From: Andi Kleen <a...@linux.intel.com> Move the cond_resched() check for CONFIG_PREEMPT_VOLUNTARY into the low level copy_*_user code. This avoids some code bloat and makes check much more efficient by avoiding unnecessary function calls.
This is currently only for the non __ variants. For the sleep debug case the call is still done in the caller. I did not do this for copy_in_user() or the nocache variants because there's no obvious place to put the check, and those calls are comparatively rare. Signed-off-by: Andi Kleen <a...@linux.intel.com> --- arch/x86/include/asm/uaccess_64.h | 4 ++-- arch/x86/lib/copy_user_64.S | 5 +++-- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 64476bb..b327057 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -58,7 +58,7 @@ static inline unsigned long __must_check copy_from_user(void *to, { int sz = __compiletime_object_size(to); - might_fault(); + might_fault_debug_only(); if (likely(sz == -1 || sz >= n)) n = _copy_from_user(to, from, n); #ifdef CONFIG_DEBUG_VM @@ -71,7 +71,7 @@ static inline unsigned long __must_check copy_from_user(void *to, static __always_inline __must_check int copy_to_user(void __user *dst, const void *src, unsigned size) { - might_fault(); + might_fault_debug_only(); return _copy_to_user(dst, src, size); } diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index a30ca15..7039fc9 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -18,6 +18,7 @@ #include <asm/alternative-asm.h> #include <asm/asm.h> #include <asm/smap.h> +#include "user-common.h" /* * By placing feature2 after feature1 in altinstructions section, we logically @@ -73,7 +74,7 @@ /* Standard copy_to_user with segment limit checking */ ENTRY(_copy_to_user) CFI_STARTPROC - GET_THREAD_INFO(%rax) + GET_THREAD_AND_SCHEDULE %rax movq %rdi,%rcx addq %rdx,%rcx jc bad_to_user @@ -88,7 +89,7 @@ ENDPROC(_copy_to_user) /* Standard copy_from_user with segment limit checking */ ENTRY(_copy_from_user) CFI_STARTPROC - GET_THREAD_INFO(%rax) + GET_THREAD_AND_SCHEDULE %rax movq %rsi,%rcx addq %rdx,%rcx jc bad_from_user -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/