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Function bodies are very similar and are going to grow more almost
identical code. Add a bool arg to determine whether SPEC_CTRL is being set
for the guest or restored to the host.
No functional changes.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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The upcoming support for the virtual SPEC_CTRL MSR on AMD needs to reuse
speculative_store_bypass_update() to avoid code duplication. Add an
argument for supplying a thread info (TIF) value and create a wrapper
speculative_store_bypass_update_current() which is used at the existing
call site.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Some AMD processors only support a non-architectural means of enabling
speculative store bypass disable (SSBD). To allow a simplified view of
this to a guest, an architectural definition has been created through a new
CPUID bit, 0x80000008_EBX[25], and a new MSR, 0xc001011f. With this, a
hypervisor can virtualize the existence of this definition and provide an
architectural method for using SSBD to a guest.
Add the new CPUID feature, the new MSR and update the existing SSBD
support to use this MSR when present.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
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AMD is proposing a VIRT_SPEC_CTRL MSR to handle the Speculative Store
Bypass Disable via MSR_AMD64_LS_CFG so that guests do not have to care
about the bit position of the SSBD bit and thus facilitate migration.
Also, the sibling coordination on Family 17H CPUs can only be done on
the host.
Extend x86_spec_ctrl_set_guest() and x86_spec_ctrl_restore_host() with an
extra argument for the VIRT_SPEC_CTRL MSR.
Hand in 0 from VMX and in SVM add a new virt_spec_ctrl member to the CPU
data structure which is going to be used in later patches for the actual
implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Add a ZEN feature bit so family-dependent static_cpu_has() optimizations
can be built for ZEN.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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The SSBD enumeration is similarly to the other bits magically shared
between Intel and AMD though the mechanisms are different.
Make X86_FEATURE_SSBD synthetic and set it depending on the vendor specific
features or family dependent setup.
Change the Intel bit to X86_FEATURE_SPEC_CTRL_SSBD to denote that SSBD is
controlled via MSR_SPEC_CTRL and fix up the usage sites.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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The availability of the SPEC_CTRL MSR is enumerated by a CPUID bit on
Intel and implied by IBRS or STIBP support on AMD. That's just confusing
and in case an AMD CPU has IBRS not supported because the underlying
problem has been fixed but has another bit valid in the SPEC_CTRL MSR,
the thing falls apart.
Add a synthetic feature bit X86_FEATURE_MSR_SPEC_CTRL to denote the
availability on both Intel and AMD.
While at it replace the boot_cpu_has() checks with static_cpu_has() where
possible. This prevents late microcode loading from exposing SPEC_CTRL, but
late loading is already very limited as it does not reevaluate the
mitigation options and other bits and pieces. Having static_cpu_has() is
the simplest and least fragile solution.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Intel and AMD have different CPUID bits hence for those use synthetic bits
which get set on the respective vendor's in init_speculation_control(). So
that debacles like what the commit message of
c65732e4f721 ("x86/cpu: Restore CPUID_8000_0008_EBX reload")
talks about don't happen anymore.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: https://lkml.kernel.org/r/20180504161815.GG9257@pd.tnic
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Replace the open coded string fetch from user-space with strncpy_from_user().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Link: http://lkml.kernel.org/r/20180515180535.89703-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The helper returns index of the matching string in an array.
Replace the open coded array lookup with match_string().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Link: http://lkml.kernel.org/r/20180515175759.89315-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Kbuild uses the first file as the name for KBUILD_MODNAME.
mtrr uses main.c as its first file, so rename that file to mtrr.c
and fixup the Makefile.
Remove the now duplicate "mtrr: " prefixes from the logging calls.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/ae1fa81a0d1fad87571967b91ea90f70f486e853.1525964384.git.joe@perches.com
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No point to have it at the call sites.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Centaur CPUs enumerate the cache topology in the same way as Intel CPUs,
but the function is unused so for. The Centaur init code also misses to
initialize x86_info::max_cores, so the CPU topology can't be described
correctly.
Initialize x86_info::max_cores and invoke init_cacheinfo() to make
CPU and cache topology information available and correct.
Signed-off-by: David Wang <davidwang@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: lukelin@viacpu.com
Cc: qiyuanwang@zhaoxin.com
Cc: gregkh@linuxfoundation.org
Cc: brucechang@via-alliance.com
Cc: timguo@zhaoxin.com
Cc: cooperyan@zhaoxin.com
Cc: hpa@zytor.com
Cc: benjaminpan@viatech.com
Link: https://lkml.kernel.org/r/1525314766-18910-4-git-send-email-davidwang@zhaoxin.com
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There is no point in having the conditional cpu_detect_cache_sizes() call
at the callsite of init_intel_cacheinfo().
Move it into init_intel_cacheinfo() and make init_intel_cacheinfo() void.
[ tglx: Made the init_intel_cacheinfo() void as the return value was
pointless. Adjust changelog accordingly ]
Signed-off-by: David Wang <davidwang@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: lukelin@viacpu.com
Cc: qiyuanwang@zhaoxin.com
Cc: gregkh@linuxfoundation.org
Cc: brucechang@via-alliance.com
Cc: timguo@zhaoxin.com
Cc: cooperyan@zhaoxin.com
Cc: hpa@zytor.com
Cc: benjaminpan@viatech.com
Link: https://lkml.kernel.org/r/1525314766-18910-3-git-send-email-davidwang@zhaoxin.com
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intel_num_cpu_cores() is a static function in intel.c which can't be used
by other files. Define another function called detect_num_cpu_cores() in
common.c to replace this function so it can be reused.
Signed-off-by: David Wang <davidwang@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: lukelin@viacpu.com
Cc: qiyuanwang@zhaoxin.com
Cc: gregkh@linuxfoundation.org
Cc: brucechang@via-alliance.com
Cc: timguo@zhaoxin.com
Cc: cooperyan@zhaoxin.com
Cc: hpa@zytor.com
Cc: benjaminpan@viatech.com
Link: https://lkml.kernel.org/r/1525314766-18910-2-git-send-email-davidwang@zhaoxin.com
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No point in exposing all these functions globaly as they are strict local
to the cpu management code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Fixes: 7bb4d366c ("x86/bugs: Make cpu_show_common() static")
Fixes: 24f7fc83b ("x86/bugs: Provide boot parameters for the spec_store_bypass_disable mitigation")
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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cpu_show_common() is not used outside of arch/x86/kernel/cpu/bugs.c, so
make it static.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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__ssb_select_mitigation() returns one of the members of enum ssb_mitigation,
not ssb_mitigation_cmd; fix the prototype to reflect that.
Fixes: 24f7fc83b9204 ("x86/bugs: Provide boot parameters for the spec_store_bypass_disable mitigation")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Intel collateral will reference the SSB mitigation bit in IA32_SPEC_CTL[2]
as SSBD (Speculative Store Bypass Disable).
Hence changing it.
It is unclear yet what the MSR_IA32_ARCH_CAPABILITIES (0x10a) Bit(4) name
is going to be. Following the rename it would be SSBD_NO but that rolls out
to Speculative Store Bypass Disable No.
Also fixed the missing space in X86_FEATURE_AMD_SSBD.
[ tglx: Fixup x86_amd_rds_enable() and rds_tif_to_amd_ls_cfg() as well ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Derive topology information from Extended Topology Enumeration (CPUID
function 0xB) when the information is available.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1524865681-112110-3-git-send-email-suravee.suthikulpanit@amd.com
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Current implementation does not communicate whether it can successfully
detect CPUID function 0xB information. Therefore, modify the function to
return success or error codes. This will be used by subsequent patches.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1524865681-112110-2-git-send-email-suravee.suthikulpanit@amd.com
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Last Level Cache ID can be calculated from the number of threads sharing
the cache, which is available from CPUID Fn0x8000001D (Cache Properties).
This is used to left-shift the APIC ID to derive LLC ID.
Therefore, default to this method unless the APIC ID enumeration does not
follow the scheme.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1524864877-111962-5-git-send-email-suravee.suthikulpanit@amd.com
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Since this file contains general cache-related information for x86,
rename the file to a more generic name.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1524864877-111962-4-git-send-email-suravee.suthikulpanit@amd.com
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Move smp_num_siblings and cpu_llc_id to cpu/common.c so that they're
always present as symbols and not only in the CONFIG_SMP case. Then,
other code using them doesn't need ugly ifdeffery anymore. Get rid of
some ifdeffery.
Signed-off-by: Borislav Petkov <bpetkov@suse.de>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1524864877-111962-2-git-send-email-suravee.suthikulpanit@amd.com
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Each of the strings that we want to put into the buf[MAX_FLAG_OPT_SIZE]
in flags_read() is two characters long. But the sprintf() adds
a trailing newline and will add a terminating NUL byte. So
MAX_FLAG_OPT_SIZE needs to be 4.
sprintf() calls vsnprintf() and *that* does return:
" * The return value is the number of characters which would
* be generated for the given input, excluding the trailing
* '\0', as per ISO C99."
Note the "excluding".
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20180427163707.ktaiysvbk3yhk4wm@agluck-desk
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Newer Centaur multi-core CPUs also support MCE broadcasting to all
cores. Add a Centaur-specific init function setting that up.
[ bp:
- make mce_centaur_feature_init() static
- flip check to do the f/m/s first for better readability
- touch up text
]
Signed-off-by: David Wang <davidwang@zhaoxin.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: lukelin@viacpu.com
Cc: qiyuanwang@zhaoxin.com
Cc: Greg KH <greg@kroah.com>
Cc: brucechang@via-alliance.com
Cc: timguo@zhaoxin.com
Cc: cooperyan@zhaoxin.com
Cc: Tony Luck <tony.luck@intel.com>
Cc: benjaminpan@viatech.com
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1524652420-17330-2-git-send-email-davidwang@zhaoxin.com
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Unless explicitly opted out of, anything running under seccomp will have
SSB mitigations enabled. Choosing the "prctl" mode will disable this.
[ tglx: Adjusted it to the new arch_seccomp_spec_mitigate() mechanism ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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The migitation control is simpler to implement in architecture code as it
avoids the extra function call to check the mode. Aside of that having an
explicit seccomp enabled mode in the architecture mitigations would require
even more workarounds.
Move it into architecture code and provide a weak function in the seccomp
code. Remove the 'which' argument as this allows the architecture to decide
which mitigations are relevant for seccomp.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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For certain use cases it is desired to enforce mitigations so they cannot
be undone afterwards. That's important for loader stubs which want to
prevent a child from disabling the mitigation again. Will also be used for
seccomp(). The extra state preserving of the prctl state for SSB is a
preparatory step for EBPF dymanic speculation control.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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There's no reason for these to be changed after boot.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Adjust arch_prctl_get/set_spec_ctrl() to operate on tasks other than
current.
This is needed both for /proc/$pid/status queries and for seccomp (since
thread-syncing can trigger seccomp in non-current threads).
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Add prctl based control for Speculative Store Bypass mitigation and make it
the default mitigation for Intel and AMD.
Andi Kleen provided the following rationale (slightly redacted):
There are multiple levels of impact of Speculative Store Bypass:
1) JITed sandbox.
It cannot invoke system calls, but can do PRIME+PROBE and may have call
interfaces to other code
2) Native code process.
No protection inside the process at this level.
3) Kernel.
4) Between processes.
The prctl tries to protect against case (1) doing attacks.
If the untrusted code can do random system calls then control is already
lost in a much worse way. So there needs to be system call protection in
some way (using a JIT not allowing them or seccomp). Or rather if the
process can subvert its environment somehow to do the prctl it can already
execute arbitrary code, which is much worse than SSB.
To put it differently, the point of the prctl is to not allow JITed code
to read data it shouldn't read from its JITed sandbox. If it already has
escaped its sandbox then it can already read everything it wants in its
address space, and do much worse.
The ability to control Speculative Store Bypass allows to enable the
protection selectively without affecting overall system performance.
Based on an initial patch from Tim Chen. Completely rewritten.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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The Speculative Store Bypass vulnerability can be mitigated with the
Reduced Data Speculation (RDS) feature. To allow finer grained control of
this eventually expensive mitigation a per task mitigation control is
required.
Add a new TIF_RDS flag and put it into the group of TIF flags which are
evaluated for mismatch in switch_to(). If these bits differ in the previous
and the next task, then the slow path function __switch_to_xtra() is
invoked. Implement the TIF_RDS dependent mitigation control in the slow
path.
If the prctl for controlling Speculative Store Bypass is disabled or no
task uses the prctl then there is no overhead in the switch_to() fast
path.
Update the KVM related speculation control functions to take TID_RDS into
account as well.
Based on a patch from Tim Chen. Completely rewritten.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Having everything in nospec-branch.h creates a hell of dependencies when
adding the prctl based switching mechanism. Move everything which is not
required in nospec-branch.h to spec-ctrl.h and fix up the includes in the
relevant files.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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AMD does not need the Speculative Store Bypass mitigation to be enabled.
The parameters for this are already available and can be done via MSR
C001_1020. Each family uses a different bit in that MSR for this.
[ tglx: Expose the bit mask via a variable and move the actual MSR fiddling
into the bugs code as that's the right thing to do and also required
to prepare for dynamic enable/disable ]
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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Intel and AMD SPEC_CTRL (0x48) MSR semantics may differ in the
future (or in fact use different MSRs for the same functionality).
As such a run-time mechanism is required to whitelist the appropriate MSR
values.
[ tglx: Made the variable __ro_after_init ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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Intel CPUs expose methods to:
- Detect whether RDS capability is available via CPUID.7.0.EDX[31],
- The SPEC_CTRL MSR(0x48), bit 2 set to enable RDS.
- MSR_IA32_ARCH_CAPABILITIES, Bit(4) no need to enable RRS.
With that in mind if spec_store_bypass_disable=[auto,on] is selected set at
boot-time the SPEC_CTRL MSR to enable RDS if the platform requires it.
Note that this does not fix the KVM case where the SPEC_CTRL is exposed to
guests which can muck with it, see patch titled :
KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS.
And for the firmware (IBRS to be set), see patch titled:
x86/spectre_v2: Read SPEC_CTRL MSR during boot and re-use reserved bits
[ tglx: Distangled it from the intel implementation and kept the call order ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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Contemporary high performance processors use a common industry-wide
optimization known as "Speculative Store Bypass" in which loads from
addresses to which a recent store has occurred may (speculatively) see an
older value. Intel refers to this feature as "Memory Disambiguation" which
is part of their "Smart Memory Access" capability.
Memory Disambiguation can expose a cache side-channel attack against such
speculatively read values. An attacker can create exploit code that allows
them to read memory outside of a sandbox environment (for example,
malicious JavaScript in a web page), or to perform more complex attacks
against code running within the same privilege level, e.g. via the stack.
As a first step to mitigate against such attacks, provide two boot command
line control knobs:
nospec_store_bypass_disable
spec_store_bypass_disable=[off,auto,on]
By default affected x86 processors will power on with Speculative
Store Bypass enabled. Hence the provided kernel parameters are written
from the point of view of whether to enable a mitigation or not.
The parameters are as follows:
- auto - Kernel detects whether your CPU model contains an implementation
of Speculative Store Bypass and picks the most appropriate
mitigation.
- on - disable Speculative Store Bypass
- off - enable Speculative Store Bypass
[ tglx: Reordered the checks so that the whole evaluation is not done
when the CPU does not support RDS ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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Add the sysfs file for the new vulerability. It does not do much except
show the words 'Vulnerable' for recent x86 cores.
Intel cores prior to family 6 are known not to be vulnerable, and so are
some Atoms and some Xeon Phi.
It assumes that older Cyrix, Centaur, etc. cores are immune.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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A guest may modify the SPEC_CTRL MSR from the value used by the
kernel. Since the kernel doesn't use IBRS, this means a value of zero is
what is needed in the host.
But the 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to
the other bits as reserved so the kernel should respect the boot time
SPEC_CTRL value and use that.
This allows to deal with future extensions to the SPEC_CTRL interface if
any at all.
Note: This uses wrmsrl() instead of native_wrmsl(). I does not make any
difference as paravirt will over-write the callq *0xfff.. with the wrmsrl
assembler code.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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The 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to all
the other bits as reserved. The Intel SDM glossary defines reserved as
implementation specific - aka unknown.
As such at bootup this must be taken it into account and proper masking for
the bits in use applied.
A copy of this document is available at
https://bugzilla.kernel.org/show_bug.cgi?id=199511
[ tglx: Made x86_spec_ctrl_base __ro_after_init ]
Suggested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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Those SysFS functions have a similar preamble, as such make common
code to handle them.
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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Combine the various logic which goes through all those
x86_cpu_id matching structures in one function.
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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The recent commt which addresses the x86_phys_bits corruption with
encrypted memory on CPUID reload after a microcode update lost the reload
of CPUID_8000_0008_EBX as well.
As a consequence IBRS and IBRS_FW are not longer detected
Restore the behaviour by bringing the reload of CPUID_8000_0008_EBX
back. This restore has a twist due to the convoluted way the cpuid analysis
works:
CPUID_8000_0008_EBX is used by AMD to enumerate IBRB, IBRS, STIBP. On Intel
EBX is not used. But the speculation control code sets the AMD bits when
running on Intel depending on the Intel specific speculation control
bits. This was done to use the same bits for alternatives.
The change which moved the 8000_0008 evaluation out of get_cpu_cap() broke
this nasty scheme due to ordering. So that on Intel the store to
CPUID_8000_0008_EBX clears the IBRB, IBRS, STIBP bits which had been set
before by software.
So the actual CPUID_8000_0008_EBX needs to go back to the place where it
was and the phys/virt address space calculation cannot touch it.
In hindsight this should have used completely synthetic bits for IBRB,
IBRS, STIBP instead of reusing the AMD bits, but that's for 4.18.
/me needs to find time to cleanup that steaming pile of ...
Fixes: d94a155c59c9 ("x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption")
Reported-by: Jörg Otte <jrg.otte@gmail.com>
Reported-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: kirill.shutemov@linux.intel.com
Cc: Borislav Petkov <bp@alien8.de
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1805021043510.1668@nanos.tec.linutronix.de
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Make kernel print the correct number of TLB entries on Intel Xeon Phi 7210
(and others)
Before:
[ 0.320005] Last level dTLB entries: 4KB 0, 2MB 0, 4MB 0, 1GB 0
After:
[ 0.320005] Last level dTLB entries: 4KB 256, 2MB 128, 4MB 128, 1GB 16
The entries do exist in the official Intel SMD but the type column there is
incorrect (states "Cache" where it should read "TLB"), but the entries for
the values 0x6B, 0x6C and 0x6D are correctly described as 'Data TLB'.
Signed-off-by: Jacek Tomaka <jacek.tomaka@poczta.fm>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20180423161425.24366-1-jacekt@dugeo.com
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Vitezslav reported a case where the
"Timeout during microcode update!"
panic would hit. After a deeper look, it turned out that his .config had
CONFIG_HOTPLUG_CPU disabled which practically made save_mc_for_early() a
no-op.
When that happened, the discovered microcode patch wasn't saved into the
cache and the late loading path wouldn't find any.
This, then, lead to early exit from __reload_late() and thus CPUs waiting
until the timeout is reached, leading to the panic.
In hindsight, that function should have been written so it does not return
before the post-synchronization. Oh well, I know better now...
Fixes: bb8c13d61a62 ("x86/microcode: Fix CPU synchronization routine")
Reported-by: Vitezslav Samel <vitezslav@samel.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vitezslav Samel <vitezslav@samel.cz>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180418081140.GA2439@pc11.op.pod.cz
Link: https://lkml.kernel.org/r/20180421081930.15741-2-bp@alien8.de
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save_mc_for_early() was a no-op on !CONFIG_HOTPLUG_CPU but the
generic_load_microcode() path saves the microcode patches it has found into
the cache of patches which is used for late loading too. Regardless of
whether CPU hotplug is used or not.
Make the saving unconditional so that late loading can find the proper
patch.
Reported-by: Vitezslav Samel <vitezslav@samel.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vitezslav Samel <vitezslav@samel.cz>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180418081140.GA2439@pc11.op.pod.cz
Link: https://lkml.kernel.org/r/20180421081930.15741-1-bp@alien8.de
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Centaur CPUs have some Intel compatible capabilities,including Permformance
Monitoring Counters and CPU virtualization capabilities. Initialize them in
the Centaur specific init code.
Signed-off-by: David Wang <davidwang@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: lukelin@viacpu.com
Cc: qiyuanwang@zhaoxin.com
Cc: gregkh@linuxfoundation.org
Cc: brucechang@via-alliance.com
Cc: timguo@zhaoxin.com
Cc: cooperyan@zhaoxin.com
Cc: hpa@zytor.com
Cc: benjaminpan@viatech.com
Link: https://lkml.kernel.org/r/1524212968-28998-1-git-send-email-davidwang@zhaoxin.com
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A set of fixes and updates for x86:
- Address a swiotlb regression which was caused by the recent DMA
rework and made driver fail because dma_direct_supported() returned
false
- Fix a signedness bug in the APIC ID validation which caused invalid
APIC IDs to be detected as valid thereby bloating the CPU possible
space.
- Fix inconsisten config dependcy/select magic for the MFD_CS5535
driver.
- Fix a corruption of the physical address space bits when encryption
has reduced the address space and late cpuinfo updates overwrite
the reduced bit information with the original value.
- Dominiks syscall rework which consolidates the architecture
specific syscall functions so all syscalls can be wrapped with the
same macros. This allows to switch x86/64 to struct pt_regs based
syscalls. Extend the clearing of user space controlled registers in
the entry patch to the lower registers"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic: Fix signedness bug in APIC ID validity checks
x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption
x86/olpc: Fix inconsistent MFD_CS5535 configuration
swiotlb: Use dma_direct_supported() for swiotlb_ops
syscalls/x86: Adapt syscall_wrapper.h to the new syscall stub naming convention
syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()
syscalls/core, syscalls/x86: Clean up compat syscall stub naming convention
syscalls/core, syscalls/x86: Clean up syscall stub naming convention
syscalls/x86: Extend register clearing on syscall entry to lower registers
syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64
syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32
syscalls/core: Prepare CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y for compat syscalls
syscalls/x86: Use 'struct pt_regs' based syscall calling convention for 64-bit syscalls
syscalls/core: Introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y
x86/syscalls: Don't pointlessly reload the system call number
x86/mm: Fix documentation of module mapping range with 4-level paging
x86/cpuid: Switch to 'static const' specifier
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