<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/tools/arch/x86, branch linux-5.18.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.18.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.18.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2022-08-11T11:20:44Z</updated>
<entry>
<title>x86/speculation: Add RSB VM Exit protections</title>
<updated>2022-08-11T11:20:44Z</updated>
<author>
<name>Daniel Sneddon</name>
</author>
<published>2022-08-02T22:47:01Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=0abdbbd9ae9c81615836278d787a8c8dcd576c36'/>
<id>urn:sha1:0abdbbd9ae9c81615836278d787a8c8dcd576c36</id>
<content type='text'>
commit 2b1299322016731d56807aa49254a5ea3080b6b3 upstream.

tl;dr: The Enhanced IBRS mitigation for Spectre v2 does not work as
documented for RET instructions after VM exits. Mitigate it with a new
one-entry RSB stuffing mechanism and a new LFENCE.

== Background ==

Indirect Branch Restricted Speculation (IBRS) was designed to help
mitigate Branch Target Injection and Speculative Store Bypass, i.e.
Spectre, attacks. IBRS prevents software run in less privileged modes
from affecting branch prediction in more privileged modes. IBRS requires
the MSR to be written on every privilege level change.

To overcome some of the performance issues of IBRS, Enhanced IBRS was
introduced.  eIBRS is an "always on" IBRS, in other words, just turn
it on once instead of writing the MSR on every privilege level change.
When eIBRS is enabled, more privileged modes should be protected from
less privileged modes, including protecting VMMs from guests.

== Problem ==

Here's a simplification of how guests are run on Linux' KVM:

void run_kvm_guest(void)
{
	// Prepare to run guest
	VMRESUME();
	// Clean up after guest runs
}

The execution flow for that would look something like this to the
processor:

1. Host-side: call run_kvm_guest()
2. Host-side: VMRESUME
3. Guest runs, does "CALL guest_function"
4. VM exit, host runs again
5. Host might make some "cleanup" function calls
6. Host-side: RET from run_kvm_guest()

Now, when back on the host, there are a couple of possible scenarios of
post-guest activity the host needs to do before executing host code:

* on pre-eIBRS hardware (legacy IBRS, or nothing at all), the RSB is not
touched and Linux has to do a 32-entry stuffing.

* on eIBRS hardware, VM exit with IBRS enabled, or restoring the host
IBRS=1 shortly after VM exit, has a documented side effect of flushing
the RSB except in this PBRSB situation where the software needs to stuff
the last RSB entry "by hand".

IOW, with eIBRS supported, host RET instructions should no longer be
influenced by guest behavior after the host retires a single CALL
instruction.

However, if the RET instructions are "unbalanced" with CALLs after a VM
exit as is the RET in #6, it might speculatively use the address for the
instruction after the CALL in #3 as an RSB prediction. This is a problem
since the (untrusted) guest controls this address.

Balanced CALL/RET instruction pairs such as in step #5 are not affected.

== Solution ==

The PBRSB issue affects a wide variety of Intel processors which
support eIBRS. But not all of them need mitigation. Today,
X86_FEATURE_RSB_VMEXIT triggers an RSB filling sequence that mitigates
PBRSB. Systems setting RSB_VMEXIT need no further mitigation - i.e.,
eIBRS systems which enable legacy IBRS explicitly.

However, such systems (X86_FEATURE_IBRS_ENHANCED) do not set RSB_VMEXIT
and most of them need a new mitigation.

Therefore, introduce a new feature flag X86_FEATURE_RSB_VMEXIT_LITE
which triggers a lighter-weight PBRSB mitigation versus RSB_VMEXIT.

The lighter-weight mitigation performs a CALL instruction which is
immediately followed by a speculative execution barrier (INT3). This
steers speculative execution to the barrier -- just like a retpoline
-- which ensures that speculation can never reach an unbalanced RET.
Then, ensure this CALL is retired before continuing execution with an
LFENCE.

In other words, the window of exposure is opened at VM exit where RET
behavior is troublesome. While the window is open, force RSB predictions
sampling for RET targets to a dead end at the INT3. Close the window
with the LFENCE.

There is a subset of eIBRS systems which are not vulnerable to PBRSB.
Add these systems to the cpu_vuln_whitelist[] as NO_EIBRS_PBRSB.
Future systems that aren't vulnerable will set ARCH_CAP_PBRSB_NO.

  [ bp: Massage, incorporate review comments from Andy Cooper. ]

Signed-off-by: Daniel Sneddon &lt;daniel.sneddon@linux.intel.com&gt;
Co-developed-by: Pawan Gupta &lt;pawan.kumar.gupta@linux.intel.com&gt;
Signed-off-by: Pawan Gupta &lt;pawan.kumar.gupta@linux.intel.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tools headers cpufeatures: Sync with the kernel sources</title>
<updated>2022-07-23T10:56:59Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
</author>
<published>2021-07-01T16:39:15Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=33e0e7fdbc2bfc615ea54b741988b8015c593024'/>
<id>urn:sha1:33e0e7fdbc2bfc615ea54b741988b8015c593024</id>
<content type='text'>
commit f098addbdb44c8a565367f5162f3ab170ed9404a upstream.

To pick the changes from:

  f43b9876e857c739 ("x86/retbleed: Add fine grained Kconfig knobs")
  a149180fbcf336e9 ("x86: Add magic AMD return-thunk")
  15e67227c49a5783 ("x86: Undo return-thunk damage")
  369ae6ffc41a3c11 ("x86/retpoline: Cleanup some #ifdefery")
  4ad3278df6fe2b08 x86/speculation: Disable RRSBA behavior
  26aae8ccbc197223 x86/cpu/amd: Enumerate BTC_NO
  9756bba28470722d x86/speculation: Fill RSB on vmexit for IBRS
  3ebc170068885b6f x86/bugs: Add retbleed=ibpb
  2dbb887e875b1de3 x86/entry: Add kernel IBRS implementation
  6b80b59b35557065 x86/bugs: Report AMD retbleed vulnerability
  a149180fbcf336e9 x86: Add magic AMD return-thunk
  15e67227c49a5783 x86: Undo return-thunk damage
  a883d624aed463c8 x86/cpufeatures: Move RETPOLINE flags to word 11
  51802186158c74a0 x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug

This only causes these perf files to be rebuilt:

  CC       /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
  CC       /tmp/build/perf/bench/mem-memset-x86-64-asm.o

And addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
  diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h
  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/disabled-features.h' differs from latest version at 'arch/x86/include/asm/disabled-features.h'
  diff -u tools/arch/x86/include/asm/disabled-features.h arch/x86/include/asm/disabled-features.h

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org
Link: https://lore.kernel.org/lkml/YtQM40VmiLTkPND2@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tools arch x86: Sync the msr-index.h copy with the kernel sources</title>
<updated>2022-07-23T10:56:59Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
</author>
<published>2021-07-01T16:32:18Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=699b83c618473c1eeca68c950b832a3e8d3ffddc'/>
<id>urn:sha1:699b83c618473c1eeca68c950b832a3e8d3ffddc</id>
<content type='text'>
commit 91d248c3b903b46a58cbc7e8d38d684d3e4007c2 upstream.

To pick up the changes from these csets:

  4ad3278df6fe2b08 ("x86/speculation: Disable RRSBA behavior")
  d7caac991feeef1b ("x86/cpu/amd: Add Spectral Chicken")

That cause no changes to tooling:

  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh &gt; before
  $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h
  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh &gt; after
  $ diff -u before after
  $

Just silences this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'
  diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Pawan Gupta &lt;pawan.kumar.gupta@linux.intel.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/lkml/YtQTm9wsB3hxQWvy@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>x86/speculation: Disable RRSBA behavior</title>
<updated>2022-07-23T10:56:57Z</updated>
<author>
<name>Pawan Gupta</name>
</author>
<published>2022-07-08T20:36:09Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=ffdd31e8db4e94f399e68727fadf776fc0a2d1ba'/>
<id>urn:sha1:ffdd31e8db4e94f399e68727fadf776fc0a2d1ba</id>
<content type='text'>
commit 4ad3278df6fe2b0852b00d5757fc2ccd8e92c26e upstream.

Some Intel processors may use alternate predictors for RETs on
RSB-underflow. This condition may be vulnerable to Branch History
Injection (BHI) and intramode-BTI.

Kernel earlier added spectre_v2 mitigation modes (eIBRS+Retpolines,
eIBRS+LFENCE, Retpolines) which protect indirect CALLs and JMPs against
such attacks. However, on RSB-underflow, RET target prediction may
fallback to alternate predictors. As a result, RET's predicted target
may get influenced by branch history.

A new MSR_IA32_SPEC_CTRL bit (RRSBA_DIS_S) controls this fallback
behavior when in kernel mode. When set, RETs will not take predictions
from alternate predictors, hence mitigating RETs as well. Support for
this is enumerated by CPUID.7.2.EDX[RRSBA_CTRL] (bit2).

For spectre v2 mitigation, when a user selects a mitigation that
protects indirect CALLs and JMPs against BHI and intramode-BTI, set
RRSBA_DIS_S also to protect RETs for RSB-underflow case.

Signed-off-by: Pawan Gupta &lt;pawan.kumar.gupta@linux.intel.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Signed-off-by: Thadeu Lima de Souza Cascardo &lt;cascardo@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>KVM: x86/speculation: Disable Fill buffer clear within guests</title>
<updated>2022-06-16T11:32:05Z</updated>
<author>
<name>Pawan Gupta</name>
</author>
<published>2022-05-20T03:35:15Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=0b4bd3f44c674ba215f8f7918e4145d045bf5396'/>
<id>urn:sha1:0b4bd3f44c674ba215f8f7918e4145d045bf5396</id>
<content type='text'>
commit 027bbb884be006b05d9c577d6401686053aa789e upstream

The enumeration of MD_CLEAR in CPUID(EAX=7,ECX=0).EDX{bit 10} is not an
accurate indicator on all CPUs of whether the VERW instruction will
overwrite fill buffers. FB_CLEAR enumeration in
IA32_ARCH_CAPABILITIES{bit 17} covers the case of CPUs that are not
vulnerable to MDS/TAA, indicating that microcode does overwrite fill
buffers.

Guests running in VMM environments may not be aware of all the
capabilities/vulnerabilities of the host CPU. Specifically, a guest may
apply MDS/TAA mitigations when a virtual CPU is enumerated as vulnerable
to MDS/TAA even when the physical CPU is not. On CPUs that enumerate
FB_CLEAR_CTRL the VMM may set FB_CLEAR_DIS to skip overwriting of fill
buffers by the VERW instruction. This is done by setting FB_CLEAR_DIS
during VMENTER and resetting on VMEXIT. For guests that enumerate
FB_CLEAR (explicitly asking for fill buffer clear capability) the VMM
will not use FB_CLEAR_DIS.

Irrespective of guest state, host overwrites CPU buffers before VMENTER
to protect itself from an MMIO capable guest, as part of mitigation for
MMIO Stale Data vulnerabilities.

Signed-off-by: Pawan Gupta &lt;pawan.kumar.gupta@linux.intel.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug</title>
<updated>2022-06-16T11:32:03Z</updated>
<author>
<name>Pawan Gupta</name>
</author>
<published>2022-05-20T03:27:08Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=d88769c6dd78a77c049a55d4d39542648740321f'/>
<id>urn:sha1:d88769c6dd78a77c049a55d4d39542648740321f</id>
<content type='text'>
commit 51802186158c74a0304f51ab963e7c2b3a2b046f upstream

Processor MMIO Stale Data is a class of vulnerabilities that may
expose data after an MMIO operation. For more details please refer to
Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst

Add the Processor MMIO Stale Data bug enumeration. A microcode update
adds new bits to the MSR IA32_ARCH_CAPABILITIES, define them.

Signed-off-by: Pawan Gupta &lt;pawan.kumar.gupta@linux.intel.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>x86/tsx: Disable TSX development mode at boot</title>
<updated>2022-04-11T07:58:40Z</updated>
<author>
<name>Pawan Gupta</name>
</author>
<published>2022-03-10T22:02:09Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=400331f8ffa3bec5c561417e5eec6848464e9160'/>
<id>urn:sha1:400331f8ffa3bec5c561417e5eec6848464e9160</id>
<content type='text'>
A microcode update on some Intel processors causes all TSX transactions
to always abort by default[*]. Microcode also added functionality to
re-enable TSX for development purposes. With this microcode loaded, if
tsx=on was passed on the cmdline, and TSX development mode was already
enabled before the kernel boot, it may make the system vulnerable to TSX
Asynchronous Abort (TAA).

To be on safer side, unconditionally disable TSX development mode during
boot. If a viable use case appears, this can be revisited later.

  [*]: Intel TSX Disable Update for Selected Processors, doc ID: 643557

  [ bp: Drop unstable web link, massage heavily. ]

Suggested-by: Andrew Cooper &lt;andrew.cooper3@citrix.com&gt;
Suggested-by: Borislav Petkov &lt;bp@alien8.de&gt;
Signed-off-by: Pawan Gupta &lt;pawan.kumar.gupta@linux.intel.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Tested-by: Neelima Krishnan &lt;neelima.krishnan@intel.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/347bd844da3a333a9793c6687d4e4eb3b2419a3e.1646943780.git.pawan.kumar.gupta@linux.intel.com
</content>
</entry>
<entry>
<title>tools headers cpufeatures: Sync with the kernel sources</title>
<updated>2022-04-01T19:19:35Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
</author>
<published>2021-07-01T16:39:15Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=5ced81243593dd84f46ee3e7bb3cb8a69ede0276'/>
<id>urn:sha1:5ced81243593dd84f46ee3e7bb3cb8a69ede0276</id>
<content type='text'>
To pick the changes from:

  991625f3dd2cbc4b ("x86/ibt: Add IBT feature, MSR and #CP handling")

This only causes these perf files to be rebuilt:

  CC       /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
  CC       /tmp/build/perf/bench/mem-memset-x86-64-asm.o

And addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
  diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h

Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/lkml/YkSCx2kr4ambH+Qe@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>tools arch x86: Sync the msr-index.h copy with the kernel sources</title>
<updated>2022-04-01T19:19:35Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
</author>
<published>2020-08-07T11:45:47Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=672b259fed48cca4210c4e2329861ed63a036f8b'/>
<id>urn:sha1:672b259fed48cca4210c4e2329861ed63a036f8b</id>
<content type='text'>
To pick up the changes in:

  991625f3dd2cbc4b ("x86/ibt: Add IBT feature, MSR and #CP handling")

Addressing these tools/perf build warnings:

    diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h
    Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'

That makes the beautification scripts to pick some new entries:

  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh &gt; before
  $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h
  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh &gt; after
  $ diff -u before after
  --- before	2022-03-29 16:23:07.678740040 -0300
  +++ after	2022-03-29 16:23:16.960978524 -0300
  @@ -220,6 +220,13 @@
   	[0x00000669] = "MC6_DEMOTION_POLICY_CONFIG",
   	[0x00000680] = "LBR_NHM_FROM",
   	[0x00000690] = "CORE_PERF_LIMIT_REASONS",
  +	[0x000006a0] = "IA32_U_CET",
  +	[0x000006a2] = "IA32_S_CET",
  +	[0x000006a4] = "IA32_PL0_SSP",
  +	[0x000006a5] = "IA32_PL1_SSP",
  +	[0x000006a6] = "IA32_PL2_SSP",
  +	[0x000006a7] = "IA32_PL3_SSP",
  +	[0x000006a8] = "IA32_INT_SSP_TAB",
   	[0x000006B0] = "GFX_PERF_LIMIT_REASONS",
   	[0x000006B1] = "RING_PERF_LIMIT_REASONS",
   	[0x000006c0] = "LBR_NHM_TO",
  $

And this gets rebuilt:

  CC      /tmp/build/perf/trace/beauty/tracepoints/x86_msr.o
  LD      /tmp/build/perf/trace/beauty/tracepoints/perf-in.o
  LD      /tmp/build/perf/trace/beauty/perf-in.o
  CC      /tmp/build/perf/util/amd-sample-raw.o
  LD      /tmp/build/perf/util/perf-in.o
  LD      /tmp/build/perf/perf-in.o
  LINK    /tmp/build/perf/perf

Now one can trace systemwide asking to see backtraces to where those
MSRs are being read/written with:

  # perf trace -e msr:*_msr/max-stack=32/ --filter="msr&gt;=IA32_U_CET &amp;&amp; msr&lt;=IA32_INT_SSP_TAB"
  ^C#

If we use -v (verbose mode) we can see what it does behind the scenes:

  # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr&gt;=IA32_U_CET &amp;&amp; msr&lt;=IA32_INT_SSP_TAB"
  Using CPUID AuthenticAMD-25-21-0
  0x6a0
  0x6a8
  New filter for msr:read_msr: (msr&gt;=0x6a0 &amp;&amp; msr&lt;=0x6a8) &amp;&amp; (common_pid != 597499 &amp;&amp; common_pid != 3313)
  0x6a0
  0x6a8
  New filter for msr:write_msr: (msr&gt;=0x6a0 &amp;&amp; msr&lt;=0x6a8) &amp;&amp; (common_pid != 597499 &amp;&amp; common_pid != 3313)
  mmap size 528384B
  ^C#

Example with a frequent msr:

  # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_SPEC_CTRL" --max-events 2
  Using CPUID AuthenticAMD-25-21-0
  0x48
  New filter for msr:read_msr: (msr==0x48) &amp;&amp; (common_pid != 2612129 &amp;&amp; common_pid != 3841)
  0x48
  New filter for msr:write_msr: (msr==0x48) &amp;&amp; (common_pid != 2612129 &amp;&amp; common_pid != 3841)
  mmap size 528384B
  Looking at the vmlinux_path (8 entries long)
  symsrc__init: build id mismatch for vmlinux.
  Using /proc/kcore for kernel data
  Using /proc/kallsyms for symbols
     0.000 Timer/2525383 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6)
                                       do_trace_write_msr ([kernel.kallsyms])
                                       do_trace_write_msr ([kernel.kallsyms])
                                       __switch_to_xtra ([kernel.kallsyms])
                                       __switch_to ([kernel.kallsyms])
                                       __schedule ([kernel.kallsyms])
                                       schedule ([kernel.kallsyms])
                                       futex_wait_queue_me ([kernel.kallsyms])
                                       futex_wait ([kernel.kallsyms])
                                       do_futex ([kernel.kallsyms])
                                       __x64_sys_futex ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       entry_SYSCALL_64_after_hwframe ([kernel.kallsyms])
                                       __futex_abstimed_wait_common64 (/usr/lib64/libpthread-2.33.so)
     0.030 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL, val: 2)
                                       do_trace_write_msr ([kernel.kallsyms])
                                       do_trace_write_msr ([kernel.kallsyms])
                                       __switch_to_xtra ([kernel.kallsyms])
                                       __switch_to ([kernel.kallsyms])
                                       __schedule ([kernel.kallsyms])
                                       schedule_idle ([kernel.kallsyms])
                                       do_idle ([kernel.kallsyms])
                                       cpu_startup_entry ([kernel.kallsyms])
                                       secondary_startup_64_no_verify ([kernel.kallsyms])
  #

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/YkNd7Ky+vi7H2Zl2@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'perf-tools-for-v5.18-2022-03-26' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux</title>
<updated>2022-03-27T20:42:32Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2022-03-27T20:42:32Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=7b58b82b86c8b65a2b57a4c6cb96a460654f9e09'/>
<id>urn:sha1:7b58b82b86c8b65a2b57a4c6cb96a460654f9e09</id>
<content type='text'>
Pull perf tools updates from Arnaldo Carvalho de Melo:
 "New features:

  perf ftrace:

   - Add -n/--use-nsec option to the 'latency' subcommand.

     Default: usecs:

     $ sudo perf ftrace latency -T dput -a sleep 1
     #   DURATION     |      COUNT | GRAPH                          |
          0 - 1    us |    2098375 | #############################  |
          1 - 2    us |         61 |                                |
          2 - 4    us |         33 |                                |
          4 - 8    us |         13 |                                |
          8 - 16   us |        124 |                                |
         16 - 32   us |        123 |                                |
         32 - 64   us |          1 |                                |
         64 - 128  us |          0 |                                |
        128 - 256  us |          1 |                                |
        256 - 512  us |          0 |                                |

     Better granularity with nsec:

     $ sudo perf ftrace latency -T dput -a -n sleep 1
     #   DURATION     |      COUNT | GRAPH                          |
          0 - 1    us |          0 |                                |
          1 - 2    ns |          0 |                                |
          2 - 4    ns |          0 |                                |
          4 - 8    ns |          0 |                                |
          8 - 16   ns |          0 |                                |
         16 - 32   ns |          0 |                                |
         32 - 64   ns |          0 |                                |
         64 - 128  ns |    1163434 | ##############                 |
        128 - 256  ns |     914102 | #############                  |
        256 - 512  ns |        884 |                                |
        512 - 1024 ns |        613 |                                |
          1 - 2    us |         31 |                                |
          2 - 4    us |         17 |                                |
          4 - 8    us |          7 |                                |
          8 - 16   us |        123 |                                |
         16 - 32   us |         83 |                                |

  perf lock:

   - Add -c/--combine-locks option to merge lock instances in the same
     class into a single entry.

     # perf lock report -c
                    Name acquired contended avg wait(ns) total wait(ns) max wait(ns) min wait(ns)

           rcu_read_lock   251225         0            0              0            0            0
      hrtimer_bases.lock    39450         0            0              0            0            0
     &amp;sb-&gt;s_type-&gt;i_l...    10301         1          662            662          662          662
        ptlock_ptr(page)    10173         2          701           1402          760          642
     &amp;(ei-&gt;i_block_re...     8732         0            0              0            0            0
            &amp;xa-&gt;xa_lock     8088         0            0              0            0            0
             &amp;base-&gt;lock     6705         0            0              0            0            0
             &amp;p-&gt;pi_lock     5549         0            0              0            0            0
     &amp;dentry-&gt;d_lockr...     5010         4         1274           5097         1844          789
               &amp;ep-&gt;lock     3958         0            0              0            0            0

      - Add -F/--field option to customize the list of fields to output:

     $ perf lock report -F contended,wait_max -k avg_wait
                     Name contended max wait(ns) avg wait(ns)

           slock-AF_INET6         1        23543        23543
        &amp;lruvec-&gt;lru_lock         5        18317        11254
           slock-AF_INET6         1        10379        10379
               rcu_node_1         1         2104         2104
      &amp;dentry-&gt;d_lockr...         1         1844         1844
      &amp;dentry-&gt;d_lockr...         1         1672         1672
         &amp;newf-&gt;file_lock        15         2279         1025
      &amp;dentry-&gt;d_lockr...         1          792          792

   - Add --synth=no option for record, as there is no need to symbolize,
     lock names comes from the tracepoints.

  perf record:

   - Threaded recording, opt-in, via the new --threads command line
     option.

   - Improve AMD IBS (Instruction-Based Sampling) error handling
     messages.

  perf script:

   - Add 'brstackinsnlen' field (use it with -F) for branch stacks.

   - Output branch sample type in 'perf script'.

  perf report:

   - Add "addr_from" and "addr_to" sort dimensions.

   - Print branch stack entry type in 'perf report --dump-raw-trace'

   - Fix symbolization for chrooted workloads.

  Hardware tracing:

  Intel PT:

   - Add CFE (Control Flow Event) and EVD (Event Data) packets support.

   - Add MODE.Exec IFLAG bit support.

     Explanation about these features from the "Intel® 64 and IA-32
     architectures software developer’s manual combined volumes: 1, 2A,
     2B, 2C, 2D, 3A, 3B, 3C, 3D, and 4" PDF at:

        https://cdrdv2.intel.com/v1/dl/getContent/671200

     At page 3951:
      "32.2.4

       Event Trace is a capability that exposes details about the
       asynchronous events, when they are generated, and when their
       corresponding software event handler completes execution. These
       include:

        o Interrupts, including NMI and SMI, including the interrupt
          vector when defined.

        o Faults, exceptions including the fault vector.

           - Page faults additionally include the page fault address,
             when in context.

        o Event handler returns, including IRET and RSM.

        o VM exits and VM entries.¹

           - VM exits include the values written to the “exit reason”
             and “exit qualification” VMCS fields. INIT and SIPI events.

        o TSX aborts, including the abort status returned for the RTM
          instructions.

        o Shutdown.

       Additionally, it provides indication of the status of the
       Interrupt Flag (IF), to indicate when interrupts are masked"

  ARM CoreSight:

   - Use advertised caps/min_interval as default sample_period on ARM
     spe.

   - Update deduction of TRCCONFIGR register for branch broadcast on
     ARM's CoreSight ETM.

  Vendor Events (JSON):

  Intel:

   - Update events and metrics for: Alderlake, Broadwell, Broadwell DE,
     BroadwellX, CascadelakeX, Elkhartlake, Bonnell, Goldmont,
     GoldmontPlus, Westmere EP-DP, Haswell, HaswellX, Icelake, IcelakeX,
     Ivybridge, Ivytown, Jaketown, Knights Landing, Nehalem EP,
     Sandybridge, Silvermont, Skylake, Skylake Server, SkylakeX,
     Tigerlake, TremontX, Westmere EP-SP, and Westmere EX.

  ARM:

   - Add support for HiSilicon CPA PMU aliasing.

  perf stat:

   - Fix forked applications enablement of counters.

   - The 'slots' should only be printed on a different order than the
     one specified on the command line when 'topdown' events are
     present, fix it.

  Miscellaneous:

   - Sync msr-index, cpufeatures header files with the kernel sources.

   - Stop using some deprecated libbpf APIs in 'perf trace'.

   - Fix some spelling mistakes.

   - Refactor the maps pointers usage to pave the way for using refcount
     debugging.

   - Only offer the --tui option on perf top, report and annotate when
     perf was built with libslang.

   - Don't mention --to-ctf in 'perf data --help' when not linking with
     the required library, libbabeltrace.

   - Use ARRAY_SIZE() instead of ad hoc equivalent, spotted by
     array_size.cocci.

   - Enhance the matching of sub-commands abbreviations:
	'perf c2c rec' -&gt; 'perf c2c record'
	'perf c2c recport -&gt; error

   - Set build-id using build-id header on new mmap records.

   - Fix generation of 'perf --version' string.

  perf test:

   - Add test for the arm_spe event.

   - Add test to check unwinding using fame-pointer (fp) mode on arm64.

   - Make metric testing more robust in 'perf test'.

   - Add error message for unsupported branch stack cases.

  libperf:

   - Add API for allocating new thread map array.

   - Fix typo in perf_evlist__open() failure error messages in libperf
     tests.

  perf c2c:

   - Replace bitmap_weight() with bitmap_empty() where appropriate"

* tag 'perf-tools-for-v5.18-2022-03-26' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (143 commits)
  perf evsel: Improve AMD IBS (Instruction-Based Sampling) error handling messages
  perf python: Add perf_env stubs that will be needed in evsel__open_strerror()
  perf tools: Enhance the matching of sub-commands abbreviations
  libperf tests: Fix typo in perf_evlist__open() failure error messages
  tools arm64: Import cputype.h
  perf lock: Add -F/--field option to control output
  perf lock: Extend struct lock_key to have print function
  perf lock: Add --synth=no option for record
  tools headers cpufeatures: Sync with the kernel sources
  tools headers cpufeatures: Sync with the kernel sources
  perf stat: Fix forked applications enablement of counters
  tools arch x86: Sync the msr-index.h copy with the kernel sources
  perf evsel: Make evsel__env() always return a valid env
  perf build-id: Fix spelling mistake "Cant" -&gt; "Can't"
  perf header: Fix spelling mistake "could't" -&gt; "couldn't"
  perf script: Add 'brstackinsnlen' for branch stacks
  perf parse-events: Move slots only with topdown
  perf ftrace latency: Update documentation
  perf ftrace latency: Add -n/--use-nsec option
  perf tools: Fix version kernel tag
  ...
</content>
</entry>
</feed>
