Change MSR_IA32_MCx_MISC() macro to msr_ops.misc() because SMCA machines
define a different set of MSRs and msr_ops will give you the correct
MISC register.
Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1468269447-8808-1-git-send-email-Yazen.Ghannam@amd.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch has no functional change; it is purely cosmetic, though
it does make it a wee bit easier to understand the code. Before, the
count of LAPICs was being stored in the variable 'x2count' and the
count of X2APICs was being stored in the variable 'count'. This
patch swaps that so that the routine acpi_parse_madt_lapic_entries()
will now consistently use x2count to refer to X2APIC info, and count
to refer to LAPIC info.
Signed-off-by: Al Stone <ahs3@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 7b02d53e7852 ("efi: Allow drivers to reserve boot services forever")
introduced a new efi_mem_reserve to reserve the boot services memory
regions forever. This reservation involves allocating a new EFI memory
range descriptor. However, allocation can only succeed if there is memory
available for the allocation. Otherwise, error such as the following may
occur:
esrt: Reserving ESRT space from 0x000000003dd6a000 to 0x000000003dd6a010.
Kernel panic - not syncing: ERROR: Failed to allocate 0x9f0 bytes below \
0x0.
CPU: 0 PID: 0 Comm: swapper Not tainted 4.7.0-rc5+ #503
0000000000000000 ffffffff81e03ce0 ffffffff8131dae8 ffffffff81bb6c50
ffffffff81e03d70 ffffffff81e03d60 ffffffff8111f4df 0000000000000018
ffffffff81e03d70 ffffffff81e03d08 00000000000009f0 00000000000009f0
Call Trace:
[<ffffffff8131dae8>] dump_stack+0x4d/0x65
[<ffffffff8111f4df>] panic+0xc5/0x206
[<ffffffff81f7c6d3>] memblock_alloc_base+0x29/0x2e
[<ffffffff81f7c6e3>] memblock_alloc+0xb/0xd
[<ffffffff81f6c86d>] efi_arch_mem_reserve+0xbc/0x134
[<ffffffff81fa3280>] efi_mem_reserve+0x2c/0x31
[<ffffffff81fa3280>] ? efi_mem_reserve+0x2c/0x31
[<ffffffff81fa40d3>] efi_esrt_init+0x19e/0x1b4
[<ffffffff81f6d2dd>] efi_init+0x398/0x44a
[<ffffffff81f5c782>] setup_arch+0x415/0xc30
[<ffffffff81f55af1>] start_kernel+0x5b/0x3ef
[<ffffffff81f55434>] x86_64_start_reservations+0x2f/0x31
[<ffffffff81f55520>] x86_64_start_kernel+0xea/0xed
---[ end Kernel panic - not syncing: ERROR: Failed to allocate 0x9f0
bytes below 0x0.
An inspection of the memblock configuration reveals that there is no memory
available for the allocation:
MEMBLOCK configuration:
memory size = 0x0 reserved size = 0x4f339c0
memory.cnt = 0x1
memory[0x0] [0x00000000000000-0xffffffffffffffff], 0x0 bytes on node 0\
flags: 0x0
reserved.cnt = 0x4
reserved[0x0] [0x0000000008c000-0x0000000008c9bf], 0x9c0 bytes flags: 0x0
reserved[0x1] [0x0000000009f000-0x000000000fffff], 0x61000 bytes\
flags: 0x0
reserved[0x2] [0x00000002800000-0x0000000394bfff], 0x114c000 bytes\
flags: 0x0
reserved[0x3] [0x000000304e4000-0x00000034269fff], 0x3d86000 bytes\
flags: 0x0
This situation can be avoided if we call efi_esrt_init after memblock has
memory regions for the allocation.
Also, the EFI ESRT driver makes use of early_memremap'pings. Therfore, we
do not want to defer efi_esrt_init for too long. We must call such function
while calls to early_memremap are still valid.
A good place to meet the two aforementioned conditions is right after
memblock_x86_fill, grouped with other EFI-related functions.
Reported-by: Scott Lawson <scott.lawson@intel.com>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Both efi_find_mirror() and efi_fake_memmap() really want to know
whether the EFI memory map is available, not just whether the machine
was booted using EFI. efi_fake_memmap() even has a check for
EFI_MEMMAP at the start of the function.
Since we've already got other code that has this dependency, merge
everything under one if() conditional, and remove the now superfluous
check from efi_fake_memmap().
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
On a large system with many CPUs, using HPET as the clock source can
have a significant impact on the overall system performance because
of the following reasons:
1) There is a single HPET counter shared by all the CPUs.
2) HPET counter reading is a very slow operation.
Using HPET as the default clock source may happen when, for example,
the TSC clock calibration exceeds the allowable tolerance. Something
the performance slowdown can be so severe that the system may crash
because of a NMI watchdog soft lockup, for example.
During the TSC clock calibration process, the default clock source
will be set temporarily to HPET. For systems with many CPUs, it is
possible that NMI watchdog soft lockup may occur occasionally during
that short time period where HPET clocking is active as is shown in
the kernel log below:
[ 71.646504] hpet0: 8 comparators, 64-bit 14.318180 MHz counter
[ 71.655313] Switching to clocksource hpet
[ 95.679135] BUG: soft lockup - CPU#144 stuck for 23s! [swapper/144:0]
[ 95.693363] BUG: soft lockup - CPU#145 stuck for 23s! [swapper/145:0]
[ 95.695580] BUG: soft lockup - CPU#582 stuck for 23s! [swapper/582:0]
[ 95.698128] BUG: soft lockup - CPU#357 stuck for 23s! [swapper/357:0]
This patch addresses the above issues by reducing HPET read contention
using the fact that if more than one CPUs are trying to access HPET at
the same time, it will be more efficient when only one CPU in the group
reads the HPET counter and shares it with the rest of the group instead
of each group member trying to read the HPET counter individually.
This is done by using a combination quadword that contains a 32-bit
stored HPET value and a 32-bit spinlock. The CPU that gets the lock
will be responsible for reading the HPET counter and storing it in
the quadword. The others will monitor the change in HPET value and
lock status and grab the latest stored HPET value accordingly. This
change is only enabled on 64-bit SMP configuration.
On a 4-socket Haswell-EX box with 144 threads (HT on), running the
AIM7 compute workload (1500 users) on a 4.8-rc1 kernel (HZ=1000)
with and without the patch has the following performance numbers
(with HPET or TSC as clock source):
TSC = 1042431 jobs/min
HPET w/o patch = 798068 jobs/min
HPET with patch = 1029445 jobs/min
The perf profile showed a reduction of the %CPU time consumed by
read_hpet from 11.19% without patch to 1.24% with patch.
[ tglx: It's really sad that we need to have such hacks just to deal with
the fact that cpu vendors have not managed to fix the TSC wreckage
within 15+ years. Were They Forgetting? ]
Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
Tested-by: Prarit Bhargava <prarit@redhat.com>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Cc: Randy Wright <rwright@hpe.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1473182530-29175-1-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
PKRU is the register that lets you disallow writes or all access to a given
protection key.
The XSAVE hardware defines an "init state" of 0 for PKRU: its most
permissive state, allowing access/writes to everything. Since we start off
all new processes with the init state, we start all processes off with the
most permissive possible PKRU.
This is unfortunate. If a thread is clone()'d [1] before a program has
time to set PKRU to a restrictive value, that thread will be able to write
to all data, no matter what pkey is set on it. This weakens any integrity
guarantees that we want pkeys to provide.
To fix this, we define a very restrictive PKRU to override the
XSAVE-provided value when we create a new FPU context. We choose a value
that only allows access to pkey 0, which is as restrictive as we can
practically make it.
This does not cause any practical problems with applications using
protection keys because we require them to specify initial permissions for
each key when it is allocated, which override the restrictive default.
In the end, this ensures that threads which do not know how to manage their
own pkey rights can not do damage to data which is pkey-protected.
I would have thought this was a pretty contrived scenario, except that I
heard a bug report from an MPX user who was creating threads in some very
early code before main(). It may be crazy, but folks evidently _do_ it.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: mgorman@techsingularity.net
Cc: arnd@arndb.de
Cc: linux-api@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: luto@kernel.org
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20160729163021.F3C25D4A@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds two new system calls:
int pkey_alloc(unsigned long flags, unsigned long init_access_rights)
int pkey_free(int pkey);
These implement an "allocator" for the protection keys
themselves, which can be thought of as analogous to the allocator
that the kernel has for file descriptors. The kernel tracks
which numbers are in use, and only allows operations on keys that
are valid. A key which was not obtained by pkey_alloc() may not,
for instance, be passed to pkey_mprotect().
These system calls are also very important given the kernel's use
of pkeys to implement execute-only support. These help ensure
that userspace can never assume that it has control of a key
unless it first asks the kernel. The kernel does not promise to
preserve PKRU (right register) contents except for allocated
pkeys.
The 'init_access_rights' argument to pkey_alloc() specifies the
rights that will be established for the returned pkey. For
instance:
pkey = pkey_alloc(flags, PKEY_DENY_WRITE);
will allocate 'pkey', but also sets the bits in PKRU[1] such that
writing to 'pkey' is already denied.
The kernel does not prevent pkey_free() from successfully freeing
in-use pkeys (those still assigned to a memory range by
pkey_mprotect()). It would be expensive to implement the checks
for this, so we instead say, "Just don't do it" since sane
software will never do it anyway.
Any piece of userspace calling pkey_alloc() needs to be prepared
for it to fail. Why? pkey_alloc() returns the same error code
(ENOSPC) when there are no pkeys and when pkeys are unsupported.
They can be unsupported for a whole host of reasons, so apps must
be prepared for this. Also, libraries or LD_PRELOADs might steal
keys before an application gets access to them.
This allocation mechanism could be implemented in userspace.
Even if we did it in userspace, we would still need additional
user/kernel interfaces to tell userspace which keys are being
used by the kernel internally (such as for execute-only
mappings). Having the kernel provide this facility completely
removes the need for these additional interfaces, or having an
implementation of this in userspace at all.
Note that we have to make changes to all of the architectures
that do not use mman-common.h because we use the new
PKEY_DENY_ACCESS/WRITE macros in arch-independent code.
1. PKRU is the Protection Key Rights User register. It is a
usermode-accessible register that controls whether writes
and/or access to each individual pkey is allowed or denied.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: arnd@arndb.de
Cc: linux-api@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: luto@kernel.org
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20160729163015.444FE75F@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The CPPC registers can also be accessed via functional fixed hardware
addresse(FFH) in X86. Add support by modifying cpc_read and cpc_write to
be able to read/write MSRs on x86 platform on per cpu basis.
Also with this change, acpi_cppc_processor_probe doesn't bail out if
address space id is not equal to PCC or memory address space and FFH
is supported on the system.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When booting a kvm guest on AMD with the latest kernel the following
messages are displayed in the boot log:
tsc: Unable to calibrate against PIT
tsc: HPET/PMTIMER calibration failed
aa297292d7 ("x86/tsc: Enumerate SKL cpu_khz and tsc_khz via CPUID")
introduced a change to account for a difference in cpu and tsc frequencies for
Intel SKL processors. Before this change the native tsc set
x86_platform.calibrate_tsc to native_calibrate_tsc() which is a hardware
calibration of the tsc, and in tsc_init() executed
tsc_khz = x86_platform.calibrate_tsc();
cpu_khz = tsc_khz;
The kvm code changed x86_platform.calibrate_tsc to kvm_get_tsc_khz() and
executed the same tsc_init() function. This meant that KVM guests did not
execute the native hardware calibration function.
After aa297292d7, there are separate native calibrations for cpu_khz and
tsc_khz. The code sets x86_platform.calibrate_tsc to native_calibrate_tsc()
which is now an Intel specific calibration function, and
x86_platform.calibrate_cpu to native_calibrate_cpu() which is the "old"
native_calibrate_tsc() function (ie, the native hardware calibration
function).
tsc_init() now does
cpu_khz = x86_platform.calibrate_cpu();
tsc_khz = x86_platform.calibrate_tsc();
if (tsc_khz == 0)
tsc_khz = cpu_khz;
else if (abs(cpu_khz - tsc_khz) * 10 > tsc_khz)
cpu_khz = tsc_khz;
The kvm code should not call the hardware initialization in
native_calibrate_cpu(), as it isn't applicable for kvm and it didn't do that
prior to aa297292d7.
This patch resolves this issue by setting x86_platform.calibrate_cpu to
kvm_get_tsc_khz().
v2: I had originally set x86_platform.calibrate_cpu to
cpu_khz_from_cpuid(), however, pbonzini pointed out that the CPUID leaf
in that function is not available in KVM. I have changed the function
pointer to kvm_get_tsc_khz().
Fixes: aa297292d7 ("x86/tsc: Enumerate SKL cpu_khz and tsc_khz via CPUID")
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Len Brown <len.brown@intel.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: "Christopher S. Hall" <christopher.s.hall@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The (start, size) tuple represents a range [start, start + size - 1],
which means "start" and "start + size - 1" should be compared to see
whether the range overflows.
For example, a range with (start, size):
(0xffffffff fffffff0, 0x00000000 00000010)
represents
[0xffffffff fffffff0, 0xffffffff ffffffff]
... would be judged overflow in the original code, while actually it is not.
This patch fixes this and makes sure it still works when size is zero.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
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: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/1471657213-31817-1-git-send-email-richard.weiyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The various functions involved in dumping the stack all do similar
things with regard to getting the stack pointer and the frame pointer
based on the regs and task arguments. Create helper functions to
do that instead.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/f448914885a35f333fe04da1b97a6c2cc1f80974.1472057064.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change printk_stack_address() to be useful when called by an unwinder
outside the context of dump_trace().
Specifically:
- printk_stack_address()'s 'data' argument is always used as the log
level string. Make that explicit.
- Call touch_nmi_watchdog().
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/9fbe0db05bacf66d337c162edbf61450d0cff1e2.1472057064.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If we get a page fault indicating kernel stack overflow, invoke
handle_stack_overflow(). To prevent us from overflowing the stack
again while handling the overflow (because we are likely to have
very little stack space left), call handle_stack_overflow() on the
double-fault stack.
Signed-off-by: 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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/6d6cf96b3fb9b4c9aa303817e1dc4de0c7c36487.1472603235.git.luto@kernel.org
[ Minor edit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If the topology package map check of the APIC ID and the CPU is a failure,
we don't generate the processor info for that APIC ID yet we increase
disabled_cpus by one - which is buggy.
Only increase num_processors once we are sure we don't fail.
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1473214893-16481-1-git-send-email-douly.fnst@cn.fujitsu.com
[ Rewrote the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As recommended by Ville Syrjala removing .is_mobile field from the
platform struct definition for vlv and hsw+ GPUs as there's no need to
make the distinction in later hardware anymore. Keep it for older GPUs
as it is still needed for ilk-ivb.
Signed-off-by: Carlos Santa <carlos.santa@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Install the callbacks via the state machine. The online & down callbacks are
invoked on the target CPU so we can avoid using smp_call_function_single().
local_irq_disable() is used because smp_call_function_single() used to invoke
the function with interrupts disabled.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160818125731.27256-15-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We now have a better way to determine if we are running on a cpu that
supports machine check recovery. Free up this feature bit.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/d5db39e08d46cf1012d94d3902275d08ba931926.1472754712.git.tony.luck@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use the mcsafe_key defined in the previous patch to make decisions on which
copy function to use. We can't use the FEATURE bit any more because PCI
quirks run too late to affect the patching of code. So we use a static key.
Turn memcpy_mcsafe() into an inline function to make life easier for
callers. The assembly code that actually does the copy is now named
memcpy_mcsafe_unrolled()
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/bfde2fc774e94f53d91b70a4321c85a0d33e7118.1472754712.git.tony.luck@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Each Xeon includes a number of capability registers in PCI space that
describe some features not enumerated by CPUID.
Use these to determine that we are running on a model that can recover from
machine checks. Hooks for Ivybridge ... Skylake provided.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/abf331dc4a3e2a2d17444129bc51127437bcf4ba.1472754711.git.tony.luck@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We do not need to add the randomization offset when the microcode is
built in.
Reported-and-tested-by: Emanuel Czirai <icanrealizeum@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20160904093736.GA11939@pd.tnic
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull x86 fix from Thomas Gleixner:
"A single fix for an AMD erratum so machines without a BIOS fix work"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/AMD: Apply erratum 665 on machines without a BIOS fix
AMD F12h machines have an erratum which can cause DIV/IDIV to behave
unpredictably. The workaround is to set MSRC001_1029[31] but sometimes
there is no BIOS update containing that workaround so let's do it
ourselves unconditionally. It is simple enough.
[ Borislav: Wrote commit message. ]
Signed-off-by: Emanuel Czirai <icanrealizeum@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Yaowu Xu <yaowu@google.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20160902053550.18097-1-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Łukasz Daniluk reported that on a RHEL kernel that his machine would lock up
after enabling function tracer. I asked him to bisect the functions within
available_filter_functions, which he did and it came down to three:
_paravirt_nop(), _paravirt_ident_32() and _paravirt_ident_64()
It was found that this is only an issue when noreplace-paravirt is added
to the kernel command line.
This means that those functions are most likely called within critical
sections of the funtion tracer, and must not be traced.
In newer kenels _paravirt_nop() is defined within gcc asm(), and is no
longer an issue. But both _paravirt_ident_{32,64}() causes the
following splat when they are traced:
mm/pgtable-generic.c:33: bad pmd ffff8800d2435150(0000000001d00054)
mm/pgtable-generic.c:33: bad pmd ffff8800d3624190(0000000001d00070)
mm/pgtable-generic.c:33: bad pmd ffff8800d36a5110(0000000001d00054)
mm/pgtable-generic.c:33: bad pmd ffff880118eb1450(0000000001d00054)
NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s! [systemd-journal:469]
Modules linked in: e1000e
CPU: 2 PID: 469 Comm: systemd-journal Not tainted 4.6.0-rc4-test+ #513
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
task: ffff880118f740c0 ti: ffff8800d4aec000 task.ti: ffff8800d4aec000
RIP: 0010:[<ffffffff81134148>] [<ffffffff81134148>] queued_spin_lock_slowpath+0x118/0x1a0
RSP: 0018:ffff8800d4aefb90 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88011eb16d40
RDX: ffffffff82485760 RSI: 000000001f288820 RDI: ffffea0000008030
RBP: ffff8800d4aefb90 R08: 00000000000c0000 R09: 0000000000000000
R10: ffffffff821c8e0e R11: 0000000000000000 R12: ffff880000200fb8
R13: 00007f7a4e3f7000 R14: ffffea000303f600 R15: ffff8800d4b562e0
FS: 00007f7a4e3d7840(0000) GS:ffff88011eb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7a4e3f7000 CR3: 00000000d3e71000 CR4: 00000000001406e0
Call Trace:
_raw_spin_lock+0x27/0x30
handle_pte_fault+0x13db/0x16b0
handle_mm_fault+0x312/0x670
__do_page_fault+0x1b1/0x4e0
do_page_fault+0x22/0x30
page_fault+0x28/0x30
__vfs_read+0x28/0xe0
vfs_read+0x86/0x130
SyS_read+0x46/0xa0
entry_SYSCALL_64_fastpath+0x1e/0xa8
Code: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 40 6d 01 00 48 03 14 c5 80 6a 5d 82 48 89 0a 8b 41 08 85 c0 75 09 f3 90 8b 41 08 <85> c0 74 f7 4c 8b 09 4d 85 c9 74 08 41 0f 18 09 eb 02 f3 90 8b
Reported-by: Łukasz Daniluk <lukasz.daniluk@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
thread_saved_pc() was using a completely bogus method to get the return
address. Since switch_to() was previously inlined, there was no sane way
to know where on the stack the return address was stored. Now with the
frame of a sleeping thread well defined, this can be implemented correctly.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1471106302-10159-7-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Instead of setting up a fake pt_regs context, put the kernel thread
function pointer and arg into the unused callee-restored registers
of 'struct fork_frame'.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1471106302-10159-6-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Move the low-level context switch code to an out-of-line asm stub instead of
using complex inline asm. This allows constructing a new stack frame for the
child process to make it seamlessly flow to ret_from_fork without an extra
test and branch in __switch_to(). It also improves code generation for
__schedule() by using the C calling convention instead of clobbering all
registers.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1471106302-10159-5-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add 'struct inactive_task_frame', which defines the layout of the stack for
a sleeping process. For now, the only defined field is the BP register
(frame pointer).
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1471106302-10159-4-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
switch_to() no longer saves EFLAGS, so it's bogus to look for it on the
stack. Set it to zero like 32-bit.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1471106302-10159-3-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Match 64-bit and set gdb_regs[GDB_PC] to zero. thread.ip is always the
same point in the scheduler (except for newly forked processes), and will
be removed in a future patch.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1471106302-10159-2-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When function graph tracing is enabled, print_context_stack_bp() can
report return_to_handler() as an unreliable address, which is confusing
and misleading: return_to_handler() is really only useful as a hint for
debugging, whereas print_context_stack_bp() users only care about the
actual 'reliable' call path.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/c51aef578d8027791b38d2ad9bac0c7f499fde91.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When function graph tracing is enabled for a function, its return
address on the stack is replaced with the address of an ftrace handler
(return_to_handler).
Currently 'return_to_handler' can be reported as reliable. That's not
ideal, and can actually be misleading. When saving or dumping the
stack, you normally only care about what led up to that point (the call
path), rather than what will happen in the future (the return path).
That's especially true in the non-oops stack trace case, which isn't
used for debugging. For example, in a perf profiling operation,
reporting return_to_handler() in the trace would just be confusing.
And in the oops case, where debugging is important, "unreliable" is also
more appropriate there because it serves as a hint that graph tracing
was involved, instead of trying to imply that return_to_handler() was
the real caller.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/f8af15749c7d632d3e7f815995831d5b7f82950d.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use the more reliable version of ftrace_graph_ret_addr() so we no longer
have to worry about the unwinder getting out of sync with the function
graph ret_stack index, which can happen if the unwinder skips any frames
before calling ftrace_graph_ret_addr().
This fixes this issue (and several others like it):
$ cat /proc/self/stack
[<ffffffff810489a2>] save_stack_trace_tsk+0x22/0x40
[<ffffffff81311a89>] proc_pid_stack+0xb9/0x110
[<ffffffff813127c4>] proc_single_show+0x54/0x80
[<ffffffff812be088>] seq_read+0x108/0x3e0
[<ffffffff812923d7>] __vfs_read+0x37/0x140
[<ffffffff812929d9>] vfs_read+0x99/0x140
[<ffffffff81293f28>] SyS_read+0x58/0xc0
[<ffffffff818af97c>] entry_SYSCALL_64_fastpath+0x1f/0xbd
[<ffffffffffffffff>] 0xffffffffffffffff
$ echo function_graph > /sys/kernel/debug/tracing/current_tracer
$ cat /proc/self/stack
[<ffffffff818b2428>] return_to_handler+0x0/0x27
[<ffffffff810394cc>] print_context_stack+0xfc/0x100
[<ffffffff818b2428>] return_to_handler+0x0/0x27
[<ffffffff8103891b>] dump_trace+0x12b/0x350
[<ffffffff818b2428>] return_to_handler+0x0/0x27
[<ffffffff810489a2>] save_stack_trace_tsk+0x22/0x40
[<ffffffff818b2428>] return_to_handler+0x0/0x27
[<ffffffff81311a89>] proc_pid_stack+0xb9/0x110
[<ffffffff818b2428>] return_to_handler+0x0/0x27
[<ffffffff813127c4>] proc_single_show+0x54/0x80
[<ffffffff818b2428>] return_to_handler+0x0/0x27
[<ffffffff812be088>] seq_read+0x108/0x3e0
[<ffffffff818b2428>] return_to_handler+0x0/0x27
[<ffffffff812923d7>] __vfs_read+0x37/0x140
[<ffffffff818b2428>] return_to_handler+0x0/0x27
[<ffffffff812929d9>] vfs_read+0x99/0x140
[<ffffffffffffffff>] 0xffffffffffffffff
Enabling function graph tracing causes the stack trace to change in two
ways:
First, the real call addresses are confusingly interspersed with
'return_to_handler' addresses. This issue will be fixed by the next
patch.
Second, the stack trace is offset by two frames, because the unwinder
skipped the first two frames and got out of sync with the ret_stack
index. This patch fixes this issue.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a6d623e36f8d08f9a17bd74d804d201177a23afd.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Storing this value will help prevent unwinders from getting out of sync
with the function graph tracer ret_stack. Now instead of needing a
stateful iterator, they can compare the return address pointer to find
the right ret_stack entry.
Note that an array of 50 ftrace_ret_stack structs is allocated for every
task. So when an arch implements this, it will add either 200 or 400
bytes of memory usage per task (depending on whether it's a 32-bit or
64-bit platform).
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a95cfcc39e8f26b89a430c56926af0bb217bc0a1.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This allows x86_64 kernels to enable vmapped stacks by setting
HAVE_ARCH_VMAP_STACK=y - which enables the CONFIG_VMAP_STACK=y
high level Kconfig option.
There are a couple of interesting bits:
First, x86 lazily faults in top-level paging entries for the vmalloc
area. This won't work if we get a page fault while trying to access
the stack: the CPU will promote it to a double-fault and we'll die.
To avoid this problem, probe the new stack when switching stacks and
forcibly populate the pgd entry for the stack when switching mms.
Second, once we have guard pages around the stack, we'll want to
detect and handle stack overflow.
I didn't enable it on x86_32. We'd need to rework the double-fault
code a bit and I'm concerned about running out of vmalloc virtual
addresses under some workloads.
This patch, by itself, will behave somewhat erratically when the
stack overflows while RSP is still more than a few tens of bytes
above the bottom of the stack. Specifically, we'll get #PF and make
it to no_context and them oops without reliably triggering a
double-fault, and no_context doesn't know about stack overflows.
The next patch will improve that case.
Thank you to Nadav and Brian for helping me pay enough attention to
the SDM to hopefully get this right.
Signed-off-by: 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: Nadav Amit <nadav.amit@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/c88f3e2920b18e6cc621d772a04a62c06869037e.1470907718.git.luto@kernel.org
[ Minor edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This is not a bugfix, but code optimization.
If the BSP's APIC ID in local APIC is unexpected,
a kernel panic will occur and the system will halt.
That means no need to enable APIC mode, and no reason
to set up the default routing for APIC.
The combination of default_setup_apic_routing() and
apic_bsp_setup() are used to enable APIC mode.
They two should be kept together, rather than being
separated by the codes of checking APIC ID.
Just like their usage in APIC_init_uniprocessor().
Signed-off-by: Wei Jiangang <weijg.fnst@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/1471576957-12961-1-git-send-email-weijg.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The comment probably meant some old AMD64 incarnation which most likely
never saw the light of day. STAR and LSTAR are two different registers
and STAR sets CS/SS(DS) selectors for *all* modes, not only 32-bit.
So simply remove that comment.
Signed-off-by: Borislav Petkov <bp@suse.de>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160823172356.15879-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
native_smp_prepare_cpus
-> default_setup_apic_routing
-> enable_IR_x2apic
-> irq_remapping_prepare
-> intel_prepare_irq_remapping
-> intel_setup_irq_remapping
So IR table is setup even if "noapic" boot parameter is added. As a result we
crash later when the interrupt affinity is set due to a half initialized
remapping infrastructure.
Prevent remap initialization when IOAPIC is disabled.
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Joerg Roedel <joro@8bytes.org>
Link: http://lkml.kernel.org/r/1471954039-3942-1-git-send-email-wanpeng.li@hotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Implement arch_klp_init_object_loaded() for x86, which applies
alternatives/paravirt patches. This fixes the order in which relocations
and alternatives/paravirt patches are applied.
Previously, if a patch module had alternatives or paravirt patches,
these were applied first by the module loader before livepatch can apply
per-object relocations. The (buggy) sequence of events was:
(1) Load patch module
(2) Apply alternatives and paravirt patches to patch module
* Note that these are applied to the new functions in the patch module
(3) Apply per-object relocations to patch module when target module loads.
* This clobbers what was written in step 2
This lead to crashes and corruption in general, since livepatch would
overwrite or step on previously applied alternative/paravirt patches.
The correct sequence of events should be:
(1) Load patch module
(2) Apply per-object relocations to patch module
(3) Apply alternatives and paravirt patches to patch module
This is fixed by delaying paravirt/alternatives patching until after
relocations are applied. Any .altinstructions or .parainstructions
sections are prefixed with ".klp.arch.${objname}" and applied in
arch_klp_init_object_loaded().
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
There has been a 64-byte gap at the end of the irq stack for at least 12
years. It predates git history, and I can't find any good reason for
it. Remove it. What's the worst that could happen?
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/14f9281c5475cc44af95945ea7546bff2e3836db.1471535549.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On x86_32, when an interrupt happens from kernel space, SS and SP aren't
pushed and the existing stack is used. So pt_regs is effectively two
words shorter, and the previous stack pointer is normally the memory
after the shortened pt_regs, aka '®s->sp'.
But in the rare case where the interrupt hits right after the stack
pointer has been changed to point to an empty stack, like for example
when call_on_stack() is used, the address immediately after the
shortened pt_regs is no longer on the stack. In that case, instead of
'®s->sp', the previous stack pointer should be retrieved from the
beginning of the current stack page.
kernel_stack_pointer() wants to do that, but it forgets to dereference
the pointer. So instead of returning a pointer to the previous stack,
it returns a pointer to the beginning of the current stack.
Note that it's probably outside of kernel_stack_pointer()'s scope to be
switching stacks at all. The x86_64 version of this function doesn't do
it, and it would be better for the caller to do it if necessary. But
that's a patch for another day. This just fixes the original intent.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 0788aa6a23 ("x86: Prepare removal of previous_esp from i386 thread_info structure")
Link: http://lkml.kernel.org/r/472453d6e9f6a2d4ab16aaed4935f43117111566.1471535549.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This zeroed word has no apparent purpose, so remove it.
Brian Gerst says:
"FYI the word used to be the SS segment selector for the LSS
instruction, which isn't needed in 64-bit mode."
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/b056855c295bbb3825b97c1e9f7958539a4d6cf2.1471535549.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When starting the dump of an exception stack, it shows "<<EOE>>" instead
of "<EOE>". print_trace_stack() already adds brackets, no need to add
them again.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/77f185fd5b81845869b400aa619415458df6b6cc.1471535549.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
