of AES_BLOCK_SIZE regardless.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
x86_64 has the "interesting" property that the instruction size is
generally a bit shorter for instructions that operate on the 32-bit (or
less) part of registers, or registers that are in the original set of 8.
This patch adjusts the AES-XTS code to take advantage of that property
by changing the LEN parameter from size_t to unsigned int (which is all
that's needed and is what the non-AVX implementation uses) and using the
%eax register for KEYLEN.
This decreases the size of aes-xts-avx-x86_64.o by 1.2%.
Note that changing the kmovq to kmovd was going to be needed anyway to
make the AVX10/256 code really work on CPUs that don't support 512-bit
vectors (since the AVX10 spec says that 64-bit opmask instructions will
only be supported on processors that support 512-bit vectors).
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
- For conditionally subtracting 16 from LEN when decrypting a message
whose length isn't a multiple of 16, use the cmovnz instruction.
- Fold the addition of 4*VL to LEN into the sub of VL or 16 from LEN.
- Remove an unnecessary test instruction.
This results in slightly shorter code, both source and binary.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Decrease the amount of code specific to the different AES variants by
"right-aligning" the sequence of round keys, and for AES-128 and AES-192
just skipping irrelevant rounds at the beginning.
This shrinks the size of aes-xts-avx-x86_64.o by 13.3%, and it improves
the efficiency of AES-128 and AES-192. The tradeoff is that for AES-256
some additional not-taken conditional jumps are now executed. But these
are predicted well and are cheap on x86.
Note that the ARMv8 CE based AES-XTS implementation uses a similar
strategy to handle the different AES variants.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since aesni_xts_enc() and aesni_xts_dec() are very similar, generate
them from a macro that's passed an argument enc=1 or enc=0. This
reduces the length of aesni-intel_asm.S by 112 lines while still
producing the exact same object file in both 32-bit and 64-bit mode.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When encrypting a message whose length isn't a multiple of 16 bytes,
encrypt the last full block in the main loop. This works because only
decryption uses the last two tweaks in reverse order, not encryption.
This improves the performance of decrypting messages whose length isn't
a multiple of the AES block length, shrinks the size of
aes-xts-avx-x86_64.o by 5.0%, and eliminates two instructions (a test
and a not-taken conditional jump) when encrypting a message whose length
*is* a multiple of the AES block length.
While it's not super useful to optimize for ciphertext stealing given
that it's rarely needed in practice, the other two benefits mentioned
above make this optimization worthwhile.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Instead of loading the message words into both MSG and \m0 and then
adding the round constants to MSG, load the message words into \m0 and
the round constants into MSG and then add \m0 to MSG. This shortens the
source code slightly. It changes the instructions slightly, but it
doesn't affect binary code size and doesn't seem to affect performance.
Suggested-by: Stefan Kanthak <stefan.kanthak@nexgo.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
- Load the SHA-256 round constants relative to a pointer that points
into the middle of the constants rather than to the beginning. Since
x86 instructions use signed offsets, this decreases the instruction
length required to access some of the later round constants.
- Use punpcklqdq or punpckhqdq instead of longer instructions such as
pshufd, pblendw, and palignr. This doesn't harm performance.
The end result is that sha256_ni_transform shrinks from 839 bytes to 791
bytes, with no loss in performance.
Suggested-by: Stefan Kanthak <stefan.kanthak@nexgo.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
MSGTMP[0-3] are used to hold the message schedule and are not temporary
registers per se. MSGTMP4 is used as a temporary register for several
different purposes and isn't really related to MSGTMP[0-3]. Rename them
to MSG[0-3] and TMP accordingly.
Also add a comment that clarifies what MSG is.
Suggested-by: Stefan Kanthak <stefan.kanthak@nexgo.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
To avoid source code duplication, do the SHA-256 rounds using macros.
This reduces the length of sha256_ni_asm.S by 153 lines while still
producing the exact same object file.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Access the AES round keys using offsets -7*16 through 7*16, instead of
0*16 through 14*16. This allows VEX-encoded instructions to address all
round keys using 1-byte offsets, whereas before some needed 4-byte
offsets. This decreases the code size of aes-xts-avx-x86_64.o by 4.2%.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Make the non-AVX implementation of AES-XTS (xts-aes-aesni) use the new
glue code that was introduced for the AVX implementations of AES-XTS.
This reduces code size, and it improves the performance of xts-aes-aesni
due to the optimization for messages that don't span page boundaries.
This required moving the new glue functions higher up in the file and
allowing the IV encryption function to be specified by the caller.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since sha512_transform_rorx() uses ymm registers, execute vzeroupper
before returning from it. This is necessary to avoid reducing the
performance of SSE code.
Fixes: e01d69cb01 ("crypto: sha512 - Optimized SHA512 x86_64 assembly routine using AVX instructions.")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since sha256_transform_rorx() uses ymm registers, execute vzeroupper
before returning from it. This is necessary to avoid reducing the
performance of SSE code.
Fixes: d34a460092 ("crypto: sha256 - Optimized sha256 x86_64 routine using AVX2's RORX instructions")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since nh_avx2() uses ymm registers, execute vzeroupper before returning
from it. This is necessary to avoid reducing the performance of SSE
code.
Fixes: 0f961f9f67 ("crypto: x86/nhpoly1305 - add AVX2 accelerated NHPoly1305")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an AES-XTS implementation "xts-aes-vaes-avx10_512" for x86_64 CPUs
with the VAES, VPCLMULQDQ, and either AVX10/512 or AVX512BW + AVX512VL
extensions. This implementation uses zmm registers to operate on four
AES blocks at a time. The assembly code is instantiated using a macro
so that most of the source code is shared with other implementations.
To avoid downclocking on older Intel CPU models, an exclusion list is
used to prevent this 512-bit implementation from being used by default
on some CPU models. They will use xts-aes-vaes-avx10_256 instead. For
now, this exclusion list is simply coded into aesni-intel_glue.c. It
may make sense to eventually move it into a more central location.
xts-aes-vaes-avx10_512 is slightly faster than xts-aes-vaes-avx10_256 on
some current CPUs. E.g., on AMD Zen 4, AES-256-XTS decryption
throughput increases by 13% with 4096-byte inputs, or 14% with 512-byte
inputs. On Intel Sapphire Rapids, AES-256-XTS decryption throughput
increases by 2% with 4096-byte inputs, or 3% with 512-byte inputs.
Future CPUs may provide stronger 512-bit support, in which case a larger
benefit should be seen.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an AES-XTS implementation "xts-aes-vaes-avx10_256" for x86_64 CPUs
with the VAES, VPCLMULQDQ, and either AVX10/256 or AVX512BW + AVX512VL
extensions. This implementation avoids using zmm registers, instead
using ymm registers to operate on two AES blocks at a time. The
assembly code is instantiated using a macro so that most of the source
code is shared with other implementations.
This is the optimal implementation on CPUs that support VAES and AVX512
but where the zmm registers should not be used due to downclocking
effects, for example Intel's Ice Lake. It should also be the optimal
implementation on future CPUs that support AVX10/256 but not AVX10/512.
The performance is slightly better than that of xts-aes-vaes-avx2, which
uses the same 256-bit vector length, due to factors such as being able
to use ymm16-ymm31 to cache the AES round keys, and being able to use
the vpternlogd instruction to do XORs more efficiently. For example, on
Ice Lake, the throughput of decrypting 4096-byte messages with
AES-256-XTS is 6.6% higher with xts-aes-vaes-avx10_256 than with
xts-aes-vaes-avx2. While this is a small improvement, it is
straightforward to provide this implementation (xts-aes-vaes-avx10_256)
as long as we are providing xts-aes-vaes-avx2 and xts-aes-vaes-avx10_512
anyway, due to the way the _aes_xts_crypt macro is structured.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an AES-XTS implementation "xts-aes-vaes-avx2" for x86_64 CPUs with
the VAES, VPCLMULQDQ, and AVX2 extensions, but not AVX512 or AVX10.
This implementation uses ymm registers to operate on two AES blocks at a
time. The assembly code is instantiated using a macro so that most of
the source code is shared with other implementations.
This is the optimal implementation on AMD Zen 3. It should also be the
optimal implementation on Intel Alder Lake, which similarly supports
VAES but not AVX512. Comparing to xts-aes-aesni-avx on Zen 3,
xts-aes-vaes-avx2 provides 70% higher AES-256-XTS decryption throughput
with 4096-byte messages, or 23% higher with 512-byte messages.
A large improvement is also seen with CPUs that do support AVX512 (e.g.,
98% higher AES-256-XTS decryption throughput on Ice Lake with 4096-byte
messages), though the following patches add AVX512 optimized
implementations to get a bit more performance on those CPUs.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an AES-XTS implementation "xts-aes-aesni-avx" for x86_64 CPUs that
have the AES-NI and AVX extensions but not VAES. It's similar to the
existing xts-aes-aesni in that uses xmm registers to operate on one AES
block at a time. It differs from xts-aes-aesni in the following ways:
- It uses the VEX-coded (non-destructive) instructions from AVX.
This improves performance slightly.
- It incorporates some additional optimizations such as interleaving the
tweak computation with AES en/decryption, handling single-page
messages more efficiently, and caching the first round key.
- It supports only 64-bit (x86_64).
- It's generated by an assembly macro that will also be used to generate
VAES-based implementations.
The performance improvement over xts-aes-aesni varies from small to
large, depending on the CPU and other factors such as the size of the
messages en/decrypted. For example, the following increases in
AES-256-XTS decryption throughput are seen on the following CPUs:
| 4096-byte messages | 512-byte messages |
----------------------+--------------------+-------------------+
Intel Skylake | 6% | 31% |
Intel Cascade Lake | 4% | 26% |
AMD Zen 1 | 61% | 73% |
AMD Zen 2 | 36% | 59% |
(The above CPUs don't support VAES, so they can't use VAES instead.)
While this isn't as large an improvement as what VAES provides, this
still seems worthwhile. This implementation is fairly easy to provide
based on the assembly macro that's needed for VAES anyway, and it will
be the best implementation on a large number of CPUs (very roughly, the
CPUs launched by Intel and AMD from 2011 to 2018).
This makes the existing xts-aes-aesni *mostly* obsolete. For now, leave
it in place to support 32-bit kernels and also CPUs like Intel Westmere
that support AES-NI but not AVX. (We could potentially remove it anyway
and just rely on the indirect acceleration via ecb-aes-aesni in those
cases, but that change will need to be considered separately.)
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an assembly file aes-xts-avx-x86_64.S which contains a macro that
expands into AES-XTS implementations for x86_64 CPUs that support at
least AES-NI and AVX, optionally also taking advantage of VAES,
VPCLMULQDQ, and AVX512 or AVX10.
This patch doesn't expand the macro at all. Later patches will do so,
adding each implementation individually so that the motivation and use
case for each individual implementation can be fully presented.
The file also provides a function aes_xts_encrypt_iv() which handles the
encryption of the IV (tweak), using AES-NI and AVX.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The aesni_set_key() implementation has no error case, yet its prototype
specifies to return an error code.
Modify the function prototype to return void and adjust the related code.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-crypto@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
aes_expandkey() already includes an AES key size check. If AES-NI is
unusable, invoke the function without the size check.
Also, use aes_check_keylen() instead of open code.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-crypto@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The x86 SHA-256 module contains four implementations: SSSE3, AVX, AVX2,
and SHA-NI. Commit 1c43c0f1f8 ("crypto: x86/sha - load modules based
on CPU features") made the module be autoloaded when SSSE3, AVX, or AVX2
is detected. The omission of SHA-NI appears to be an oversight, perhaps
because of the outdated file-level comment. This patch fixes this,
though in practice this makes no difference because SSSE3 is a subset of
the other three features anyway. Indeed, sha256_ni_transform() executes
SSSE3 instructions such as pshufb.
Reviewed-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The x86 SHA-1 module contains four implementations: SSSE3, AVX, AVX2,
and SHA-NI. Commit 1c43c0f1f8 ("crypto: x86/sha - load modules based
on CPU features") made the module be autoloaded when SSSE3, AVX, or AVX2
is detected. The omission of SHA-NI appears to be an oversight, perhaps
because of the outdated file-level comment. This patch fixes this,
though in practice this makes no difference because SSSE3 is a subset of
the other three features anyway. Indeed, sha1_ni_transform() executes
SSSE3 instructions such as pshufb.
Reviewed-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Implement the ->digest method to improve performance on single-page
messages by reducing the number of indirect calls.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Implement a ->digest function for sha256-ssse3, sha256-avx, sha256-avx2,
and sha256-ni. This improves the performance of crypto_shash_digest()
with these algorithms by reducing the number of indirect calls that are
made.
For now, don't bother with this for sha224, since sha224 is rarely used.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently, the alignment of each field in struct aesni_xts_ctx occurs
right before every access. However, it's possible to perform this
alignment ahead of time.
Introduce a helper function that converts struct crypto_skcipher *tfm
to struct aesni_xts_ctx *ctx and returns an aligned address. Utilize
this helper function at the beginning of each XTS function and then
eliminate redundant alignment code.
Suggested-by: Eric Biggers <ebiggers@kernel.org>
Link: https://lore.kernel.org/all/ZFWQ4sZEVu%2FLHq+Q@gmail.com/
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Cc: linux-crypto@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently, every field in struct aesni_xts_ctx is defined as a byte
array of the same size as struct crypto_aes_ctx. This data type
is obscure and the choice lacks justification.
To rectify this, update the field type in struct aesni_xts_ctx to
match its actual structure.
Suggested-by: Eric Biggers <ebiggers@kernel.org>
Link: https://lore.kernel.org/all/ZFWQ4sZEVu%2FLHq+Q@gmail.com/
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Cc: linux-crypto@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
x86 optimized crypto modules are built as modules rather than build-in and
they are not loaded when the crypto API is initialized, resulting in the
generic builtin module (sha1-generic) being used instead.
It was discovered when creating a sha1/sha256 checksum of a 2Gb file by
using kcapi-tools because it would take significantly longer than creating
a sha512 checksum of the same file. trace-cmd showed that for sha1/256 the
generic module was used, whereas for sha512 the optimized module was used
instead.
Add module aliases() for these x86 optimized crypto modules based on CPU
feature bits so udev gets a chance to load them later in the boot
process. This resulted in ~3x decrease in the real-time execution of
kcapi-dsg.
Fix is inspired from commit
aa031b8f70 ("crypto: x86/sha512 - load based on CPU features")
where a similar fix was done for sha512.
Cc: stable@vger.kernel.org # 5.15+
Suggested-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Suggested-by: Julian Andres Klode <julian.klode@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The 'tfm' parameter to aes_set_key_common() is never used, so remove it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
aes_set_key_common() performs runtime alignment to the void *raw_ctx
pointer. This facilitates consistent access to the 16byte-aligned
address during key extension.
However, the alignment is already handlded in the GCM-related setkey
functions before invoking the common function. Consequently, the
alignment in the common function is unnecessary for those functions.
To establish a consistent approach throughout the glue code, remove
the aes_ctx() call from its current location. Instead, place it at
each call site where the runtime alignment is currently absent.
Link: https://lore.kernel.org/lkml/20230605024623.GA4653@quark.localdomain/
Suggested-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Cc: linux-crypto@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The GFNI routines in the AVX version of the ARIA implementation now use
explicit VMOVDQA instructions to load the constant input vectors, which
means they must be 16 byte aligned. So ensure that this is the case, by
dropping the section split and the incorrect .align 8 directive, and
emitting the constants into the 16-byte aligned section instead.
Note that the AVX2 version of this code deviates from this pattern, and
does not require a similar fix, given that it loads these contants as
8-byte memory operands, for which AVX2 permits any alignment.
Cc: Taehee Yoo <ap420073@gmail.com>
Fixes: 8b84475318 ("crypto: x86/aria-avx - Do not use avx2 instructions")
Reported-by: syzbot+a6abcf08bad8b18fd198@syzkaller.appspotmail.com
Tested-by: syzbot+a6abcf08bad8b18fd198@syzkaller.appspotmail.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The summary of the changes for this pull requests is:
* Song Liu's new struct module_memory replacement
* Nick Alcock's MODULE_LICENSE() removal for non-modules
* My cleanups and enhancements to reduce the areas where we vmalloc
module memory for duplicates, and the respective debug code which
proves the remaining vmalloc pressure comes from userspace.
Most of the changes have been in linux-next for quite some time except
the minor fixes I made to check if a module was already loaded
prior to allocating the final module memory with vmalloc and the
respective debug code it introduces to help clarify the issue. Although
the functional change is small it is rather safe as it can only *help*
reduce vmalloc space for duplicates and is confirmed to fix a bootup
issue with over 400 CPUs with KASAN enabled. I don't expect stable
kernels to pick up that fix as the cleanups would have also had to have
been picked up. Folks on larger CPU systems with modules will want to
just upgrade if vmalloc space has been an issue on bootup.
Given the size of this request, here's some more elaborate details
on this pull request.
The functional change change in this pull request is the very first
patch from Song Liu which replaces the struct module_layout with a new
struct module memory. The old data structure tried to put together all
types of supported module memory types in one data structure, the new
one abstracts the differences in memory types in a module to allow each
one to provide their own set of details. This paves the way in the
future so we can deal with them in a cleaner way. If you look at changes
they also provide a nice cleanup of how we handle these different memory
areas in a module. This change has been in linux-next since before the
merge window opened for v6.3 so to provide more than a full kernel cycle
of testing. It's a good thing as quite a bit of fixes have been found
for it.
Jason Baron then made dynamic debug a first class citizen module user by
using module notifier callbacks to allocate / remove module specific
dynamic debug information.
Nick Alcock has done quite a bit of work cross-tree to remove module
license tags from things which cannot possibly be module at my request
so to:
a) help him with his longer term tooling goals which require a
deterministic evaluation if a piece a symbol code could ever be
part of a module or not. But quite recently it is has been made
clear that tooling is not the only one that would benefit.
Disambiguating symbols also helps efforts such as live patching,
kprobes and BPF, but for other reasons and R&D on this area
is active with no clear solution in sight.
b) help us inch closer to the now generally accepted long term goal
of automating all the MODULE_LICENSE() tags from SPDX license tags
In so far as a) is concerned, although module license tags are a no-op
for non-modules, tools which would want create a mapping of possible
modules can only rely on the module license tag after the commit
8b41fc4454 ("kbuild: create modules.builtin without Makefile.modbuiltin
or tristate.conf"). Nick has been working on this *for years* and
AFAICT I was the only one to suggest two alternatives to this approach
for tooling. The complexity in one of my suggested approaches lies in
that we'd need a possible-obj-m and a could-be-module which would check
if the object being built is part of any kconfig build which could ever
lead to it being part of a module, and if so define a new define
-DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've
suggested would be to have a tristate in kconfig imply the same new
-DPOSSIBLE_MODULE as well but that means getting kconfig symbol names
mapping to modules always, and I don't think that's the case today. I am
not aware of Nick or anyone exploring either of these options. Quite
recently Josh Poimboeuf has pointed out that live patching, kprobes and
BPF would benefit from resolving some part of the disambiguation as
well but for other reasons. The function granularity KASLR (fgkaslr)
patches were mentioned but Joe Lawrence has clarified this effort has
been dropped with no clear solution in sight [1].
In the meantime removing module license tags from code which could never
be modules is welcomed for both objectives mentioned above. Some
developers have also welcomed these changes as it has helped clarify
when a module was never possible and they forgot to clean this up,
and so you'll see quite a bit of Nick's patches in other pull
requests for this merge window. I just picked up the stragglers after
rc3. LWN has good coverage on the motivation behind this work [2] and
the typical cross-tree issues he ran into along the way. The only
concrete blocker issue he ran into was that we should not remove the
MODULE_LICENSE() tags from files which have no SPDX tags yet, even if
they can never be modules. Nick ended up giving up on his efforts due
to having to do this vetting and backlash he ran into from folks who
really did *not understand* the core of the issue nor were providing
any alternative / guidance. I've gone through his changes and dropped
the patches which dropped the module license tags where an SPDX
license tag was missing, it only consisted of 11 drivers. To see
if a pull request deals with a file which lacks SPDX tags you
can just use:
./scripts/spdxcheck.py -f \
$(git diff --name-only commid-id | xargs echo)
You'll see a core module file in this pull request for the above,
but that's not related to his changes. WE just need to add the SPDX
license tag for the kernel/module/kmod.c file in the future but
it demonstrates the effectiveness of the script.
Most of Nick's changes were spread out through different trees,
and I just picked up the slack after rc3 for the last kernel was out.
Those changes have been in linux-next for over two weeks.
The cleanups, debug code I added and final fix I added for modules
were motivated by David Hildenbrand's report of boot failing on
a systems with over 400 CPUs when KASAN was enabled due to running
out of virtual memory space. Although the functional change only
consists of 3 lines in the patch "module: avoid allocation if module is
already present and ready", proving that this was the best we can
do on the modules side took quite a bit of effort and new debug code.
The initial cleanups I did on the modules side of things has been
in linux-next since around rc3 of the last kernel, the actual final
fix for and debug code however have only been in linux-next for about a
week or so but I think it is worth getting that code in for this merge
window as it does help fix / prove / evaluate the issues reported
with larger number of CPUs. Userspace is not yet fixed as it is taking
a bit of time for folks to understand the crux of the issue and find a
proper resolution. Worst come to worst, I have a kludge-of-concept [3]
of how to make kernel_read*() calls for modules unique / converge them,
but I'm currently inclined to just see if userspace can fix this
instead.
[0] https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/
[1] https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com
[2] https://lwn.net/Articles/927569/
[3] https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org
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Merge tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull module updates from Luis Chamberlain:
"The summary of the changes for this pull requests is:
- Song Liu's new struct module_memory replacement
- Nick Alcock's MODULE_LICENSE() removal for non-modules
- My cleanups and enhancements to reduce the areas where we vmalloc
module memory for duplicates, and the respective debug code which
proves the remaining vmalloc pressure comes from userspace.
Most of the changes have been in linux-next for quite some time except
the minor fixes I made to check if a module was already loaded prior
to allocating the final module memory with vmalloc and the respective
debug code it introduces to help clarify the issue. Although the
functional change is small it is rather safe as it can only *help*
reduce vmalloc space for duplicates and is confirmed to fix a bootup
issue with over 400 CPUs with KASAN enabled. I don't expect stable
kernels to pick up that fix as the cleanups would have also had to
have been picked up. Folks on larger CPU systems with modules will
want to just upgrade if vmalloc space has been an issue on bootup.
Given the size of this request, here's some more elaborate details:
The functional change change in this pull request is the very first
patch from Song Liu which replaces the 'struct module_layout' with a
new 'struct module_memory'. The old data structure tried to put
together all types of supported module memory types in one data
structure, the new one abstracts the differences in memory types in a
module to allow each one to provide their own set of details. This
paves the way in the future so we can deal with them in a cleaner way.
If you look at changes they also provide a nice cleanup of how we
handle these different memory areas in a module. This change has been
in linux-next since before the merge window opened for v6.3 so to
provide more than a full kernel cycle of testing. It's a good thing as
quite a bit of fixes have been found for it.
Jason Baron then made dynamic debug a first class citizen module user
by using module notifier callbacks to allocate / remove module
specific dynamic debug information.
Nick Alcock has done quite a bit of work cross-tree to remove module
license tags from things which cannot possibly be module at my request
so to:
a) help him with his longer term tooling goals which require a
deterministic evaluation if a piece a symbol code could ever be
part of a module or not. But quite recently it is has been made
clear that tooling is not the only one that would benefit.
Disambiguating symbols also helps efforts such as live patching,
kprobes and BPF, but for other reasons and R&D on this area is
active with no clear solution in sight.
b) help us inch closer to the now generally accepted long term goal
of automating all the MODULE_LICENSE() tags from SPDX license tags
In so far as a) is concerned, although module license tags are a no-op
for non-modules, tools which would want create a mapping of possible
modules can only rely on the module license tag after the commit
8b41fc4454 ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf").
Nick has been working on this *for years* and AFAICT I was the only
one to suggest two alternatives to this approach for tooling. The
complexity in one of my suggested approaches lies in that we'd need a
possible-obj-m and a could-be-module which would check if the object
being built is part of any kconfig build which could ever lead to it
being part of a module, and if so define a new define
-DPOSSIBLE_MODULE [0].
A more obvious yet theoretical approach I've suggested would be to
have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as
well but that means getting kconfig symbol names mapping to modules
always, and I don't think that's the case today. I am not aware of
Nick or anyone exploring either of these options. Quite recently Josh
Poimboeuf has pointed out that live patching, kprobes and BPF would
benefit from resolving some part of the disambiguation as well but for
other reasons. The function granularity KASLR (fgkaslr) patches were
mentioned but Joe Lawrence has clarified this effort has been dropped
with no clear solution in sight [1].
In the meantime removing module license tags from code which could
never be modules is welcomed for both objectives mentioned above. Some
developers have also welcomed these changes as it has helped clarify
when a module was never possible and they forgot to clean this up, and
so you'll see quite a bit of Nick's patches in other pull requests for
this merge window. I just picked up the stragglers after rc3. LWN has
good coverage on the motivation behind this work [2] and the typical
cross-tree issues he ran into along the way. The only concrete blocker
issue he ran into was that we should not remove the MODULE_LICENSE()
tags from files which have no SPDX tags yet, even if they can never be
modules. Nick ended up giving up on his efforts due to having to do
this vetting and backlash he ran into from folks who really did *not
understand* the core of the issue nor were providing any alternative /
guidance. I've gone through his changes and dropped the patches which
dropped the module license tags where an SPDX license tag was missing,
it only consisted of 11 drivers. To see if a pull request deals with a
file which lacks SPDX tags you can just use:
./scripts/spdxcheck.py -f \
$(git diff --name-only commid-id | xargs echo)
You'll see a core module file in this pull request for the above, but
that's not related to his changes. WE just need to add the SPDX
license tag for the kernel/module/kmod.c file in the future but it
demonstrates the effectiveness of the script.
Most of Nick's changes were spread out through different trees, and I
just picked up the slack after rc3 for the last kernel was out. Those
changes have been in linux-next for over two weeks.
The cleanups, debug code I added and final fix I added for modules
were motivated by David Hildenbrand's report of boot failing on a
systems with over 400 CPUs when KASAN was enabled due to running out
of virtual memory space. Although the functional change only consists
of 3 lines in the patch "module: avoid allocation if module is already
present and ready", proving that this was the best we can do on the
modules side took quite a bit of effort and new debug code.
The initial cleanups I did on the modules side of things has been in
linux-next since around rc3 of the last kernel, the actual final fix
for and debug code however have only been in linux-next for about a
week or so but I think it is worth getting that code in for this merge
window as it does help fix / prove / evaluate the issues reported with
larger number of CPUs. Userspace is not yet fixed as it is taking a
bit of time for folks to understand the crux of the issue and find a
proper resolution. Worst come to worst, I have a kludge-of-concept [3]
of how to make kernel_read*() calls for modules unique / converge
them, but I'm currently inclined to just see if userspace can fix this
instead"
Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0]
Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1]
Link: https://lwn.net/Articles/927569/ [2]
Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3]
* tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits)
module: add debugging auto-load duplicate module support
module: stats: fix invalid_mod_bytes typo
module: remove use of uninitialized variable len
module: fix building stats for 32-bit targets
module: stats: include uapi/linux/module.h
module: avoid allocation if module is already present and ready
module: add debug stats to help identify memory pressure
module: extract patient module check into helper
modules/kmod: replace implementation with a semaphore
Change DEFINE_SEMAPHORE() to take a number argument
module: fix kmemleak annotations for non init ELF sections
module: Ignore L0 and rename is_arm_mapping_symbol()
module: Move is_arm_mapping_symbol() to module_symbol.h
module: Sync code of is_arm_mapping_symbol()
scripts/gdb: use mem instead of core_layout to get the module address
interconnect: remove module-related code
interconnect: remove MODULE_LICENSE in non-modules
zswap: remove MODULE_LICENSE in non-modules
zpool: remove MODULE_LICENSE in non-modules
x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules
...
Avoid cluttering up the kallsyms symbol table with entries that should
not end up in things like backtraces, as they have undescriptive and
generated identifiers.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Avoid cluttering up the kallsyms symbol table with entries that should
not end up in things like backtraces, as they have undescriptive and
generated identifiers.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Avoid cluttering up the kallsyms symbol table with entries that should
not end up in things like backtraces, as they have undescriptive and
generated identifiers.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Co-developed-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Co-developed-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tony Luck