From: Zhen Lei thunder.leizhen@huawei.com
hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8JVJ3 CVE: NA
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access_ok() is used to preliminarily check 'uaddr' to avoid unnecessary page fault caused by invalid input. The page fault will do the accurate address verification based on task's mm. It's also used to do a check on the get_fs(), see the comments of __access_ok().
But now the support for get_fs() on arm64 has been deleted by commit edf84200127a ("arm64: uaccess: remove set_fs()"). So access_ok() does not need to perform such strict checks for compat tasks.
Remove the is_compact_task() check can improve the performance of syscalls. For example, all test items of libMicro can be improved by 4.89% on average.
The next patch will avoid calling is_ilp32_compat_task() by default by close its build option, because ILP32 has specific requirements.
Signed-off-by: Zhen Lei thunder.leizhen@huawei.com Reviewed-by: Cheng Jian cj.chengjian@huawei.com Reviewed-by: liuchao (CR) liuchao173@huawei.com Reviewed-by: Liu Chao (CR) < liuchao173@huawei.com > Reviewed-by: Xiongfeng Wang wangxiongfeng2@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Signed-off-by: Jinjie Ruan ruanjinjie@huawei.com --- arch/arm64/include/asm/processor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index abb704640577..10aae8d9c667 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -55,7 +55,7 @@ #define TASK_SIZE_64 (UL(1) << vabits_actual)
#ifdef CONFIG_COMPAT -#define TASK_SIZE_MAX (is_compat_task() ? \ +#define TASK_SIZE_MAX (is_ilp32_compat_task() ? \ UL(0x100000000) : (UL(1) << VA_BITS)) #if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS) /*