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@armlinux.org.uk Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com
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@arm.com 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@armlinux.org.uk> Reported-by: Guenter Roeck <linux@roeck-us.net> Investigated-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
WFM.
Tested-by: Guenter Roeck linux@roeck-us.net
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);