void
cpu_lwp_exit(void)
{
struct thread *td = curthread;
struct pcb *pcb;
npxexit();
pcb = td->td_pcb;
/* Some i386 functionality was dropped */
KKASSERT(pcb->pcb_ext == NULL);
/*
* disable all hardware breakpoints
*/
if (pcb->pcb_flags & PCB_DBREGS) {
reset_dbregs();
pcb->pcb_flags &= ~PCB_DBREGS;
}
td->td_gd->gd_cnt.v_swtch++;
crit_enter_quick(td);
if (td->td_flags & TDF_TSLEEPQ)
tsleep_remove(td);
lwkt_deschedule_self(td);
lwkt_remove_tdallq(td);
cpu_thread_exit();
}
/*
* Reset registers to default values on exec.
*/
static void
linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
{
struct trapframe *regs = td->td_frame;
struct pcb *pcb = td->td_pcb;
mtx_lock(&dt_lock);
if (td->td_proc->p_md.md_ldt != NULL)
user_ldt_free(td);
else
mtx_unlock(&dt_lock);
pcb->pcb_fsbase = 0;
pcb->pcb_gsbase = 0;
clear_pcb_flags(pcb, PCB_32BIT);
pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
set_pcb_flags(pcb, PCB_FULL_IRET);
bzero((char *)regs, sizeof(struct trapframe));
regs->tf_rip = imgp->entry_addr;
regs->tf_rsp = stack;
regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T);
regs->tf_ss = _udatasel;
regs->tf_cs = _ucodesel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _ufssel;
regs->tf_gs = _ugssel;
regs->tf_flags = TF_HASSEGS;
/*
* Reset the hardware debug registers if they were in use.
* They won't have any meaning for the newly exec'd process.
*/
if (pcb->pcb_flags & PCB_DBREGS) {
pcb->pcb_dr0 = 0;
pcb->pcb_dr1 = 0;
pcb->pcb_dr2 = 0;
pcb->pcb_dr3 = 0;
pcb->pcb_dr6 = 0;
pcb->pcb_dr7 = 0;
if (pcb == curpcb) {
/*
* Clear the debug registers on the running
* CPU, otherwise they will end up affecting
* the next process we switch to.
*/
reset_dbregs();
}
clear_pcb_flags(pcb, PCB_DBREGS);
}
/*
* Drop the FP state if we hold it, so that the process gets a
* clean FP state if it uses the FPU again.
*/
fpstate_drop(td);
}
void
cpu_thread_exit(struct thread *td)
{
struct pcb *pcb;
critical_enter();
if (td == PCPU_GET(fpcurthread))
fpudrop();
critical_exit();
pcb = td->td_pcb;
/* Disable any hardware breakpoints. */
if (pcb->pcb_flags & PCB_DBREGS) {
reset_dbregs();
clear_pcb_flags(pcb, PCB_DBREGS);
}
}
void
cpu_lwp_exit(void)
{
struct thread *td = curthread;
struct pcb *pcb;
struct pcb_ext *ext;
/*
* If we were using a private TSS do a forced-switch to ourselves
* to switch back to the common TSS before freeing it.
*/
pcb = td->td_pcb;
if ((ext = pcb->pcb_ext) != NULL) {
crit_enter();
pcb->pcb_ext = NULL;
lwkt_switch_return(td->td_switch(td));
crit_exit();
kmem_free(&kernel_map, (vm_offset_t)ext, ctob(IOPAGES + 1));
}
user_ldt_free(pcb);
if (pcb->pcb_flags & PCB_DBREGS) {
/*
* disable all hardware breakpoints
*/
reset_dbregs();
pcb->pcb_flags &= ~PCB_DBREGS;
}
td->td_gd->gd_cnt.v_swtch++;
crit_enter_quick(td);
if (td->td_flags & TDF_TSLEEPQ)
tsleep_remove(td);
lwkt_deschedule_self(td);
lwkt_remove_tdallq(td);
cpu_thread_exit();
}
/*
* Clear registers on exec
*/
void
exec_setregs(u_long entry, u_long stack, u_long ps_strings)
{
struct thread *td = curthread;
struct lwp *lp = td->td_lwp;
struct trapframe *regs = lp->lwp_md.md_regs;
struct pcb *pcb = lp->lwp_thread->td_pcb;
/* was i386_user_cleanup() in NetBSD */
user_ldt_free(pcb);
bzero((char *)regs, sizeof(struct trapframe));
regs->tf_eip = entry;
regs->tf_esp = stack;
regs->tf_eflags = PSL_USER | (regs->tf_eflags & PSL_T);
regs->tf_ss = 0;
regs->tf_ds = 0;
regs->tf_es = 0;
regs->tf_fs = 0;
regs->tf_gs = 0;
regs->tf_cs = 0;
/* PS_STRINGS value for BSD/OS binaries. It is 0 for non-BSD/OS. */
regs->tf_ebx = ps_strings;
/*
* Reset the hardware debug registers if they were in use.
* They won't have any meaning for the newly exec'd process.
*/
if (pcb->pcb_flags & PCB_DBREGS) {
pcb->pcb_dr0 = 0;
pcb->pcb_dr1 = 0;
pcb->pcb_dr2 = 0;
pcb->pcb_dr3 = 0;
pcb->pcb_dr6 = 0;
pcb->pcb_dr7 = 0;
if (pcb == td->td_pcb) {
/*
* Clear the debug registers on the running
* CPU, otherwise they will end up affecting
* the next process we switch to.
*/
reset_dbregs();
}
pcb->pcb_flags &= ~PCB_DBREGS;
}
/*
* Initialize the math emulator (if any) for the current process.
* Actually, just clear the bit that says that the emulator has
* been initialized. Initialization is delayed until the process
* traps to the emulator (if it is done at all) mainly because
* emulators don't provide an entry point for initialization.
*/
pcb->pcb_flags &= ~FP_SOFTFP;
/*
* note: do not set CR0_TS here. npxinit() must do it after clearing
* gd_npxthread. Otherwise a preemptive interrupt thread may panic
* in npxdna().
*/
crit_enter();
#if 0
load_cr0(rcr0() | CR0_MP);
#endif
#if NNPX > 0
/* Initialize the npx (if any) for the current process. */
npxinit();
#endif
crit_exit();
/*
* note: linux emulator needs edx to be 0x0 on entry, which is
* handled in execve simply by setting the 64 bit syscall
* return value to 0.
*/
}
