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<title>kernel/linux.git/tools/testing/selftests/x86, branch v5.4.168</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v5.4.168</id>
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<updated>2021-07-14T14:53:47+00:00</updated>
<entry>
<title>selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random</title>
<updated>2021-07-14T14:53:47+00:00</updated>
<author>
<name>Dave Hansen</name>
<email>dave.hansen@linux.intel.com</email>
</author>
<published>2021-07-01T01:56:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=b00da826cab4c21d86b5565e9501bb74afbd3db8'/>
<id>urn:sha1:b00da826cab4c21d86b5565e9501bb74afbd3db8</id>
<content type='text'>
[ Upstream commit f36ef407628835a7d7fb3d235b1f1aac7022d9a3 ]

Patch series "selftests/vm/pkeys: Bug fixes and a new test".

There has been a lot of activity on the x86 front around the XSAVE
architecture which is used to context-switch processor state (among other
things).  In addition, AMD has recently joined the protection keys club by
adding processor support for PKU.

The AMD implementation helped uncover a kernel bug around the PKRU "init
state", which actually applied to Intel's implementation but was just
harder to hit.  This series adds a test which is expected to help find
this class of bug both on AMD and Intel.  All the work around pkeys on x86
also uncovered a few bugs in the selftest.

This patch (of 4):

The "random" pkey allocation code currently does the good old:

	srand((unsigned int)time(NULL));

*But*, it unfortunately does this on every random pkey allocation.

There may be thousands of these a second.  time() has a one second
resolution.  So, each time alloc_random_pkey() is called, the PRNG is
*RESET* to time().  This is nasty.  Normally, if you do:

	srand(&lt;ANYTHING&gt;);
	foo = rand();
	bar = rand();

You'll be quite guaranteed that 'foo' and 'bar' are different.  But, if
you do:

	srand(1);
	foo = rand();
	srand(1);
	bar = rand();

You are quite guaranteed that 'foo' and 'bar' are the *SAME*.  The recent
"fix" effectively forced the test case to use the same "random" pkey for
the whole test, unless the test run crossed a second boundary.

Only run srand() once at program startup.

This explains some very odd and persistent test failures I've been seeing.

Link: https://lkml.kernel.org/r/20210611164153.91B76FB8@viggo.jf.intel.com
Link: https://lkml.kernel.org/r/20210611164155.192D00FF@viggo.jf.intel.com
Fixes: 6e373263ce07 ("selftests/vm/pkeys: fix alloc_random_pkey() to make it really random")
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Cc: Ram Pai &lt;linuxram@us.ibm.com&gt;
Cc: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
Cc: Florian Weimer &lt;fweimer@redhat.com&gt;
Cc: "Desnes A. Nunes do Rosario" &lt;desnesn@linux.vnet.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Thiago Jung Bauermann &lt;bauerman@linux.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Michal Suchanek &lt;msuchanek@suse.de&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests/x86/fsgsbase: Test PTRACE_PEEKUSER for GSBASE with invalid LDT GS</title>
<updated>2020-11-05T10:43:23+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2020-08-26T17:00:46+00:00</published>
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<id>urn:sha1:3674b0445b70e49105f03db7f3ac16eea1051d8c</id>
<content type='text'>
commit 1b9abd1755ad947d7c9913e92e7837b533124c90 upstream.

This tests commit:

  8ab49526b53d ("x86/fsgsbase/64: Fix NULL deref in 86_fsgsbase_read_task")

Unpatched kernels will OOPS.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/c618ae86d1f757e01b1a8e79869f553cb88acf9a.1598461151.git.luto@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>selftests/x86/fsgsbase: Reap a forgotten child</title>
<updated>2020-11-05T10:43:15+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2020-08-26T17:00:45+00:00</published>
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<id>urn:sha1:ac437801e3c212e183ac373f75c3d75dbacf2dc8</id>
<content type='text'>
[ Upstream commit ab2dd173330a3f07142e68cd65682205036cd00f ]

The ptrace() test forgot to reap its child.  Reap it.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/e7700a503f30e79ab35a63103938a19893dbeff2.1598461151.git.luto@kernel.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests/x86/syscall_nt: Clear weird flags after each test</title>
<updated>2020-10-01T11:18:10+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2020-06-26T17:21:15+00:00</published>
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<id>urn:sha1:eb7833e0ee0118100fbcbffb84a449eec5baf039</id>
<content type='text'>
[ Upstream commit a61fa2799ef9bf6c4f54cf7295036577cececc72 ]

Clear the weird flags before logging to improve strace output --
logging results while, say, TF is set does no one any favors.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lkml.kernel.org/r/907bfa5a42d4475b8245e18b67a04b13ca51ffdb.1593191971.git.luto@kernel.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests/vm/pkeys: fix alloc_random_pkey() to make it really random</title>
<updated>2020-06-24T15:50:39+00:00</updated>
<author>
<name>Ram Pai</name>
<email>linuxram@us.ibm.com</email>
</author>
<published>2020-06-04T23:52:05+00:00</published>
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<id>urn:sha1:718d9a863eb303343b81f6a1129e35d7508b4152</id>
<content type='text'>
[ Upstream commit 6e373263ce07eeaa6410843179535fbdf561fc31 ]

alloc_random_pkey() was allocating the same pkey every time.  Not all
pkeys were geting tested.  This fixes it.

Signed-off-by: Ram Pai &lt;linuxram@us.ibm.com&gt;
Signed-off-by: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Acked-by: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Florian Weimer &lt;fweimer@redhat.com&gt;
Cc: "Desnes A. Nunes do Rosario" &lt;desnesn@linux.vnet.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Thiago Jung Bauermann &lt;bauerman@linux.ibm.com&gt;
Cc: "Aneesh Kumar K.V" &lt;aneesh.kumar@linux.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Michal Suchanek &lt;msuchanek@suse.de&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&gt;
Link: http://lkml.kernel.org/r/0162f55816d4e783a0d6e49e554d0ab9a3c9a23b.1585646528.git.sandipan@linux.ibm.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests/x86/ptrace_syscall_32: Fix no-vDSO segfault</title>
<updated>2020-04-17T08:50:02+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2020-03-12T22:35:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=75434bcc659394df665f01ebe0119cb638b7984a'/>
<id>urn:sha1:75434bcc659394df665f01ebe0119cb638b7984a</id>
<content type='text'>
[ Upstream commit 630b99ab60aa972052a4202a1ff96c7e45eb0054 ]

If AT_SYSINFO is not present, don't try to call a NULL pointer.

Reported-by: kbuild test robot &lt;lkp@intel.com&gt;
Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Link: https://lkml.kernel.org/r/faaf688265a7e1a5b944d6f8bc0f6368158306d3.1584052409.git.luto@kernel.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests/x86/sigreturn/32: Invalidate DS and ES when abusing the kernel</title>
<updated>2019-11-29T09:09:59+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2019-11-20T19:58:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=92f8c688b2ce3600dab434eb0c97d458db00f742'/>
<id>urn:sha1:92f8c688b2ce3600dab434eb0c97d458db00f742</id>
<content type='text'>
commit 4d2fa82d98d2d296043a04eb517d7dbade5b13b8 upstream.

If the kernel accidentally uses DS or ES while the user values are
loaded, it will work fine for sane userspace.  In the interest of
simulating maximally insane userspace, make sigreturn_32 zero out DS
and ES for the nasty parts so that inadvertent use of these segments
will crash.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>selftests/x86/mov_ss_trap: Fix the SYSENTER test</title>
<updated>2019-11-29T09:09:58+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2019-11-20T20:59:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=72e521b167ffba300d3381699718f8757e5559e7'/>
<id>urn:sha1:72e521b167ffba300d3381699718f8757e5559e7</id>
<content type='text'>
commit 8caa016bfc129f2c925d52da43022171d1d1de91 upstream.

For reasons that I haven't quite fully diagnosed, running
mov_ss_trap_32 on a 32-bit kernel results in an infinite loop in
userspace.  This appears to be because the hacky SYSENTER test
doesn't segfault as desired; instead it corrupts the program state
such that it infinite loops.

Fix it by explicitly clearing EBP before doing SYSENTER.  This will
give a more reliable segfault.

Fixes: 59c2a7226fc5 ("x86/selftests: Add mov_to_ss test")
Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>Merge branch 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2019-09-17T02:06:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-09-17T02:06:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=e0d60a1e68a3fbf42cdf3546004e00230d9048ba'/>
<id>urn:sha1:e0d60a1e68a3fbf42cdf3546004e00230d9048ba</id>
<content type='text'>
Pull x86 entry updates from Ingo Molnar:
 "This contains x32 and compat syscall improvements, the biggest one of
  which splits x32 syscalls into their own table, which allows new
  syscalls to share the x32 and x86-64 number - which turns the
  512-547 special syscall numbers range into a legacy wart that won't be
  extended going forward"

* 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/syscalls: Split the x32 syscalls into their own table
  x86/syscalls: Disallow compat entries for all types of 64-bit syscalls
  x86/syscalls: Use the compat versions of rt_sigsuspend() and rt_sigprocmask()
  x86/syscalls: Make __X32_SYSCALL_BIT be unsigned long
</content>
</entry>
<entry>
<title>Merge branch 'x86/cleanups' into x86/cpu, to pick up dependent changes</title>
<updated>2019-09-06T05:30:23+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2019-09-06T05:30:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=9326011edfcb7f7c3ad70f8a1cde6b391604808e'/>
<id>urn:sha1:9326011edfcb7f7c3ad70f8a1cde6b391604808e</id>
<content type='text'>
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
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