/* * Finish a fork operation, with process p2 nearly set up. * Copy and update the pcb, set up the stack so that the child * ready to run and return to user mode. */ void cpu_fork(register struct thread *td1,register struct proc *p2, struct thread *td2,int flags) { register struct proc *p1; struct pcb *pcb2; p1 = td1->td_proc; if ((flags & RFPROC) == 0) return; /* It is assumed that the vm_thread_alloc called * cpu_thread_alloc() before cpu_fork is called. */ /* Point the pcb to the top of the stack */ pcb2 = td2->td_pcb; /* Copy p1's pcb, note that in this case * our pcb also includes the td_frame being copied * too. The older mips2 code did an additional copy * of the td_frame, for us that's not needed any * longer (this copy does them both) */ bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); /* Point mdproc and then copy over td1's contents * md_proc is empty for MIPS */ td2->td_md.md_flags = td1->td_md.md_flags & MDTD_FPUSED; /* * Set up return-value registers as fork() libc stub expects. */ td2->td_frame->v0 = 0; td2->td_frame->v1 = 1; td2->td_frame->a3 = 0; if (td1 == PCPU_GET(fpcurthread)) MipsSaveCurFPState(td1); pcb2->pcb_context[PCB_REG_RA] = (register_t)(intptr_t)fork_trampoline; /* Make sp 64-bit aligned */ pcb2->pcb_context[PCB_REG_SP] = (register_t)(((vm_offset_t)td2->td_pcb & ~(sizeof(__int64_t) - 1)) - CALLFRAME_SIZ); pcb2->pcb_context[PCB_REG_S0] = (register_t)(intptr_t)fork_return; pcb2->pcb_context[PCB_REG_S1] = (register_t)(intptr_t)td2; pcb2->pcb_context[PCB_REG_S2] = (register_t)(intptr_t)td2->td_frame; pcb2->pcb_context[PCB_REG_SR] = mips_rd_status() & (MIPS_SR_KX | MIPS_SR_UX | MIPS_SR_INT_MASK); /* * FREEBSD_DEVELOPERS_FIXME: * Setup any other CPU-Specific registers (Not MIPS Standard) * and/or bits in other standard MIPS registers (if CPU-Specific) * that are needed. */ td2->td_md.md_tls = td1->td_md.md_tls; td2->td_md.md_saved_intr = MIPS_SR_INT_IE; td2->td_md.md_spinlock_count = 1; #ifdef CPU_CNMIPS if (td1->td_md.md_flags & MDTD_COP2USED) { if (td1->td_md.md_cop2owner == COP2_OWNER_USERLAND) { if (td1->td_md.md_ucop2) octeon_cop2_save(td1->td_md.md_ucop2); else panic("cpu_fork: ucop2 is NULL but COP2 is enabled"); } else { if (td1->td_md.md_cop2) octeon_cop2_save(td1->td_md.md_cop2); else panic("cpu_fork: cop2 is NULL but COP2 is enabled"); } } if (td1->td_md.md_cop2) { td2->td_md.md_cop2 = octeon_cop2_alloc_ctx(); memcpy(td2->td_md.md_cop2, td1->td_md.md_cop2, sizeof(*td1->td_md.md_cop2)); } if (td1->td_md.md_ucop2) { td2->td_md.md_ucop2 = octeon_cop2_alloc_ctx(); memcpy(td2->td_md.md_ucop2, td1->td_md.md_ucop2, sizeof(*td1->td_md.md_ucop2)); } td2->td_md.md_cop2owner = td1->td_md.md_cop2owner; pcb2->pcb_context[PCB_REG_SR] |= MIPS_SR_PX | MIPS_SR_UX | MIPS_SR_KX | MIPS_SR_SX; /* Clear COP2 bits for userland & kernel */ td2->td_frame->sr &= ~MIPS_SR_COP_2_BIT; pcb2->pcb_context[PCB_REG_SR] &= ~MIPS_SR_COP_2_BIT; #endif }
/* * Clear registers on exec * $sp is set to the stack pointer passed in. $pc is set to the entry * point given by the exec_package passed in, as is $t9 (used for PIC * code by the MIPS elf abi). */ void exec_setregs(struct thread *td, struct image_params *imgp, u_long stack) { bzero((caddr_t)td->td_frame, sizeof(struct trapframe)); /* * The stack pointer has to be aligned to accommodate the largest * datatype at minimum. This probably means it should be 16-byte * aligned, but for now we're 8-byte aligning it. */ td->td_frame->sp = ((register_t) stack) & ~(sizeof(__int64_t) - 1); /* * If we're running o32 or n32 programs but have 64-bit registers, * GCC may use stack-relative addressing near the top of user * address space that, due to sign extension, will yield an * invalid address. For instance, if sp is 0x7fffff00 then GCC * might do something like this to load a word from 0x7ffffff0: * * addu sp, sp, 32768 * lw t0, -32528(sp) * * On systems with 64-bit registers, sp is sign-extended to * 0xffffffff80007f00 and the load is instead done from * 0xffffffff7ffffff0. * * To prevent this, we subtract 64K from the stack pointer here. * * For consistency, we should just always do this unless we're * running n64 programs. For now, since we don't support * COMPAT_FREEBSD32 on n64 kernels, we just do it unless we're * running n64 kernels. */ #if !defined(__mips_n64) td->td_frame->sp -= 65536; #endif td->td_frame->pc = imgp->entry_addr & ~3; td->td_frame->t9 = imgp->entry_addr & ~3; /* abicall req */ td->td_frame->sr = MIPS_SR_KSU_USER | MIPS_SR_EXL | MIPS_SR_INT_IE | (mips_rd_status() & MIPS_SR_INT_MASK); #if defined(__mips_n32) td->td_frame->sr |= MIPS_SR_PX; #elif defined(__mips_n64) td->td_frame->sr |= MIPS_SR_PX | MIPS_SR_UX | MIPS_SR_KX; #endif #ifdef CPU_CNMIPS td->td_frame->sr |= MIPS_SR_COP_2_BIT | MIPS_SR_PX | MIPS_SR_UX | MIPS_SR_KX | MIPS_SR_SX; #endif /* * FREEBSD_DEVELOPERS_FIXME: * Setup any other CPU-Specific registers (Not MIPS Standard) * and/or bits in other standard MIPS registers (if CPU-Specific) * that are needed. */ /* * Set up arguments for the rtld-capable crt0: * a0 stack pointer * a1 rtld cleanup (filled in by dynamic loader) * a2 rtld object (filled in by dynamic loader) * a3 ps_strings */ td->td_frame->a0 = (register_t) stack; td->td_frame->a1 = 0; td->td_frame->a2 = 0; td->td_frame->a3 = (register_t)imgp->ps_strings; td->td_md.md_flags &= ~MDTD_FPUSED; if (PCPU_GET(fpcurthread) == td) PCPU_SET(fpcurthread, (struct thread *)0); td->td_md.md_ss_addr = 0; }