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);
}
