On Wed, Dec 04, 2019 at 05:15:26PM +0000, Vincenzo Frascino wrote: > Hi Guenter, > > On 12/4/19 4:16 PM, Guenter Roeck wrote: > > On Wed, Dec 04, 2019 at 01:58:25PM +0000, Vincenzo Frascino wrote: > >> Hi Guenter, > >> > >> On 12/4/19 1:51 PM, Guenter Roeck wrote: > >>> On Fri, Jun 21, 2019 at 10:52:43AM +0100, Vincenzo Frascino wrote: > >>>> The arm vDSO library requires some adaptations to use to take advantage > >>>> of the newly introduced generic vDSO library. > >>>> > >>>> Introduce the following changes: > >>>> - Modification vdso.c to be compliant with the common vdso datapage > >>>> - Use of lib/vdso for gettimeofday > >>>> - Implementation of elf note > >>>> > >>>> Cc: Russell King <linux@xxxxxxxxxxxxxxx> > >>>> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> > >>> > >>> This patch causes a crash with qemu's mcimx6ul-evk emulation while running > >>> imx_v6_v7_defconfig. > >>> > >> > >> Thank you for reporting this. Could you please provide some details on how I can > >> reproduce the scenario you are describing? > >> > > - Build imx_v6_v7_defconfig > > - Get root file system or initrd, for example from > > https://github.com/groeck/linux-build-test/tree/master/rootfs/arm > > - Run image. Example, with initrd: > > qemu-system-arm -M mcimx6ul-evk -kernel arch/arm/boot/zImage \ > > -no-reboot -initrd rootfs-armv7a.cpio \ > > -m 256 -display none -serial null \ > > --append 'rdinit=/sbin/init earlycon=ec_imx6q,mmio,0x21e8000,115200n8 console=ttymxc1,115200' > > -dtb arch/arm/boot/dts/imx6ul-14x14-evk.dtb \ > > -nographic -monitor null -serial stdio > > > > qemu has to be v3.1 or later to support the machine. > > > > Thanks for this. Could you please try the patch below the scissors? Seems fixing > the issue for me. > > > Hope this helps, > > Guenter > > > > -- > Regards, > Vincenzo > > --->8--- > > Author: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> > Date: Wed Dec 4 16:58:55 2019 +0000 > > arm: Fix __arch_get_hw_counter() access to CNTVCT > > __arch_get_hw_counter() should check clock_mode to see if it can access > CNTVCT. With the conversion to unified vDSO this check has been left out. > > This causes on imx v6 and v7 (imx_v6_v7_defconfig) and other platforms to > hang at boot during the execution of the init process as per below: > > [ 19.976852] Run /sbin/init as init process > [ 20.044931] Kernel panic - not syncing: Attempted to kill init! > exitcode=0x00000004 > > Fix the problem verifying that clock_mode is set coherently before > accessing CNTVCT. > > Cc: Russell King <linux@xxxxxxxxxxxxxxx> > Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx> > Investigated-by: Arnd Bergmann <arnd@xxxxxxxx> > Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> > WFM. Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> Guenter > diff --git a/arch/arm/include/asm/vdso/gettimeofday.h > b/arch/arm/include/asm/vdso/gettimeofday.h > index 5b879ae7afc1..0ad2429c324f 100644 > --- a/arch/arm/include/asm/vdso/gettimeofday.h > +++ b/arch/arm/include/asm/vdso/gettimeofday.h > @@ -75,6 +75,9 @@ static __always_inline u64 __arch_get_hw_counter(int clock_mode) > #ifdef CONFIG_ARM_ARCH_TIMER > u64 cycle_now; > > + if (!clock_mode) > + return -EINVAL; > + > isb(); > cycle_now = read_sysreg(CNTVCT); > >
