svn commit: r209198 - head/sys/amd64/amd64
Konstantin Belousov
kib at FreeBSD.org
Tue Jun 15 09:19:33 UTC 2010
Author: kib
Date: Tue Jun 15 09:19:33 2010
New Revision: 209198
URL: http://svn.freebsd.org/changeset/base/209198
Log:
Use critical sections instead of disabling local interrupts to ensure
the consistency between PCPU fpcurthread and the state of the FPU.
Explicitely assert that the calling conventions for fpudrop() are
adhered too. In cpu_thread_exit(), add missed critical section entrance.
Reviewed by: bde
Tested by: pho
MFC after: 1 month
Modified:
head/sys/amd64/amd64/fpu.c
head/sys/amd64/amd64/machdep.c
head/sys/amd64/amd64/vm_machdep.c
Modified: head/sys/amd64/amd64/fpu.c
==============================================================================
--- head/sys/amd64/amd64/fpu.c Tue Jun 15 09:18:27 2010 (r209197)
+++ head/sys/amd64/amd64/fpu.c Tue Jun 15 09:19:33 2010 (r209198)
@@ -115,6 +115,9 @@ fpuinit(void)
u_int mxcsr;
u_short control;
+ /*
+ * It is too early for critical_enter() to work on AP.
+ */
savecrit = intr_disable();
stop_emulating();
fninit();
@@ -141,16 +144,15 @@ fpuinit(void)
void
fpuexit(struct thread *td)
{
- register_t savecrit;
- savecrit = intr_disable();
+ critical_enter();
if (curthread == PCPU_GET(fpcurthread)) {
stop_emulating();
fxsave(PCPU_GET(curpcb)->pcb_save);
start_emulating();
PCPU_SET(fpcurthread, 0);
}
- intr_restore(savecrit);
+ critical_exit();
}
int
@@ -351,10 +353,9 @@ static char fpetable[128] = {
int
fputrap()
{
- register_t savecrit;
u_short control, status;
- savecrit = intr_disable();
+ critical_enter();
/*
* Interrupt handling (for another interrupt) may have pushed the
@@ -371,7 +372,7 @@ fputrap()
if (PCPU_GET(fpcurthread) == curthread)
fnclex();
- intr_restore(savecrit);
+ critical_exit();
return (fpetable[status & ((~control & 0x3f) | 0x40)]);
}
@@ -389,12 +390,13 @@ void
fpudna(void)
{
struct pcb *pcb;
- register_t s;
+ critical_enter();
if (PCPU_GET(fpcurthread) == curthread) {
printf("fpudna: fpcurthread == curthread %d times\n",
++err_count);
stop_emulating();
+ critical_exit();
return;
}
if (PCPU_GET(fpcurthread) != NULL) {
@@ -404,7 +406,6 @@ fpudna(void)
curthread, curthread->td_proc->p_pid);
panic("fpudna");
}
- s = intr_disable();
stop_emulating();
/*
* Record new context early in case frstor causes a trap.
@@ -428,19 +429,17 @@ fpudna(void)
pcb->pcb_flags |= PCB_USERFPUINITDONE;
} else
fxrstor(pcb->pcb_save);
- intr_restore(s);
+ critical_exit();
}
-/*
- * This should be called with interrupts disabled and only when the owning
- * FPU thread is non-null.
- */
void
fpudrop()
{
struct thread *td;
td = PCPU_GET(fpcurthread);
+ KASSERT(td == curthread, ("fpudrop: fpcurthread != curthread"));
+ CRITSECT_ASSERT(td);
PCPU_SET(fpcurthread, NULL);
td->td_pcb->pcb_flags &= ~PCB_FPUINITDONE;
start_emulating();
@@ -454,7 +453,6 @@ int
fpugetuserregs(struct thread *td, struct savefpu *addr)
{
struct pcb *pcb;
- register_t s;
pcb = td->td_pcb;
if ((pcb->pcb_flags & PCB_USERFPUINITDONE) == 0) {
@@ -462,13 +460,13 @@ fpugetuserregs(struct thread *td, struct
addr->sv_env.en_cw = pcb->pcb_initial_fpucw;
return (_MC_FPOWNED_NONE);
}
- s = intr_disable();
+ critical_enter();
if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) {
fxsave(addr);
- intr_restore(s);
+ critical_exit();
return (_MC_FPOWNED_FPU);
} else {
- intr_restore(s);
+ critical_exit();
bcopy(&pcb->pcb_user_save, addr, sizeof(*addr));
return (_MC_FPOWNED_PCB);
}
@@ -478,7 +476,6 @@ int
fpugetregs(struct thread *td, struct savefpu *addr)
{
struct pcb *pcb;
- register_t s;
pcb = td->td_pcb;
if ((pcb->pcb_flags & PCB_FPUINITDONE) == 0) {
@@ -486,13 +483,13 @@ fpugetregs(struct thread *td, struct sav
addr->sv_env.en_cw = pcb->pcb_initial_fpucw;
return (_MC_FPOWNED_NONE);
}
- s = intr_disable();
+ critical_enter();
if (td == PCPU_GET(fpcurthread)) {
fxsave(addr);
- intr_restore(s);
+ critical_exit();
return (_MC_FPOWNED_FPU);
} else {
- intr_restore(s);
+ critical_exit();
bcopy(pcb->pcb_save, addr, sizeof(*addr));
return (_MC_FPOWNED_PCB);
}
@@ -505,16 +502,15 @@ void
fpusetuserregs(struct thread *td, struct savefpu *addr)
{
struct pcb *pcb;
- register_t s;
pcb = td->td_pcb;
- s = intr_disable();
+ critical_enter();
if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) {
fxrstor(addr);
- intr_restore(s);
+ critical_exit();
pcb->pcb_flags |= PCB_FPUINITDONE | PCB_USERFPUINITDONE;
} else {
- intr_restore(s);
+ critical_exit();
bcopy(addr, &td->td_pcb->pcb_user_save, sizeof(*addr));
if (PCB_USER_FPU(pcb))
pcb->pcb_flags |= PCB_FPUINITDONE;
@@ -526,15 +522,14 @@ void
fpusetregs(struct thread *td, struct savefpu *addr)
{
struct pcb *pcb;
- register_t s;
pcb = td->td_pcb;
- s = intr_disable();
+ critical_enter();
if (td == PCPU_GET(fpcurthread)) {
fxrstor(addr);
- intr_restore(s);
+ critical_exit();
} else {
- intr_restore(s);
+ critical_exit();
bcopy(addr, td->td_pcb->pcb_save, sizeof(*addr));
}
if (PCB_USER_FPU(pcb))
@@ -652,13 +647,12 @@ int
fpu_kern_leave(struct thread *td, struct fpu_kern_ctx *ctx)
{
struct pcb *pcb;
- register_t savecrit;
pcb = td->td_pcb;
- savecrit = intr_disable();
+ critical_enter();
if (curthread == PCPU_GET(fpcurthread))
fpudrop();
- intr_restore(savecrit);
+ critical_exit();
pcb->pcb_save = ctx->prev;
if (pcb->pcb_save == &pcb->pcb_user_save) {
if ((pcb->pcb_flags & PCB_USERFPUINITDONE) != 0)
Modified: head/sys/amd64/amd64/machdep.c
==============================================================================
--- head/sys/amd64/amd64/machdep.c Tue Jun 15 09:18:27 2010 (r209197)
+++ head/sys/amd64/amd64/machdep.c Tue Jun 15 09:19:33 2010 (r209198)
@@ -2119,10 +2119,9 @@ set_fpcontext(struct thread *td, const m
void
fpstate_drop(struct thread *td)
{
- register_t s;
KASSERT(PCB_USER_FPU(td->td_pcb), ("fpstate_drop: kernel-owned fpu"));
- s = intr_disable();
+ critical_enter();
if (PCPU_GET(fpcurthread) == td)
fpudrop();
/*
@@ -2137,7 +2136,7 @@ fpstate_drop(struct thread *td)
*/
curthread->td_pcb->pcb_flags &= ~(PCB_FPUINITDONE |
PCB_USERFPUINITDONE);
- intr_restore(s);
+ critical_exit();
}
int
Modified: head/sys/amd64/amd64/vm_machdep.c
==============================================================================
--- head/sys/amd64/amd64/vm_machdep.c Tue Jun 15 09:18:27 2010 (r209197)
+++ head/sys/amd64/amd64/vm_machdep.c Tue Jun 15 09:19:33 2010 (r209198)
@@ -265,8 +265,10 @@ cpu_thread_exit(struct thread *td)
{
struct pcb *pcb;
+ critical_enter();
if (td == PCPU_GET(fpcurthread))
fpudrop();
+ critical_exit();
pcb = td->td_pcb;
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