sysenter后内核在开中断的情况下执行系统调用

diff --git a/kernel/syscall.S b/kernel/syscall.S
index b11cdee51bcd528d5b2127d81a8d75347b74cfaa..6526d4580c88a53224ea61f845e5a0fd07a2ec97 100644 (file)
--- a/kernel/syscall.S
+++ b/kernel/syscall.S
@@ -33,6 +33,10 @@ syscall_entry:
 #if FIX_SYSENTER_ESP_MODE
     movl    (%esp),%esp 
 #endif
+
+    // sysenter have cleared IF, and sysexit will not set IF.
+    sti
+
     // 这段代码纯是为了pt_regs_t准备的
     // 后续看看直接优化掉
     pushl   $(SELECTOR_USER_SS)
@@ -82,7 +86,6 @@ ret_from_fork_user:
     // sysexit指令从ecx中恢复用户态esp
     xchgl   %ebp, %ecx
 
-    sti        /* sysenter have cleared IF, and sysexit will not set IF. */
     sysexit