3.10-stable review patch. If anyone has any objections, please let me know.
------------------ From: Mark Rutland <[email protected]> commit 82b2f495fba338d1e3098dde1df54944a9c19751 upstream. Secondary CPUs write to __boot_cpu_mode with caches disabled, and thus a cached value of __boot_cpu_mode may be incoherent with that in memory. This could lead to a failure to detect mismatched boot modes. This patch adds flushing to ensure that writes by secondaries to __boot_cpu_mode are made visible before we test against it. Signed-off-by: Mark Rutland <[email protected]> Cc: Marc Zyngier <[email protected]> Cc: Christoffer Dall <[email protected]> Signed-off-by: Catalin Marinas <[email protected]> Cc: Mark Brown <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/arm64/include/asm/virt.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -21,6 +21,7 @@ #define BOOT_CPU_MODE_EL2 (0x0e12b007) #ifndef __ASSEMBLY__ +#include <asm/cacheflush.h> /* * __boot_cpu_mode records what mode CPUs were booted in. @@ -36,9 +37,20 @@ extern u32 __boot_cpu_mode[2]; void __hyp_set_vectors(phys_addr_t phys_vector_base); phys_addr_t __hyp_get_vectors(void); +static inline void sync_boot_mode(void) +{ + /* + * As secondaries write to __boot_cpu_mode with caches disabled, we + * must flush the corresponding cache entries to ensure the visibility + * of their writes. + */ + __flush_dcache_area(__boot_cpu_mode, sizeof(__boot_cpu_mode)); +} + /* Reports the availability of HYP mode */ static inline bool is_hyp_mode_available(void) { + sync_boot_mode(); return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 && __boot_cpu_mode[1] == BOOT_CPU_MODE_EL2); } @@ -46,6 +58,7 @@ static inline bool is_hyp_mode_available /* Check if the bootloader has booted CPUs in different modes */ static inline bool is_hyp_mode_mismatched(void) { + sync_boot_mode(); return __boot_cpu_mode[0] != __boot_cpu_mode[1]; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
