Date: Tue, 19 Oct 2010 21:53:04 +0000 From: Paul B Mahol <onemda@gmail.com> To: net@freebsd.org Subject: ndis: patch for review Message-ID: <AANLkTin6Pt-SbUPJ=gdZw=4Fym8MayoQOYkupGrikxMY@mail.gmail.com>
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Hi,
First: we should pin curthread on CPU before we check on which CPU is curthread.
Second: instead of sti & cli use critical sections when saving %fs register.
Third: I do not know what happens if we get preempted while windows
code were running,
so leave critical section only _after_ executing windows code.
diff --git a/sys/compat/ndis/kern_windrv.c b/sys/compat/ndis/kern_windrv.c
index f231863..ba29fd2 100644
--- a/sys/compat/ndis/kern_windrv.c
+++ b/sys/compat/ndis/kern_windrv.c
@@ -613,8 +613,6 @@ struct gdt {
extern uint16_t x86_getfs(void);
extern void x86_setfs(uint16_t);
extern void *x86_gettid(void);
-extern void x86_critical_enter(void);
-extern void x86_critical_exit(void);
extern void x86_getldt(struct gdt *, uint16_t *);
extern void x86_setldt(struct gdt *, uint16_t);
@@ -668,8 +666,10 @@ extern void x86_setldt(struct gdt *, uint16_t);
void
ctxsw_utow(void)
{
- struct tid *t;
+ struct tid *t;
+ sched_pin();
+ critical_enter();
t = &my_tids[curthread->td_oncpu];
/*
@@ -685,12 +685,9 @@ ctxsw_utow(void)
if (t->tid_self != t)
x86_newldt(NULL);
- x86_critical_enter();
t->tid_oldfs = x86_getfs();
t->tid_cpu = curthread->td_oncpu;
- sched_pin();
x86_setfs(SEL_TO_FS(t->tid_selector));
- x86_critical_exit();
/* Now entering Windows land, population: you. */
}
@@ -706,11 +703,10 @@ ctxsw_wtou(void)
{
struct tid *t;
- x86_critical_enter();
t = x86_gettid();
x86_setfs(t->tid_oldfs);
+ critical_exit();
sched_unpin();
- x86_critical_exit();
/* Welcome back to UNIX land, we missed you. */
diff --git a/sys/compat/ndis/winx32_wrap.S b/sys/compat/ndis/winx32_wrap.S
index c051504..fa4aa87 100644
--- a/sys/compat/ndis/winx32_wrap.S
+++ b/sys/compat/ndis/winx32_wrap.S
@@ -375,11 +375,3 @@ ENTRY(x86_setfs)
ENTRY(x86_gettid)
mov %fs:12,%eax
ret
-
-ENTRY(x86_critical_enter)
- cli
- ret
-
-ENTRY(x86_critical_exit)
- sti
- ret
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