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| author | Nicholas Piggin <npiggin@gmail.com> | 2020-02-25 20:35:25 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-04-01 05:42:12 +0300 |
| commit | 2babd6ea43edacfc1577432baa187a7d212f3f4f (patch) | |
| tree | 3c1e7f7df92915c79139b66761f6385883074d22 /arch/powerpc/include/asm/time.h | |
| parent | 9d598f934470dc455dac01f0dcbebecf1604606f (diff) | |
| download | linux-2babd6ea43edacfc1577432baa187a7d212f3f4f.tar.xz | |
powerpc/64s/exception: Avoid touching the stack in hdecrementer
The hdec interrupt handler is reported to sometimes fire in Linux if
KVM leaves it pending after a guest exists. This is harmless, so there
is a no-op handler for it.
The interrupt handler currently uses the regular kernel stack. Change
this to avoid touching the stack entirely.
This should be the last place where the regular Linux stack can be
accessed with asynchronous interrupts (including PMI) soft-masked.
It might be possible to take advantage of this invariant, e.g., to
context switch the kernel stack SLB entry without clearing MSR[EE].
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-17-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/include/asm/time.h')
| -rw-r--r-- | arch/powerpc/include/asm/time.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h index 08dbe3e6831c..e0107495c4de 100644 --- a/arch/powerpc/include/asm/time.h +++ b/arch/powerpc/include/asm/time.h @@ -24,7 +24,6 @@ extern struct clock_event_device decrementer_clockevent; extern void generic_calibrate_decr(void); -extern void hdec_interrupt(struct pt_regs *regs); /* Some sane defaults: 125 MHz timebase, 1GHz processor */ extern unsigned long ppc_proc_freq; |