Replace uses of sme_active() with the more generic cc_platform_has()
using CC_ATTR_HOST_MEM_ENCRYPT. If future support is added for other
memory encryption technologies, the use of CC_ATTR_HOST_MEM_ENCRYPT
can be updated, as required.
This also replaces two usages of sev_active() that are really geared
towards detecting if SME is active.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210928191009.32551-6-bp@alien8.de
All Zen or newer CPU which support C3 shares cache. Its not necessary to
flush the caches in software before entering C3. This will cause drop in
performance for the cores which share some caches. ARB_DIS is not used
with current AMD C state implementation. So set related flags correctly.
Signed-off-by: Deepak Sharma <deepak.sharma@amd.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull more kvm fixes from Paolo Bonzini:
"Small x86 fixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: selftests: Ensure all migrations are performed when test is affined
KVM: x86: Swap order of CPUID entry "index" vs. "significant flag" checks
ptp: Fix ptp_kvm_getcrosststamp issue for x86 ptp_kvm
x86/kvmclock: Move this_cpu_pvti into kvmclock.h
selftests: KVM: Don't clobber XMM register when read
KVM: VMX: Fix a TSX_CTRL_CPUID_CLEAR field mask issue
On recent Intel systems the HPET stops working when the system reaches PC10
idle state.
The approach of adding PCI ids to the early quirks to disable HPET on
these systems is a whack a mole game which makes no sense.
Check for PC10 instead and force disable HPET if supported. The check is
overbroad as it does not take ACPI, intel_idle enablement and command
line parameters into account. That's fine as long as there is at least
PMTIMER available to calibrate the TSC frequency. The decision can be
overruled by adding "hpet=force" on the kernel command line.
Remove the related early PCI quirks for affected Ice Cake and Coffin Lake
systems as they are not longer required. That should also cover all
other systems, i.e. Tiger Rag and newer generations, which are most
likely affected by this as well.
Fixes: Yet another hardware trainwreck
Reported-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Cc: stable@vger.kernel.org
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
In x86, the fake return address on the stack saved by
__kretprobe_trampoline() will be replaced with the real return
address after returning from trampoline_handler(). Before fixing
the return address, the real return address can be found in the
'current->kretprobe_instances'.
However, since there is a window between updating the
'current->kretprobe_instances' and fixing the address on the stack,
if an interrupt happens at that timing and the interrupt handler
does stacktrace, it may fail to unwind because it can not get
the correct return address from 'current->kretprobe_instances'.
This will eliminate that window by fixing the return address
right before updating 'current->kretprobe_instances'.
Link: https://lkml.kernel.org/r/163163057094.489837.9044470370440745866.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since the kretprobe replaces the function return address with
the kretprobe_trampoline on the stack, x86 unwinders can not
continue the stack unwinding at that point, or record
kretprobe_trampoline instead of correct return address.
To fix this issue, find the correct return address from task's
kretprobe_instances as like as function-graph tracer does.
With this fix, the unwinder can correctly unwind the stack
from kretprobe event on x86, as below.
<...>-135 [003] ...1 6.722338: r_full_proxy_read_0: (vfs_read+0xab/0x1a0 <- full_proxy_read)
<...>-135 [003] ...1 6.722377: <stack trace>
=> kretprobe_trace_func+0x209/0x2f0
=> kretprobe_dispatcher+0x4a/0x70
=> __kretprobe_trampoline_handler+0xca/0x150
=> trampoline_handler+0x44/0x70
=> kretprobe_trampoline+0x2a/0x50
=> vfs_read+0xab/0x1a0
=> ksys_read+0x5f/0xe0
=> do_syscall_64+0x33/0x40
=> entry_SYSCALL_64_after_hwframe+0x44/0xae
Link: https://lkml.kernel.org/r/163163055130.489837.5161749078833497255.stgit@devnote2
Reported-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Change __kretprobe_trampoline() to push the address of the
__kretprobe_trampoline() as a fake return address at the bottom
of the stack frame. This fake return address will be replaced
with the correct return address in the trampoline_handler().
With this change, the ORC unwinder can check whether the return
address is modified by kretprobes or not.
Link: https://lkml.kernel.org/r/163163054185.489837.14338744048957727386.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The __kretprobe_trampoline_handler() callback, called from low level
arch kprobes methods, has the 'trampoline_address' parameter, which is
entirely superfluous as it basically just replicates:
dereference_kernel_function_descriptor(kretprobe_trampoline)
In fact we had bugs in arch code where it wasn't replicated correctly.
So remove this superfluous parameter and use kretprobe_trampoline_addr()
instead.
Link: https://lkml.kernel.org/r/163163044546.489837.13505751885476015002.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since get_optimized_kprobe() is only used inside kprobes,
it doesn't need to use 'unsigned long' type for 'addr' parameter.
Make it use 'kprobe_opcode_t *' for the 'addr' parameter and
subsequent call of arch_within_optimized_kprobe() also should use
'kprobe_opcode_t *'.
Note that MAX_OPTIMIZED_LENGTH and RELATIVEJUMP_SIZE are defined
by byte-size, but the size of 'kprobe_opcode_t' depends on the
architecture. Therefore, we must be careful when calculating
addresses using those macros.
Link: https://lkml.kernel.org/r/163163040680.489837.12133032364499833736.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
PREEMPT_RT preempts softirqs and the current implementation avoids
do_softirq_own_stack() and only uses __do_softirq().
Disable the unused softirqs stacks on PREEMPT_RT to safe some memory and
ensure that do_softirq_own_stack() is not used which is not expected.
[ bigeasy: commit description. ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210924161245.2357247-1-bigeasy@linutronix.de
After four years in the wild, those have not fullfilled their
initial purpose of pushing people to fix their software to not use
UMIP-emulated instructions, and to warn users about the degraded
emulation performance.
Yet, the only thing that "degrades" performance is overflowing dmesg
with those:
[Di Sep 7 00:24:05 2021] umip_printk: 1345 callbacks suppressed
[Di Sep 7 00:24:05 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b7c0: SIDT instruction cannot be used by applications.
[Di Sep 7 00:24:05 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b7c0: For now, expensive software emulation returns the result.
...
[Di Sep 7 00:26:06 2021] umip_printk: 2227 callbacks suppressed
[Di Sep 7 00:26:06 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b940: SIDT instruction cannot be used by applications.
and users don't really care about that - they just want to play their
games in wine.
So convert those to debug loglevel - in case someone is still interested
in them, someone can boot with "debug" on the kernel cmdline.
Reported-by: Marcus Rückert <mrueckert@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Link: https://lkml.kernel.org/r/20210907200454.30458-1-bp@alien8.de
Get rid of the indirect function pointer and use flags settings instead
to steer execution.
Now that it is not an indirect call any longer, drop the instrumentation
annotation for objtool too.
No functional changes.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20210922165101.18951-3-bp@alien8.de
Current code has an explicit check for hitting the task stack guard;
but overflowing any of the other stacks will get you a non-descript
general #DF warning.
Improve matters by using get_stack_info_noinstr() to detetrmine if and
which stack guard page got hit, enabling a better stack warning.
In specific, Michael Wang reported what turned out to be an NMI
exception stack overflow, which is now clearly reported as such:
[] BUG: NMI stack guard page was hit at 0000000085fd977b (stack is 000000003a55b09e..00000000d8cce1a5)
Reported-by: Michael Wang <yun.wang@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Wang <yun.wang@linux.alibaba.com>
Link: https://lkml.kernel.org/r/YUTE/NuqnaWbST8n@hirez.programming.kicks-ass.net
Since commit c8137ace56 ("x86/iopl: Restrict iopl() permission
scope") it's possible to emulate iopl(3) using ioperm(), except for
the CLI/STI usage.
Userspace CLI/STI usage is very dubious (read broken), since any
exception taken during that window can lead to rescheduling anyway (or
worse). The IOPL(2) manpage even states that usage of CLI/STI is highly
discouraged and might even crash the system.
Of course, that won't stop people and HP has the dubious honour of
being the first vendor to be found using this in their hp-health
package.
In order to enable this 'software' to still 'work', have the #GP treat
the CLI/STI instructions as NOPs when iopl(3). Warn the user that
their program is doing dubious things.
Fixes: a24ca99768 ("x86/iopl: Remove legacy IOPL option")
Reported-by: Ondrej Zary <linux@zary.sk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org # v5.5+
Link: https://lkml.kernel.org/r/20210918090641.GD5106@worktop.programming.kicks-ass.net
Commit in Fixes introduced early_reserve_memory() to do all needed
initial memblock_reserve() calls in one function. Unfortunately, the call
of early_reserve_memory() is done too late for Xen dom0, as in some
cases a Xen hook called by e820__memory_setup() will need those memory
reservations to have happened already.
Move the call of early_reserve_memory() before the call of
e820__memory_setup() in order to avoid such problems.
Fixes: a799c2bd29 ("x86/setup: Consolidate early memory reservations")
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210920120421.29276-1-jgross@suse.com
Pull x86 fixes from Borislav Petkov:
- Prevent a infinite loop in the MCE recovery on return to user space,
which was caused by a second MCE queueing work for the same page and
thereby creating a circular work list.
- Make kern_addr_valid() handle existing PMD entries, which are marked
not present in the higher level page table, correctly instead of
blindly dereferencing them.
- Pass a valid address to sanitize_phys(). This was caused by the
mixture of inclusive and exclusive ranges. memtype_reserve() expect
'end' being exclusive, but sanitize_phys() wants it inclusive. This
worked so far, but with end being the end of the physical address
space the fail is exposed.
- Increase the maximum supported GPIO numbers for 64bit. Newer SoCs
exceed the previous maximum.
* tag 'x86_urgent_for_v5.15_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Avoid infinite loop for copy from user recovery
x86/mm: Fix kern_addr_valid() to cope with existing but not present entries
x86/platform: Increase maximum GPIO number for X86_64
x86/pat: Pass valid address to sanitize_phys()
Coverity warns of an unused value in arch_scale_freq_tick():
CID 100778 (#1 of 1): Unused value (UNUSED_VALUE)
assigned_value: Assigning value 1024ULL to freq_scale here, but that stored
value is overwritten before it can be used.
It was introduced by commit:
e2b0d619b4 ("x86, sched: check for counters overflow in frequency invariant accounting")
Remove the variable initializer.
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Link: https://lkml.kernel.org/r/20210910184405.24422-1-tim.gardner@canonical.com
The boot-time allocation interface for memblock is a mess, with
'memblock_alloc()' returning a virtual pointer, but then you are
supposed to free it with 'memblock_free()' that takes a _physical_
address.
Not only is that all kinds of strange and illogical, but it actually
causes bugs, when people then use it like a normal allocation function,
and it fails spectacularly on a NULL pointer:
https://lore.kernel.org/all/20210912140820.GD25450@xsang-OptiPlex-9020/
or just random memory corruption if the debug checks don't catch it:
https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/
I really don't want to apply patches that treat the symptoms, when the
fundamental cause is this horribly confusing interface.
I started out looking at just automating a sane replacement sequence,
but because of this mix or virtual and physical addresses, and because
people have used the "__pa()" macro that can take either a regular
kernel pointer, or just the raw "unsigned long" address, it's all quite
messy.
So this just introduces a new saner interface for freeing a virtual
address that was allocated using 'memblock_alloc()', and that was kept
as a regular kernel pointer. And then it converts a couple of users
that are obvious and easy to test, including the 'xbc_nodes' case in
lib/bootconfig.c that caused problems.
Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: 40caa127f3 ("init: bootconfig: Remove all bootconfig data when the init memory is removed")
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the direct saving of the FPU registers to the user space sigframe
fails, copy_fpregs_to_sigframe() attempts to clear the user buffer.
The most likely reason for such a fail is a page fault. As
copy_fpregs_to_sigframe() is invoked with pagefaults disabled the chance
that __clear_user() succeeds is minuscule.
Move the clearing out into the caller which replaces the
fault_in_pages_writeable() in that error handling path.
The return value confusion will be cleaned up separately.
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210908132525.679356300@linutronix.de
There are two cases for machine check recovery:
1) The machine check was triggered by ring3 (application) code.
This is the simpler case. The machine check handler simply queues
work to be executed on return to user. That code unmaps the page
from all users and arranges to send a SIGBUS to the task that
triggered the poison.
2) The machine check was triggered in kernel code that is covered by
an exception table entry. In this case the machine check handler
still queues a work entry to unmap the page, etc. but this will
not be called right away because the #MC handler returns to the
fix up code address in the exception table entry.
Problems occur if the kernel triggers another machine check before the
return to user processes the first queued work item.
Specifically, the work is queued using the ->mce_kill_me callback
structure in the task struct for the current thread. Attempting to queue
a second work item using this same callback results in a loop in the
linked list of work functions to call. So when the kernel does return to
user, it enters an infinite loop processing the same entry for ever.
There are some legitimate scenarios where the kernel may take a second
machine check before returning to the user.
1) Some code (e.g. futex) first tries a get_user() with page faults
disabled. If this fails, the code retries with page faults enabled
expecting that this will resolve the page fault.
2) Copy from user code retries a copy in byte-at-time mode to check
whether any additional bytes can be copied.
On the other side of the fence are some bad drivers that do not check
the return value from individual get_user() calls and may access
multiple user addresses without noticing that some/all calls have
failed.
Fix by adding a counter (current->mce_count) to keep track of repeated
machine checks before task_work() is called. First machine check saves
the address information and calls task_work_add(). Subsequent machine
checks before that task_work call back is executed check that the address
is in the same page as the first machine check (since the callback will
offline exactly one page).
Expected worst case is four machine checks before moving on (e.g. one
user access with page faults disabled, then a repeat to the same address
with page faults enabled ... repeat in copy tail bytes). Just in case
there is some code that loops forever enforce a limit of 10.
[ bp: Massage commit message, drop noinstr, fix typo, extend panic
messages. ]
Fixes: 5567d11c21 ("x86/mce: Send #MC singal from task work")
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/YT/IJ9ziLqmtqEPu@agluck-desk2.amr.corp.intel.com
