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Differential D6731 Diff 17628 head/sys/amd64/amd64/vm_machdep.c

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head/sys/amd64/amd64/vm_machdep.c

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/* /*
* Intercept the return address from a freshly forked process that has NOT * Intercept the return address from a freshly forked process that has NOT
* been scheduled yet. * been scheduled yet.
* *
* This is needed to make kernel threads stay in kernel mode. * This is needed to make kernel threads stay in kernel mode.
*/ */
void void
cpu_set_fork_handler(td, func, arg) cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg)
struct thread *td;
void (*func)(void *);
void *arg;
{ {
/* /*
* Note that the trap frame follows the args, so the function * Note that the trap frame follows the args, so the function
* is really called like this: func(arg, frame); * is really called like this: func(arg, frame);
*/ */
td->td_pcb->pcb_r12 = (long) func; /* function */ td->td_pcb->pcb_r12 = (long) func; /* function */
td->td_pcb->pcb_rbx = (long) arg; /* first arg */ td->td_pcb->pcb_rbx = (long) arg; /* first arg */
} }
▲ Show 20 Lines • Show All 116 Lines • ▼ Show 20 Linescpu_set_syscall_retval(struct thread *td, int error)
default: default:
td->td_frame->tf_rax = SV_ABI_ERRNO(td->td_proc, error); td->td_frame->tf_rax = SV_ABI_ERRNO(td->td_proc, error);
td->td_frame->tf_rflags |= PSL_C; td->td_frame->tf_rflags |= PSL_C;
break; break;
} }
} }
/* /*
* Initialize machine state (pcb and trap frame) for a new thread about to * Initialize machine state, mostly pcb and trap frame for a new
* upcall. Put enough state in the new thread's PCB to get it to go back * thread, about to return to userspace. Put enough state in the new
* userret(), where we can intercept it again to set the return (upcall) * thread's PCB to get it to go back to the fork_return(), which
* Address and stack, along with those from upcals that are from other sources * finalizes the thread state and handles peculiarities of the first
* such as those generated in thread_userret() itself. * return to userspace for the new thread.
*/ */
void void
cpu_set_upcall(struct thread *td, struct thread *td0) cpu_copy_thread(struct thread *td, struct thread *td0)
{ {
struct pcb *pcb2; struct pcb *pcb2;
/* Point the pcb to the top of the stack. */ /* Point the pcb to the top of the stack. */
pcb2 = td->td_pcb; pcb2 = td->td_pcb;
/* /*
* Copy the upcall pcb. This loads kernel regs. * Copy the upcall pcb. This loads kernel regs.
Show All 39 Linescpu_copy_thread(struct thread *td, struct thread *td0)
*/ */
/* Setup to release spin count in fork_exit(). */ /* Setup to release spin count in fork_exit(). */
td->td_md.md_spinlock_count = 1; td->td_md.md_spinlock_count = 1;
td->td_md.md_saved_flags = PSL_KERNEL | PSL_I; td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
} }
/* /*
* Set that machine state for performing an upcall that has to * Set that machine state for performing an upcall that starts
* be done in thread_userret() so that those upcalls generated * the entry function with the given argument.
* in thread_userret() itself can be done as well.
*/ */
void void
cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg, cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg,
stack_t *stack) stack_t *stack)
{ {
/* /*
* Do any extra cleaning that needs to be done. * Do any extra cleaning that needs to be done.
* The thread may have optional components * The thread may have optional components
* that are not present in a fresh thread. * that are not present in a fresh thread.
* This may be a recycled thread so make it look * This may be a recycled thread so make it look
* as though it's newly allocated. * as though it's newly allocated.
*/ */
cpu_thread_clean(td); cpu_thread_clean(td);
#ifdef COMPAT_FREEBSD32 #ifdef COMPAT_FREEBSD32
if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
/* /*
* Set the trap frame to point at the beginning of the uts * Set the trap frame to point at the beginning of the entry
* function. * function.
*/ */
td->td_frame->tf_rbp = 0; td->td_frame->tf_rbp = 0;
td->td_frame->tf_rsp = td->td_frame->tf_rsp =
(((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
td->td_frame->tf_rip = (uintptr_t)entry; td->td_frame->tf_rip = (uintptr_t)entry;
/* /* Pass the argument to the entry point. */
* Pass the address of the mailbox for this kse to the uts
* function as a parameter on the stack.
*/
suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)), suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)),
(uint32_t)(uintptr_t)arg); (uint32_t)(uintptr_t)arg);
return; return;
} }
#endif #endif
/* /*
* Set the trap frame to point at the beginning of the uts * Set the trap frame to point at the beginning of the uts
* function. * function.
*/ */
td->td_frame->tf_rbp = 0; td->td_frame->tf_rbp = 0;
td->td_frame->tf_rsp = td->td_frame->tf_rsp =
((register_t)stack->ss_sp + stack->ss_size) & ~0x0f; ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f;
td->td_frame->tf_rsp -= 8; td->td_frame->tf_rsp -= 8;
td->td_frame->tf_rip = (register_t)entry; td->td_frame->tf_rip = (register_t)entry;
td->td_frame->tf_ds = _udatasel; td->td_frame->tf_ds = _udatasel;
td->td_frame->tf_es = _udatasel; td->td_frame->tf_es = _udatasel;
td->td_frame->tf_fs = _ufssel; td->td_frame->tf_fs = _ufssel;
td->td_frame->tf_gs = _ugssel; td->td_frame->tf_gs = _ugssel;
td->td_frame->tf_flags = TF_HASSEGS; td->td_frame->tf_flags = TF_HASSEGS;
/* /* Pass the argument to the entry point. */
* Pass the address of the mailbox for this kse to the uts
* function as a parameter on the stack.
*/
td->td_frame->tf_rdi = (register_t)arg; td->td_frame->tf_rdi = (register_t)arg;
} }
int int
cpu_set_user_tls(struct thread *td, void *tls_base) cpu_set_user_tls(struct thread *td, void *tls_base)
{ {
struct pcb *pcb; struct pcb *pcb;
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