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  1. 05 7月, 2018 4 次提交
    • W
      arm64: locking: Replace ticket lock implementation with qspinlock · c1109047
      由 Will Deacon 提交于 
      It's fair to say that our ticket lock has served us well over time, but
it's time to bite the bullet and start using the generic qspinlock code
so we can make use of explicit MCS queuing and potentially better PV
performance in future.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      c1109047
    • W
      arm64: barrier: Implement smp_cond_load_relaxed · 598865c5
      由 Will Deacon 提交于 
      We can provide an implementation of smp_cond_load_relaxed using READ_ONCE
and __cmpwait_relaxed.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      598865c5
    • M
      arm64: kexec: always reset to EL2 if present · 76f4e2da
      由 Mark Rutland 提交于 
      Currently machine_kexec() doesn't reset to EL2 in the case of a
crashdump kernel. This leaves potentially dodgy state active at EL2, and
means that if the crashdump kernel attempts to online secondary CPUs,
these will be booted as mismatched ELs.

Let's reset to EL2, as we do in all other cases, and simplify things. If
EL2 state is corrupt, things are already sufficiently bad that kdump is
unlikely to work, and it's best-effort regardless.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      76f4e2da
    • M
      arm64: fix infinite stacktrace · 7e7df71f
      由 Mikulas Patocka 提交于 
      I've got this infinite stacktrace when debugging another problem:
[  908.795225] INFO: rcu_preempt detected stalls on CPUs/tasks:
[  908.796176]  1-...!: (1 GPs behind) idle=952/1/4611686018427387904 softirq=1462/1462 fqs=355
[  908.797692]  2-...!: (1 GPs behind) idle=f42/1/4611686018427387904 softirq=1550/1551 fqs=355
[  908.799189]  (detected by 0, t=2109 jiffies, g=130, c=129, q=235)
[  908.800284] Task dump for CPU 1:
[  908.800871] kworker/1:1     R  running task        0    32      2 0x00000022
[  908.802127] Workqueue: writecache-writeabck writecache_writeback [dm_writecache]
[  908.820285] Call trace:
[  908.824785]  __switch_to+0x68/0x90
[  908.837661]  0xfffffe00603afd90
[  908.844119]  0xfffffe00603afd90
[  908.850091]  0xfffffe00603afd90
[  908.854285]  0xfffffe00603afd90
[  908.863538]  0xfffffe00603afd90
[  908.865523]  0xfffffe00603afd90

The machine just locked up and kept on printing the same line over and
over again. This patch fixes it.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      7e7df71f
  3. 02 7月, 2018 1 次提交
  5. 29 6月, 2018 2 次提交
  7. 28 6月, 2018 8 次提交
  9. 27 6月, 2018 2 次提交
  11. 24 6月, 2018 1 次提交
  13. 23 6月, 2018 4 次提交
  15. 21 6月, 2018 4 次提交
    • D
      KVM: arm64: Avoid mistaken attempts to save SVE state for vcpus · 2955bcc8
      由 Dave Martin 提交于 
      Commit e6b673b7 ("KVM: arm64: Optimise FPSIMD handling to reduce
guest/host thrashing") uses fpsimd_save() to save the FPSIMD state
for a vcpu when scheduling the vcpu out.  However, currently
current's value of TIF_SVE is restored before calling fpsimd_save()
which means that fpsimd_save() may erroneously attempt to save SVE
state from the vcpu.  This enables current's vector state to be
polluted with guest data.  current->thread.sve_state may be
unallocated or not large enough, so this can also trigger a NULL
dereference or buffer overrun.

Instead of this, TIF_SVE should be configured properly for the
guest when calling fpsimd_save() with the vcpu context loaded.

This patch ensures this by delaying restoration of current's
TIF_SVE until after the call to fpsimd_save().

Fixes: e6b673b7 ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing")
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      2955bcc8
    • D
      KVM: arm64/sve: Fix SVE trap restoration for non-current tasks · b3eb56b6
      由 Dave Martin 提交于 
      Commit e6b673b7 ("KVM: arm64: Optimise FPSIMD handling to reduce
guest/host thrashing") attempts to restore the configuration of
userspace SVE trapping via a call to fpsimd_bind_task_to_cpu(), but
the logic for determining when to do this is not correct.

The patch makes the errnoenous assumption that the only task that
may try to enter userspace with the currently loaded FPSIMD/SVE
register content is current.  This may not be the case however:  if
some other user task T is scheduled on the CPU during the execution
of the KVM run loop, and the vcpu does not try to use the registers
in the meantime, then T's state may be left there intact.  If T
happens to be the next task to enter userspace on this CPU then the
hooks for reloading the register state and configuring traps will
be skipped.

(Also, current never has SVE state at this point anyway and should
always have the trap enabled, as a side-effect of the ioctl()
syscall needed to reach the KVM run loop in the first place.)

This patch instead restores the state of the EL0 trap from the
state observed at the most recent vcpu_load(), ensuring that the
trap is set correctly for the loaded context (if any).

Fixes: e6b673b7 ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing")
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      b3eb56b6
    • D
      KVM: arm64: Don't mask softirq with IRQs disabled in vcpu_put() · b045e4d0
      由 Dave Martin 提交于 
      Commit e6b673b7 ("KVM: arm64: Optimise FPSIMD handling to reduce
guest/host thrashing") introduces a specific helper
kvm_arch_vcpu_put_fp() for saving the vcpu FPSIMD state during
vcpu_put().

This function uses local_bh_disable()/_enable() to protect the
FPSIMD context manipulation from interruption by softirqs.

This approach is not correct, because vcpu_put() can be invoked
either from the KVM host vcpu thread (when exiting the vcpu run
loop), or via a preempt notifier.  In the former case, only
preemption is disabled.  In the latter case, the function is called
from inside __schedule(), which means that IRQs are disabled.

Use of local_bh_disable()/_enable() with IRQs disabled is considerd
an error, resulting in lockdep splats while running VMs if lockdep
is enabled.

This patch disables IRQs instead of attempting to disable softirqs,
avoiding the problem of calling local_bh_enable() with IRQs
disabled in the __schedule() path.  This creates an additional
interrupt blackout during vcpu run loop exit, but this is the rare
case and the blackout latency is still less than that of
__schedule().

Fixes: e6b673b7 ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing")
Reported-by: NAndre Przywara <andre.przywara@arm.com>
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      b045e4d0
    • M
      arm64: Introduce sysreg_clear_set() · 6ebdf4db
      由 Mark Rutland 提交于 
      Currently we have a couple of helpers to manipulate bits in particular
sysregs:

 * config_sctlr_el1(u32 clear, u32 set)

 * change_cpacr(u64 val, u64 mask)

The parameters of these differ in naming convention, order, and size,
which is unfortunate. They also differ slightly in behaviour, as
change_cpacr() skips the sysreg write if the bits are unchanged, which
is a useful optimization when sysreg writes are expensive.

Before we gain yet another sysreg manipulation function, let's
unify these with a common helper, providing a consistent order for
clear/set operands, and the write skipping behaviour from
change_cpacr(). Code will be migrated to the new helper in subsequent
patches.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NDave Martin <dave.martin@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      6ebdf4db
  17. 19 6月, 2018 7 次提交
  19. 16 6月, 2018 1 次提交
  21. 15 6月, 2018 3 次提交
  23. 14 6月, 2018 1 次提交
    • L
      Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables · 050e9baa
      由 Linus Torvalds 提交于 
      The changes to automatically test for working stack protector compiler
support in the Kconfig files removed the special STACKPROTECTOR_AUTO
option that picked the strongest stack protector that the compiler
supported.

That was all a nice cleanup - it makes no sense to have the AUTO case
now that the Kconfig phase can just determine the compiler support
directly.

HOWEVER.

It also meant that doing "make oldconfig" would now _disable_ the strong
stackprotector if you had AUTO enabled, because in a legacy config file,
the sane stack protector configuration would look like

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  # CONFIG_CC_STACKPROTECTOR_NONE is not set
  # CONFIG_CC_STACKPROTECTOR_REGULAR is not set
  # CONFIG_CC_STACKPROTECTOR_STRONG is not set
  CONFIG_CC_STACKPROTECTOR_AUTO=y

and when you ran this through "make oldconfig" with the Kbuild changes,
it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had
been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just
CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version
used to be disabled (because it was really enabled by AUTO), and would
disable it in the new config, resulting in:

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
  CONFIG_CC_STACKPROTECTOR=y
  # CONFIG_CC_STACKPROTECTOR_STRONG is not set
  CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

That's dangerously subtle - people could suddenly find themselves with
the weaker stack protector setup without even realizing.

The solution here is to just rename not just the old RECULAR stack
protector option, but also the strong one.  This does that by just
removing the CC_ prefix entirely for the user choices, because it really
is not about the compiler support (the compiler support now instead
automatially impacts _visibility_ of the options to users).

This results in "make oldconfig" actually asking the user for their
choice, so that we don't have any silent subtle security model changes.
The end result would generally look like this:

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
  CONFIG_STACKPROTECTOR=y
  CONFIG_STACKPROTECTOR_STRONG=y
  CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

where the "CC_" versions really are about internal compiler
infrastructure, not the user selections.
Acked-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      050e9baa
  25. 13 6月, 2018 1 次提交
    • K
      treewide: kzalloc() -> kcalloc() · 6396bb22
      由 Kees Cook 提交于 
      The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

        kzalloc(a * b, gfp)

with:
        kcalloc(a * b, gfp)

as well as handling cases of:

        kzalloc(a * b * c, gfp)

with:

        kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kzalloc(sizeof(THING) * C2, ...)
|
  kzalloc(sizeof(TYPE) * C2, ...)
|
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	E1 * E2
+	E1, E2
  , ...)
)
Signed-off-by: NKees Cook <keescook@chromium.org>
      6396bb22
  27. 08 6月, 2018 1 次提交
    • D
      arm64: Fix syscall restarting around signal suppressed by tracer · 0fe42512
      由 Dave Martin 提交于 
      Commit 17c28958 ("arm64: Abstract syscallno manipulation") abstracts
out the pt_regs.syscallno value for a syscall cancelled by a tracer
as NO_SYSCALL, and provides helpers to set and check for this
condition.  However, the way this was implemented has the
unintended side-effect of disabling part of the syscall restart
logic.

This comes about because the second in_syscall() check in
do_signal() re-evaluates the "in a syscall" condition based on the
updated pt_regs instead of the original pt_regs.  forget_syscall()
is explicitly called prior to the second check in order to prevent
restart logic in the ret_to_user path being spuriously triggered,
which means that the second in_syscall() check always yields false.

This triggers a failure in
tools/testing/selftests/seccomp/seccomp_bpf.c, when using ptrace to
suppress a signal that interrups a nanosleep() syscall.

Misbehaviour of this type is only expected in the case where a
tracer suppresses a signal and the target process is either being
single-stepped or the interrupted syscall attempts to restart via
-ERESTARTBLOCK.

This patch restores the old behaviour by performing the
in_syscall() check only once at the start of the function.

Fixes: 17c28958 ("arm64: Abstract syscallno manipulation")
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Reported-by: NSumit Semwal <sumit.semwal@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org> # 4.14.x-
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      0fe42512