<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/x86/Makefile, branch v4.4.97</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6</title>
<updated>2015-11-04T17:11:12+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-11-04T17:11:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ccc9d4a6d640cbde05d519edeb727881646cf71b'/>
<id>ccc9d4a6d640cbde05d519edeb727881646cf71b</id>
<content type='text'>
Pull crypto update from Herbert Xu:
 "API:

   - Add support for cipher output IVs in testmgr
   - Add missing crypto_ahash_blocksize helper
   - Mark authenc and des ciphers as not allowed under FIPS.

Algorithms:

   - Add CRC support to 842 compression
   - Add keywrap algorithm
   - A number of changes to the akcipher interface:
      + Separate functions for setting public/private keys.
      + Use SG lists.

Drivers:

   - Add Intel SHA Extension optimised SHA1 and SHA256
   - Use dma_map_sg instead of custom functions in crypto drivers
   - Add support for STM32 RNG
   - Add support for ST RNG
   - Add Device Tree support to exynos RNG driver
   - Add support for mxs-dcp crypto device on MX6SL
   - Add xts(aes) support to caam
   - Add ctr(aes) and xts(aes) support to qat
   - A large set of fixes from Russell King for the marvell/cesa driver"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (115 commits)
  crypto: asymmetric_keys - Fix unaligned access in x509_get_sig_params()
  crypto: akcipher - Don't #include crypto/public_key.h as the contents aren't used
  hwrng: exynos - Add Device Tree support
  hwrng: exynos - Fix missing configuration after suspend to RAM
  hwrng: exynos - Add timeout for waiting on init done
  dt-bindings: rng: Describe Exynos4 PRNG bindings
  crypto: marvell/cesa - use __le32 for hardware descriptors
  crypto: marvell/cesa - fix missing cpu_to_le32() in mv_cesa_dma_add_op()
  crypto: marvell/cesa - use memcpy_fromio()/memcpy_toio()
  crypto: marvell/cesa - use gfp_t for gfp flags
  crypto: marvell/cesa - use dma_addr_t for cur_dma
  crypto: marvell/cesa - use readl_relaxed()/writel_relaxed()
  crypto: caam - fix indentation of close braces
  crypto: caam - only export the state we really need to export
  crypto: caam - fix non-block aligned hash calculation
  crypto: caam - avoid needlessly saving and restoring caam_hash_ctx
  crypto: caam - print errno code when hash registration fails
  crypto: marvell/cesa - fix memory leak
  crypto: marvell/cesa - fix first-fragment handling in mv_cesa_ahash_dma_last_req()
  crypto: marvell/cesa - rearrange handling for sw padded hashes
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull crypto update from Herbert Xu:
 "API:

   - Add support for cipher output IVs in testmgr
   - Add missing crypto_ahash_blocksize helper
   - Mark authenc and des ciphers as not allowed under FIPS.

Algorithms:

   - Add CRC support to 842 compression
   - Add keywrap algorithm
   - A number of changes to the akcipher interface:
      + Separate functions for setting public/private keys.
      + Use SG lists.

Drivers:

   - Add Intel SHA Extension optimised SHA1 and SHA256
   - Use dma_map_sg instead of custom functions in crypto drivers
   - Add support for STM32 RNG
   - Add support for ST RNG
   - Add Device Tree support to exynos RNG driver
   - Add support for mxs-dcp crypto device on MX6SL
   - Add xts(aes) support to caam
   - Add ctr(aes) and xts(aes) support to qat
   - A large set of fixes from Russell King for the marvell/cesa driver"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (115 commits)
  crypto: asymmetric_keys - Fix unaligned access in x509_get_sig_params()
  crypto: akcipher - Don't #include crypto/public_key.h as the contents aren't used
  hwrng: exynos - Add Device Tree support
  hwrng: exynos - Fix missing configuration after suspend to RAM
  hwrng: exynos - Add timeout for waiting on init done
  dt-bindings: rng: Describe Exynos4 PRNG bindings
  crypto: marvell/cesa - use __le32 for hardware descriptors
  crypto: marvell/cesa - fix missing cpu_to_le32() in mv_cesa_dma_add_op()
  crypto: marvell/cesa - use memcpy_fromio()/memcpy_toio()
  crypto: marvell/cesa - use gfp_t for gfp flags
  crypto: marvell/cesa - use dma_addr_t for cur_dma
  crypto: marvell/cesa - use readl_relaxed()/writel_relaxed()
  crypto: caam - fix indentation of close braces
  crypto: caam - only export the state we really need to export
  crypto: caam - fix non-block aligned hash calculation
  crypto: caam - avoid needlessly saving and restoring caam_hash_ctx
  crypto: caam - print errno code when hash registration fails
  crypto: marvell/cesa - fix memory leak
  crypto: marvell/cesa - fix first-fragment handling in mv_cesa_ahash_dma_last_req()
  crypto: marvell/cesa - rearrange handling for sw padded hashes
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/asm: Re-add parts of the manual CFI infrastructure</title>
<updated>2015-10-09T07:41:05+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2015-10-06T00:47:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7b956f035a9ef8bd3ef5490f49fc1bd834d8a70a'/>
<id>7b956f035a9ef8bd3ef5490f49fc1bd834d8a70a</id>
<content type='text'>
Commit:

  131484c8da97 ("x86/debug: Remove perpetually broken, unmaintainable dwarf annotations")

removed all the manual DWARF annotations outside the vDSO.  It also removed
the macros we used for the manual annotations.

Re-add these macros so that we can clean up the vDSO annotations.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/4c70bb98a8b773c8ccfaabf6745e569ff43e7f65.1444091584.git.luto@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit:

  131484c8da97 ("x86/debug: Remove perpetually broken, unmaintainable dwarf annotations")

removed all the manual DWARF annotations outside the vDSO.  It also removed
the macros we used for the manual annotations.

Re-add these macros so that we can clean up the vDSO annotations.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/4c70bb98a8b773c8ccfaabf6745e569ff43e7f65.1444091584.git.luto@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: x86/sha - Add build support for Intel SHA Extensions optimized SHA1 and SHA256</title>
<updated>2015-09-21T14:01:06+00:00</updated>
<author>
<name>tim</name>
<email>tim.c.chen@linux.intel.com</email>
</author>
<published>2015-09-10T22:27:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e38b6b7fcfd11fb83dcac54a33cbca3739c45a09'/>
<id>e38b6b7fcfd11fb83dcac54a33cbca3739c45a09</id>
<content type='text'>
This patch provides the configuration and build support to
include and build the optimized SHA1 and SHA256 update transforms
for the kernel's crypto library.

Originally-by: Chandramouli Narayanan &lt;mouli_7982@yahoo.com&gt;
Signed-off-by: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch provides the configuration and build support to
include and build the optimized SHA1 and SHA256 update transforms
for the kernel's crypto library.

Originally-by: Chandramouli Narayanan &lt;mouli_7982@yahoo.com&gt;
Signed-off-by: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2015-09-01T15:40:25+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-09-01T15:40:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5778077d03cb25aac9b6a428e18970642fc019e3'/>
<id>5778077d03cb25aac9b6a428e18970642fc019e3</id>
<content type='text'>
Pull x86 asm changes from Ingo Molnar:
 "The biggest changes in this cycle were:

   - Revamp, simplify (and in some cases fix) Time Stamp Counter (TSC)
     primitives.  (Andy Lutomirski)

   - Add new, comprehensible entry and exit handlers written in C.
     (Andy Lutomirski)

   - vm86 mode cleanups and fixes.  (Brian Gerst)

   - 32-bit compat code cleanups.  (Brian Gerst)

  The amount of simplification in low level assembly code is already
  palpable:

     arch/x86/entry/entry_32.S                          | 130 +----
     arch/x86/entry/entry_64.S                          | 197 ++-----

  but more simplifications are planned.

  There's also the usual laudry mix of low level changes - see the
  changelog for details"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (83 commits)
  x86/asm: Drop repeated macro of X86_EFLAGS_AC definition
  x86/asm/msr: Make wrmsrl() a function
  x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer
  x86/asm: Add MONITORX/MWAITX instruction support
  x86/traps: Weaken context tracking entry assertions
  x86/asm/tsc: Add rdtscll() merge helper
  selftests/x86: Add syscall_nt selftest
  selftests/x86: Disable sigreturn_64
  x86/vdso: Emit a GNU hash
  x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks
  x86/entry/32: Migrate to C exit path
  x86/entry/32: Remove 32-bit syscall audit optimizations
  x86/vm86: Rename vm86-&gt;v86flags and v86mask
  x86/vm86: Rename vm86-&gt;vm86_info to user_vm86
  x86/vm86: Clean up vm86.h includes
  x86/vm86: Move the vm86 IRQ definitions to vm86.h
  x86/vm86: Use the normal pt_regs area for vm86
  x86/vm86: Eliminate 'struct kernel_vm86_struct'
  x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86'
  x86/vm86: Move vm86 fields out of 'thread_struct'
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 asm changes from Ingo Molnar:
 "The biggest changes in this cycle were:

   - Revamp, simplify (and in some cases fix) Time Stamp Counter (TSC)
     primitives.  (Andy Lutomirski)

   - Add new, comprehensible entry and exit handlers written in C.
     (Andy Lutomirski)

   - vm86 mode cleanups and fixes.  (Brian Gerst)

   - 32-bit compat code cleanups.  (Brian Gerst)

  The amount of simplification in low level assembly code is already
  palpable:

     arch/x86/entry/entry_32.S                          | 130 +----
     arch/x86/entry/entry_64.S                          | 197 ++-----

  but more simplifications are planned.

  There's also the usual laudry mix of low level changes - see the
  changelog for details"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (83 commits)
  x86/asm: Drop repeated macro of X86_EFLAGS_AC definition
  x86/asm/msr: Make wrmsrl() a function
  x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer
  x86/asm: Add MONITORX/MWAITX instruction support
  x86/traps: Weaken context tracking entry assertions
  x86/asm/tsc: Add rdtscll() merge helper
  selftests/x86: Add syscall_nt selftest
  selftests/x86: Disable sigreturn_64
  x86/vdso: Emit a GNU hash
  x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks
  x86/entry/32: Migrate to C exit path
  x86/entry/32: Remove 32-bit syscall audit optimizations
  x86/vm86: Rename vm86-&gt;v86flags and v86mask
  x86/vm86: Rename vm86-&gt;vm86_info to user_vm86
  x86/vm86: Clean up vm86.h includes
  x86/vm86: Move the vm86 IRQ definitions to vm86.h
  x86/vm86: Use the normal pt_regs area for vm86
  x86/vm86: Eliminate 'struct kernel_vm86_struct'
  x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86'
  x86/vm86: Move vm86 fields out of 'thread_struct'
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/ras: Move AMD MCE injector to arch/x86/ras/</title>
<updated>2015-08-13T08:12:54+00:00</updated>
<author>
<name>Borislav Petkov</name>
<email>bp@suse.de</email>
</author>
<published>2015-08-12T16:29:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6c36dfe949187dc2729abfad4b083758ac5c2e0e'/>
<id>6c36dfe949187dc2729abfad4b083758ac5c2e0e</id>
<content type='text'>
This is an x86-specific module and would benefit from being
closer to the arch code. Move it there. Update copyright while
at it.

Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Link: http://lkml.kernel.org/r/1439396985-12812-14-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is an x86-specific module and would benefit from being
closer to the arch code. Move it there. Update copyright while
at it.

Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Link: http://lkml.kernel.org/r/1439396985-12812-14-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/build: Fix detection of GCC -mpreferred-stack-boundary support</title>
<updated>2015-07-22T06:20:29+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2015-07-21T16:27:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b2c51106c7581866c37ffc77c5d739f3d4b7cbc9'/>
<id>b2c51106c7581866c37ffc77c5d739f3d4b7cbc9</id>
<content type='text'>
As per:

  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383

GCC only allows -mpreferred-stack-boundary=3 on x86_64 if -mno-sse is set.
That means that cc-option will not detect -mpreferred-stack-boundary=3
support, because we test for it before setting -mno-sse.

Fix it by reordering the Makefile bits.

Compile-tested only.  This should help avoid code generation
issues such as the one that was worked around in:

  b96fecbfa8c8 ("x86/fpu: Fix boot crash in the early FPU code")

I'm a bit concerned that we could still have problems on older
GCC versions given that our asm code does not respect GCC's idea
of the ABI-required stack alignment.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/f5297c192969adfa0d28b84cf8a22d59573db26d.1436126872.git.luto@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As per:

  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383

GCC only allows -mpreferred-stack-boundary=3 on x86_64 if -mno-sse is set.
That means that cc-option will not detect -mpreferred-stack-boundary=3
support, because we test for it before setting -mno-sse.

Fix it by reordering the Makefile bits.

Compile-tested only.  This should help avoid code generation
issues such as the one that was worked around in:

  b96fecbfa8c8 ("x86/fpu: Fix boot crash in the early FPU code")

I'm a bit concerned that we could still have problems on older
GCC versions given that our asm code does not respect GCC's idea
of the ABI-required stack alignment.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/f5297c192969adfa0d28b84cf8a22d59573db26d.1436126872.git.luto@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/asm/entry: Move the arch/x86/syscalls/ definitions to arch/x86/entry/syscalls/</title>
<updated>2015-06-04T05:37:37+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2015-06-03T16:36:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1f57d5d85ba7f1f467173ff33f51d01a91f9aaf1'/>
<id>1f57d5d85ba7f1f467173ff33f51d01a91f9aaf1</id>
<content type='text'>
The build time generated syscall definitions are entry code related, move
them into the arch/x86/entry/ directory.

Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The build time generated syscall definitions are entry code related, move
them into the arch/x86/entry/ directory.

Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/</title>
<updated>2015-06-03T16:51:37+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2015-06-03T16:05:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d603c8e184d882cc3f55c599f4185bad956ee0a7'/>
<id>d603c8e184d882cc3f55c599f4185bad956ee0a7</id>
<content type='text'>
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/debug: Remove perpetually broken, unmaintainable dwarf annotations</title>
<updated>2015-06-02T05:57:48+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2015-05-28T10:21:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=131484c8da97ed600c18dd9d03b661e8ae052df6'/>
<id>131484c8da97ed600c18dd9d03b661e8ae052df6</id>
<content type='text'>
So the dwarf2 annotations in low level assembly code have
become an increasing hindrance: unreadable, messy macros
mixed into some of the most security sensitive code paths
of the Linux kernel.

These debug info annotations don't even buy the upstream
kernel anything: dwarf driven stack unwinding has caused
problems in the past so it's out of tree, and the upstream
kernel only uses the much more robust framepointers based
stack unwinding method.

In addition to that there's a steady, slow bitrot going
on with these annotations, requiring frequent fixups.
There's no tooling and no functionality upstream that
keeps it correct.

So burn down the sick forest, allowing new, healthier growth:

   27 files changed, 350 insertions(+), 1101 deletions(-)

Someone who has the willingness and time to do this
properly can attempt to reintroduce dwarf debuginfo in x86
assembly code plus dwarf unwinding from first principles,
with the following conditions:

 - it should be maximally readable, and maximally low-key to
   'ordinary' code reading and maintenance.

 - find a build time method to insert dwarf annotations
   automatically in the most common cases, for pop/push
   instructions that manipulate the stack pointer. This could
   be done for example via a preprocessing step that just
   looks for common patterns - plus special annotations for
   the few cases where we want to depart from the default.
   We have hundreds of CFI annotations, so automating most of
   that makes sense.

 - it should come with build tooling checks that ensure that
   CFI annotations are sensible. We've seen such efforts from
   the framepointer side, and there's no reason it couldn't be
   done on the dwarf side.

Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: Frédéric Weisbecker &lt;fweisbec@gmail.com
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Jan Beulich &lt;JBeulich@suse.com&gt;
Cc: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
So the dwarf2 annotations in low level assembly code have
become an increasing hindrance: unreadable, messy macros
mixed into some of the most security sensitive code paths
of the Linux kernel.

These debug info annotations don't even buy the upstream
kernel anything: dwarf driven stack unwinding has caused
problems in the past so it's out of tree, and the upstream
kernel only uses the much more robust framepointers based
stack unwinding method.

In addition to that there's a steady, slow bitrot going
on with these annotations, requiring frequent fixups.
There's no tooling and no functionality upstream that
keeps it correct.

So burn down the sick forest, allowing new, healthier growth:

   27 files changed, 350 insertions(+), 1101 deletions(-)

Someone who has the willingness and time to do this
properly can attempt to reintroduce dwarf debuginfo in x86
assembly code plus dwarf unwinding from first principles,
with the following conditions:

 - it should be maximally readable, and maximally low-key to
   'ordinary' code reading and maintenance.

 - find a build time method to insert dwarf annotations
   automatically in the most common cases, for pop/push
   instructions that manipulate the stack pointer. This could
   be done for example via a preprocessing step that just
   looks for common patterns - plus special annotations for
   the few cases where we want to depart from the default.
   We have hundreds of CFI annotations, so automating most of
   that makes sense.

 - it should come with build tooling checks that ensure that
   CFI annotations are sensible. We've seen such efforts from
   the framepointer side, and there's no reason it couldn't be
   done on the dwarf side.

Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: Frédéric Weisbecker &lt;fweisbec@gmail.com
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Jan Beulich &lt;JBeulich@suse.com&gt;
Cc: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: Pack loops tightly as well</title>
<updated>2015-05-17T05:56:54+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2015-05-17T05:56:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=52648e83c9a6b9f7fc3dd272d4d10175e93aa62a'/>
<id>52648e83c9a6b9f7fc3dd272d4d10175e93aa62a</id>
<content type='text'>
Packing loops tightly (-falign-loops=1) is beneficial to code size:

     text        data    bss     dec              filename
 12566391        1617840 1089536 15273767         vmlinux.align.16-byte
 12224951        1617840 1089536 14932327         vmlinux.align.1-byte
 11976567        1617840 1089536 14683943         vmlinux.align.1-byte.funcs-1-byte
 11903735        1617840 1089536 14611111         vmlinux.align.1-byte.funcs-1-byte.loops-1-byte

Which reduces the size of the kernel by another 0.6%, so the
the total combined size reduction of the alignment-packing
patches is ~5.5%.

The x86 decoder bandwidth and caching arguments laid out in:

  be6cb02779ca ("x86: Align jump targets to 1-byte boundaries")

apply to loop alignment as well.

Furtermore, modern CPU uarchs have a loop cache/buffer that
is a L0 cache before even any uop cache, covering a few
dozen most recently executed instructions.

This loop cache generally does not have the 16-byte alignment
restrictions of the uop cache.

Now loop alignment can still be beneficial if:

 - a loop is cache-hot and its surroundings are not.

 - if the loop is so cache hot that the instruction
   flow becomes x86 decoder bandwidth limited

But loop alignment is harmful if:

 - a loop is cache-cold

 - a loop's surroundings are cache-hot as well

 - two cache-hot loops are close to each other

 - if the loop fits into the loop cache

 - if the code flow is not decoder bandwidth limited

and I'd argue that the latter five scenarios are much
more common in the kernel, as our hottest loops are
typically:

 - pointer chasing: this should fit into the loop cache
   in most cases and is typically data cache and address
   generation limited

 - generic memory ops (memset, memcpy, etc.): these generally
   fit into the loop cache as well, and are likewise data
   cache limited.

So this patch packs loop addresses tightly as well.

Acked-by: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Aswin Chandramouleeswaran &lt;aswin@hp.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Jason Low &lt;jason.low2@hp.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Link: http://lkml.kernel.org/r/20150410123017.GB19918@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Packing loops tightly (-falign-loops=1) is beneficial to code size:

     text        data    bss     dec              filename
 12566391        1617840 1089536 15273767         vmlinux.align.16-byte
 12224951        1617840 1089536 14932327         vmlinux.align.1-byte
 11976567        1617840 1089536 14683943         vmlinux.align.1-byte.funcs-1-byte
 11903735        1617840 1089536 14611111         vmlinux.align.1-byte.funcs-1-byte.loops-1-byte

Which reduces the size of the kernel by another 0.6%, so the
the total combined size reduction of the alignment-packing
patches is ~5.5%.

The x86 decoder bandwidth and caching arguments laid out in:

  be6cb02779ca ("x86: Align jump targets to 1-byte boundaries")

apply to loop alignment as well.

Furtermore, modern CPU uarchs have a loop cache/buffer that
is a L0 cache before even any uop cache, covering a few
dozen most recently executed instructions.

This loop cache generally does not have the 16-byte alignment
restrictions of the uop cache.

Now loop alignment can still be beneficial if:

 - a loop is cache-hot and its surroundings are not.

 - if the loop is so cache hot that the instruction
   flow becomes x86 decoder bandwidth limited

But loop alignment is harmful if:

 - a loop is cache-cold

 - a loop's surroundings are cache-hot as well

 - two cache-hot loops are close to each other

 - if the loop fits into the loop cache

 - if the code flow is not decoder bandwidth limited

and I'd argue that the latter five scenarios are much
more common in the kernel, as our hottest loops are
typically:

 - pointer chasing: this should fit into the loop cache
   in most cases and is typically data cache and address
   generation limited

 - generic memory ops (memset, memcpy, etc.): these generally
   fit into the loop cache as well, and are likewise data
   cache limited.

So this patch packs loop addresses tightly as well.

Acked-by: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Aswin Chandramouleeswaran &lt;aswin@hp.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Jason Low &lt;jason.low2@hp.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Link: http://lkml.kernel.org/r/20150410123017.GB19918@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
