37598 Commits

Author SHA1 Message Date
Chen Zhongjin
b55d6ea965 x86/unwind/orc: Fix unreliable stack dump with gcov
[ Upstream commit 230db82413c091bc16acee72650f48d419cebe49 ]

When a console stack dump is initiated with CONFIG_GCOV_PROFILE_ALL
enabled, show_trace_log_lvl() gets out of sync with the ORC unwinder,
causing the stack trace to show all text addresses as unreliable:

  # echo l > /proc/sysrq-trigger
  [  477.521031] sysrq: Show backtrace of all active CPUs
  [  477.523813] NMI backtrace for cpu 0
  [  477.524492] CPU: 0 PID: 1021 Comm: bash Not tainted 6.0.0 #65
  [  477.525295] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014
  [  477.526439] Call Trace:
  [  477.526854]  <TASK>
  [  477.527216]  ? dump_stack_lvl+0xc7/0x114
  [  477.527801]  ? dump_stack+0x13/0x1f
  [  477.528331]  ? nmi_cpu_backtrace.cold+0xb5/0x10d
  [  477.528998]  ? lapic_can_unplug_cpu+0xa0/0xa0
  [  477.529641]  ? nmi_trigger_cpumask_backtrace+0x16a/0x1f0
  [  477.530393]  ? arch_trigger_cpumask_backtrace+0x1d/0x30
  [  477.531136]  ? sysrq_handle_showallcpus+0x1b/0x30
  [  477.531818]  ? __handle_sysrq.cold+0x4e/0x1ae
  [  477.532451]  ? write_sysrq_trigger+0x63/0x80
  [  477.533080]  ? proc_reg_write+0x92/0x110
  [  477.533663]  ? vfs_write+0x174/0x530
  [  477.534265]  ? handle_mm_fault+0x16f/0x500
  [  477.534940]  ? ksys_write+0x7b/0x170
  [  477.535543]  ? __x64_sys_write+0x1d/0x30
  [  477.536191]  ? do_syscall_64+0x6b/0x100
  [  477.536809]  ? entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [  477.537609]  </TASK>

This happens when the compiled code for show_stack() has a single word
on the stack, and doesn't use a tail call to show_stack_log_lvl().
(CONFIG_GCOV_PROFILE_ALL=y is the only known case of this.)  Then the
__unwind_start() skip logic hits an off-by-one bug and fails to unwind
all the way to the intended starting frame.

Fix it by reverting the following commit:

  f1d9a2abff66 ("x86/unwind/orc: Don't skip the first frame for inactive tasks")

The original justification for that commit no longer exists.  That
original issue was later fixed in a different way, with the following
commit:

  f2ac57a4c49d ("x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels")

Fixes: f1d9a2abff66 ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
[jpoimboe: rewrite commit log]
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-03 23:57:51 +09:00
Maxim Levitsky
fb94152aae perf/x86/intel/lbr: Use setup_clear_cpu_cap() instead of clear_cpu_cap()
[ Upstream commit b329f5ddc9ce4b622d9c7aaf5c6df4de52caf91a ]

clear_cpu_cap(&boot_cpu_data) is very similar to setup_clear_cpu_cap()
except that the latter also sets a bit in 'cpu_caps_cleared' which
later clears the same cap in secondary cpus, which is likely what is
meant here.

Fixes: 47125db27e47 ("perf/x86/intel/lbr: Support Architectural LBR")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lkml.kernel.org/r/20220718141123.136106-2-mlevitsk@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-03 23:57:51 +09:00
Nathan Chancellor
6ab2287b26 x86/Kconfig: Drop check for -mabi=ms for CONFIG_EFI_STUB
commit 33806e7cb8d50379f55c3e8f335e91e1b359dc7b upstream.

A recent change in LLVM made CONFIG_EFI_STUB unselectable because it no
longer pretends to support -mabi=ms, breaking the dependency in
Kconfig. Lack of CONFIG_EFI_STUB can prevent kernels from booting via
EFI in certain circumstances.

This check was added by

  8f24f8c2fc82 ("efi/libstub: Annotate firmware routines as __efiapi")

to ensure that __attribute__((ms_abi)) was available, as -mabi=ms is
not actually used in any cflags.

According to the GCC documentation, this attribute has been supported
since GCC 4.4.7. The kernel currently requires GCC 5.1 so this check is
not necessary; even when that change landed in 5.6, the kernel required
GCC 4.9 so it was unnecessary then as well.

Clang supports __attribute__((ms_abi)) for all versions that are
supported for building the kernel so no additional check is needed.
Remove the 'depends on' line altogether to allow CONFIG_EFI_STUB to be
selected when CONFIG_EFI is enabled, regardless of compiler.

Fixes: 8f24f8c2fc82 ("efi/libstub: Annotate firmware routines as __efiapi")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Cc: stable@vger.kernel.org
Link: d1ad006a8f
[nathan: Fix conflict due to lack of c6dbd3e5e69c in older trees]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-30 09:41:19 +01:00
Adrian Hunter
da54c5f4b5 perf/x86/intel/pt: Relax address filter validation
commit c243cecb58e3905baeace8827201c14df8481e2a upstream.

The requirement for 64-bit address filters is that they are canonical
addresses. In other respects any address range is allowed which would
include user space addresses.

That can be useful for tracing virtual machine guests because address
filtering can be used to advantage in place of current privilege level
(CPL) filtering.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220131072453.2839535-2-adrian.hunter@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-30 09:41:19 +01:00
Charlotte Tan
ef11e8ec00 iommu/vt-d: Allow NVS regions in arch_rmrr_sanity_check()
[ Upstream commit 5566e68d829f5d87670d5984c1c2ccb4c518405f ]

arch_rmrr_sanity_check() warns if the RMRR is not covered by an ACPI
Reserved region, but it seems like it should accept an NVS region as
well. The ACPI spec
https://uefi.org/specs/ACPI/6.5/15_System_Address_Map_Interfaces.html
uses similar wording for "Reserved" and "NVS" region types; for NVS
regions it says "This range of addresses is in use or reserved by the
system and must not be used by the operating system."

There is an old comment on this mailing list that also suggests NVS
regions should pass the arch_rmrr_sanity_check() test:

 The warnings come from arch_rmrr_sanity_check() since it checks whether
 the region is E820_TYPE_RESERVED. However, if the purpose of the check
 is to detect RMRR has regions that may be used by OS as free memory,
 isn't  E820_TYPE_NVS safe, too?

This patch overlaps with another proposed patch that would add the region
type to the log since sometimes the bug reporter sees this log on the
console but doesn't know to include the kernel log:

https://lore.kernel.org/lkml/20220611204859.234975-3-atomlin@redhat.com/

Here's an example of the "Firmware Bug" apparent false positive (wrapped
for line length):

 DMAR: [Firmware Bug]: No firmware reserved region can cover this RMRR
       [0x000000006f760000-0x000000006f762fff], contact BIOS vendor for
       fixes
 DMAR: [Firmware Bug]: Your BIOS is broken; bad RMRR
       [0x000000006f760000-0x000000006f762fff]

This is the snippet from the e820 table:

 BIOS-e820: [mem 0x0000000068bff000-0x000000006ebfefff] reserved
 BIOS-e820: [mem 0x000000006ebff000-0x000000006f9fefff] ACPI NVS
 BIOS-e820: [mem 0x000000006f9ff000-0x000000006fffefff] ACPI data

Fixes: f036c7fa0ab6 ("iommu/vt-d: Check VT-d RMRR region in BIOS is reported as reserved")
Cc: Will Mortensen <will@extrahop.com>
Link: https://lore.kernel.org/linux-iommu/64a5843d-850d-e58c-4fc2-0a0eeeb656dc@nec.com/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216443
Signed-off-by: Charlotte Tan <charlotte@extrahop.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Link: https://lore.kernel.org/r/20220929044449.32515-1-charlotte@extrahop.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-30 09:41:17 +01:00
Borislav Petkov
0fb04676c4 x86/microcode/AMD: Apply the patch early on every logical thread
commit e7ad18d1169c62e6c78c01ff693fd362d9d65278 upstream.

Currently, the patch application logic checks whether the revision
needs to be applied on each logical CPU (SMT thread). Therefore, on SMT
designs where the microcode engine is shared between the two threads,
the application happens only on one of them as that is enough to update
the shared microcode engine.

However, there are microcode patches which do per-thread modification,
see Link tag below.

Therefore, drop the revision check and try applying on each thread. This
is what the BIOS does too so this method is very much tested.

Btw, change only the early paths. On the late loading paths, there's no
point in doing per-thread modification because if is it some case like
in the bugzilla below - removing a CPUID flag - the kernel cannot go and
un-use features it has detected are there early. For that, one should
use early loading anyway.

  [ bp: Fixes does not contain the oldest commit which did check for
    equality but that is good enough. ]

Fixes: 8801b3fcb574 ("x86/microcode/AMD: Rework container parsing")
Reported-by:  Ștefan Talpalaru <stefantalpalaru@yahoo.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by:  Ștefan Talpalaru <stefantalpalaru@yahoo.com>
Cc: <stable@vger.kernel.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216211
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-30 09:41:15 +01:00
Kees Cook
1f730d4ae6 x86/entry: Work around Clang __bdos() bug
[ 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 <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: xen-devel@lists.xenproject.org
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/lkml/41527d69-e8ab-3f86-ff37-6b298c01d5bc@oracle.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 13:25:45 +02:00
Vitaly Kuznetsov
7ae8bed908 x86/hyperv: Fix 'struct hv_enlightened_vmcs' definition
[ 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 <mlevitsk@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220830133737.1539624-2-vkuznets@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 13:25:40 +02:00
Luciano Leão
1ef5798638 x86/cpu: Include the header of init_ia32_feat_ctl()'s prototype
[ 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 <lucianorsleao@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nícolas F. R. A. Prado <n@nfraprado.net>
Link: https://lore.kernel.org/r/20220922200053.1357470-1-lucianorsleao@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 13:25:21 +02:00
Kees Cook
6ed7b05a35 x86/microcode/AMD: Track patch allocation size explicitly
[ 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 <danielmicay@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/lkml/CA+DvKQ+bp7Y7gmaVhacjv9uF6Ar-o4tet872h4Q8RPYPJjcJQA@mail.gmail.com/
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 13:25:21 +02:00
Kohei Tarumizu
294395caac x86/resctrl: Fix to restore to original value when re-enabling hardware prefetch register
[ 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 <tarumizu.kohei@fujitsu.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/eb660f3c2010b79a792c573c02d01e8e841206ad.1661358182.git.reinette.chatre@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 13:25:19 +02:00
Sean Christopherson
ceeb8d4a43 KVM: VMX: Drop bits 31:16 when shoving exception error code into VMCS
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 <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20220830231614.3580124-3-seanjc@google.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:25:16 +02:00
Sean Christopherson
83fe0b009b KVM: nVMX: Unconditionally purge queued/injected events on nested "exit"
commit d953540430c5af57f5de97ea9e36253908204027 upstream.

Drop pending exceptions and events queued for re-injection when leaving
nested guest mode, even if the "exit" is due to VM-Fail, SMI, or forced
by host userspace.  Failure to purge events could result in an event
belonging to L2 being injected into L1.

This _should_ never happen for VM-Fail as all events should be blocked by
nested_run_pending, but it's possible if KVM, not the L1 hypervisor, is
the source of VM-Fail when running vmcs02.

SMI is a nop (barring unknown bugs) as recognition of SMI and thus entry
to SMM is blocked by pending exceptions and re-injected events.

Forced exit is definitely buggy, but has likely gone unnoticed because
userspace probably follows the forced exit with KVM_SET_VCPU_EVENTS (or
some other ioctl() that purges the queue).

Fixes: 4f350c6dbcb9 ("kvm: nVMX: Handle deferred early VMLAUNCH/VMRESUME failure properly")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20220830231614.3580124-2-seanjc@google.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:25:16 +02:00
Michal Luczaj
085ca1d33b KVM: x86/emulator: Fix handing of POP SS to correctly set interruptibility
commit 6aa5c47c351b22c21205c87977c84809cd015fcf upstream.

The emulator checks the wrong variable while setting the CPU
interruptibility state, the target segment is embedded in the instruction
opcode, not the ModR/M register.  Fix the condition.

Signed-off-by: Michal Luczaj <mhal@rbox.co>
Fixes: a5457e7bcf9a ("KVM: emulate: POP SS triggers a MOV SS shadow too")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20220821215900.1419215-1-mhal@rbox.co
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:25:16 +02:00
David Gow
3287f0d727 arch: um: Mark the stack non-executable to fix a binutils warning
[ Upstream commit bd71558d585ac61cfd799db7f25e78dca404dd7a ]

Since binutils 2.39, ld will print a warning if any stack section is
executable, which is the default for stack sections on files without a
.note.GNU-stack section.

This was fixed for x86 in commit ffcf9c5700e4 ("x86: link vdso and boot with -z noexecstack --no-warn-rwx-segments"),
but remained broken for UML, resulting in several warnings:

/usr/bin/ld: warning: arch/x86/um/vdso/vdso.o: missing .note.GNU-stack section implies executable stack
/usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms1 has a LOAD segment with RWX permissions
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms1.o: missing .note.GNU-stack section implies executable stack
/usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms2 has a LOAD segment with RWX permissions
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms2.o: missing .note.GNU-stack section implies executable stack
/usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
/usr/bin/ld: warning: vmlinux has a LOAD segment with RWX permissions

Link both the VDSO and vmlinux with -z noexecstack, fixing the warnings
about .note.GNU-stack sections. In addition, pass --no-warn-rwx-segments
to dodge the remaining warnings about LOAD segments with RWX permissions
in the kallsyms objects. (Note that this flag is apparently not
available on lld, so hide it behind a test for BFD, which is what the
x86 patch does.)

Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ffcf9c5700e49c0aee42dcba9a12ba21338e8136
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Tested-by: Lukas Straub <lukasstraub2@web.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-15 07:55:53 +02:00
Lukas Straub
aeb8315593 um: Cleanup compiler warning in arch/x86/um/tls_32.c
[ Upstream commit d27fff3499671dc23a08efd01cdb8b3764a391c4 ]

arch.tls_array is statically allocated so checking for NULL doesn't
make sense. This causes the compiler warning below.

Remove the checks to silence these warnings.

../arch/x86/um/tls_32.c: In function 'get_free_idx':
../arch/x86/um/tls_32.c:68:13: warning: the comparison will always evaluate as 'true' for the address of 'tls_array' will never be NULL [-Waddress]
   68 |         if (!t->arch.tls_array)
      |             ^
In file included from ../arch/x86/um/asm/processor.h:10,
                 from ../include/linux/rcupdate.h:30,
                 from ../include/linux/rculist.h:11,
                 from ../include/linux/pid.h:5,
                 from ../include/linux/sched.h:14,
                 from ../arch/x86/um/tls_32.c:7:
../arch/x86/um/asm/processor_32.h:22:31: note: 'tls_array' declared here
   22 |         struct uml_tls_struct tls_array[GDT_ENTRY_TLS_ENTRIES];
      |                               ^~~~~~~~~
../arch/x86/um/tls_32.c: In function 'get_tls_entry':
../arch/x86/um/tls_32.c:243:13: warning: the comparison will always evaluate as 'true' for the address of 'tls_array' will never be NULL [-Waddress]
  243 |         if (!t->arch.tls_array)
      |             ^
../arch/x86/um/asm/processor_32.h:22:31: note: 'tls_array' declared here
   22 |         struct uml_tls_struct tls_array[GDT_ENTRY_TLS_ENTRIES];
      |                               ^~~~~~~~~

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-15 07:55:53 +02:00
Lukas Straub
6d4deaba06 um: Cleanup syscall_handler_t cast in syscalls_32.h
[ Upstream commit 61670b4d270c71219def1fbc9441debc2ac2e6e9 ]

Like in f4f03f299a56ce4d73c5431e0327b3b6cb55ebb9
"um: Cleanup syscall_handler_t definition/cast, fix warning",
remove the cast to to fix the compiler warning.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-15 07:55:52 +02:00
Nadav Amit
b12d0489e4 x86/alternative: Fix race in try_get_desc()
commit efd608fa7403ba106412b437f873929e2c862e28 upstream.

I encountered some occasional crashes of poke_int3_handler() when
kprobes are set, while accessing desc->vec.

The text poke mechanism claims to have an RCU-like behavior, but it
does not appear that there is any quiescent state to ensure that
nobody holds reference to desc. As a result, the following race
appears to be possible, which can lead to memory corruption.

  CPU0					CPU1
  ----					----
  text_poke_bp_batch()
  -> smp_store_release(&bp_desc, &desc)

  [ notice that desc is on
    the stack			]

					poke_int3_handler()

					[ int3 might be kprobe's
					  so sync events are do not
					  help ]

					-> try_get_desc(descp=&bp_desc)
					   desc = __READ_ONCE(bp_desc)

					   if (!desc) [false, success]
  WRITE_ONCE(bp_desc, NULL);
  atomic_dec_and_test(&desc.refs)

  [ success, desc space on the stack
    is being reused and might have
    non-zero value. ]
					arch_atomic_inc_not_zero(&desc->refs)

					[ might succeed since desc points to
					  stack memory that was freed and might
					  be reused. ]

Fix this issue with small backportable patch. Instead of trying to
make RCU-like behavior for bp_desc, just eliminate the unnecessary
level of indirection of bp_desc, and hold the whole descriptor as a
global.  Anyhow, there is only a single descriptor at any given
moment.

Fixes: 1f676247f36a4 ("x86/alternatives: Implement a better poke_int3_handler() completion scheme")
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@kernel.org
Link: https://lkml.kernel.org/r/20220920224743.3089-1-namit@vmware.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-05 10:38:43 +02:00
Jim Mattson
374d4c3075 KVM: x86: Hide IA32_PLATFORM_DCA_CAP[31:0] from the guest
[ Upstream commit aae2e72229cdb21f90df2dbe4244c977e5d3265b ]

The only thing reported by CPUID.9 is the value of
IA32_PLATFORM_DCA_CAP[31:0] in EAX. This MSR doesn't even exist in the
guest, since CPUID.1:ECX.DCA[bit 18] is clear in the guest.

Clear CPUID.9 in KVM_GET_SUPPORTED_CPUID.

Fixes: 24c82e576b78 ("KVM: Sanitize cpuid")
Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20220922231854.249383-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-05 10:38:43 +02:00
Mingwei Zhang
a60babeb60 KVM: SEV: add cache flush to solve SEV cache incoherency issues
commit 683412ccf61294d727ead4a73d97397396e69a6b upstream.

Flush the CPU caches when memory is reclaimed from an SEV guest (where
reclaim also includes it being unmapped from KVM's memslots).  Due to lack
of coherency for SEV encrypted memory, failure to flush results in silent
data corruption if userspace is malicious/broken and doesn't ensure SEV
guest memory is properly pinned and unpinned.

Cache coherency is not enforced across the VM boundary in SEV (AMD APM
vol.2 Section 15.34.7). Confidential cachelines, generated by confidential
VM guests have to be explicitly flushed on the host side. If a memory page
containing dirty confidential cachelines was released by VM and reallocated
to another user, the cachelines may corrupt the new user at a later time.

KVM takes a shortcut by assuming all confidential memory remain pinned
until the end of VM lifetime. Therefore, KVM does not flush cache at
mmu_notifier invalidation events. Because of this incorrect assumption and
the lack of cache flushing, malicous userspace can crash the host kernel:
creating a malicious VM and continuously allocates/releases unpinned
confidential memory pages when the VM is running.

Add cache flush operations to mmu_notifier operations to ensure that any
physical memory leaving the guest VM get flushed. In particular, hook
mmu_notifier_invalidate_range_start and mmu_notifier_release events and
flush cache accordingly. The hook after releasing the mmu lock to avoid
contention with other vCPUs.

Cc: stable@vger.kernel.org
Suggested-by: Sean Christpherson <seanjc@google.com>
Reported-by: Mingwei Zhang <mizhang@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Message-Id: <20220421031407.2516575-4-mizhang@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[OP: applied kvm_arch_guest_memory_reclaimed() calls in kvm_set_memslot() and
kvm_mmu_notifier_invalidate_range_start();
OP: adjusted kvm_arch_guest_memory_reclaimed() to not use static_call_cond()]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-28 11:10:28 +02:00
Peter Zijlstra
35371fd688 x86/ftrace: Use alternative RET encoding
commit 1f001e9da6bbf482311e45e48f53c2bd2179e59c upstream.

Use the return thunk in ftrace trampolines, if needed.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: use memcpy(text_gen_insn) as there is no __text_gen_insn]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-20 12:38:33 +02:00
Peter Zijlstra
4586df06a0 x86/ibt,ftrace: Make function-graph play nice
commit e52fc2cf3f662828cc0d51c4b73bed73ad275fce upstream.

Return trampoline must not use indirect branch to return; while this
preserves the RSB, it is fundamentally incompatible with IBT. Instead
use a retpoline like ROP gadget that defeats IBT while not unbalancing
the RSB.

And since ftrace_stub is no longer a plain RET, don't use it to copy
from. Since RET is a trivial instruction, poke it directly.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154318.347296408@infradead.org
[cascardo: remove ENDBR]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
[OP: adjusted context for 5.10-stable]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-20 12:38:33 +02:00
Thadeu Lima de Souza Cascardo
33015556a9 Revert "x86/ftrace: Use alternative RET encoding"
This reverts commit 00b136bb6254e0abf6aaafe62c4da5f6c4fea4cb.

This temporarily reverts the backport of upstream commit
1f001e9da6bbf482311e45e48f53c2bd2179e59c. It was not correct to copy the
ftrace stub as it would contain a relative jump to the return thunk which
would not apply to the context where it was being copied to, leading to
ftrace support to be broken.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-20 12:38:33 +02:00
Jim Mattson
eb0c614c42 KVM: x86: Mask off unsupported and unknown bits of IA32_ARCH_CAPABILITIES
[ Upstream commit 0204750bd4c6ccc2fb7417618477f10373b33f56 ]

KVM should not claim to virtualize unknown IA32_ARCH_CAPABILITIES
bits. When kvm_get_arch_capabilities() was originally written, there
were only a few bits defined in this MSR, and KVM could virtualize all
of them. However, over the years, several bits have been defined that
KVM cannot just blindly pass through to the guest without additional
work (such as virtualizing an MSR promised by the
IA32_ARCH_CAPABILITES feature bit).

Define a mask of supported IA32_ARCH_CAPABILITIES bits, and mask off
any other bits that are set in the hardware MSR.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Fixes: 5b76a3cff011 ("KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry")
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20220830174947.2182144-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-08 11:11:38 +02:00
Peter Zijlstra
e5796ff9ac x86/nospec: Fix i386 RSB stuffing
commit 332924973725e8cdcc783c175f68cf7e162cb9e5 upstream.

Turns out that i386 doesn't unconditionally have LFENCE, as such the
loop in __FILL_RETURN_BUFFER isn't actually speculation safe on such
chips.

Fixes: ba6e31af2be9 ("x86/speculation: Add LFENCE to RSB fill sequence")
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/Yv9tj9vbQ9nNlXoY@worktop.programming.kicks-ass.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:28:54 +02:00
Peter Zijlstra
adee8f3082 x86/nospec: Unwreck the RSB stuffing
commit 4e3aa9238277597c6c7624f302d81a7b568b6f2d upstream.

Commit 2b1299322016 ("x86/speculation: Add RSB VM Exit protections")
made a right mess of the RSB stuffing, rewrite the whole thing to not
suck.

Thanks to Andrew for the enlightening comment about Post-Barrier RSB
things so we can make this code less magical.

Cc: stable@vger.kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YvuNdDWoUZSBjYcm@worktop.programming.kicks-ass.net
[bwh: Backported to 5.10: adjust context]
Signed-off-by: Ben Hutchings <benh@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:28:54 +02:00
Stephane Eranian
c0ba9aa95b perf/x86/intel/uncore: Fix broken read_counter() for SNB IMC PMU
commit 11745ecfe8fea4b4a4c322967a7605d2ecbd5080 upstream.

Existing code was generating bogus counts for the SNB IMC bandwidth counters:

$ perf stat -a -I 1000 -e uncore_imc/data_reads/,uncore_imc/data_writes/
     1.000327813           1,024.03 MiB  uncore_imc/data_reads/
     1.000327813              20.73 MiB  uncore_imc/data_writes/
     2.000580153         261,120.00 MiB  uncore_imc/data_reads/
     2.000580153              23.28 MiB  uncore_imc/data_writes/

The problem was introduced by commit:
  07ce734dd8ad ("perf/x86/intel/uncore: Clean up client IMC")

Where the read_counter callback was replace to point to the generic
uncore_mmio_read_counter() function.

The SNB IMC counters are freerunnig 32-bit counters laid out contiguously in
MMIO. But uncore_mmio_read_counter() is using a readq() call to read from
MMIO therefore reading 64-bit from MMIO. Although this is okay for the
uncore_perf_event_update() function because it is shifting the value based
on the actual counter width to compute a delta, it is not okay for the
uncore_pmu_event_start() which is simply reading the counter  and therefore
priming the event->prev_count with a bogus value which is responsible for
causing bogus deltas in the perf stat command above.

The fix is to reintroduce the custom callback for read_counter for the SNB
IMC PMU and use readl() instead of readq(). With the change the output of
perf stat is back to normal:
$ perf stat -a -I 1000 -e uncore_imc/data_reads/,uncore_imc/data_writes/
     1.000120987             296.94 MiB  uncore_imc/data_reads/
     1.000120987             138.42 MiB  uncore_imc/data_writes/
     2.000403144             175.91 MiB  uncore_imc/data_reads/
     2.000403144              68.50 MiB  uncore_imc/data_writes/

Fixes: 07ce734dd8ad ("perf/x86/intel/uncore: Clean up client IMC")
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20220803160031.1379788-1-eranian@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31 17:15:24 +02:00
Pawan Gupta
14cbbb9c99 x86/bugs: Add "unknown" reporting for MMIO Stale Data
commit 7df548840c496b0141fb2404b889c346380c2b22 upstream.

Older Intel CPUs that are not in the affected processor list for MMIO
Stale Data vulnerabilities currently report "Not affected" in sysfs,
which may not be correct. Vulnerability status for these older CPUs is
unknown.

Add known-not-affected CPUs to the whitelist. Report "unknown"
mitigation status for CPUs that are not in blacklist, whitelist and also
don't enumerate MSR ARCH_CAPABILITIES bits that reflect hardware
immunity to MMIO Stale Data vulnerabilities.

Mitigation is not deployed when the status is unknown.

  [ bp: Massage, fixup. ]

Fixes: 8d50cdf8b834 ("x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data")
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Suggested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/a932c154772f2121794a5f2eded1a11013114711.1657846269.git.pawan.kumar.gupta@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31 17:15:22 +02:00
Chen Zhongjin
e3e0d11729 x86/unwind/orc: Unwind ftrace trampolines with correct ORC entry
commit fc2e426b1161761561624ebd43ce8c8d2fa058da upstream.

When meeting ftrace trampolines in ORC unwinding, unwinder uses address
of ftrace_{regs_}call address to find the ORC entry, which gets next frame at
sp+176.

If there is an IRQ hitting at sub $0xa8,%rsp, the next frame should be
sp+8 instead of 176. It makes unwinder skip correct frame and throw
warnings such as "wrong direction" or "can't access registers", etc,
depending on the content of the incorrect frame address.

By adding the base address ftrace_{regs_}caller with the offset
*ip - ops->trampoline*, we can get the correct address to find the ORC entry.

Also change "caller" to "tramp_addr" to make variable name conform to
its content.

[ mingo: Clarified the changelog a bit. ]

Fixes: 6be7fa3c74d1 ("ftrace, orc, x86: Handle ftrace dynamically allocated trampolines")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220819084334.244016-1-chenzhongjin@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31 17:15:22 +02:00
Kan Liang
090f0ac167 perf/x86/lbr: Enable the branch type for the Arch LBR by default
commit 32ba156df1b1c8804a4e5be5339616945eafea22 upstream.

On the platform with Arch LBR, the HW raw branch type encoding may leak
to the perf tool when the SAVE_TYPE option is not set.

In the intel_pmu_store_lbr(), the HW raw branch type is stored in
lbr_entries[].type. If the SAVE_TYPE option is set, the
lbr_entries[].type will be converted into the generic PERF_BR_* type
in the intel_pmu_lbr_filter() and exposed to the user tools.
But if the SAVE_TYPE option is NOT set by the user, the current perf
kernel doesn't clear the field. The HW raw branch type leaks.

There are two solutions to fix the issue for the Arch LBR.
One is to clear the field if the SAVE_TYPE option is NOT set.
The other solution is to unconditionally convert the branch type and
expose the generic type to the user tools.

The latter is implemented here, because
- The branch type is valuable information. I don't see a case where
  you would not benefit from the branch type. (Stephane Eranian)
- Not having the branch type DOES NOT save any space in the
  branch record (Stephane Eranian)
- The Arch LBR HW can retrieve the common branch types from the
  LBR_INFO. It doesn't require the high overhead SW disassemble.

Fixes: 47125db27e47 ("perf/x86/intel/lbr: Support Architectural LBR")
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20220816125612.2042397-1-kan.liang@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31 17:15:22 +02:00
Aaron Lu
6876b4804b x86/mm: Use proper mask when setting PUD mapping
commit 88e0a74902f894fbbc55ad3ad2cb23b4bfba555c upstream.

Commit c164fbb40c43f("x86/mm: thread pgprot_t through
init_memory_mapping()") mistakenly used __pgprot() which doesn't respect
__default_kernel_pte_mask when setting PUD mapping.

Fix it by only setting the one bit we actually need (PSE) and leaving
the other bits (that have been properly masked) alone.

Fixes: c164fbb40c43 ("x86/mm: thread pgprot_t through init_memory_mapping()")
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:37:49 +02:00
Aaron Lewis
98b20e1612 kvm: x86/pmu: Fix the compare function used by the pmu event filter
commit 4ac19ead0dfbabd8e0bfc731f507cfb0b95d6c99 upstream.

When returning from the compare function the u64 is truncated to an
int.  This results in a loss of the high nybble[1] in the event select
and its sign if that nybble is in use.  Switch from using a result that
can end up being truncated to a result that can only be: 1, 0, -1.

[1] bits 35:32 in the event select register and bits 11:8 in the event
    select.

Fixes: 7ff775aca48ad ("KVM: x86/pmu: Use binary search to check filtered events")
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220517051238.2566934-1-aaronlewis@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21 15:16:26 +02:00
Vitaly Kuznetsov
ac7de8c2ba KVM: x86: Avoid theoretical NULL pointer dereference in kvm_irq_delivery_to_apic_fast()
commit 00b5f37189d24ac3ed46cb7f11742094778c46ce upstream

When kvm_irq_delivery_to_apic_fast() is called with APIC_DEST_SELF
shorthand, 'src' must not be NULL. Crash the VM with KVM_BUG_ON()
instead of crashing the host.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220325132140.25650-3-vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21 15:16:25 +02:00
Vitaly Kuznetsov
4c85e207c1 KVM: x86: Check lapic_in_kernel() before attempting to set a SynIC irq
commit 7ec37d1cbe17d8189d9562178d8b29167fe1c31a upstream

When KVM_CAP_HYPERV_SYNIC{,2} is activated, KVM already checks for
irqchip_in_kernel() so normally SynIC irqs should never be set. It is,
however,  possible for a misbehaving VMM to write to SYNIC/STIMER MSRs
causing erroneous behavior.

The immediate issue being fixed is that kvm_irq_delivery_to_apic()
(kvm_irq_delivery_to_apic_fast()) crashes when called with
'irq.shorthand = APIC_DEST_SELF' and 'src == NULL'.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220325132140.25650-2-vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21 15:16:25 +02:00
Like Xu
b788508a09 KVM: x86/pmu: Ignore pmu->global_ctrl check if vPMU doesn't support global_ctrl
[ Upstream commit 98defd2e17803263f49548fea930cfc974d505aa ]

MSR_CORE_PERF_GLOBAL_CTRL is introduced as part of Architecture PMU V2,
as indicated by Intel SDM 19.2.2 and the intel_is_valid_msr() function.

So in the absence of global_ctrl support, all PMCs are enabled as AMD does.

Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220509102204.62389-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:22 +02:00
Sean Christopherson
6b4addec2f KVM: VMX: Mark all PERF_GLOBAL_(OVF)_CTRL bits reserved if there's no vPMU
[ Upstream commit 93255bf92939d948bc86d81c6bb70bb0fecc5db1 ]

Mark all MSR_CORE_PERF_GLOBAL_CTRL and MSR_CORE_PERF_GLOBAL_OVF_CTRL bits
as reserved if there is no guest vPMU.  The nVMX VM-Entry consistency
checks do not check for a valid vPMU prior to consuming the masks via
kvm_valid_perf_global_ctrl(), i.e. may incorrectly allow a non-zero mask
to be loaded via VM-Enter or VM-Exit (well, attempted to be loaded, the
actual MSR load will be rejected by intel_is_valid_msr()).

Fixes: f5132b01386b ("KVM: Expose a version 2 architectural PMU to a guests")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722224409.1336532-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:22 +02:00
Like Xu
46ec3d8e90 KVM: x86/pmu: Introduce the ctrl_mask value for fixed counter
[ Upstream commit 2c985527dd8d283e786ad7a67e532ef7f6f00fac ]

The mask value of fixed counter control register should be dynamic
adjusted with the number of fixed counters. This patch introduces a
variable that includes the reserved bits of fixed counter control
registers. This is a generic code refactoring.

Co-developed-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-6-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:22 +02:00
Jim Mattson
2ba1feb143 KVM: x86/pmu: Use different raw event masks for AMD and Intel
[ Upstream commit 95b065bf5c431c06c68056a03a5853b660640ecc ]

The third nybble of AMD's event select overlaps with Intel's IN_TX and
IN_TXCP bits. Therefore, we can't use AMD64_RAW_EVENT_MASK on Intel
platforms that support TSX.

Declare a raw_event_mask in the kvm_pmu structure, initialize it in
the vendor-specific pmu_refresh() functions, and use that mask for
PERF_TYPE_RAW configurations in reprogram_gp_counter().

Fixes: 710c47651431 ("KVM: x86/pmu: Use AMD64_RAW_EVENT_MASK for PERF_TYPE_RAW")
Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20220308012452.3468611-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:22 +02:00
Jim Mattson
4bbfc055d3 KVM: x86/pmu: Use binary search to check filtered events
[ Upstream commit 7ff775aca48adc854436b92c060e5eebfffb6a4a ]

The PMU event filter may contain up to 300 events. Replace the linear
search in reprogram_gp_counter() with a binary search.

Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220115052431.447232-2-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:21 +02:00
Paolo Bonzini
441726394e KVM: x86/pmu: preserve IA32_PERF_CAPABILITIES across CPUID refresh
[ Upstream commit a755753903a40d982f6dd23d65eb96b248a2577a ]

Once MSR_IA32_PERF_CAPABILITIES is changed via vmx_set_msr(), the
value should not be changed by cpuid(). To ensure that the new value
is kept, the default initialization path is moved to intel_pmu_init().
The effective value of the MSR will be 0 if PDCM is clear, however.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:21 +02:00
Sean Christopherson
a7d0b21c6b KVM: nVMX: Inject #UD if VMXON is attempted with incompatible CR0/CR4
[ Upstream commit c7d855c2aff2d511fd60ee2e356134c4fb394799 ]

Inject a #UD if L1 attempts VMXON with a CR0 or CR4 that is disallowed
per the associated nested VMX MSRs' fixed0/1 settings.  KVM cannot rely
on hardware to perform the checks, even for the few checks that have
higher priority than VM-Exit, as (a) KVM may have forced CR0/CR4 bits in
hardware while running the guest, (b) there may incompatible CR0/CR4 bits
that have lower priority than VM-Exit, e.g. CR0.NE, and (c) userspace may
have further restricted the allowed CR0/CR4 values by manipulating the
guest's nested VMX MSRs.

Note, despite a very strong desire to throw shade at Jim, commit
70f3aac964ae ("kvm: nVMX: Remove superfluous VMX instruction fault checks")
is not to blame for the buggy behavior (though the comment...).  That
commit only removed the CR0.PE, EFLAGS.VM, and COMPATIBILITY mode checks
(though it did erroneously drop the CPL check, but that has already been
remedied).  KVM may force CR0.PE=1, but will do so only when also
forcing EFLAGS.VM=1 to emulate Real Mode, i.e. hardware will still #UD.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216033
Fixes: ec378aeef9df ("KVM: nVMX: Implement VMXON and VMXOFF")
Reported-by: Eric Li <ercli@ucdavis.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:21 +02:00
Sean Christopherson
c72a9b1d0d KVM: x86: Move vendor CR4 validity check to dedicated kvm_x86_ops hook
[ Upstream commit c2fe3cd4604ac87c587db05d41843d667dc43815 ]

Split out VMX's checks on CR4.VMXE to a dedicated hook, .is_valid_cr4(),
and invoke the new hook from kvm_valid_cr4().  This fixes an issue where
KVM_SET_SREGS would return success while failing to actually set CR4.

Fixing the issue by explicitly checking kvm_x86_ops.set_cr4()'s return
in __set_sregs() is not a viable option as KVM has already stuffed a
variety of vCPU state.

Note, kvm_valid_cr4() and is_valid_cr4() have different return types and
inverted semantics.  This will be remedied in a future patch.

Fixes: 5e1746d6205d ("KVM: nVMX: Allow setting the VMXE bit in CR4")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20201007014417.29276-5-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:21 +02:00
Sean Christopherson
2f04a04d06 KVM: SVM: Drop VMXE check from svm_set_cr4()
[ Upstream commit 311a06593b9a3944a63ed176b95cb8d857f7c83b ]

Drop svm_set_cr4()'s explicit check CR4.VMXE now that common x86 handles
the check by incorporating VMXE into the CR4 reserved bits, via
kvm_cpu_caps.  SVM obviously does not set X86_FEATURE_VMX.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20201007014417.29276-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:21 +02:00
Sean Christopherson
da7f731f2e KVM: VMX: Drop explicit 'nested' check from vmx_set_cr4()
[ Upstream commit a447e38a7fadb2e554c3942dda183e55cccd5df0 ]

Drop vmx_set_cr4()'s explicit check on the 'nested' module param now
that common x86 handles the check by incorporating VMXE into the CR4
reserved bits, via kvm_cpu_caps.  X86_FEATURE_VMX is set in kvm_cpu_caps
(by vmx_set_cpu_caps()), if and only if 'nested' is true.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20201007014417.29276-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:21 +02:00
Sean Christopherson
8b8b376903 KVM: VMX: Drop guest CPUID check for VMXE in vmx_set_cr4()
[ Upstream commit d3a9e4146a6f79f19430bca3f2a4d6ebaaffe36b ]

Drop vmx_set_cr4()'s somewhat hidden guest_cpuid_has() check on VMXE now
that common x86 handles the check by incorporating VMXE into the CR4
reserved bits, i.e. in cr4_guest_rsvd_bits.  This fixes a bug where KVM
incorrectly rejects KVM_SET_SREGS with CR4.VMXE=1 if it's executed
before KVM_SET_CPUID{,2}.

Fixes: 5e1746d6205d ("KVM: nVMX: Allow setting the VMXE bit in CR4")
Reported-by: Stas Sergeev <stsp@users.sourceforge.net>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20201007014417.29276-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:21 +02:00
Sean Christopherson
e7ccee2f09 KVM: x86: Signal #GP, not -EPERM, on bad WRMSR(MCi_CTL/STATUS)
[ Upstream commit 2368048bf5c2ec4b604ac3431564071e89a0bc71 ]

Return '1', not '-1', when handling an illegal WRMSR to a MCi_CTL or
MCi_STATUS MSR.  The behavior of "all zeros' or "all ones" for CTL MSRs
is architectural, as is the "only zeros" behavior for STATUS MSRs.  I.e.
the intent is to inject a #GP, not exit to userspace due to an unhandled
emulation case.  Returning '-1' gets interpreted as -EPERM up the stack
and effecitvely kills the guest.

Fixes: 890ca9aefa78 ("KVM: Add MCE support")
Fixes: 9ffd986c6e4e ("KVM: X86: #GP when guest attempts to write MCi_STATUS register w/o 0")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20220512222716.4112548-2-seanjc@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:17 +02:00
Lev Kujawski
f5385a590d KVM: set_msr_mce: Permit guests to ignore single-bit ECC errors
[ Upstream commit 0471a7bd1bca2a47a5f378f2222c5cf39ce94152 ]

Certain guest operating systems (e.g., UNIXWARE) clear bit 0 of
MC1_CTL to ignore single-bit ECC data errors.  Single-bit ECC data
errors are always correctable and thus are safe to ignore because they
are informational in nature rather than signaling a loss of data
integrity.

Prior to this patch, these guests would crash upon writing MC1_CTL,
with resultant error messages like the following:

error: kvm run failed Operation not permitted
EAX=fffffffe EBX=fffffffe ECX=00000404 EDX=ffffffff
ESI=ffffffff EDI=00000001 EBP=fffdaba4 ESP=fffdab20
EIP=c01333a5 EFL=00000246 [---Z-P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0108 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0100 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0108 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0108 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0000 00000000 ffffffff 00c00000
GS =0000 00000000 ffffffff 00c00000
LDT=0118 c1026390 00000047 00008200 DPL=0 LDT
TR =0110 ffff5af0 00000067 00008b00 DPL=0 TSS32-busy
GDT=     ffff5020 000002cf
IDT=     ffff52f0 000007ff
CR0=8001003b CR2=00000000 CR3=0100a000 CR4=00000230
DR0=00000000 DR1=00000000 DR2=00000000 DR3=00000000
DR6=ffff0ff0 DR7=00000400
EFER=0000000000000000
Code=08 89 01 89 51 04 c3 8b 4c 24 08 8b 01 8b 51 04 8b 4c 24 04 <0f>
30 c3 f7 05 a4 6d ff ff 10 00 00 00 74 03 0f 31 c3 33 c0 33 d2 c3 8d
74 26 00 0f 31 c3

Signed-off-by: Lev Kujawski <lkujaw@member.fsf.org>
Message-Id: <20220521081511.187388-1-lkujaw@member.fsf.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:17 +02:00
Alexander Lobakin
ce19182b43 x86/olpc: fix 'logical not is only applied to the left hand side'
commit 3a2ba42cbd0b669ce3837ba400905f93dd06c79f upstream.

The bitops compile-time optimization series revealed one more
problem in olpc-xo1-sci.c:send_ebook_state(), resulted in GCC
warnings:

arch/x86/platform/olpc/olpc-xo1-sci.c: In function 'send_ebook_state':
arch/x86/platform/olpc/olpc-xo1-sci.c:83:63: warning: logical not is only applied to the left hand side of comparison [-Wlogical-not-parentheses]
   83 |         if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
      |                                                               ^~
arch/x86/platform/olpc/olpc-xo1-sci.c:83:13: note: add parentheses around left hand side expression to silence this warning

Despite this code working as intended, this redundant double
negation of boolean value, together with comparing to `char`
with no explicit conversion to bool, makes compilers think
the author made some unintentional logical mistakes here.
Make it the other way around and negate the char instead
to silence the warnings.

Fixes: d2aa37411b8e ("x86/olpc/xo1/sci: Produce wakeup events for buttons and switches")
Cc: stable@vger.kernel.org # 3.5+
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21 15:16:14 +02:00
Steven Rostedt (Google)
43e059d016 ftrace/x86: Add back ftrace_expected assignment
commit ac6c1b2ca77e722a1e5d651f12f437f2f237e658 upstream.

When a ftrace_bug happens (where ftrace fails to modify a location) it is
helpful to have what was at that location as well as what was expected to
be there.

But with the conversion to text_poke() the variable that assigns the
expected for debugging was dropped. Unfortunately, I noticed this when I
needed it. Add it back.

Link: https://lkml.kernel.org/r/20220726101851.069d2e70@gandalf.local.home

Cc: "x86@kernel.org" <x86@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: 768ae4406a5c ("x86/ftrace: Use text_poke()")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21 15:16:14 +02:00
Kim Phillips
fd96b61389 x86/bugs: Enable STIBP for IBPB mitigated RETBleed
commit e6cfcdda8cbe81eaf821c897369a65fec987b404 upstream.

AMD's "Technical Guidance for Mitigating Branch Type Confusion,
Rev. 1.0 2022-07-12" whitepaper, under section 6.1.2 "IBPB On
Privileged Mode Entry / SMT Safety" says:

  Similar to the Jmp2Ret mitigation, if the code on the sibling thread
  cannot be trusted, software should set STIBP to 1 or disable SMT to
  ensure SMT safety when using this mitigation.

So, like already being done for retbleed=unret, and now also for
retbleed=ibpb, force STIBP on machines that have it, and report its SMT
vulnerability status accordingly.

 [ bp: Remove the "we" and remove "[AMD]" applicability parameter which
   doesn't work here. ]

Fixes: 3ebc17006888 ("x86/bugs: Add retbleed=ibpb")
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org # 5.10, 5.15, 5.19
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Link: https://lore.kernel.org/r/20220804192201.439596-1-kim.phillips@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21 15:16:14 +02:00