diff --git a/arch/Kconfig b/arch/Kconfig index f192281439..7d34b56f4d 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -16,6 +16,7 @@ config ARCH_8051 config ARCH_ARM bool "ARM" select ARCH_HAVE_INTERRUPTSTACK + select ARCH_HAVE_VFORK ---help--- The ARM architectures @@ -124,6 +125,10 @@ config ADDRENV bool default n +config ARCH_HAVE_VFORK + bool + default n + config ARCH_STACKDUMP bool "Dump stack on assertions" default n diff --git a/arch/arm/src/arm/vfork.S b/arch/arm/src/arm/vfork.S index f0fe17f738..b498fd7f70 100644 --- a/arch/arm/src/arm/vfork.S +++ b/arch/arm/src/arm/vfork.S @@ -50,7 +50,7 @@ ************************************************************************************/ .file "vfork.S" - .globl task_vfork + .globl up_vfork /************************************************************************************ * Public Functions @@ -66,7 +66,7 @@ * from the function in which vfork() was called, or calls any other function before * successfully calling _exit() or one of the exec family of functions. * - * This thin layer implements vfork by simply calling task_vfork() with the vfork() + * This thin layer implements vfork by simply calling up_vfork() with the vfork() * context as an argument. The overall sequence is: * * 1) User code calls vfork(). vfork() collects context information and @@ -121,12 +121,12 @@ vfork: str r0, [sp, #VFORK_SP_OFFSET] str lr, [sp, #VFORK_LR_OFFSET] - /* Then, call task_vfork(), passing it a pointer to the stack structure */ + /* Then, call up_vfork(), passing it a pointer to the stack structure */ mov r0, sp - bl task_vfork + bl up_vfork - /* Release the stack data and return the value returned by task_vfork */ + /* Release the stack data and return the value returned by up_vfork */ add sp, sp, #VFORK_SIZEOF mov pc, lr diff --git a/arch/arm/src/armv7-m/vfork.S b/arch/arm/src/armv7-m/vfork.S index aceded4001..0d9e144cdf 100644 --- a/arch/arm/src/armv7-m/vfork.S +++ b/arch/arm/src/armv7-m/vfork.S @@ -52,7 +52,7 @@ .syntax unified .thumb .file "vfork.S" - .globl task_vfork + .globl up_vfork /************************************************************************************ * Public Functions @@ -68,7 +68,7 @@ * from the function in which vfork() was called, or calls any other function before * successfully calling _exit() or one of the exec family of functions. * - * This thin layer implements vfork by simply calling task_vfork() with the vfork() + * This thin layer implements vfork by simply calling up_vfork() with the vfork() * context as an argument. The overall sequence is: * * 1) User code calls vfork(). vfork() collects context information and @@ -124,12 +124,12 @@ vfork: str r0, [sp, #VFORK_SP_OFFSET] str lr, [sp, #VFORK_LR_OFFSET] - /* Then, call task_vfork(), passing it a pointer to the stack structure */ + /* Then, call up_vfork(), passing it a pointer to the stack structure */ mov r0, sp - bl task_vfork + bl up_vfork - /* Release the stack data and return the value returned by task_vfork */ + /* Release the stack data and return the value returned by up_vfork */ add sp, sp, #VFORK_SIZEOF bx lr diff --git a/arch/arm/src/common/up_vfork.c b/arch/arm/src/common/up_vfork.c index 404abd1f83..2e3c2d4a1b 100644 --- a/arch/arm/src/common/up_vfork.c +++ b/arch/arm/src/common/up_vfork.c @@ -43,6 +43,7 @@ #include #include #include +#include #include #include @@ -129,17 +130,28 @@ pid_t up_vfork(struct vfork_s *context) _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); + 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. @@ -152,15 +164,18 @@ pid_t up_vfork(struct vfork_s *context) 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? */ - DEBUGASSERT(parent->adj_stack_ptr > context->sp); + 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 pointer and other * content that will not work in the child context. However, if the @@ -170,8 +185,26 @@ pid_t up_vfork(struct vfork_s *context) newsp = (uint32_t)child->adj_stack_ptr - stackutil; memcpy((void *)newsp, (const void *)context->sp, stackutil); - - /* Update the stack pointer, frame pointer, and voltile registers. When + + /* 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 voltile 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 @@ -185,8 +218,8 @@ pid_t up_vfork(struct vfork_s *context) 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] = context->fp; /* Frame pointer */ - child->xcp.regs[REG_SP] = context->sp; /* Stack pointer */ + 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().