pid_t up_vfork(const struct vfork_s *context) { _TCB *parent = (FAR _TCB *)g_readytorun.head; _TCB *child; size_t stacksize; uint32_t newsp; uint32_t newfp; uint32_t stackutil; int ret; svdbg("r4:%08x r5:%08x r6:%08x r7:%08x\n", context->r4, context->r5, context->r6, context->r7); svdbg("r8:%08x r9:%08x r10:%08x\n", context->r8, context->r9, context->r10); svdbg("fp:%08x sp:%08x lr:%08x\n", context->fp, context->sp, context->lr); /* Allocate and initialize a TCB for the child task. */ child = task_vforksetup((start_t)(context->lr & ~1)); if (!child) { sdbg("task_vforksetup failed\n"); return (pid_t)ERROR; } svdbg("Parent=%p Child=%p\n", parent, child); /* Get the size of the parent task's stack. Due to alignment operations, * the adjusted stack size may be smaller than the stack size originally * requrested. */ stacksize = parent->adj_stack_size + CONFIG_STACK_ALIGNMENT - 1; /* Allocate the stack for the TCB */ ret = up_create_stack(child, stacksize); if (ret != OK) { sdbg("up_create_stack failed: %d\n", ret); task_vforkabort(child, -ret); return (pid_t)ERROR; } /* How much of the parent's stack was utilized? The ARM uses * a push-down stack so that the current stack pointer should * be lower than the initial, adjusted stack pointer. The * stack usage should be the difference between those two. */ DEBUGASSERT((uint32_t)parent->adj_stack_ptr > context->sp); stackutil = (uint32_t)parent->adj_stack_ptr - context->sp; svdbg("stacksize:%d stackutil:%d\n", stacksize, stackutil); /* Make some feeble effort to perserve the stack contents. This is * feeble because the stack surely contains invalid pointers and other * content that will not work in the child context. However, if the * user follows all of the caveats of vfor() usage, even this feeble * effort is overkill. */ newsp = (uint32_t)child->adj_stack_ptr - stackutil; memcpy((void *)newsp, (const void *)context->sp, stackutil); /* Was there a frame pointer in place before? */ if (context->fp <= (uint32_t)parent->adj_stack_ptr && context->fp >= (uint32_t)parent->adj_stack_ptr - stacksize) { uint32_t frameutil = (uint32_t)parent->adj_stack_ptr - context->fp; newfp = (uint32_t)child->adj_stack_ptr - frameutil; } else { newfp = context->fp; } svdbg("Old stack base:%08x SP:%08x FP:%08x\n", parent->adj_stack_ptr, context->sp, context->fp); svdbg("New stack base:%08x SP:%08x FP:%08x\n", child->adj_stack_ptr, newsp, newfp); /* Update the stack pointer, frame pointer, and volatile registers. When * the child TCB was initialized, all of the values were set to zero. * up_initial_state() altered a few values, but the return value in R0 * should be cleared to zero, providing the indication to the newly started * child thread. */ child->xcp.regs[REG_R4] = context->r4; /* Volatile register r4 */ child->xcp.regs[REG_R5] = context->r5; /* Volatile register r5 */ child->xcp.regs[REG_R6] = context->r6; /* Volatile register r6 */ child->xcp.regs[REG_R7] = context->r7; /* Volatile register r7 */ child->xcp.regs[REG_R8] = context->r8; /* Volatile register r8 */ child->xcp.regs[REG_R9] = context->r9; /* Volatile register r9 */ child->xcp.regs[REG_R10] = context->r10; /* Volatile register r10 */ child->xcp.regs[REG_FP] = newfp; /* Frame pointer */ child->xcp.regs[REG_SP] = newsp; /* Stack pointer */ /* And, finally, start the child task. On a failure, task_vforkstart() * will discard the TCB by calling task_vforkabort(). */ return task_vforkstart(child); }
pid_t up_vfork(const struct vfork_s *context) { struct tcb_s *parent = (FAR struct tcb_s *)g_readytorun.head; struct task_tcb_s *child; size_t stacksize; uint32_t newsp; uint32_t newfp; uint32_t stackutil; int ret; svdbg("vfork context [%p]:\n", context); svdbg(" r4:%08x r5:%08x r6:%08x r7:%08x\n", context->r4, context->r5, context->r6, context->r7); svdbg(" r8:%08x r9:%08x r10:%08x\n", context->r8, context->r9, context->r10); svdbg(" fp:%08x sp:%08x lr:%08x\n", context->fp, context->sp, context->lr); /* Allocate and initialize a TCB for the child task. */ child = task_vforksetup((start_t)(context->lr & ~1)); if (!child) { sdbg("ERROR: task_vforksetup failed\n"); return (pid_t)ERROR; } svdbg("TCBs: Parent=%p Child=%p\n", parent, child); /* Get the size of the parent task's stack. Due to alignment operations, * the adjusted stack size may be smaller than the stack size originally * requested. */ stacksize = parent->adj_stack_size + CONFIG_STACK_ALIGNMENT - 1; /* Allocate the stack for the TCB */ ret = up_create_stack((FAR struct tcb_s *)child, stacksize, parent->flags & TCB_FLAG_TTYPE_MASK); if (ret != OK) { sdbg("ERROR: up_create_stack failed: %d\n", ret); task_vforkabort(child, -ret); return (pid_t)ERROR; } /* How much of the parent's stack was utilized? The ARM uses * a push-down stack so that the current stack pointer should * be lower than the initial, adjusted stack pointer. The * stack usage should be the difference between those two. */ DEBUGASSERT((uint32_t)parent->adj_stack_ptr > context->sp); stackutil = (uint32_t)parent->adj_stack_ptr - context->sp; svdbg("Parent: stacksize:%d stackutil:%d\n", stacksize, stackutil); /* Make some feeble effort to preserve the stack contents. This is * feeble because the stack surely contains invalid pointers and other * content that will not work in the child context. However, if the * user follows all of the caveats of vfork() usage, even this feeble * effort is overkill. */ newsp = (uint32_t)child->cmn.adj_stack_ptr - stackutil; memcpy((void *)newsp, (const void *)context->sp, stackutil); /* Was there a frame pointer in place before? */ if (context->fp <= (uint32_t)parent->adj_stack_ptr && context->fp >= (uint32_t)parent->adj_stack_ptr - stacksize) { uint32_t frameutil = (uint32_t)parent->adj_stack_ptr - context->fp; newfp = (uint32_t)child->cmn.adj_stack_ptr - frameutil; } else { newfp = context->fp; } svdbg("Parent: stack base:%08x SP:%08x FP:%08x\n", parent->adj_stack_ptr, context->sp, context->fp); svdbg("Child: stack base:%08x SP:%08x FP:%08x\n", child->cmn.adj_stack_ptr, newsp, newfp); /* Update the stack pointer, frame pointer, and volatile registers. When * the child TCB was initialized, all of the values were set to zero. * up_initial_state() altered a few values, but the return value in R0 * should be cleared to zero, providing the indication to the newly started * child thread. */ child->cmn.xcp.regs[REG_R4] = context->r4; /* Volatile register r4 */ child->cmn.xcp.regs[REG_R5] = context->r5; /* Volatile register r5 */ child->cmn.xcp.regs[REG_R6] = context->r6; /* Volatile register r6 */ child->cmn.xcp.regs[REG_R7] = context->r7; /* Volatile register r7 */ child->cmn.xcp.regs[REG_R8] = context->r8; /* Volatile register r8 */ child->cmn.xcp.regs[REG_R9] = context->r9; /* Volatile register r9 */ child->cmn.xcp.regs[REG_R10] = context->r10; /* Volatile register r10 */ child->cmn.xcp.regs[REG_FP] = newfp; /* Frame pointer */ child->cmn.xcp.regs[REG_SP] = newsp; /* Stack pointer */ #ifdef CONFIG_LIB_SYSCALL /* If we got here via a syscall, then we are going to have to setup some * syscall return information as well. */ if (parent->xcp.nsyscalls > 0) { int index; for (index = 0; index < parent->xcp.nsyscalls; index++) { child->cmn.xcp.syscall[index].sysreturn = parent->xcp.syscall[index].sysreturn; /* REVISIT: This logic is *not* common. */ #if defined(CONFIG_ARCH_CORTEXA5) || defined(CONFIG_ARCH_CORTEXA8) # ifdef CONFIG_BUILD_KERNEL child->cmn.xcp.syscall[index].cpsr = parent->xcp.syscall[index].cpsr; # endif #elif defined(CONFIG_ARCH_CORTEXM3) || defined(CONFIG_ARCH_CORTEXM4) || \ defined(CONFIG_ARCH_CORTEXM0) || defined(CONFIG_ARCH_CORTEXM7) child->cmn.xcp.syscall[index].excreturn = parent->xcp.syscall[index].excreturn; #else # error Missing logic #endif } child->cmn.xcp.nsyscalls = parent->xcp.nsyscalls; } #endif /* And, finally, start the child task. On a failure, task_vforkstart() * will discard the TCB by calling task_vforkabort(). */ return task_vforkstart(child); }
pid_t up_vfork(const struct vfork_s *context) { struct tcb_s *parent = (FAR struct tcb_s *)g_readytorun.head; struct task_tcb_s *child; size_t stacksize; uint32_t newsp; #if CONFIG_MIPS32_FRAMEPOINTER uint32_t newfp; #endif uint32_t stackutil; int ret; svdbg("s0:%08x s1:%08x s2:%08x s3:%08x s4:%08x\n", context->s0, context->s1, context->s2, context->s3, context->s4); #if CONFIG_MIPS32_FRAMEPOINTER svdbg("s5:%08x s6:%08x s7:%08x\n", context->s5, context->s6, context->s7); #ifdef MIPS32_SAVE_GP svdbg("fp:%08x sp:%08x ra:%08x gp:%08x\n", context->fp, context->sp, context->ra, context->gp); #else svdbg("fp:%08x sp:%08x ra:%08x\n", context->fp context->sp, context->ra); #endif #else svdbg("s5:%08x s6:%08x s7:%08x s8:%08x\n", context->s5, context->s6, context->s7, context->s8); #ifdef MIPS32_SAVE_GP svdbg("sp:%08x ra:%08x gp:%08x\n", context->sp, context->ra, context->gp); #else svdbg("sp:%08x ra:%08x\n", context->sp, context->ra); #endif #endif /* Allocate and initialize a TCB for the child task. */ child = task_vforksetup((start_t)context->ra); if (!child) { sdbg("task_vforksetup failed\n"); return (pid_t)ERROR; } svdbg("Parent=%p Child=%p\n", parent, child); /* Get the size of the parent task's stack. Due to alignment operations, * the adjusted stack size may be smaller than the stack size originally * requrested. */ stacksize = parent->adj_stack_size + CONFIG_STACK_ALIGNMENT - 1; /* Allocate the stack for the TCB */ ret = up_create_stack((FAR struct tcb_s *)child, stacksize, parent->flags & TCB_FLAG_TTYPE_MASK); if (ret != OK) { sdbg("up_create_stack failed: %d\n", ret); task_vforkabort(child, -ret); return (pid_t)ERROR; } /* How much of the parent's stack was utilized? The MIPS uses * a push-down stack so that the current stack pointer should * be lower than the initial, adjusted stack pointer. The * stack usage should be the difference between those two. */ DEBUGASSERT((uint32_t)parent->adj_stack_ptr > context->sp); stackutil = (uint32_t)parent->adj_stack_ptr - context->sp; svdbg("stacksize:%d stackutil:%d\n", stacksize, stackutil); /* Make some feeble effort to perserve the stack contents. This is * feeble because the stack surely contains invalid pointers and other * content that will not work in the child context. However, if the * user follows all of the caveats of vfork() usage, even this feeble * effort is overkill. */ newsp = (uint32_t)child->cmn.adj_stack_ptr - stackutil; memcpy((void *)newsp, (const void *)context->sp, stackutil); /* Was there a frame pointer in place before? */ #if CONFIG_MIPS32_FRAMEPOINTER if (context->fp <= (uint32_t)parent->adj_stack_ptr && context->fp >= (uint32_t)parent->adj_stack_ptr - stacksize) { uint32_t frameutil = (uint32_t)parent->adj_stack_ptr - context->fp; newfp = (uint32_t)child->cmn.adj_stack_ptr - frameutil; } else { newfp = context->fp; } svdbg("Old stack base:%08x SP:%08x FP:%08x\n", parent->adj_stack_ptr, context->sp, context->fp); svdbg("New stack base:%08x SP:%08x FP:%08x\n", child->cmn.adj_stack_ptr, newsp, newfp); #else svdbg("Old stack base:%08x SP:%08x\n", parent->adj_stack_ptr, context->sp); svdbg("New stack base:%08x SP:%08x\n", child->cmn.adj_stack_ptr, newsp); #endif /* Update the stack pointer, frame pointer, global pointer and saved * registers. When the child TCB was initialized, all of the values * were set to zero. up_initial_state() altered a few values, but the * return value in v0 should be cleared to zero, providing the * indication to the newly started child thread. */ child->cmn.xcp.regs[REG_S0] = context->s0; /* Saved register s0 */ child->cmn.xcp.regs[REG_S1] = context->s1; /* Saved register s1 */ child->cmn.xcp.regs[REG_S2] = context->s2; /* Saved register s2 */ child->cmn.xcp.regs[REG_S3] = context->s3; /* Volatile register s3 */ child->cmn.xcp.regs[REG_S4] = context->s4; /* Volatile register s4 */ child->cmn.xcp.regs[REG_S5] = context->s5; /* Volatile register s5 */ child->cmn.xcp.regs[REG_S6] = context->s6; /* Volatile register s6 */ child->cmn.xcp.regs[REG_S7] = context->s7; /* Volatile register s7 */ #if CONFIG_MIPS32_FRAMEPOINTER child->cmn.xcp.regs[REG_FP] = newfp; /* Frame pointer */ #else child->cmn.xcp.regs[REG_S8] = context->s8; /* Volatile register s8 */ #endif child->cmn.xcp.regs[REG_SP] = newsp; /* Stack pointer */ #if MIPS32_SAVE_GP child->cmn.xcp.regs[REG_GP] = newsp; /* Global pointer */ #endif /* And, finally, start the child task. On a failure, task_vforkstart() * will discard the TCB by calling task_vforkabort(). */ return task_vforkstart(child); }