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authorVincenzo Frascino <vincenzo.frascino@arm.com>2019-12-05 11:04:51 +0100
committerRussell King <rmk+kernel@armlinux.org.uk>2019-12-06 11:51:03 +0000
commit04bb96427d4ee33fbdf15648ddf578c6ba1aef54 (patch)
treef68ba6c7c2e8fdc5825412c5787cb9c1cb432413 /arch
parentff98a5f624d2910de050f1fc7f2a32769da86b51 (diff)
ARM: 8947/1: 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. Investigated-by: Arnd Bergmann <arnd@arndb.de> Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/include/asm/vdso/gettimeofday.h3
1 files changed, 3 insertions, 0 deletions
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);