From: acevest <zhaoyanbai@126.com>
Date: Mon, 1 Nov 2021 08:20:17 +0000 (+0800)
Subject: syscall_entry里不再间接寻址进程的内核栈esp0
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/named-checkconf.html?a=commitdiff_plain;h=b504ddc79bda7fb2aa3a01871778109d3b885ffa;p=kernel.git

syscall_entry里不再间接寻址进程的内核栈esp0
---

diff --git a/kernel/sched.c b/kernel/sched.c
index a72b401..6dde76d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -18,6 +18,7 @@
 #include "assert.h"
 #include "mm.h"
 #include "init.h"
+#include "msr.h"
 
 task_union root_task __attribute__((__aligned__(PAGE_SIZE)));
 
@@ -66,6 +67,7 @@ void init_root_tsk()
     root_task.cr3 = (unsigned long)init_pgd;
 
     tss.esp0 = root_task.esp0;
+    wrmsr(MSR_SYSENTER_ESP, root_task.esp0, 0);
 
     printk("init_root_task tss.esp0 %08x\n", tss.esp0);
 }
@@ -96,6 +98,7 @@ void switch_to()
 {
     LOAD_CR3(current->cr3);
     tss.esp0 = current->esp0;
+    wrmsr(MSR_SYSENTER_ESP, current->esp0, 0);
 }
 
 void context_switch(task_union *prev, task_union *next)
diff --git a/kernel/syscall.S b/kernel/syscall.S
index 7a44a44..fdd9772 100644
--- a/kernel/syscall.S
+++ b/kernel/syscall.S
@@ -30,8 +30,6 @@
 .global syscall_exit
 
 syscall_entry:
-    movl    (%esp),%esp
-
     pushl   $(SELECTOR_USER_SS)
     pushl   %ebp
     pushfl
diff --git a/kernel/syscall.c b/kernel/syscall.c
index a1e4108..ef98edb 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -27,7 +27,7 @@ void setup_sysc()
 {
     wrmsr(MSR_SYSENTER_CS, SELECTOR_KRNL_CS, 0);
     wrmsr(MSR_SYSENTER_EIP, syscall_entry, 0);
-    wrmsr(MSR_SYSENTER_ESP, &(tss.esp0), 0);
+    //wrmsr(MSR_SYSENTER_ESP, &(tss.esp0), 0);
 
     init_sysc_handler_table();
 }