Before offlining a CPU its required to check whether there are enough free
irq vectors available so interrupts can be migrated away from the CPU.
This check is executed whether its required or not and neither stops
searching when the number of required free vectors are reached.
Bypass the free vector check if the current CPU has no irq to migrate and
leave the for_each_online_cpu() loop when the free vector count reaches the
number of required vectors.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Len Brown <lenb@kernel.orq>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/1492357410-510-1-git-send-email-yu.c.chen@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
mce_usable_address() does a bunch of basic sanity checks to verify
whether the address reported with the error is usable for further
processing. However, we do check MCi_STATUS[MISCV] and that is not
needed on AMD as that bit says that there's additional information about
the logged error in the MCi_MISCj banks.
But we don't need that to know whether the address is usable - we only
need to know whether the physical address is valid - i.e., ADDRV.
On Intel the MISCV bit is needed to perform additional checks to determine
whether the reported address is a physical one, etc.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20170418183924.6agjkebilwqj26or@pd.tnic
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
On x86-32, 32-bit stack values printed by unwind_dump() are confusingly
zero-padded to 16 characters (64 bits):
unwind stack type:0 next_sp: (null) mask:a graph_idx:0
f50cdebc: 00000000f50cdec4 (0xf50cdec4)
f50cdec0: 00000000c40489b7 (irq_exit+0x87/0xa0)
...
Instead, base the field width on the size of a long integer so that it
looks right on both x86-32 and x86-64.
x86-32:
unwind stack type:1 next_sp: (null) mask:0x2 graph_idx:0
c0ee9d98: c0ee9de0 (init_thread_union+0x1de0/0x2000)
c0ee9d9c: c043fd90 (__save_stack_trace+0x50/0xe0)
...
x86-64:
unwind stack type:1 next_sp: (null) mask:0x2 graph_idx:0
ffffffff81e03b88: ffffffff81e03c10 (init_thread_union+0x3c10/0x4000)
ffffffff81e03b90: ffffffff81048f8e (__save_stack_trace+0x5e/0x100)
...
Reported-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/36b743812e7eb291d74af4e5067736736622daad.1492520933.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The NFIT MCE handler callback (for handling media errors on NVDIMMs)
takes a mutex to add the location of a memory error to a list. But since
the notifier call chain for machine checks (x86_mce_decoder_chain) is
atomic, we get a lockdep splat like:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
in_atomic(): 1, irqs_disabled(): 0, pid: 4, name: kworker/0:0
[..]
Call Trace:
dump_stack
___might_sleep
__might_sleep
mutex_lock_nested
? __lock_acquire
nfit_handle_mce
notifier_call_chain
atomic_notifier_call_chain
? atomic_notifier_call_chain
mce_gen_pool_process
Convert the notifier to a blocking one which gets to run only in process
context.
Boris: remove the notifier call in atomic context in print_mce(). For
now, let's print the MCE on the atomic path so that we can make sure
they go out and get logged at least.
Fixes: 6839a6d96f ("nfit: do an ARS scrub on hitting a latent media error")
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20170411224457.24777-1-vishal.l.verma@intel.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
With frame pointers disabled, on some older versions of GCC (like
4.8.3), it's possible for the stack pointer to get aligned at a
half-word boundary:
00000000000004d0 <fib_table_lookup>:
4d0: 41 57 push %r15
4d2: 41 56 push %r14
4d4: 41 55 push %r13
4d6: 41 54 push %r12
4d8: 55 push %rbp
4d9: 53 push %rbx
4da: 48 83 ec 24 sub $0x24,%rsp
In such a case, the unwinder ends up reading the entire stack at the
wrong alignment. Then the last read goes past the end of the stack,
hitting the stack guard page:
BUG: stack guard page was hit at ffffc900217c4000 (stack is ffffc900217c0000..ffffc900217c3fff)
kernel stack overflow (page fault): 0000 [#1] SMP
...
Fix it by ensuring the stack pointer is properly aligned before
unwinding.
Reported-by: Jirka Hladky <jhladky@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 7c7900f897 ("x86/unwind: Add new unwind interface and implementations")
Link: http://lkml.kernel.org/r/cff33847cc9b02fa548625aa23268ac574460d8d.1492436590.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the x86 arch's apic clockevent driver initialize these fields
properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
CC: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
The files in the info directory for MBA are as follows:
num_closids
The maximum number of CLOSids available for MBA
min_bandwidth
The minimum memory bandwidth percentage value
bandwidth_gran
The granularity of the bandwidth control in percent for the
particular CPU SKU. Intermediate values entered are rounded off
to the previous control step available. Available bandwidth
control steps are minimum_bandwidth + N * bandwidth_gran.
delay_linear
When set, the OS writes a linear percentage based value to the
control MSRs ranging from minimum_bandwidth to 100 percent.
This value is informational and has no influence on the values
written to the schemata files. The values written to the
schemata are always bandwidth percentage that is requested.
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: vikas.shivappa@intel.com
Link: http://lkml.kernel.org/r/1491611637-20417-7-git-send-email-vikas.shivappa@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Memory bandwidth allocation requires different information than cache
allocation.
To avoid a lump of data in struct rdt_resource, move all cache related
information into a seperate structure and add that to struct rdt_resource.
Sanitize the data types while at it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: vikas.shivappa@intel.com
The classic PC rtc-coms driver has a workaround for broken ACPI device
nodes for it which lack an irq resource. This workaround used to
unconditionally hardcode the irq to 8 in these cases.
This was causing irq conflict problems on systems without a legacy-pic
so a recent patch added an if (nr_legacy_irqs()) guard to the
workaround to avoid this irq conflict.
nr_legacy_irqs() uses the legacy_pic symbol under the hood causing
an undefined symbol error if the rtc-cmos code is build as a module.
This commit exports the legacy_pic symbol to fix this.
Cc: rtc-linux@googlegroups.com
Cc: alexandre.belloni@free-electrons.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
On x86-32, with CONFIG_FIRMWARE and multiple CPUs, if you enable function
graph tracing and then suspend to RAM, it will triple fault and reboot when
it resumes.
The first fault happens when booting a secondary CPU:
startup_32_smp()
load_ucode_ap()
prepare_ftrace_return()
ftrace_graph_is_dead()
(accesses 'kill_ftrace_graph')
The early head_32.S code calls into load_ucode_ap(), which has an an
ftrace hook, so it calls prepare_ftrace_return(), which calls
ftrace_graph_is_dead(), which tries to access the global
'kill_ftrace_graph' variable with a virtual address, causing a fault
because the CPU is still in real mode.
The fix is to add a check in prepare_ftrace_return() to make sure it's
running in protected mode before continuing. The check makes sure the
stack pointer is a virtual kernel address. It's a bit of a hack, but
it's not very intrusive and it works well enough.
For reference, here are a few other (more difficult) ways this could
have potentially been fixed:
- Move startup_32_smp()'s call to load_ucode_ap() down to *after* paging
is enabled. (No idea what that would break.)
- Track down load_ucode_ap()'s entire callee tree and mark all the
functions 'notrace'. (Probably not realistic.)
- Pause graph tracing in ftrace_suspend_notifier_call() or bringup_cpu()
or __cpu_up(), and ensure that the pause facility can be queried from
real mode.
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>
Cc: linux-acpi@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: stable@kernel.org
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/5c1272269a580660703ed2eccf44308e790c7a98.1492123841.git.jpoimboe@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
A few people have reported unwinder warnings like the following:
WARNING: kernel stack frame pointer at ffffc90000fe7ff0 in rsync:1157 has bad value (null)
unwind stack type:0 next_sp: (null) mask:2 graph_idx:0
ffffc90000fe7f98: ffffc90000fe7ff0 (0xffffc90000fe7ff0)
ffffc90000fe7fa0: ffffffffb7000f56 (trace_hardirqs_off_thunk+0x1a/0x1c)
ffffc90000fe7fa8: 0000000000000246 (0x246)
ffffc90000fe7fb0: 0000000000000000 ...
ffffc90000fe7fc0: 00007ffe3af639bc (0x7ffe3af639bc)
ffffc90000fe7fc8: 0000000000000006 (0x6)
ffffc90000fe7fd0: 00007f80af433fc5 (0x7f80af433fc5)
ffffc90000fe7fd8: 00007ffe3af638e0 (0x7ffe3af638e0)
ffffc90000fe7fe0: 00007ffe3af638e0 (0x7ffe3af638e0)
ffffc90000fe7fe8: 00007ffe3af63970 (0x7ffe3af63970)
ffffc90000fe7ff0: 0000000000000000 ...
ffffc90000fe7ff8: ffffffffb7b74b9a (entry_SYSCALL_64_after_swapgs+0x17/0x4f)
This warning can happen when unwinding a code path where an interrupt
occurred in x86 entry code before it set up the first stack frame.
Silently ignore any warnings for this case.
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: c32c47c68a ("x86/unwind: Warn on bad frame pointer")
Link: http://lkml.kernel.org/r/dbd6838826466a60dc23a52098185bc973ce2f1e.1492020577.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
virt_xxx memory barriers are implemented trivially using the low-level
__smp_xxx macros, __smp_xxx is equal to a compiler barrier for strong
TSO memory model, however, mandatory barriers will unconditional add
memory barriers, this patch replaces the rmb() in kvm_steal_clock() by
virt_rmb().
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Since commit:
4bcc595ccd "printk: reinstate KERN_CONT for printing"
... the debug output of signal_fault(), do_trap() and do_general_protection()
looks garbled, e.g.:
traps: conftest[9335] trap invalid opcode ip:400428 sp:7ffeaba1b0d8 error:0
in conftest[400000+1000]
(note the unintended line break.)
Fix the bug by adding KERN_CONTs.
Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de>
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>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There's a conflict between ongoing level-5 paging support and
the E820 rewrite. Since the E820 rewrite is essentially ready,
merge it into x86/mm to reduce tree conflicts.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The E820 rework in WIP.x86/boot has gone through a couple of weeks
of exposure in -tip, merge it in a wider fashion.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
