On Mon, Feb 02, 2015 at 05:36:33PM +0000, Mark Rutland wrote: > From: Catalin Marinas <[email protected]> > > Commit 0b46b8a718c6 got back-ported to stable, but the later fix in commit > d6ad36913083d683 didn't as it wasn't appropriately Cc'd. This has left arm64 > broken in stable when booted at EL2: > > BUG: failure at > ./arch/arm64/include/asm/arch_timer.h:112/arch_counter_get_cntpct()! >
Looks like the 3.16 kernel is also affected, as it includes a backport of commit 0b46b8a718c6. I'll queue this for the 3.16 kernel as well. Cheers, -- Luís > Mark. > > ---->8---- > Commit d6ad36913083d683aad4e02e53580c995f1a6ede upstream. > > Commit 0b46b8a718c6 (clocksource: arch_timer: Fix code to use physical > timers when requested) introduces the use of physical counters in the > ARM architected timer driver. However, he arm64 kernel uses CNTVCT in > VDSO. When booting in EL2, the kernel switches to the physical timers to > make things easier for KVM but it continues to use the virtual counter > both in user and kernel. While in such scenario CNTVCT == CNTPCT (since > CNTVOFF is initialised by the kernel to 0), we want to spot firmware > bugs corrupting CNTVOFF early (which would affect CNTVCT). > > Signed-off-by: Catalin Marinas <[email protected]> > Tested-by: Yingjoe Chen <[email protected]> > Cc: Daniel Lezcano <[email protected]> > Signed-off-by: Arnd Bergmann <[email protected]> > Fixes: 0b46b8a718c6 ("clocksource: arch_timer: Fix code to use physical > timers when requested") > Cc: Ian Campbell <[email protected]> > Cc: [email protected] # 3.18.x > Signed-off-by: Mark Rutland <[email protected]> > --- > drivers/clocksource/arm_arch_timer.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/clocksource/arm_arch_timer.c > b/drivers/clocksource/arm_arch_timer.c > index 1fa2af9..84b4c8b 100644 > --- a/drivers/clocksource/arm_arch_timer.c > +++ b/drivers/clocksource/arm_arch_timer.c > @@ -462,7 +462,7 @@ static void __init arch_counter_register(unsigned type) > > /* Register the CP15 based counter if we have one */ > if (type & ARCH_CP15_TIMER) { > - if (arch_timer_use_virtual) > + if (IS_ENABLED(CONFIG_ARM64) || arch_timer_use_virtual) > arch_timer_read_counter = arch_counter_get_cntvct; > else > arch_timer_read_counter = arch_counter_get_cntpct; > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
