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- Kill the have_giant parameter to userret() along with all instances of

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that name as a variable.  Use mtx_owned(&Giant) where appropriate
  instead.
- Proc locking.
- P_FOO -> PS_FOO.
- Update comments about enable interrupts during trap and why this may be
  bad if we trap while holding a spin mutex.
- Don't bother resetting p to curproc in syscall() in case we are the child
  returning from fork.  The child hasn't returned from fork through syscall
  in a while.
- Remove fork_return() as it has been superseded by the MI version.
This commit is contained in:
John Baldwin 2001-01-24 09:53:49 +00:00
parent 16fdce5377
commit 625c76db3a
3 changed files with 225 additions and 300 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

175
sys/amd64/amd64/trap.c
View File

@ -148,9 +148,6 @@ static char *trap_msg[] = {
"machine check trap", /* 28 T_MCHK */
};
static __inline int userret __P((struct proc *p, struct trapframe *frame,
u_quad_t oticks, int have_giant));
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
extern int has_f00f_bug;
#endif
@ -168,23 +165,21 @@ SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
extern char *syscallnames[];
#endif
static __inline int
userret(p, frame, oticks, have_giant)
void
userret(p, frame, oticks)
struct proc *p;
struct trapframe *frame;
u_quad_t oticks;
int have_giant;
{
int sig, s;
int sig;
while ((sig = CURSIG(p)) != 0) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
postsig(sig);
}
mtx_enter(&sched_lock, MTX_SPIN);
p->p_priority = p->p_usrpri;
if (resched_wanted()) {
/*
@ -195,36 +190,34 @@ userret(p, frame, oticks, have_giant)
* mi_switch()'ed, we might not be on the queue indicated by
* our priority.
*/
s = splhigh();
mtx_enter(&sched_lock, MTX_SPIN);
DROP_GIANT_NOSWITCH();
setrunqueue(p);
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
mtx_exit(&sched_lock, MTX_SPIN);
PICKUP_GIANT();
splx(s);
while ((sig = CURSIG(p)) != 0) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
postsig(sig);
}
mtx_enter(&sched_lock, MTX_SPIN);
}
/*
* Charge system time if profiling.
*/
if (p->p_flag & P_PROFIL) {
if (have_giant == 0) {
if (p->p_sflag & PS_PROFIL) {
mtx_exit(&sched_lock, MTX_SPIN);
/* XXX - do we need Giant? */
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
mtx_enter(&sched_lock, MTX_SPIN);
addupc_task(p, frame->tf_eip,
(u_int)(p->p_sticks - oticks) * psratio);
}
curpriority = p->p_priority;
return(have_giant);
mtx_exit(&sched_lock, MTX_SPIN);
}
/*
@ -254,8 +247,8 @@ trap(frame)
* interrupts and then trapped. Enabling interrupts
* now is wrong, but it is better than running with
* interrupts disabled until they are accidentally
* enabled later. XXX Consider whether is this still
* correct.
* enabled later. XXX This is really bad if we trap
* while holding a spin lock.
*/
type = frame.tf_trapno;
if (ISPL(frame.tf_cs) == SEL_UPL || (frame.tf_eflags & PSL_VM))
@ -269,6 +262,10 @@ trap(frame)
*/
printf("kernel trap %d with interrupts disabled\n",
type);
/*
* We should walk p_heldmtx here and see if any are
* spin mutexes, and not do this if so.
*/
enable_intr();
}
@ -298,7 +295,9 @@ restart:
((frame.tf_eflags & PSL_VM) && !in_vm86call)) {
/* user trap */
mtx_enter(&sched_lock, MTX_SPIN);
sticks = p->p_sticks;
mtx_exit(&sched_lock, MTX_SPIN);
p->p_md.md_regs = &frame;
switch (type) {
@ -649,9 +648,10 @@ restart:
#endif
user:
userret(p, &frame, sticks, 1);
userret(p, &frame, sticks);
out:
mtx_exit(&Giant, MTX_DEF);
if (mtx_owned(&Giant))
mtx_exit(&Giant, MTX_DEF);
}
#ifdef notyet
@ -709,7 +709,9 @@ trap_pfault(frame, usermode, eva)
* Keep swapout from messing with us during this
* critical time.
*/
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
/*
* Grow the stack if necessary
@ -722,7 +724,9 @@ trap_pfault(frame, usermode, eva)
*/
if (!grow_stack (p, va)) {
rv = KERN_FAILURE;
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
goto nogo;
}
@ -731,7 +735,9 @@ trap_pfault(frame, usermode, eva)
(ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
: VM_FAULT_NORMAL);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
} else {
/*
* Don't allow user-mode faults in kernel address space.
@ -824,7 +830,9 @@ trap_pfault(frame, usermode, eva)
* Keep swapout from messing with us during this
* critical time.
*/
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
/*
* Grow the stack if necessary
@ -837,7 +845,9 @@ trap_pfault(frame, usermode, eva)
*/
if (!grow_stack (p, va)) {
rv = KERN_FAILURE;
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
goto nogo;
}
@ -846,10 +856,13 @@ trap_pfault(frame, usermode, eva)
(ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
: VM_FAULT_NORMAL);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
} else {
/*
* Don't have to worry about process locking or stacks in the kernel.
* Don't have to worry about process locking or stacks in the
* kernel.
*/
rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
}
@ -1006,10 +1019,14 @@ int trapwrite(addr)
p = curproc;
vm = p->p_vmspace;
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
if (!grow_stack (p, va)) {
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
return (1);
}
@ -1018,7 +1035,9 @@ int trapwrite(addr)
*/
rv = vm_fault(&vm->vm_map, va, VM_PROT_WRITE, VM_FAULT_DIRTY);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
if (rv != KERN_SUCCESS)
return 1;
@ -1049,7 +1068,6 @@ syscall2(frame)
int error;
int narg;
int args[8];
int have_giant = 0;
u_int code;
atomic_add_int(&cnt.v_syscall, 1);
@ -1062,13 +1080,9 @@ syscall2(frame)
}
#endif
/*
* handle atomicy by looping since interrupts are enabled and the
* MP lock is not held.
*/
sticks = ((volatile struct proc *)p)->p_sticks;
while (sticks != ((volatile struct proc *)p)->p_sticks)
sticks = ((volatile struct proc *)p)->p_sticks;
mtx_enter(&sched_lock, MTX_SPIN);
sticks = p->p_sticks;
mtx_exit(&sched_lock, MTX_SPIN);
p->p_md.md_regs = &frame;
params = (caddr_t)frame.tf_esp + sizeof(int);
@ -1118,7 +1132,6 @@ syscall2(frame)
if (params && (i = narg * sizeof(int)) &&
(error = copyin(params, (caddr_t)args, (u_int)i))) {
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, narg, args);
@ -1133,15 +1146,12 @@ syscall2(frame)
*/
if ((callp->sy_narg & SYF_MPSAFE) == 0) {
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL)) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
ktrsyscall(p->p_tracep, code, narg, args);
}
#endif
@ -1157,11 +1167,6 @@ syscall2(frame)
*/
switch (error) {
case 0:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
frame.tf_eax = p->p_retval[0];
frame.tf_edx = p->p_retval[1];
frame.tf_eflags &= ~PSL_C;
@ -1195,10 +1200,8 @@ bad:
* Traced syscall. trapsignal() is not MP aware.
*/
if ((frame.tf_eflags & PSL_T) && !(frame.tf_eflags & PSL_VM)) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
frame.tf_eflags &= ~PSL_T;
trapsignal(p, SIGTRAP, 0);
}
@ -1206,14 +1209,12 @@ bad:
/*
* Handle reschedule and other end-of-syscall issues
*/
have_giant = userret(p, &frame, sticks, have_giant);
userret(p, &frame, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET)) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
ktrsysret(p->p_tracep, code, error, p->p_retval[0]);
}
#endif
@ -1226,19 +1227,19 @@ bad:
STOPEVENT(p, S_SCX, code);
/*
* Release the MP lock if we had to get it
* Release Giant if we had to get it
*/
if (have_giant)
if (mtx_owned(&Giant))
mtx_exit(&Giant, MTX_DEF);
mtx_assert(&sched_lock, MA_NOTOWNED);
mtx_assert(&Giant, MA_NOTOWNED);
#ifdef WITNESS
if (witness_list(p)) {
panic("system call %s returning with mutex(s) held\n",
syscallnames[code]);
}
#endif
mtx_assert(&sched_lock, MA_NOTOWNED);
mtx_assert(&Giant, MA_NOTOWNED);
}
void
@ -1248,64 +1249,38 @@ ast(frame)
struct proc *p = CURPROC;
u_quad_t sticks;
/*
* handle atomicy by looping since interrupts are enabled and the
* MP lock is not held.
*/
sticks = ((volatile struct proc *)p)->p_sticks;
while (sticks != ((volatile struct proc *)p)->p_sticks)
sticks = ((volatile struct proc *)p)->p_sticks;
mtx_enter(&sched_lock, MTX_SPIN);
sticks = p->p_sticks;
astoff();
atomic_add_int(&cnt.v_soft, 1);
if (p->p_flag & P_OWEUPC) {
if (p->p_sflag & PS_OWEUPC) {
p->p_sflag &= ~PS_OWEUPC;
mtx_exit(&sched_lock, MTX_SPIN);
mtx_enter(&Giant, MTX_DEF);
p->p_flag &= ~P_OWEUPC;
mtx_enter(&sched_lock, MTX_SPIN);
addupc_task(p, p->p_stats->p_prof.pr_addr,
p->p_stats->p_prof.pr_ticks);
}
if (p->p_flag & P_ALRMPEND) {
if (p->p_sflag & PS_ALRMPEND) {
p->p_sflag &= ~PS_ALRMPEND;
mtx_exit(&sched_lock, MTX_SPIN);
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
p->p_flag &= ~P_ALRMPEND;
psignal(p, SIGVTALRM);
mtx_enter(&sched_lock, MTX_SPIN);
}
if (p->p_flag & P_PROFPEND) {
if (p->p_sflag & PS_PROFPEND) {
p->p_sflag &= ~PS_PROFPEND;
mtx_exit(&sched_lock, MTX_SPIN);
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
p->p_flag &= ~P_PROFPEND;
psignal(p, SIGPROF);
}
if (userret(p, &frame, sticks, mtx_owned(&Giant)) != 0)
mtx_exit(&Giant, MTX_DEF);
}
/*
* Simplified back end of syscall(), used when returning from fork()
* directly into user mode. Giant is not held on entry, and must not
* be held on return.
*/
void
fork_return(p, frame)
struct proc *p;
struct trapframe frame;
{
int have_giant;
frame.tf_eax = 0; /* Child returns zero */
frame.tf_eflags &= ~PSL_C; /* success */
frame.tf_edx = 1;
have_giant = userret(p, &frame, 0, mtx_owned(&Giant));
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET)) {
if (have_giant == 0) {
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
ktrsysret(p->p_tracep, SYS_fork, 0, 0);
}
#endif
if (have_giant)
} else
mtx_exit(&sched_lock, MTX_SPIN);
userret(p, &frame, sticks);
if (mtx_owned(&Giant))
mtx_exit(&Giant, MTX_DEF);
}

175
sys/i386/i386/trap.c
View File

@ -148,9 +148,6 @@ static char *trap_msg[] = {
"machine check trap", /* 28 T_MCHK */
};
static __inline int userret __P((struct proc *p, struct trapframe *frame,
u_quad_t oticks, int have_giant));
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
extern int has_f00f_bug;
#endif
@ -168,23 +165,21 @@ SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
extern char *syscallnames[];
#endif
static __inline int
userret(p, frame, oticks, have_giant)
void
userret(p, frame, oticks)
struct proc *p;
struct trapframe *frame;
u_quad_t oticks;
int have_giant;
{
int sig, s;
int sig;
while ((sig = CURSIG(p)) != 0) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
postsig(sig);
}
mtx_enter(&sched_lock, MTX_SPIN);
p->p_priority = p->p_usrpri;
if (resched_wanted()) {
/*
@ -195,36 +190,34 @@ userret(p, frame, oticks, have_giant)
* mi_switch()'ed, we might not be on the queue indicated by
* our priority.
*/
s = splhigh();
mtx_enter(&sched_lock, MTX_SPIN);
DROP_GIANT_NOSWITCH();
setrunqueue(p);
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
mtx_exit(&sched_lock, MTX_SPIN);
PICKUP_GIANT();
splx(s);
while ((sig = CURSIG(p)) != 0) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
postsig(sig);
}
mtx_enter(&sched_lock, MTX_SPIN);
}
/*
* Charge system time if profiling.
*/
if (p->p_flag & P_PROFIL) {
if (have_giant == 0) {
if (p->p_sflag & PS_PROFIL) {
mtx_exit(&sched_lock, MTX_SPIN);
/* XXX - do we need Giant? */
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
mtx_enter(&sched_lock, MTX_SPIN);
addupc_task(p, frame->tf_eip,
(u_int)(p->p_sticks - oticks) * psratio);
}
curpriority = p->p_priority;
return(have_giant);
mtx_exit(&sched_lock, MTX_SPIN);
}
/*
@ -254,8 +247,8 @@ trap(frame)
* interrupts and then trapped. Enabling interrupts
* now is wrong, but it is better than running with
* interrupts disabled until they are accidentally
* enabled later. XXX Consider whether is this still
* correct.
* enabled later. XXX This is really bad if we trap
* while holding a spin lock.
*/
type = frame.tf_trapno;
if (ISPL(frame.tf_cs) == SEL_UPL || (frame.tf_eflags & PSL_VM))
@ -269,6 +262,10 @@ trap(frame)
*/
printf("kernel trap %d with interrupts disabled\n",
type);
/*
* We should walk p_heldmtx here and see if any are
* spin mutexes, and not do this if so.
*/
enable_intr();
}
@ -298,7 +295,9 @@ restart:
((frame.tf_eflags & PSL_VM) && !in_vm86call)) {
/* user trap */
mtx_enter(&sched_lock, MTX_SPIN);
sticks = p->p_sticks;
mtx_exit(&sched_lock, MTX_SPIN);
p->p_md.md_regs = &frame;
switch (type) {
@ -649,9 +648,10 @@ restart:
#endif
user:
userret(p, &frame, sticks, 1);
userret(p, &frame, sticks);
out:
mtx_exit(&Giant, MTX_DEF);
if (mtx_owned(&Giant))
mtx_exit(&Giant, MTX_DEF);
}
#ifdef notyet
@ -709,7 +709,9 @@ trap_pfault(frame, usermode, eva)
* Keep swapout from messing with us during this
* critical time.
*/
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
/*
* Grow the stack if necessary
@ -722,7 +724,9 @@ trap_pfault(frame, usermode, eva)
*/
if (!grow_stack (p, va)) {
rv = KERN_FAILURE;
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
goto nogo;
}
@ -731,7 +735,9 @@ trap_pfault(frame, usermode, eva)
(ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
: VM_FAULT_NORMAL);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
} else {
/*
* Don't allow user-mode faults in kernel address space.
@ -824,7 +830,9 @@ trap_pfault(frame, usermode, eva)
* Keep swapout from messing with us during this
* critical time.
*/
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
/*
* Grow the stack if necessary
@ -837,7 +845,9 @@ trap_pfault(frame, usermode, eva)
*/
if (!grow_stack (p, va)) {
rv = KERN_FAILURE;
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
goto nogo;
}
@ -846,10 +856,13 @@ trap_pfault(frame, usermode, eva)
(ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
: VM_FAULT_NORMAL);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
} else {
/*
* Don't have to worry about process locking or stacks in the kernel.
* Don't have to worry about process locking or stacks in the
* kernel.
*/
rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
}
@ -1006,10 +1019,14 @@ int trapwrite(addr)
p = curproc;
vm = p->p_vmspace;
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
if (!grow_stack (p, va)) {
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
return (1);
}
@ -1018,7 +1035,9 @@ int trapwrite(addr)
*/
rv = vm_fault(&vm->vm_map, va, VM_PROT_WRITE, VM_FAULT_DIRTY);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
if (rv != KERN_SUCCESS)
return 1;
@ -1049,7 +1068,6 @@ syscall2(frame)
int error;
int narg;
int args[8];
int have_giant = 0;
u_int code;
atomic_add_int(&cnt.v_syscall, 1);
@ -1062,13 +1080,9 @@ syscall2(frame)
}
#endif
/*
* handle atomicy by looping since interrupts are enabled and the
* MP lock is not held.
*/
sticks = ((volatile struct proc *)p)->p_sticks;
while (sticks != ((volatile struct proc *)p)->p_sticks)
sticks = ((volatile struct proc *)p)->p_sticks;
mtx_enter(&sched_lock, MTX_SPIN);
sticks = p->p_sticks;
mtx_exit(&sched_lock, MTX_SPIN);
p->p_md.md_regs = &frame;
params = (caddr_t)frame.tf_esp + sizeof(int);
@ -1118,7 +1132,6 @@ syscall2(frame)
if (params && (i = narg * sizeof(int)) &&
(error = copyin(params, (caddr_t)args, (u_int)i))) {
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, narg, args);
@ -1133,15 +1146,12 @@ syscall2(frame)
*/
if ((callp->sy_narg & SYF_MPSAFE) == 0) {
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL)) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
ktrsyscall(p->p_tracep, code, narg, args);
}
#endif
@ -1157,11 +1167,6 @@ syscall2(frame)
*/
switch (error) {
case 0:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
frame.tf_eax = p->p_retval[0];
frame.tf_edx = p->p_retval[1];
frame.tf_eflags &= ~PSL_C;
@ -1195,10 +1200,8 @@ bad:
* Traced syscall. trapsignal() is not MP aware.
*/
if ((frame.tf_eflags & PSL_T) && !(frame.tf_eflags & PSL_VM)) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
frame.tf_eflags &= ~PSL_T;
trapsignal(p, SIGTRAP, 0);
}
@ -1206,14 +1209,12 @@ bad:
/*
* Handle reschedule and other end-of-syscall issues
*/
have_giant = userret(p, &frame, sticks, have_giant);
userret(p, &frame, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET)) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
ktrsysret(p->p_tracep, code, error, p->p_retval[0]);
}
#endif
@ -1226,19 +1227,19 @@ bad:
STOPEVENT(p, S_SCX, code);
/*
* Release the MP lock if we had to get it
* Release Giant if we had to get it
*/
if (have_giant)
if (mtx_owned(&Giant))
mtx_exit(&Giant, MTX_DEF);
mtx_assert(&sched_lock, MA_NOTOWNED);
mtx_assert(&Giant, MA_NOTOWNED);
#ifdef WITNESS
if (witness_list(p)) {
panic("system call %s returning with mutex(s) held\n",
syscallnames[code]);
}
#endif
mtx_assert(&sched_lock, MA_NOTOWNED);
mtx_assert(&Giant, MA_NOTOWNED);
}
void
@ -1248,64 +1249,38 @@ ast(frame)
struct proc *p = CURPROC;
u_quad_t sticks;
/*
* handle atomicy by looping since interrupts are enabled and the
* MP lock is not held.
*/
sticks = ((volatile struct proc *)p)->p_sticks;
while (sticks != ((volatile struct proc *)p)->p_sticks)
sticks = ((volatile struct proc *)p)->p_sticks;
mtx_enter(&sched_lock, MTX_SPIN);
sticks = p->p_sticks;
astoff();
atomic_add_int(&cnt.v_soft, 1);
if (p->p_flag & P_OWEUPC) {
if (p->p_sflag & PS_OWEUPC) {
p->p_sflag &= ~PS_OWEUPC;
mtx_exit(&sched_lock, MTX_SPIN);
mtx_enter(&Giant, MTX_DEF);
p->p_flag &= ~P_OWEUPC;
mtx_enter(&sched_lock, MTX_SPIN);
addupc_task(p, p->p_stats->p_prof.pr_addr,
p->p_stats->p_prof.pr_ticks);
}
if (p->p_flag & P_ALRMPEND) {
if (p->p_sflag & PS_ALRMPEND) {
p->p_sflag &= ~PS_ALRMPEND;
mtx_exit(&sched_lock, MTX_SPIN);
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
p->p_flag &= ~P_ALRMPEND;
psignal(p, SIGVTALRM);
mtx_enter(&sched_lock, MTX_SPIN);
}
if (p->p_flag & P_PROFPEND) {
if (p->p_sflag & PS_PROFPEND) {
p->p_sflag &= ~PS_PROFPEND;
mtx_exit(&sched_lock, MTX_SPIN);
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
p->p_flag &= ~P_PROFPEND;
psignal(p, SIGPROF);
}
if (userret(p, &frame, sticks, mtx_owned(&Giant)) != 0)
mtx_exit(&Giant, MTX_DEF);
}
/*
* Simplified back end of syscall(), used when returning from fork()
* directly into user mode. Giant is not held on entry, and must not
* be held on return.
*/
void
fork_return(p, frame)
struct proc *p;
struct trapframe frame;
{
int have_giant;
frame.tf_eax = 0; /* Child returns zero */
frame.tf_eflags &= ~PSL_C; /* success */
frame.tf_edx = 1;
have_giant = userret(p, &frame, 0, mtx_owned(&Giant));
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET)) {
if (have_giant == 0) {
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
ktrsysret(p->p_tracep, SYS_fork, 0, 0);
}
#endif
if (have_giant)
} else
mtx_exit(&sched_lock, MTX_SPIN);
userret(p, &frame, sticks);
if (mtx_owned(&Giant))
mtx_exit(&Giant, MTX_DEF);
}

175
sys/kern/subr_trap.c
View File

@ -148,9 +148,6 @@ static char *trap_msg[] = {
"machine check trap", /* 28 T_MCHK */
};
static __inline int userret __P((struct proc *p, struct trapframe *frame,
u_quad_t oticks, int have_giant));
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
extern int has_f00f_bug;
#endif
@ -168,23 +165,21 @@ SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
extern char *syscallnames[];
#endif
static __inline int
userret(p, frame, oticks, have_giant)
void
userret(p, frame, oticks)
struct proc *p;
struct trapframe *frame;
u_quad_t oticks;
int have_giant;
{
int sig, s;
int sig;
while ((sig = CURSIG(p)) != 0) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
postsig(sig);
}
mtx_enter(&sched_lock, MTX_SPIN);
p->p_priority = p->p_usrpri;
if (resched_wanted()) {
/*
@ -195,36 +190,34 @@ userret(p, frame, oticks, have_giant)
* mi_switch()'ed, we might not be on the queue indicated by
* our priority.
*/
s = splhigh();
mtx_enter(&sched_lock, MTX_SPIN);
DROP_GIANT_NOSWITCH();
setrunqueue(p);
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
mtx_exit(&sched_lock, MTX_SPIN);
PICKUP_GIANT();
splx(s);
while ((sig = CURSIG(p)) != 0) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
postsig(sig);
}
mtx_enter(&sched_lock, MTX_SPIN);
}
/*
* Charge system time if profiling.
*/
if (p->p_flag & P_PROFIL) {
if (have_giant == 0) {
if (p->p_sflag & PS_PROFIL) {
mtx_exit(&sched_lock, MTX_SPIN);
/* XXX - do we need Giant? */
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
mtx_enter(&sched_lock, MTX_SPIN);
addupc_task(p, frame->tf_eip,
(u_int)(p->p_sticks - oticks) * psratio);
}
curpriority = p->p_priority;
return(have_giant);
mtx_exit(&sched_lock, MTX_SPIN);
}
/*
@ -254,8 +247,8 @@ trap(frame)
* interrupts and then trapped. Enabling interrupts
* now is wrong, but it is better than running with
* interrupts disabled until they are accidentally
* enabled later. XXX Consider whether is this still
* correct.
* enabled later. XXX This is really bad if we trap
* while holding a spin lock.
*/
type = frame.tf_trapno;
if (ISPL(frame.tf_cs) == SEL_UPL || (frame.tf_eflags & PSL_VM))
@ -269,6 +262,10 @@ trap(frame)
*/
printf("kernel trap %d with interrupts disabled\n",
type);
/*
* We should walk p_heldmtx here and see if any are
* spin mutexes, and not do this if so.
*/
enable_intr();
}
@ -298,7 +295,9 @@ restart:
((frame.tf_eflags & PSL_VM) && !in_vm86call)) {
/* user trap */
mtx_enter(&sched_lock, MTX_SPIN);
sticks = p->p_sticks;
mtx_exit(&sched_lock, MTX_SPIN);
p->p_md.md_regs = &frame;
switch (type) {
@ -649,9 +648,10 @@ restart:
#endif
user:
userret(p, &frame, sticks, 1);
userret(p, &frame, sticks);
out:
mtx_exit(&Giant, MTX_DEF);
if (mtx_owned(&Giant))
mtx_exit(&Giant, MTX_DEF);
}
#ifdef notyet
@ -709,7 +709,9 @@ trap_pfault(frame, usermode, eva)
* Keep swapout from messing with us during this
* critical time.
*/
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
/*
* Grow the stack if necessary
@ -722,7 +724,9 @@ trap_pfault(frame, usermode, eva)
*/
if (!grow_stack (p, va)) {
rv = KERN_FAILURE;
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
goto nogo;
}
@ -731,7 +735,9 @@ trap_pfault(frame, usermode, eva)
(ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
: VM_FAULT_NORMAL);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
} else {
/*
* Don't allow user-mode faults in kernel address space.
@ -824,7 +830,9 @@ trap_pfault(frame, usermode, eva)
* Keep swapout from messing with us during this
* critical time.
*/
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
/*
* Grow the stack if necessary
@ -837,7 +845,9 @@ trap_pfault(frame, usermode, eva)
*/
if (!grow_stack (p, va)) {
rv = KERN_FAILURE;
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
goto nogo;
}
@ -846,10 +856,13 @@ trap_pfault(frame, usermode, eva)
(ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
: VM_FAULT_NORMAL);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
} else {
/*
* Don't have to worry about process locking or stacks in the kernel.
* Don't have to worry about process locking or stacks in the
* kernel.
*/
rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
}
@ -1006,10 +1019,14 @@ int trapwrite(addr)
p = curproc;
vm = p->p_vmspace;
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
if (!grow_stack (p, va)) {
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
return (1);
}
@ -1018,7 +1035,9 @@ int trapwrite(addr)
*/
rv = vm_fault(&vm->vm_map, va, VM_PROT_WRITE, VM_FAULT_DIRTY);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
if (rv != KERN_SUCCESS)
return 1;
@ -1049,7 +1068,6 @@ syscall2(frame)
int error;
int narg;
int args[8];
int have_giant = 0;
u_int code;
atomic_add_int(&cnt.v_syscall, 1);
@ -1062,13 +1080,9 @@ syscall2(frame)
}
#endif
/*
* handle atomicy by looping since interrupts are enabled and the
* MP lock is not held.
*/
sticks = ((volatile struct proc *)p)->p_sticks;
while (sticks != ((volatile struct proc *)p)->p_sticks)
sticks = ((volatile struct proc *)p)->p_sticks;
mtx_enter(&sched_lock, MTX_SPIN);
sticks = p->p_sticks;
mtx_exit(&sched_lock, MTX_SPIN);
p->p_md.md_regs = &frame;
params = (caddr_t)frame.tf_esp + sizeof(int);
@ -1118,7 +1132,6 @@ syscall2(frame)
if (params && (i = narg * sizeof(int)) &&
(error = copyin(params, (caddr_t)args, (u_int)i))) {
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, narg, args);
@ -1133,15 +1146,12 @@ syscall2(frame)
*/
if ((callp->sy_narg & SYF_MPSAFE) == 0) {
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL)) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
ktrsyscall(p->p_tracep, code, narg, args);
}
#endif
@ -1157,11 +1167,6 @@ syscall2(frame)
*/
switch (error) {
case 0:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
frame.tf_eax = p->p_retval[0];
frame.tf_edx = p->p_retval[1];
frame.tf_eflags &= ~PSL_C;
@ -1195,10 +1200,8 @@ bad:
* Traced syscall. trapsignal() is not MP aware.
*/
if ((frame.tf_eflags & PSL_T) && !(frame.tf_eflags & PSL_VM)) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
frame.tf_eflags &= ~PSL_T;
trapsignal(p, SIGTRAP, 0);
}
@ -1206,14 +1209,12 @@ bad:
/*
* Handle reschedule and other end-of-syscall issues
*/
have_giant = userret(p, &frame, sticks, have_giant);
userret(p, &frame, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET)) {
if (have_giant == 0) {
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
ktrsysret(p->p_tracep, code, error, p->p_retval[0]);
}
#endif
@ -1226,19 +1227,19 @@ bad:
STOPEVENT(p, S_SCX, code);
/*
* Release the MP lock if we had to get it
* Release Giant if we had to get it
*/
if (have_giant)
if (mtx_owned(&Giant))
mtx_exit(&Giant, MTX_DEF);
mtx_assert(&sched_lock, MA_NOTOWNED);
mtx_assert(&Giant, MA_NOTOWNED);
#ifdef WITNESS
if (witness_list(p)) {
panic("system call %s returning with mutex(s) held\n",
syscallnames[code]);
}
#endif
mtx_assert(&sched_lock, MA_NOTOWNED);
mtx_assert(&Giant, MA_NOTOWNED);
}
void
@ -1248,64 +1249,38 @@ ast(frame)
struct proc *p = CURPROC;
u_quad_t sticks;
/*
* handle atomicy by looping since interrupts are enabled and the
* MP lock is not held.
*/
sticks = ((volatile struct proc *)p)->p_sticks;
while (sticks != ((volatile struct proc *)p)->p_sticks)
sticks = ((volatile struct proc *)p)->p_sticks;
mtx_enter(&sched_lock, MTX_SPIN);
sticks = p->p_sticks;
astoff();
atomic_add_int(&cnt.v_soft, 1);
if (p->p_flag & P_OWEUPC) {
if (p->p_sflag & PS_OWEUPC) {
p->p_sflag &= ~PS_OWEUPC;
mtx_exit(&sched_lock, MTX_SPIN);
mtx_enter(&Giant, MTX_DEF);
p->p_flag &= ~P_OWEUPC;
mtx_enter(&sched_lock, MTX_SPIN);
addupc_task(p, p->p_stats->p_prof.pr_addr,
p->p_stats->p_prof.pr_ticks);
}
if (p->p_flag & P_ALRMPEND) {
if (p->p_sflag & PS_ALRMPEND) {
p->p_sflag &= ~PS_ALRMPEND;
mtx_exit(&sched_lock, MTX_SPIN);
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
p->p_flag &= ~P_ALRMPEND;
psignal(p, SIGVTALRM);
mtx_enter(&sched_lock, MTX_SPIN);
}
if (p->p_flag & P_PROFPEND) {
if (p->p_sflag & PS_PROFPEND) {
p->p_sflag &= ~PS_PROFPEND;
mtx_exit(&sched_lock, MTX_SPIN);
if (!mtx_owned(&Giant))
mtx_enter(&Giant, MTX_DEF);
p->p_flag &= ~P_PROFPEND;
psignal(p, SIGPROF);
}
if (userret(p, &frame, sticks, mtx_owned(&Giant)) != 0)
mtx_exit(&Giant, MTX_DEF);
}
/*
* Simplified back end of syscall(), used when returning from fork()
* directly into user mode. Giant is not held on entry, and must not
* be held on return.
*/
void
fork_return(p, frame)
struct proc *p;
struct trapframe frame;
{
int have_giant;
frame.tf_eax = 0; /* Child returns zero */
frame.tf_eflags &= ~PSL_C; /* success */
frame.tf_edx = 1;
have_giant = userret(p, &frame, 0, mtx_owned(&Giant));
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET)) {
if (have_giant == 0) {
mtx_enter(&Giant, MTX_DEF);
have_giant = 1;
}
ktrsysret(p->p_tracep, SYS_fork, 0, 0);
}
#endif
if (have_giant)
} else
mtx_exit(&sched_lock, MTX_SPIN);
userret(p, &frame, sticks);
if (mtx_owned(&Giant))
mtx_exit(&Giant, MTX_DEF);
}