<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/git/stable/linux.git/arch/x86, branch linux-5.19.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<id>https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=linux-5.19.y</id>
<link rel='self' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=linux-5.19.y'/>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/'/>
<updated>2022-10-24T07:58:15+00:00</updated>
<entry>
<title>bpf: use bpf_prog_pack for bpf_dispatcher</title>
<updated>2022-10-24T07:58:15+00:00</updated>
<author>
<name>Song Liu</name>
<email>song@kernel.org</email>
</author>
<published>2022-09-26T18:47:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=44bd0d19c580005a5afb2bc23f0c9391e1c12165'/>
<id>urn:sha1:44bd0d19c580005a5afb2bc23f0c9391e1c12165</id>
<content type='text'>
[ Upstream commit 19c02415da2345d0dda2b5c4495bc17cc14b18b5 ]

Allocate bpf_dispatcher with bpf_prog_pack_alloc so that bpf_dispatcher
can share pages with bpf programs.

arch_prepare_bpf_dispatcher() is updated to provide a RW buffer as working
area for arch code to write to.

This also fixes CPA W^X warnning like:

CPA refuse W^X violation: 8000000000000163 -&gt; 0000000000000163 range: ...

Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20220926184739.3512547-2-song@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/apic: Don't disable x2APIC if locked</title>
<updated>2022-10-24T07:58:12+00:00</updated>
<author>
<name>Daniel Sneddon</name>
<email>daniel.sneddon@linux.intel.com</email>
</author>
<published>2022-08-16T23:19:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=05785ba834f23272f9d23427ae4a80ac505a5296'/>
<id>urn:sha1:05785ba834f23272f9d23427ae4a80ac505a5296</id>
<content type='text'>
[ Upstream commit b8d1d163604bd1e600b062fb00de5dc42baa355f ]

The APIC supports two modes, legacy APIC (or xAPIC), and Extended APIC
(or x2APIC).  X2APIC mode is mostly compatible with legacy APIC, but
it disables the memory-mapped APIC interface in favor of one that uses
MSRs.  The APIC mode is controlled by the EXT bit in the APIC MSR.

The MMIO/xAPIC interface has some problems, most notably the APIC LEAK
[1].  This bug allows an attacker to use the APIC MMIO interface to
extract data from the SGX enclave.

Introduce support for a new feature that will allow the BIOS to lock
the APIC in x2APIC mode.  If the APIC is locked in x2APIC mode and the
kernel tries to disable the APIC or revert to legacy APIC mode a GP
fault will occur.

Introduce support for a new MSR (IA32_XAPIC_DISABLE_STATUS) and handle
the new locked mode when the LEGACY_XAPIC_DISABLED bit is set by
preventing the kernel from trying to disable the x2APIC.

On platforms with the IA32_XAPIC_DISABLE_STATUS MSR, if SGX or TDX are
enabled the LEGACY_XAPIC_DISABLED will be set by the BIOS.  If
legacy APIC is required, then it SGX and TDX need to be disabled in the
BIOS.

[1]: https://aepicleak.com/aepicleak.pdf

Signed-off-by: Daniel Sneddon &lt;daniel.sneddon@linux.intel.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Acked-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Tested-by: Neelima Krishnan &lt;neelima.krishnan@intel.com&gt;
Link: https://lkml.kernel.org/r/20220816231943.1152579-1-daniel.sneddon@linux.intel.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/mce: Retrieve poison range from hardware</title>
<updated>2022-10-24T07:58:11+00:00</updated>
<author>
<name>Jane Chu</name>
<email>jane.chu@oracle.com</email>
</author>
<published>2022-08-26T23:38:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a9c5c9ce7e58a893af66a07917d80fe47b0f3257'/>
<id>urn:sha1:a9c5c9ce7e58a893af66a07917d80fe47b0f3257</id>
<content type='text'>
[ Upstream commit f9781bb18ed828e7b83b7bac4a4ad7cd497ee7d7 ]

When memory poison consumption machine checks fire, MCE notifier
handlers like nfit_handle_mce() record the impacted physical address
range which is reported by the hardware in the MCi_MISC MSR. The error
information includes data about blast radius, i.e. how many cachelines
did the hardware determine are impacted. A recent change

  7917f9cdb503 ("acpi/nfit: rely on mce-&gt;misc to determine poison granularity")

updated nfit_handle_mce() to stop hard coding the blast radius value of
1 cacheline, and instead rely on the blast radius reported in 'struct
mce' which can be up to 4K (64 cachelines).

It turns out that apei_mce_report_mem_error() had a similar problem in
that it hard coded a blast radius of 4K rather than reading the blast
radius from the error information. Fix apei_mce_report_mem_error() to
convey the proper poison granularity.

Signed-off-by: Jane Chu &lt;jane.chu@oracle.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Reviewed-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/7ed50fd8-521e-cade-77b1-738b8bfb8502@oracle.com
Link: https://lore.kernel.org/r/20220826233851.1319100-1-jane.chu@oracle.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/entry: Work around Clang __bdos() bug</title>
<updated>2022-10-24T07:58:10+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2022-09-20T02:45:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7b593b50f20c949316581a03cd77f85974f6d652'/>
<id>urn:sha1:7b593b50f20c949316581a03cd77f85974f6d652</id>
<content type='text'>
[ Upstream commit 3e1730842f142add55dc658929221521a9ea62b6 ]

Clang produces a false positive when building with CONFIG_FORTIFY_SOURCE=y
and CONFIG_UBSAN_BOUNDS=y when operating on an array with a dynamic
offset. Work around this by using a direct assignment of an empty
instance. Avoids this warning:

../include/linux/fortify-string.h:309:4: warning: call to __write_overflow_field declared with 'warn
ing' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wat
tribute-warning]
                        __write_overflow_field(p_size_field, size);
                        ^

which was isolated to the memset() call in xen_load_idt().

Note that this looks very much like another bug that was worked around:
https://github.com/ClangBuiltLinux/linux/issues/1592

Cc: Juergen Gross &lt;jgross@suse.com&gt;
Cc: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: x86@kernel.org
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: xen-devel@lists.xenproject.org
Reviewed-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Link: https://lore.kernel.org/lkml/41527d69-e8ab-3f86-ff37-6b298c01d5bc@oracle.com
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/hyperv: Fix 'struct hv_enlightened_vmcs' definition</title>
<updated>2022-10-24T07:58:03+00:00</updated>
<author>
<name>Vitaly Kuznetsov</name>
<email>vkuznets@redhat.com</email>
</author>
<published>2022-08-30T13:37:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=99ac12f287d6c227e9ba8b718b3a0312e1714f86'/>
<id>urn:sha1:99ac12f287d6c227e9ba8b718b3a0312e1714f86</id>
<content type='text'>
[ Upstream commit ea9da788a61e47e7ab9cbad397453e51cd82ac0d ]

Section 1.9 of TLFS v6.0b says:

"All structures are padded in such a way that fields are aligned
naturally (that is, an 8-byte field is aligned to an offset of 8 bytes
and so on)".

'struct enlightened_vmcs' has a glitch:

...
        struct {
                u32                nested_flush_hypercall:1; /*   836: 0  4 */
                u32                msr_bitmap:1;         /*   836: 1  4 */
                u32                reserved:30;          /*   836: 2  4 */
        } hv_enlightenments_control;                     /*   836     4 */
        u32                        hv_vp_id;             /*   840     4 */
        u64                        hv_vm_id;             /*   844     8 */
        u64                        partition_assist_page; /*   852     8 */
...

And the observed values in 'partition_assist_page' make no sense at
all. Fix the layout by padding the structure properly.

Fixes: 68d1eb72ee99 ("x86/hyper-v: define struct hv_enlightened_vmcs and clean field bits")
Reviewed-by: Maxim Levitsky &lt;mlevitsk@redhat.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Signed-off-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Link: https://lore.kernel.org/r/20220830133737.1539624-2-vkuznets@redhat.com
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/cpu: Include the header of init_ia32_feat_ctl()'s prototype</title>
<updated>2022-10-24T07:57:12+00:00</updated>
<author>
<name>Luciano Leão</name>
<email>lucianorsleao@gmail.com</email>
</author>
<published>2022-09-22T20:00:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3c5b8e7ca8befdce12e0bcdcf67693e4167e74e3'/>
<id>urn:sha1:3c5b8e7ca8befdce12e0bcdcf67693e4167e74e3</id>
<content type='text'>
[ Upstream commit 30ea703a38ef76ca119673cd8bdd05c6e068e2ac ]

Include the header containing the prototype of init_ia32_feat_ctl(),
solving the following warning:

  $ make W=1 arch/x86/kernel/cpu/feat_ctl.o
  arch/x86/kernel/cpu/feat_ctl.c:112:6: warning: no previous prototype for ‘init_ia32_feat_ctl’ [-Wmissing-prototypes]
    112 | void init_ia32_feat_ctl(struct cpuinfo_x86 *c)

This warning appeared after commit

  5d5103595e9e5 ("x86/cpu: Reinitialize IA32_FEAT_CTL MSR on BSP during wakeup")

had moved the function init_ia32_feat_ctl()'s prototype from
arch/x86/kernel/cpu/cpu.h to arch/x86/include/asm/cpu.h.

Note that, before the commit mentioned above, the header include "cpu.h"
(arch/x86/kernel/cpu/cpu.h) was added by commit

  0e79ad863df43 ("x86/cpu: Fix a -Wmissing-prototypes warning for init_ia32_feat_ctl()")

solely to fix init_ia32_feat_ctl()'s missing prototype. So, the header
include "cpu.h" is no longer necessary.

  [ bp: Massage commit message. ]

Fixes: 5d5103595e9e5 ("x86/cpu: Reinitialize IA32_FEAT_CTL MSR on BSP during wakeup")
Signed-off-by: Luciano Leão &lt;lucianorsleao@gmail.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Nícolas F. R. A. Prado &lt;n@nfraprado.net&gt;
Link: https://lore.kernel.org/r/20220922200053.1357470-1-lucianorsleao@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/microcode/AMD: Track patch allocation size explicitly</title>
<updated>2022-10-24T07:57:12+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2022-09-22T03:10:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bbcc38c4450e689ce2ea0e1c2109e7f7a3a75ae8'/>
<id>urn:sha1:bbcc38c4450e689ce2ea0e1c2109e7f7a3a75ae8</id>
<content type='text'>
[ Upstream commit 712f210a457d9c32414df246a72781550bc23ef6 ]

In preparation for reducing the use of ksize(), record the actual
allocation size for later memcpy(). This avoids copying extra
(uninitialized!) bytes into the patch buffer when the requested
allocation size isn't exactly the size of a kmalloc bucket.
Additionally, fix potential future issues where runtime bounds checking
will notice that the buffer was allocated to a smaller value than
returned by ksize().

Fixes: 757885e94a22 ("x86, microcode, amd: Early microcode patch loading support for AMD")
Suggested-by: Daniel Micay &lt;danielmicay@gmail.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Link: https://lore.kernel.org/lkml/CA+DvKQ+bp7Y7gmaVhacjv9uF6Ar-o4tet872h4Q8RPYPJjcJQA@mail.gmail.com/
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/resctrl: Fix to restore to original value when re-enabling hardware prefetch register</title>
<updated>2022-10-24T07:57:06+00:00</updated>
<author>
<name>Kohei Tarumizu</name>
<email>tarumizu.kohei@fujitsu.com</email>
</author>
<published>2022-08-24T16:44:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3345cd3612b57f229017f82b270b9dde3fb5f5b8'/>
<id>urn:sha1:3345cd3612b57f229017f82b270b9dde3fb5f5b8</id>
<content type='text'>
[ Upstream commit 499c8bb4693d1c8d8f3d6dd38e5bdde3ff5bd906 ]

The current pseudo_lock.c code overwrites the value of the
MSR_MISC_FEATURE_CONTROL to 0 even if the original value is not 0.
Therefore, modify it to save and restore the original values.

Fixes: 018961ae5579 ("x86/intel_rdt: Pseudo-lock region creation/removal core")
Fixes: 443810fe6160 ("x86/intel_rdt: Create debugfs files for pseudo-locking testing")
Fixes: 8a2fc0e1bc0c ("x86/intel_rdt: More precise L2 hit/miss measurements")
Signed-off-by: Kohei Tarumizu &lt;tarumizu.kohei@fujitsu.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Acked-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Link: https://lkml.kernel.org/r/eb660f3c2010b79a792c573c02d01e8e841206ad.1661358182.git.reinette.chatre@intel.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/paravirt: add extra clobbers with ZERO_CALL_USED_REGS enabled</title>
<updated>2022-10-24T07:57:04+00:00</updated>
<author>
<name>Bill Wendling</name>
<email>morbo@google.com</email>
</author>
<published>2022-09-02T21:37:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=082eb9beed5db6f3cc918f786cfeef04ab643aec'/>
<id>urn:sha1:082eb9beed5db6f3cc918f786cfeef04ab643aec</id>
<content type='text'>
[ Upstream commit 8c86f29bfb18465d15b05cfd26a6454ec787b793 ]

The ZERO_CALL_USED_REGS feature may zero out caller-saved registers
before returning.

In spurious_kernel_fault(), the "pte_offset_kernel()" call results in
this assembly code:

.Ltmp151:
        #APP
        # ALT: oldnstr
.Ltmp152:
.Ltmp153:
.Ltmp154:
        .section        .discard.retpoline_safe,"",@progbits
        .quad   .Ltmp154
        .text

        callq   *pv_ops+536(%rip)

.Ltmp155:
        .section        .parainstructions,"a",@progbits
        .p2align        3, 0x0
        .quad   .Ltmp153
        .byte   67
        .byte   .Ltmp155-.Ltmp153
        .short  1
        .text
.Ltmp156:
        # ALT: padding
        .zero   (-(((.Ltmp157-.Ltmp158)-(.Ltmp156-.Ltmp152))&gt;0))*((.Ltmp157-.Ltmp158)-(.Ltmp156-.Ltmp152)),144
.Ltmp159:
        .section        .altinstructions,"a",@progbits
.Ltmp160:
        .long   .Ltmp152-.Ltmp160
.Ltmp161:
        .long   .Ltmp158-.Ltmp161
        .short  33040
        .byte   .Ltmp159-.Ltmp152
        .byte   .Ltmp157-.Ltmp158
        .text

        .section        .altinstr_replacement,"ax",@progbits
        # ALT: replacement 1
.Ltmp158:
        movq    %rdi, %rax
.Ltmp157:
        .text
        #NO_APP
.Ltmp162:
        testb   $-128, %dil

The "testb" here is using %dil, but the %rdi register was cleared before
returning from "callq *pv_ops+536(%rip)". Adding the proper constraints
results in the use of a different register:

        movq    %r11, %rdi

        # Similar to above.

        testb   $-128, %r11b

Link: https://github.com/KSPP/linux/issues/192
Signed-off-by: Bill Wendling &lt;morbo@google.com&gt;
Reported-and-tested-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Fixes: 035f7f87b729 ("randstruct: Enable Clang support")
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/lkml/fa6df43b-8a1a-8ad1-0236-94d2a0b588fa@suse.com/
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20220902213750.1124421-3-morbo@google.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>KVM: VMX: Drop bits 31:16 when shoving exception error code into VMCS</title>
<updated>2022-10-24T07:56:59+00:00</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2022-08-30T23:15:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dd8cf031cf9f40a7e8e3fa74e66e51337156be79'/>
<id>urn:sha1:dd8cf031cf9f40a7e8e3fa74e66e51337156be79</id>
<content type='text'>
commit eba9799b5a6efe2993cf92529608e4aa8163d73b upstream.

Deliberately truncate the exception error code when shoving it into the
VMCS (VM-Entry field for vmcs01 and vmcs02, VM-Exit field for vmcs12).
Intel CPUs are incapable of handling 32-bit error codes and will never
generate an error code with bits 31:16, but userspace can provide an
arbitrary error code via KVM_SET_VCPU_EVENTS.  Failure to drop the bits
on exception injection results in failed VM-Entry, as VMX disallows
setting bits 31:16.  Setting the bits on VM-Exit would at best confuse
L1, and at worse induce a nested VM-Entry failure, e.g. if L1 decided to
reinject the exception back into L2.

Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Reviewed-by: Jim Mattson &lt;jmattson@google.com&gt;
Reviewed-by: Maxim Levitsky &lt;mlevitsk@redhat.com&gt;
Link: https://lore.kernel.org/r/20220830231614.3580124-3-seanjc@google.com
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
