diff options
| author | Greg Hackmann <ghackmann@google.com> | 2017-09-19 10:55:17 -0700 |
|---|---|---|
| committer | Tao Huang <huangtao@rock-chips.com> | 2018-01-11 10:44:36 +0800 |
| commit | e2a963621bf61a101aba90a8bf8605a8a16c9f89 (patch) | |
| tree | 9f3e1f524d3fc900ebbff744ff7aa2f8e58501cd | |
| parent | fe1b88d895b85dafde1a740fcfb4253a6b11a48a (diff) | |
clocksource: arch_timer: make virtual counter access configurable
CVE-2017-13218
Change-Id: Ibdb1fd768b748002b90bfc165612c12c8311f8a2
| -rw-r--r-- | drivers/clocksource/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/clocksource/arm_arch_timer.c | 5 |
2 files changed, 12 insertions, 1 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 9b7d1067b448..c8ff4b4d749e 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -161,6 +161,14 @@ config ARM_ARCH_TIMER_EVTSTREAM This must be disabled for hardware validation purposes to detect any hardware anomalies of missing events. +config ARM_ARCH_TIMER_VCT_ACCESS + bool "Support for ARM architected timer virtual counter access in userspace" + default !ARM64 + depends on ARM_ARCH_TIMER + help + This option enables support for reading the ARM architected timer's + virtual counter in userspace. + config ARM_GLOBAL_TIMER bool select CLKSRC_OF if OF diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index c64d543d64bf..1c029b49f96d 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -333,7 +333,10 @@ static void arch_counter_set_user_access(void) | ARCH_TIMER_USR_PCT_ACCESS_EN); /* Enable user access to the virtual counter */ - cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN; + if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_VCT_ACCESS)) + cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN; + else + cntkctl &= ~ARCH_TIMER_USR_VCT_ACCESS_EN; arch_timer_set_cntkctl(cntkctl); } |