Fix boot crash that triggers if this driver is built into a kernel and
run on non-AMD systems.
AMD northbridges users call amd_cache_northbridges() and it returns
a negative value to signal that we weren't able to cache/detect any
northbridges on the system.
At least, it should do so as all its callers expect it to do so. But it
does return a negative value only when kmalloc() fails.
Fix it to return -ENODEV if there are no NBs cached as otherwise, amd_nb
users like amd64_edac, for example, which relies on it to know whether
it should load or not, gets loaded on systems like Intel Xeons where it
shouldn't.
Reported-and-tested-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
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/1466097230-5333-2-git-send-email-bp@alien8.de
Link: https://lkml.kernel.org/r/5761BEB0.9000807@cybernetics.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There is a generic function __pvclock_read_cycles to be used to get both
flags and cycles. For function pvclock_read_flags, it's useless to get
cycles value. To make this function be more effective, get this variable
flags directly in function.
Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Protocol for the "version" fields is: hypervisor raises it (making it
uneven) before it starts updating the fields and raises it again (making
it even) when it is done. Thus the guest can make sure the time values
it got are consistent by checking the version before and after reading
them.
Add CPU barries after getting version value just like what function
vread_pvclock does, because all of callees in this function is inline.
Fixes: 502dfeff23
Cc: stable@vger.kernel.org
Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull x86 kprobe fix from Thomas Gleixner:
"A single fix clearing the TF bit when a fault is single stepped"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kprobes/x86: Clear TF bit in fault on single-stepping
Merge misc fixes from Andrew Morton:
"Two weeks worth of fixes here"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (41 commits)
init/main.c: fix initcall_blacklisted on ia64, ppc64 and parisc64
autofs: don't get stuck in a loop if vfs_write() returns an error
mm/page_owner: avoid null pointer dereference
tools/vm/slabinfo: fix spelling mistake: "Ocurrences" -> "Occurrences"
fs/nilfs2: fix potential underflow in call to crc32_le
oom, suspend: fix oom_reaper vs. oom_killer_disable race
ocfs2: disable BUG assertions in reading blocks
mm, compaction: abort free scanner if split fails
mm: prevent KASAN false positives in kmemleak
mm/hugetlb: clear compound_mapcount when freeing gigantic pages
mm/swap.c: flush lru pvecs on compound page arrival
memcg: css_alloc should return an ERR_PTR value on error
memcg: mem_cgroup_migrate() may be called with irq disabled
hugetlb: fix nr_pmds accounting with shared page tables
Revert "mm: disable fault around on emulated access bit architecture"
Revert "mm: make faultaround produce old ptes"
mailmap: add Boris Brezillon's email
mailmap: add Antoine Tenart's email
mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask
mm: mempool: kasan: don't poot mempool objects in quarantine
...
As the actual pointer value is the same for the thread stack allocation
and the thread_info, code that confused the two worked fine, but will
break when the thread info is moved away from the stack allocation. It
also looks very confusing.
For example, the kprobe code wanted to know the current top of stack.
To do that, it used this:
(unsigned long)current_thread_info() + THREAD_SIZE
which did indeed give the correct value. But it's not only a fairly
nonsensical expression, it's also rather complex, especially since we
actually have this:
static inline unsigned long current_top_of_stack(void)
which not only gives us the value we are interested in, but happens to
be how "current_thread_info()" is currently defined as:
(struct thread_info *)(current_top_of_stack() - THREAD_SIZE);
so using current_thread_info() to figure out the top of the stack really
is a very round-about thing to do.
The other cases are just simpler confusion about task_thread_info() vs
task_stack_page(), which currently return the same pointer - but if you
want the stack page, you really should be using the latter one.
And there was one entirely unused assignment of the current stack to a
thread_info pointer.
All cleaned up to make more sense today, and make it easier to move the
thread_info away from the stack in the future.
No semantic changes.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
None of the code actually wants a thread_info, it all wants a
task_struct, and it's just converting to a thread_info pointer much too
early.
No semantic change.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Refer initrd_start, initrd_end directly from drivers/acpi/tables.c.
This allows to use the table upgrade feature in architectures
other than x86. Also this simplifies header files.
The patch renames acpi_table_initrd_init() to acpi_table_upgrade()
(what reflects the purpose of the function) and removes the unneeded
wraps early_acpi_table_init() and early_initrd_acpi_init().
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Acked-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There were at least 3 features added to the __SI_FAULT area of the
siginfo struct that did not make it to the compat siginfo:
1. The si_addr_lsb used in SIGBUS's sent for machine checks
2. The upper/lower bounds for MPX SIGSEGV faults
3. The protection key for pkey faults
There was also some turmoil when I was attempting to add the pkey
field because it needs to be a fixed size on 32 and 64-bit and
not have any alignment constraints.
This patch adds some compile-time checks to the compat code to
make it harder to screw this up. Basically, the checks are
supposed to trip any time someone changes the siginfo structure.
That sounds bad, but it's what we want. If someone changes
siginfo, we want them to also be _forced_ to go look at the
compat code.
The details are in the comments.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/20160608172534.C73DAFC3@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The 32-bit siginfo is a different binary format than the 64-bit
one. So, when running 32-bit binaries on 64-bit kernels, we have
to convert the kernel's 64-bit version to a 32-bit version that
userspace can grok.
We've added a few features to siginfo over the past few years and
neglected to add them to arch/x86/kernel/signal_compat.c:
1. The si_addr_lsb used in SIGBUS's sent for machine checks
2. The upper/lower bounds for MPX SIGSEGV faults
3. The protection key for pkey faults
I caught this with some protection keys unit tests and realized
it affected a few more features.
This was tested only with my protection keys patch that looks
for a proper value in si_pkey. I didn't actually test the machine
check or MPX code.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/20160608172533.F8F05637@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fix kprobe_fault_handler() to clear the TF (trap flag) bit of
the flags register in the case of a fault fixup on single-stepping.
If we put a kprobe on the instruction which caused a
page fault (e.g. actual mov instructions in copy_user_*),
that fault happens on the single-stepping buffer. In this
case, kprobes resets running instance so that the CPU can
retry execution on the original ip address.
However, current code forgets to reset the TF bit. Since this
fault happens with TF bit set for enabling single-stepping,
when it retries, it causes a debug exception and kprobes
can not handle it because it already reset itself.
On the most of x86-64 platform, it can be easily reproduced
by using kprobe tracer. E.g.
# cd /sys/kernel/debug/tracing
# echo p copy_user_enhanced_fast_string+5 > kprobe_events
# echo 1 > events/kprobes/enable
And you'll see a kernel panic on do_debug(), since the debug
trap is not handled by kprobes.
To fix this problem, we just need to clear the TF bit when
resetting running kprobe.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
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: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: systemtap@sourceware.org
Cc: stable@vger.kernel.org # All the way back to ancient kernels
Link: http://lkml.kernel.org/r/20160611140648.25885.37482.stgit@devbox
[ Updated the comments. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The NMI watchdog uses either the fixed cycles or a generic cycles
counter. This causes a lot of conflicts with users of the PMU who want
to run a full group including the cycles fixed counter, for example
the --topdown support recently added to perf stat. The code needs to
fall back to not use groups, which can cause measurement inaccuracy
due to multiplexing errors.
This patch switches the NMI watchdog to use reference cycles
on Intel systems. This is actually more accurate than cycles,
because cycles can tick faster than the measured CPU Frequency
due to Turbo mode.
The ref cycles always tick at their frequency, or slower when
the system is idling. That means the NMI watchdog can never
expire too early, unlike with cycles.
The reference cycles tick roughly at the frequency of the TSC,
so the same period computation can be used.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: http://lkml.kernel.org/r/1465478079-19993-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Sometimes, after CPU hotplug you can observe a spike in stolen time
(100%) followed by the CPU being marked as 100% idle when it's actually
busy with a CPU hog task. The trace looks like the following:
cpuhp/1-12 [001] d.h1 167.461657: account_process_tick: steal = 1291385514, prev_steal_time = 0
cpuhp/1-12 [001] d.h1 167.461659: account_process_tick: steal_jiffies = 1291
<idle>-0 [001] d.h1 167.462663: account_process_tick: steal = 18732255, prev_steal_time = 1291000000
<idle>-0 [001] d.h1 167.462664: account_process_tick: steal_jiffies = 18446744072437
The sudden decrease of "steal" causes steal_jiffies to underflow.
The root cause is kvm_steal_time being reset to 0 after hot-plugging
back in a CPU. Instead, the preexisting value can be used, which is
what the core scheduler code expects.
John Stultz also reported a similar issue after guest S3.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1465813966-3116-2-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On a 4-socket Brickland system, hot-removing one ioapic is fine.
Hot-removing the 2nd one causes panic in mp_unregister_ioapic()
while calling release_resource().
It is because the iomem_res pointer has already been released
when removing the first ioapic.
To explain the use of &res[num] here: res is assigned to ioapic_resources,
and later in ioapic_insert_resources() we do:
struct resource *r = ioapic_resources;
for_each_ioapic(i) {
insert_resource(&iomem_resource, r);
r++;
}
Here 'r' is treated as an arry of 'struct resource', and the r++ ensures
that each element of the array is inserted separately. Thus we should call
release_resouce() on each element at &res[num].
Fix it by assigning the correct pointers to ioapics[i].iomem_res in
ioapic_setup_resources().
Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: tony.luck@intel.com
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: bhelgaas@google.com
Link: http://lkml.kernel.org/r/1465369193-4816-3-git-send-email-rui.y.wang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use CC_SET()/CC_OUT() and static_cpu_has(). This produces code good
enough to eliminate ad hoc use of alternatives in <asm/archrandom.h>,
greatly simplifying the code.
While we are at it, make x86_init_rdrand() compile out completely if
we don't need it.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1465414726-197858-11-git-send-email-hpa@linux.intel.com
v2: fix a conflict between <linux/random.h> and <asm/archrandom.h>
discovered by Ingo Molnar. There are a few places in x86-specific
code where we need all of <arch/archrandom.h> even when
CONFIG_ARCH_RANDOM is disabled, so <linux/random.h> does not
suffice.
People complained about ARCH_HWEIGHT_CFLAGS and how it throws a wrench
into kcov, lto, etc, experimentations.
Add asm versions for __sw_hweight{32,64}() and do explicit saving and
restoring of clobbered registers. This gets rid of the special calling
convention. We get to call those functions on !X86_FEATURE_POPCNT CPUs.
We still need to hardcode POPCNT and register operands as some old gas
versions which we support, do not know about POPCNT.
Btw, remove redundant REX prefix from 32-bit POPCNT because alternatives
can do padding now.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@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/1464605787-20603-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
I've been carrying this patch around for a bit and it's helped me
solve at least a couple FPU-related bugs. In addition to using
it for debugging, I also drug it out because using AVX (and
AVX2/AVX-512) can have serious power consequences for a modern
core. It's very important to be able to figure out who is using
it.
It's also insanely useful to go out and see who is using a given
feature, like MPX or Memory Protection Keys. If you, for
instance, want to find all processes using protection keys, you
can do:
echo 'xfeatures & 0x200' > filter
Since 0x200 is the protection keys feature bit.
Note that this touches the KVM code. KVM did a CREATE_TRACE_POINTS
and then included a bunch of random headers. If anyone one of
those included other tracepoints, it would have defined the *OTHER*
tracepoints. That's bogus, so move it to the right place.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160601174220.3CDFB90E@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
