From: acevest <zhaoyanbai@126.com>
Date: Tue, 16 May 2023 01:00:00 +0000 (+0800)
Subject: sysenter后内核在开中断的情况下执行系统调用
X-Git-Url: http://zhaoyanbai.com/repos/Bv9ARM.ch10.html?a=commitdiff_plain;h=1d8973528475d9669617c1f4f83ef551989a3b68;p=kernel.git

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 b11cdee..6526d45 100644
--- 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