Pull crypto update from Herbert Xu:
"API:
- Add support for AEAD in simd
- Add fuzz testing to testmgr
- Add panic_on_fail module parameter to testmgr
- Use per-CPU struct instead multiple variables in scompress
- Change verify API for akcipher
Algorithms:
- Convert x86 AEAD algorithms over to simd
- Forbid 2-key 3DES in FIPS mode
- Add EC-RDSA (GOST 34.10) algorithm
Drivers:
- Set output IV with ctr-aes in crypto4xx
- Set output IV in rockchip
- Fix potential length overflow with hashing in sun4i-ss
- Fix computation error with ctr in vmx
- Add SM4 protected keys support in ccree
- Remove long-broken mxc-scc driver
- Add rfc4106(gcm(aes)) cipher support in cavium/nitrox"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (179 commits)
crypto: ccree - use a proper le32 type for le32 val
crypto: ccree - remove set but not used variable 'du_size'
crypto: ccree - Make cc_sec_disable static
crypto: ccree - fix spelling mistake "protedcted" -> "protected"
crypto: caam/qi2 - generate hash keys in-place
crypto: caam/qi2 - fix DMA mapping of stack memory
crypto: caam/qi2 - fix zero-length buffer DMA mapping
crypto: stm32/cryp - update to return iv_out
crypto: stm32/cryp - remove request mutex protection
crypto: stm32/cryp - add weak key check for DES
crypto: atmel - remove set but not used variable 'alg_name'
crypto: picoxcell - Use dev_get_drvdata()
crypto: crypto4xx - get rid of redundant using_sd variable
crypto: crypto4xx - use sync skcipher for fallback
crypto: crypto4xx - fix cfb and ofb "overran dst buffer" issues
crypto: crypto4xx - fix ctr-aes missing output IV
crypto: ecrdsa - select ASN1 and OID_REGISTRY for EC-RDSA
crypto: ux500 - use ccflags-y instead of CFLAGS_<basename>.o
crypto: ccree - handle tee fips error during power management resume
crypto: ccree - add function to handle cryptocell tee fips error
...
This patch fixes the NITROX-V family part name format. The fix includes
ZIP core performance (feature option) in the part name to differentiate
various HW devices. The complete HW part name format is mentioned below
Part name: CNN55<core option>-<freq>BG676-<feature option>-<rev>
Signed-off-by: Nagadheeraj Rottela <rnagadheeraj@marvell.com>
Reviewed-by: Srikanth Jampala <jsrikanth@marvell.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The cavium crypto driver adds 'sizeof(struct ablkcipher_request)' to its
request size because "the cryptd daemon uses this memory for request_ctx
information". This is incorrect and unnecessary; cryptd doesn't require
wrapped algorithms to reserve extra request space. So remove this.
Also remove the unneeded memset() of the tfm context to 0.
It's already zeroed on allocation.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
mmiowb() is now implied by spin_unlock() on architectures that require
it, so there is no reason to call it from driver code. This patch was
generated using coccinelle:
@mmiowb@
@@
- mmiowb();
and invoked as:
$ for d in drivers include/linux/qed sound; do \
spatch --include-headers --sp-file mmiowb.cocci --dir $d --in-place; done
NOTE: mmiowb() has only ever guaranteed ordering in conjunction with
spin_unlock(). However, pairing each mmiowb() removal in this patch with
the corresponding call to spin_unlock() is not at all trivial, so there
is a small chance that this change may regress any drivers incorrectly
relying on mmiowb() to order MMIO writes between CPUs using lock-free
synchronisation. If you've ended up bisecting to this commit, you can
reintroduce the mmiowb() calls using wmb() instead, which should restore
the old behaviour on all architectures other than some esoteric ia64
systems.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Fix sparse warning:
drivers/crypto/cavium/cpt/cptvf_main.c:644:6:
warning: symbol 'cptvf_device_init' was not declared. Should it be static?
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fix following sparse warnings:
drivers/crypto/cavium/zip/zip_crypto.c:72:5: warning: symbol 'zip_ctx_init' was not declared. Should it be static?
drivers/crypto/cavium/zip/zip_crypto.c:110:6: warning: symbol 'zip_ctx_exit' was not declared. Should it be static?
drivers/crypto/cavium/zip/zip_crypto.c:122:5: warning: symbol 'zip_compress' was not declared. Should it be static?
drivers/crypto/cavium/zip/zip_crypto.c:158:5: warning: symbol 'zip_decompress' was not declared. Should it be static?
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fix sparse warnings:
drivers/crypto/cavium/cpt/cptvf_reqmanager.c:226:5: warning: symbol 'send_cpt_command' was not declared. Should it be static?
drivers/crypto/cavium/cpt/cptvf_reqmanager.c:273:6: warning: symbol 'do_request_cleanup' was not declared. Should it be static?
drivers/crypto/cavium/cpt/cptvf_reqmanager.c:319:6: warning: symbol 'do_post_process' was not declared. Should it be static?
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
cptvf_mbox_send_ack and cptvf_mbox_send_nack are never
used since introdution in commit c694b23329 ("crypto: cavium
- Add the Virtual Function driver for CPT")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto update from Herbert Xu:
"API:
- Add helper for simple skcipher modes.
- Add helper to register multiple templates.
- Set CRYPTO_TFM_NEED_KEY when setkey fails.
- Require neither or both of export/import in shash.
- AEAD decryption test vectors are now generated from encryption
ones.
- New option CONFIG_CRYPTO_MANAGER_EXTRA_TESTS that includes random
fuzzing.
Algorithms:
- Conversions to skcipher and helper for many templates.
- Add more test vectors for nhpoly1305 and adiantum.
Drivers:
- Add crypto4xx prng support.
- Add xcbc/cmac/ecb support in caam.
- Add AES support for Exynos5433 in s5p.
- Remove sha384/sha512 from artpec7 as hardware cannot do partial
hash"
[ There is a merge of the Freescale SoC tree in order to pull in changes
required by patches to the caam/qi2 driver. ]
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (174 commits)
crypto: s5p - add AES support for Exynos5433
dt-bindings: crypto: document Exynos5433 SlimSSS
crypto: crypto4xx - add missing of_node_put after of_device_is_available
crypto: cavium/zip - fix collision with generic cra_driver_name
crypto: af_alg - use struct_size() in sock_kfree_s()
crypto: caam - remove redundant likely/unlikely annotation
crypto: s5p - update iv after AES-CBC op end
crypto: x86/poly1305 - Clear key material from stack in SSE2 variant
crypto: caam - generate hash keys in-place
crypto: caam - fix DMA mapping xcbc key twice
crypto: caam - fix hash context DMA unmap size
hwrng: bcm2835 - fix probe as platform device
crypto: s5p-sss - Use AES_BLOCK_SIZE define instead of number
crypto: stm32 - drop pointless static qualifier in stm32_hash_remove()
crypto: chelsio - Fixed Traffic Stall
crypto: marvell - Remove set but not used variable 'ivsize'
crypto: ccp - Update driver messages to remove some confusion
crypto: adiantum - add 1536 and 4096-byte test vectors
crypto: nhpoly1305 - add a test vector with len % 16 != 0
crypto: arm/aes-ce - update IV after partial final CTR block
...
The cavium/zip implementation of the deflate compression algorithm is
incorrectly being registered under the generic driver name, which
prevents the generic implementation from being registered with the
crypto API when CONFIG_CRYPTO_DEV_CAVIUM_ZIP=y. Similarly the lzs
algorithm (which does not currently have a generic implementation...)
is incorrectly being registered as lzs-generic.
Fix the naming collision by adding a suffix "-cavium" to the
cra_driver_name of the cavium/zip algorithms.
Fixes: 640035a2dc ("crypto: zip - Add ThunderX ZIP driver core")
Cc: Mahipal Challa <mahipalreddy2006@gmail.com>
Cc: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto fix from Herbert Xu:
"This fixes a bug in cavium/nitrox where the callback is invoked prior
to the DMA unmap"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: cavium/nitrox - Invoke callback after DMA unmap
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Cc: Yangtao Li <tiny.windzz@gmail.com>
Cc: Gadam Sreerama <sgadam@cavium.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Robert Richter <rrichter@cavium.com>
Cc: Jan Glauber <jglauber@cavium.com>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In process_response_list() invoke the callback handler after unmapping
the DMA buffers. It ensures DMA data is synced form device to cpu
before the client code access the data from callback handler.
Fixes: c9613335bf ("crypto: cavium/nitrox - Added AEAD cipher support")
Signed-off-by: Nagadheeraj Rottela <rnagadheeraj@marvell.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto fixes from Herbert Xu:
"This fixes the following issues:
- Zero-length DMA mapping in caam
- Invalidly mapping stack memory for DMA in talitos
- Use after free in cavium/nitrox
- Key parsing in authenc
- Undefined shift in sm3
- Bogus completion call in authencesn
- SHA support detection in caam"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: sm3 - fix undefined shift by >= width of value
crypto: talitos - fix ablkcipher for CONFIG_VMAP_STACK
crypto: talitos - reorder code in talitos_edesc_alloc()
crypto: adiantum - initialize crypto_spawn::inst
crypto: cavium/nitrox - Use after free in process_response_list()
crypto: authencesn - Avoid twice completion call in decrypt path
crypto: caam - fix SHA support detection
crypto: caam - fix zero-length buffer DMA mapping
crypto: ccree - convert to use crypto_authenc_extractkeys()
crypto: bcm - convert to use crypto_authenc_extractkeys()
crypto: authenc - fix parsing key with misaligned rta_len
We free "sr" and then dereference it on the next line.
Fixes: c9613335bf ("crypto: cavium/nitrox - Added AEAD cipher support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
We already need to zero out memory for dma_alloc_coherent(), as such
using dma_zalloc_coherent() is superflous. Phase it out.
This change was generated with the following Coccinelle SmPL patch:
@ replace_dma_zalloc_coherent @
expression dev, size, data, handle, flags;
@@
-dma_zalloc_coherent(dev, size, handle, flags)
+dma_alloc_coherent(dev, size, handle, flags)
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
[hch: re-ran the script on the latest tree]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Added support to offload AEAD ciphers to NITROX. Currently supported
AEAD cipher is 'gcm(aes)'.
Signed-off-by: Nagadheeraj Rottela <rnagadheeraj@marvell.com>
Reviewed-by: Srikanth Jampala <jsrikanth@marvell.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Enabled the PF->VF Mailbox support. Mailbox message are interpreted
as {type, opcode, data}. Supported message types are REQ, ACK and NACK.
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Enable the available interrupt vectors for PF in SR-IOV Mode.
Only single vector entry 192 is valid of PF. This is used to
notify any hardware errors and mailbox messages from VF(s).
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
nitrox_skcipher_crypt() will do the necessary formatting/ordering of
input and output sglists based on the algorithm requirements.
It will also accommodate the mandatory output buffers required for
NITROX hardware like Output request headers (ORH) and Completion headers.
Signed-off-by: Nagadheeraj Rottela <rottela.nagadheeraj@cavium.com>
Reviewed-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In crypto_alloc_context(), a DMA pool is allocated through dma_pool_alloc()
to hold the crypto context. The meta data of the DMA pool, including the
pool used for the allocation 'ndev->ctx_pool' and the base address of the
DMA pool used by the device 'dma', are then stored to the beginning of the
pool. These meta data are eventually used in crypto_free_context() to free
the DMA pool through dma_pool_free(). However, given that the DMA pool can
also be accessed by the device, a malicious device can modify these meta
data, especially when the device is controlled to deploy an attack. This
can cause an unexpected DMA pool free failure.
To avoid the above issue, this patch introduces a new structure
crypto_ctx_hdr and a new field chdr in the structure nitrox_crypto_ctx hold
the meta data information of the DMA pool after the allocation. Note that
the original structure ctx_hdr is not changed to ensure the compatibility.
Cc: <stable@vger.kernel.org>
Signed-off-by: Wenwen Wang <wang6495@umn.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
replace pci_enable_msix_exact() with pci_alloc_irq_vectors(). get the
required vector count from pci_msix_vec_count().
use struct nitrox_q_vector as the argument to tasklets.
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Reviewed-by: Gadam Sreerama <sgadam@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Use node based allocations for queues. consider the dma address
alignment changes, while calculating the queue base address.
added checks in cleanup functions. Minor changes to queue variable names
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Reviewed-by: Gadam Sreerama <sgadam@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
check the flr capability using pcie_has_flr() and do the flr.
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Reviewed-by: Gadam Sreerama <sgadam@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
fix compilation warnings with nitrox_debugfs.c while printing
atomic64_t types on arm64. typecast the atomic64_read() value to u64
This issue is reported by Ard Biesheuvel
drivers/crypto/cavium/nitrox/nitrox_debugfs.c:62:30:
warning: format ‘%lld’ expects argument of type ‘long long int’,
but argument 3 has type ‘long int’ [-Wformat=]
seq_printf(s, " Posted: %lld\n", atomic64_read(&ndev->stats.posted));
^
Fixes: 2a8780be9c (crypto: cavium/nitrox - updated debugfs information)
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Reviewed-by: Gadam Sreerama <sgadam@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
kfree has taken the null pointer into account. hence it is safe
to remove the redundant null pointer check before kfree.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Updated debugfs to provide device partname and frequency etc.
New file "stats" shows the number of requests posted, dropped and
completed.
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add per device statistics like number of requests posted,
dropped and completed etc.
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Get the device partname based on it's capabilities like,
core frequency, number of cores and revision id.
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
use dma_pool_zalloc() instead of dma_pool_alloc with __GFP_ZERO flag.
crypto dma pool renamed to "nitrox-context".
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Added support to configure SR-IOV using sysfs interface.
Supported VF modes are 16, 32, 64 and 128. Grouped the
hardware configuration functions to "nitrox_hal.h" file.
Changed driver version to "1.1".
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Reviewed-by: Gadam Sreerama <sgadam@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Earlier used to post the current command without checking queue full
after backlog submissions. So, post the current command only after
confirming the space in queue after backlog submissions.
Maintain host write index instead of reading device registers
to get the next free slot to post the command.
Return -ENOSPC in queue full case.
Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Reviewed-by: Gadam Sreerama <sgadam@cavium.com>
Tested-by: Jha, Chandan <Chandan.Jha@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto_alloc_context() is only called by nitrox_skcipher_init(), which is
never called in atomic context.
crypto_alloc_context() calls dma_pool_alloc() with GFP_ATOMIC,
which is not necessary.
GFP_ATOMIC can be replaced with GFP_KERNEL.
This is found by a static analysis tool named DCNS written by myself.
I also manually check the kernel code before reporting it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The structure algs is local to the source and does not need to be in
global scope, so make it static.
Cleans up sparse warning:
drivers/crypto/cavium/cpt/cptvf_algs.c:354:19: warning: symbol 'algs'
was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Switch to raw_smp_processor_id() to prevent a number of
warnings from kernel debugging. We do not care about
preemption here, as the CPU number is only used as a
poor mans load balancing or device selection. If preemption
happens during a compress/decompress operation a small performance
hit will occur but everything will continue to work, so just
ignore it.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Reviewed-by: Robert Richter <rrichter@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The pending request counter was read from the wrong register. While
at it, there is no need to use an atomic for it as it is only read
localy in a loop.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Reviewed-by: Robert Richter <rrichter@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Avoid two potential divisions by zero when calculating average
values for the zip statistics.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Reviewed-by: Robert Richter <rrichter@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
After issuing a request an endless loop was used to read the
completion state from memory which is asynchronously updated
by the ZIP coprocessor.
Add an upper bound to the retry attempts to prevent a CPU getting stuck
forever in case of an error. Additionally, add a read memory barrier
and a small delay between the reading attempts.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Reviewed-by: Robert Richter <rrichter@cavium.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Enabling virtual mapped kernel stacks breaks the thunderx_zip
driver. On compression or decompression the executing CPU hangs
in an endless loop. The reason for this is the usage of __pa
by the driver which does no longer work for an address that is
not part of the 1:1 mapping.
The zip driver allocates a result struct on the stack and needs
to tell the hardware the physical address within this struct
that is used to signal the completion of the request.
As the hardware gets the wrong address after the broken __pa
conversion it writes to an arbitrary address. The zip driver then
waits forever for the completion byte to contain a non-zero value.
Allocating the result struct from 1:1 mapped memory resolves this
bug.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Reviewed-by: Robert Richter <rrichter@cavium.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
cpt_device_init() is never called in atomic context.
The call chain ending up at cpt_device_init() is:
[1] cpt_device_init() <- cpt_probe()
cpt_probe() is only set as ".probe" in pci_driver structure
"cpt_pci_driver".
Despite never getting called from atomic context, cpt_device_init() calls
mdelay(100), i.e. busy wait for 100ms.
That is not necessary and can be replaced with msleep to
avoid busy waiting.
This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
These duplicate includes have been found with scripts/checkincludes.pl but
they have been removed manually to avoid removing false positives.
Signed-off-by: Pravin Shedge <pravin.shedge4linux@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The object info is being leaked on an error return path, fix this
by setting ret to -ENOMEM and exiting via the request_cleanup path
that will free info.
Detected by CoverityScan, CID#1408439 ("Resource Leak")
Fixes: c694b23329 ("crypto: cavium - Add the Virtual Function driver for CPT")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Linus Torvalds