In the !CONFIG_SPARSEMEM_EXTREME case, mem_section is a static
2-dimensional array and so the check "!mem_section[SECTION_NR_TO_ROOT(nr)]"
doesn't make sense.
Fix this warning by moving the "!mem_section[SECTION_NR_TO_ROOT(nr)]"
check up inside the CONFIG_SPARSEMEM_EXTREME block and adding an
explicit NR_SECTION_ROOTS check to make sure that there is no
out-of-bound array access.
At the moment the GIC IRQ domain translation routine happily converts
ACPI table GSI numbers below 16 to GIC SGIs (Software Generated
Interrupts aka IPIs). On the Devicetree side we explicitly forbid this
translation, actually the function will never return HWIRQs below 16 when
using a DT based domain translation.
We expect SGIs to be handled in the first part of the function, and any
further occurrence should be treated as a firmware bug, so add a check
and print to report this explicitly and avoid lengthy debug sessions.
Fixes: 64b499d8df40 ("irqchip/gic-v3: Configure SGIs as standard interrupts")
Signed-off-by: Andre Przywara <email address hidden>
Signed-off-by: Marc Zyngier <email address hidden>
Link: https://<email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
0a8cd9a...
by
Christophe Leroy <email address hidden>
powerpc/64: Fix build failure with allyesconfig in book3s_64_entry.S
Using conditional branches between two files is hasardous,
they may get linked too far from each other.
arch/powerpc/kvm/book3s_64_entry.o:(.text+0x3ec): relocation truncated
to fit: R_PPC64_REL14 (stub) against symbol `system_reset_common'
defined in .text section in arch/powerpc/kernel/head_64.o
Reorganise the code to use non conditional branches.
Fixes: 89d35b239101 ("KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C")
Signed-off-by: Christophe Leroy <email address hidden>
[mpe: Avoid odd-looking bne ., use named local labels]
Signed-off-by: Michael Ellerman <email address hidden>
Link: https://lore.kernel.org/r/89cf27bf43ee07a0b2879b9e8e2f5cd6386a3645<email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
The way KVM drives GICv4.{0,1} is as follows:
- vcpu_load() makes the VPE resident, instructing the RD to start
scanning for interrupts
- just before entering the guest, we check that the RD has finished
scanning and that we can start running the vcpu
- on preemption, we deschedule the VPE by making it invalid on
the RD
However, we are preemptible between the first two steps. If it so
happens *and* that the RD was still scanning, we nonetheless write
to the GICR_VPENDBASER register while Dirty is set, and bad things
happen (we're in UNPRED land).
This affects both the 4.0 and 4.1 implementations.
Make sure Dirty is cleared before performing the deschedule,
meaning that its_clear_vpend_valid() becomes a sort of full VPE
residency barrier.
Reported-by: Jingyi Wang <email address hidden>
Tested-by: Nianyao Tang <email address hidden>
Signed-off-by: Marc Zyngier <email address hidden>
Fixes: 57e3cebd022f ("KVM: arm64: Delay the polling of the GICR_VPENDBASER.Dirty bit")
Link: https://<email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
5b4b6fe...
by
Peter Zijlstra <email address hidden>
x86,static_call: Fix __static_call_return0 for i386
Paolo reported that the instruction sequence that is used to replace:
call __static_call_return0
namely:
66 66 48 31 c0 data16 data16 xor %rax,%rax
decodes to something else on i386, namely:
66 66 48 data16 dec %ax
31 c0 xor %eax,%eax
Which is a nonsensical sequence that happens to have the same outcome.
*However* an important distinction is that it consists of 2
instructions which is a problem when the thing needs to be overwriten
with a regular call instruction again.
As such, replace the instruction with something that decodes the same
on both i386 and x86_64.
try_steal_cookie() looks at task_struct::cpus_mask to decide if the
task could be moved to `this' CPU. It ignores that the task might be in
a migration disabled section while not on the CPU. In this case the task
must not be moved otherwise per-CPU assumption are broken.
Use is_cpu_allowed(), as suggested by Peter Zijlstra, to decide if the a
task can be moved.
Fixes: d2dfa17bc7de6 ("sched: Trivial forced-newidle balancer")
Signed-off-by: Sebastian Andrzej Siewior <email address hidden>
Signed-off-by: Peter Zijlstra (Intel) <email address hidden>
Link: https://<email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
The macro __WARN_FLAGS() uses a local variable named "f". This being a
common name, there is a risk of shadowing other variables.
For example, GCC would yield:
| In file included from ./include/linux/bug.h:5,
| from ./include/linux/cpumask.h:14,
| from ./arch/x86/include/asm/cpumask.h:5,
| from ./arch/x86/include/asm/msr.h:11,
| from ./arch/x86/include/asm/processor.h:22,
| from ./arch/x86/include/asm/timex.h:5,
| from ./include/linux/timex.h:65,
| from ./include/linux/time32.h:13,
| from ./include/linux/time.h:60,
| from ./include/linux/stat.h:19,
| from ./include/linux/module.h:13,
| from virt/lib/irqbypass.mod.c:1:
| ./include/linux/rcupdate.h: In function 'rcu_head_after_call_rcu':
| ./arch/x86/include/asm/bug.h:80:21: warning: declaration of 'f' shadows a parameter [-Wshadow]
| 80 | __auto_type f = BUGFLAG_WARNING|(flags); \
| | ^
| ./include/asm-generic/bug.h:106:17: note: in expansion of macro '__WARN_FLAGS'
| 106 | __WARN_FLAGS(BUGFLAG_ONCE | \
| | ^~~~~~~~~~~~
| ./include/linux/rcupdate.h:1007:9: note: in expansion of macro 'WARN_ON_ONCE'
| 1007 | WARN_ON_ONCE(func != (rcu_callback_t)~0L);
| | ^~~~~~~~~~~~
| In file included from ./include/linux/rbtree.h:24,
| from ./include/linux/mm_types.h:11,
| from ./include/linux/buildid.h:5,
| from ./include/linux/module.h:14,
| from virt/lib/irqbypass.mod.c:1:
| ./include/linux/rcupdate.h:1001:62: note: shadowed declaration is here
| 1001 | rcu_head_after_call_rcu(struct rcu_head *rhp, rcu_callback_t f)
| | ~~~~~~~~~~~~~~~^
For reference, sparse also warns about it, c.f. [1].
This patch renames the variable from f to __flags (with two underscore
prefixes as suggested in the Linux kernel coding style [2]) in order
to prevent collisions.
