@@ -160,8 +160,19 @@ typedef struct user_fpsimd_state elf_fpregset_t;
#define SET_PERSONALITY(ex) \
({ \
+ if (IS_ENABLED(CONFIG_ARM64_ERRATUM_1418040)) \
+ preempt_disable(); \
+ \
clear_thread_flag(TIF_32BIT); \
current->personality &= ~READ_IMPLIES_EXEC; \
+ \
+ if (IS_ENABLED(CONFIG_ARM64_ERRATUM_1418040) && \
+ this_cpu_has_cap(ARM64_WORKAROUND_1418040)) \
+ sysreg_clear_set(cntkctl_el1, 0, \
+ ARCH_TIMER_USR_VCT_ACCESS_EN); \
+ \
+ if (IS_ENABLED(CONFIG_ARM64_ERRATUM_1418040)) \
+ preempt_enable(); \
})
/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
@@ -223,7 +234,18 @@ int compat_elf_check_arch(const struct elf32_hdr *);
*/
#define COMPAT_SET_PERSONALITY(ex) \
({ \
+ if (IS_ENABLED(CONFIG_ARM64_ERRATUM_1418040)) \
+ preempt_disable(); \
+ \
set_thread_flag(TIF_32BIT); \
+ \
+ if (IS_ENABLED(CONFIG_ARM64_ERRATUM_1418040) && \
+ this_cpu_has_cap(ARM64_WORKAROUND_1418040)) \
+ sysreg_clear_set(cntkctl_el1, \
+ ARCH_TIMER_USR_VCT_ACCESS_EN, 0); \
+ \
+ if (IS_ENABLED(CONFIG_ARM64_ERRATUM_1418040)) \
+ preempt_enable(); \
})
#ifdef CONFIG_COMPAT_VDSO
#define COMPAT_ARCH_DLINFO \
The erratum 1418040 workaround changes vct access trapping when switching between compat and non-compat threads. The workaround logic assumes that the hardware vct trapping state matches the previous task's compat-ness. However, when a non-compat task execs a compat binary or vice versa, the cntkctl state and task compat-ness get out of sync. Keep the hardware trapping state in sync with the task personality. Fixes: d49f7d7376d0 ("arm64: Move handling of erratum 1418040 into C code") Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: <stable@vger.kernel.org> # 5.4.x --- v3: - Un-nest conditionals (Marc) v2: - Use sysreg_clear_set instead of open coding (Marc) - guard this_cpu_has_cap() check under IS_ENABLED() to avoid tons of WARN_ON(preemptible()) when built with !CONFIG_ARM64_ERRATUM_1418040 arch/arm64/include/asm/elf.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)