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This initial vfork() check-in was a little pollyanna-ish

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5487 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2013-01-07 19:35:47 +00:00
parent c82c7095f9
commit 8811cbdb94
24 changed files with 598 additions and 75 deletions
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62
arch/arm/src/arm/up_vfork.S → arch/arm/src/arm/vfork.S
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@ -1,5 +1,5 @@
/************************************************************************************
* arch/arm/src/arm/up_vfork.S
* arch/arm/src/arm/vfork.S
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
@ -39,6 +39,8 @@
#include <nuttx/config.h>
#include "up_vfork.h"
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
@ -47,8 +49,8 @@
* Global Symbols
************************************************************************************/
.file "up_vfork.S"
.globl __vfork
.file "vfork.S"
.globl task_vfork
/************************************************************************************
* Public Functions
@ -64,8 +66,25 @@
* 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 __vfork() with the vfork()
* return address as an argument.
* This thin layer implements vfork by simply calling task_vfork() with the vfork()
* context as an argument. The overall sequence is:
*
* 1) User code calls vfork(). vfork() collects context information and
* transfers control up up_vfork().
* 2) up_vfork()and calls task_vforksetup().
* 3) task_vforksetup() allocates and configures the child task's TCB. This
* consists of:
* - Allocation of the child task's TCB.
* - Initialization of file descriptors and streams
* - Configuration of environment variables
* - Setup the intput parameters for the task.
* - Initialization of the TCB (including call to up_initial_state()
* 4) up_vfork() provides any additional operating context. up_vfork must:
* - Allocate and initialize the stack
* - Initialize special values in any CPU registers that were not
* already configured by up_initial_state()
* 5) up_vfork() then calls task_vforkstart()
* 6) task_vforkstart() then executes the child thread.
*
* Input Paremeters:
* None
@ -81,12 +100,35 @@
.globl vfork
.type vfork, function
vfork:
/* Create a stack frame */
/* I know, I could have used the GCC's return address builtin and done this all
* in C. But this works even if there is no builtin.
*/
mov r0, sp /* Save the value of the stack frame on entry */
sub sp, sp, #VFORK_SIZEOF /* Allocate the structure on the stack */
mov r0, lr
b __vfork
/* Save the volatile registers */
str r4, [sp, #VFORK_R4_OFFSET]
str r5, [sp, #VFORK_R5_OFFSET]
str r6, [sp, #VFORK_R6_OFFSET]
str r7, [sp, #VFORK_R7_OFFSET]
str r8, [sp, #VFORK_R8_OFFSET]
str r9, [sp, #VFORK_R9_OFFSET]
str r10, [sp, #VFORK_R10_OFFSET]
/* Save the frame pointer, stack pointer, and return address */
str fp, [sp, #VFORK_FP_OFFSET]
str r0, [sp, #VFORK_SP_OFFSET]
str lr, [sp, #VFORK_LR_OFFSET]
/* Then, call task_vfork(), passing it a pointer to the stack structure */
mov r0, sp
bl task_vfork
/* Release the stack data and return the value returned by task_vfork */
add sp, sp, #VFORK_SIZEOF
mov pc, lr
.size vfork, .-vfork
.end

62
arch/arm/src/armv7-m/up_vfork.S → arch/arm/src/armv7-m/vfork.S
View File

@ -1,5 +1,5 @@
/************************************************************************************
* arch/arm/src/armv7-m/up_vfork.S
* arch/arm/src/armv7-m/vfork.S
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
@ -39,6 +39,8 @@
#include <nuttx/config.h>
#include "up_vfork.h"
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
@ -49,8 +51,8 @@
.syntax unified
.thumb
.file "up_vfork.S"
.globl __vfork
.file "vfork.S"
.globl task_vfork
/************************************************************************************
* Public Functions
@ -66,8 +68,25 @@
* 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 __vfork() with the vfork()
* return address as an argument.
* This thin layer implements vfork by simply calling task_vfork() with the vfork()
* context as an argument. The overall sequence is:
*
* 1) User code calls vfork(). vfork() collects context information and
* transfers control up up_vfork().
* 2) up_vfork()and calls task_vforksetup().
* 3) task_vforksetup() allocates and configures the child task's TCB. This
* consists of:
* - Allocation of the child task's TCB.
* - Initialization of file descriptors and streams
* - Configuration of environment variables
* - Setup the intput parameters for the task.
* - Initialization of the TCB (including call to up_initial_state()
* 4) up_vfork() provides any additional operating context. up_vfork must:
* - Allocate and initialize the stack
* - Initialize special values in any CPU registers that were not
* already configured by up_initial_state()
* 5) up_vfork() then calls task_vforkstart()
* 6) task_vforkstart() then executes the child thread.
*
* Input Paremeters:
* None
@ -84,13 +103,36 @@
.globl vfork
.type vfork, function
vfork:
/* Create a stack frame */
/* I know, I could have used the GCC's return address builtin and done this all
* in C. But this works even if there is no builtin.
*/
mov r0, sp /* Save the value of the stack frame on entry */
sub sp, sp, #VFORK_SIZEOF /* Allocate the structure on the stack */
mov r0, lr
b __vfork
/* Save the volatile registers */
str r4, [sp, #VFORK_R4_OFFSET]
str r5, [sp, #VFORK_R5_OFFSET]
str r6, [sp, #VFORK_R6_OFFSET]
str r7, [sp, #VFORK_R7_OFFSET]
str r8, [sp, #VFORK_R8_OFFSET]
str r9, [sp, #VFORK_R9_OFFSET]
str r10, [sp, #VFORK_R10_OFFSET]
/* Save the frame pointer, stack pointer, and return address */
str fp, [sp, #VFORK_FP_OFFSET]
str r0, [sp, #VFORK_SP_OFFSET]
str lr, [sp, #VFORK_LR_OFFSET]
/* Then, call task_vfork(), passing it a pointer to the stack structure */
mov r0, sp
bl task_vfork
/* Release the stack data and return the value returned by task_vfork */
add sp, sp, #VFORK_SIZEOF
bx lr
.size vfork, .-vfork
.end

4
arch/arm/src/c5471/Make.defs
View File

@ -35,14 +35,14 @@
HEAD_ASRC = up_nommuhead.S
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_vfork.S
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S vfork.S
CMN_CSRCS = up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
up_createstack.c up_dataabort.c up_mdelay.c up_udelay.c up_doirq.c \
up_exit.c up_idle.c up_initialize.c up_initialstate.c \
up_interruptcontext.c up_prefetchabort.c up_releasepending.c \
up_releasestack.c up_reprioritizertr.c up_schedulesigaction.c \
up_sigdeliver.c up_syscall.c up_unblocktask.c \
up_undefinedinsn.c up_usestack.c up__vfork.c
up_undefinedinsn.c up_usestack.c up_vfork.c
ifeq ($(CONFIG_ELF),y)
CMN_CSRCS += up_elf.c

4
arch/arm/src/calypso/Make.defs
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@ -39,14 +39,14 @@
HEAD_ASRC = calypso_head.S
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_vectors.S \
up_nommuhead.S up_vfork.S
up_nommuhead.S vfork.S
CMN_CSRCS = up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
up_createstack.c up_dataabort.c up_mdelay.c up_udelay.c up_doirq.c \
up_exit.c up_idle.c up_initialstate.c up_initialize.c \
up_interruptcontext.c up_prefetchabort.c up_releasepending.c \
up_releasestack.c up_reprioritizertr.c up_schedulesigaction.c \
up_sigdeliver.c up_syscall.c up_unblocktask.c \
up_undefinedinsn.c up_usestack.c calypso_power.c up__vfork.c
up_undefinedinsn.c up_usestack.c calypso_power.c up_vfork.c
ifeq ($(CONFIG_ELF),y)
CMN_CSRCS += up_elf.c

110
arch/arm/src/common/up__vfork.c → arch/arm/src/common/up_vfork.c
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@ -1,5 +1,5 @@
/****************************************************************************
* arch/arm/src/common/up__vfork
* arch/arm/src/common/up_vfork.c
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
@ -39,10 +39,16 @@
#include <nuttx/config.h>
#include <sched.h>
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/sched.h>
#include <nuttx/arch.h>
#include <arch/irq.h>
#include "up_vfork.h"
#include "os_internal.h"
/****************************************************************************
@ -75,7 +81,7 @@
****************************************************************************/
/****************************************************************************
* Name: __vfork
* Name: up_vfork
*
* Description:
* The vfork() function has the same effect as fork(), except that the
@ -85,11 +91,29 @@
* called, or calls any other function before successfully calling _exit()
* or one of the exec family of functions.
*
* This thin layer starts the vfork child by simply spawning a new thread
* that begins at the return address of vfork().
* The overall sequence is:
*
* 1) User code calls vfork(). vfork() collects context information and
* transfers control up up_vfork().
* 2) up_vfork()and calls task_vforksetup().
* 3) task_vforksetup() allocates and configures the child task's TCB. This
* consists of:
* - Allocation of the child task's TCB.
* - Initialization of file descriptors and streams
* - Configuration of environment variables
* - Setup the intput parameters for the task.
* - Initialization of the TCB (including call to up_initial_state()
* 4) up_vfork() provides any additional operating context. up_vfork must:
* - Allocate and initialize the stack
* - Initialize special values in any CPU registers that were not
* already configured by up_initial_state()
* 5) up_vfork() then calls task_vforkstart()
* 6) task_vforkstart() then executes the child thread.
*
* task_vforkabort() may be called if an error occurs between steps 3 and 6.
*
* Input Paremeters:
* retaddr - The return address of vfork()
* context - Caller context information saved by vfork()
*
* Return:
* Upon successful completion, vfork() returns 0 to the child process and
@ -99,11 +123,22 @@
*
****************************************************************************/
pid_t __vfork(uint32_t retaddr)
pid_t up_vfork(struct vfork_s *context)
{
FAR _TCB *parent = (FAR _TCB *)g_readytorun.head;
_TCB *parent = (FAR _TCB *)g_readytorun.head;
_TCB *child;
size_t stacksize;
int priority;
uint32_t newsp;
uint32_t stackutil;
int ret;
/* Allocate and initialize a TCB for the child task. */
child = task_vforksetup((start_t)context->lr);
if (!child)
{
return (pid_t)ERROR;
}
/* 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
@ -112,23 +147,50 @@ pid_t __vfork(uint32_t retaddr)
stacksize = parent->adj_stack_size + CONFIG_STACK_ALIGNMENT - 1;
/* Get the current priority of the parent task */
/* Allocate the stack for the TCB */
#ifdef CONFIG_PRIORITY_INHERITANCE
priority = parent->base_priority; /* "Normal," unboosted priority */
#else
priority = parent->sched_priority; /* Current priority */
#endif
ret = up_create_stack(child, stacksize);
if (ret != OK)
{
task_vforkabort(child, -ret);
return (pid_t)ERROR;
}
/* Start the child thread at the vfork return address. TASK_CREATE will
* return the PID of the new thread. Otherwise a negative value will be
* returned and the errno will be set appropriately.
*
* When the registers are initialized, the return value in R0 should be
* cleared to zero, providing the indication to the newly started child
* thread.
/* How much of the parent's stack was utilized? */
DEBUGASSERT(parent->adj_stack_ptr > context->sp);
stackutil = (uint32_t)parent->adj_stack_ptr - context->sp;
/* 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
* 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);
/* 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
* child thread.
*/
return TASK_CREATE("init", priority, stacksize, (main_t)retaddr,
(const char **)NULL);
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] = context->fp; /* Frame pointer */
child->xcp.regs[REG_SP] = context->sp; /* 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);
}

82
arch/arm/src/common/up_vfork.h Normal file
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@ -0,0 +1,82 @@
/****************************************************************************
* arch/arm/src/common/arm-vfork.h
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __ARCH_ARM_SRC_ARM_VFORK_H
#define __ARCH_ARM_SRC_ARM_VFORK_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define VFORK_R4_OFFSET (0*4) /* Volatile register r4 */
#define VFORK_R5_OFFSET (1*4) /* Volatile register r5 */
#define VFORK_R6_OFFSET (2*4) /* Volatile register r6 */
#define VFORK_R7_OFFSET (3*4) /* Volatile register r7 */
#define VFORK_R8_OFFSET (4*4) /* Volatile register r8 */
#define VFORK_R9_OFFSET (5*4) /* Volatile register r9 */
#define VFORK_R10_OFFSET (6*4) /* Volatile register r10 */
#define VFORK_FP_OFFSET (7*4) /* Frame pointer */
#define VFORK_SP_OFFSET (8*4) /* Stack pointer*/
#define VFORK_LR_OFFSET (9*4) /* Return address*/
#define VFORK_SIZEOF (10*4)
/****************************************************************************
* Public Types
****************************************************************************/
#ifndef __ASSEMBLY__
struct vfork_s
{
uint32_t r4; /* Volatile register r4 */
uint32_t r5; /* Volatile register r5 */
uint32_t r6; /* Volatile register r6 */
uint32_t r7; /* Volatile register r7 */
uint32_t r8; /* Volatile register r8 */
uint32_t r9; /* Volatile register r9 */
uint32_t r10; /* Volatile register r10 */
uint32_t fp; /* Frame pointer */
uint32_t sp; /* Stack pointer*/
uint32_t lr; /* Return address*/
};
#endif
#endif /* __ARCH_ARM_SRC_ARM_VFORK_H */

4
arch/arm/src/dm320/Make.defs
View File

@ -36,14 +36,14 @@
HEAD_ASRC = up_head.S
CMN_ASRCS = up_cache.S up_fullcontextrestore.S up_saveusercontext.S \
up_vectors.S up_vectoraddrexcptn.S up_vectortab.S up_vfork.S
up_vectors.S up_vectoraddrexcptn.S up_vectortab.S vfork.S
CMN_CSRCS = up_assert.c up_blocktask.c up_copystate.c up_createstack.c \
up_dataabort.c up_mdelay.c up_udelay.c up_exit.c up_idle.c \
up_initialize.c up_initialstate.c up_interruptcontext.c \
up_prefetchabort.c up_releasepending.c up_releasestack.c \
up_reprioritizertr.c up_schedulesigaction.c \
up_sigdeliver.c up_syscall.c up_unblocktask.c \
up_undefinedinsn.c up_usestack.c up__vfork.c
up_undefinedinsn.c up_usestack.c up_vfork.c
ifeq ($(CONFIG_ELF),y)
CMN_CSRCS += up_elf.c

4
arch/arm/src/imx/Make.defs
View File

@ -36,14 +36,14 @@
HEAD_ASRC = up_head.S
CMN_ASRCS = up_cache.S up_fullcontextrestore.S up_saveusercontext.S \
up_vectors.S up_vectoraddrexcptn.S up_vectortab.S up_vfork.S
up_vectors.S up_vectoraddrexcptn.S up_vectortab.S vfork.S
CMN_CSRCS = up_assert.c up_blocktask.c up_copystate.c up_createstack.c \
up_dataabort.c up_mdelay.c up_udelay.c up_exit.c up_idle.c \
up_initialize.c up_initialstate.c up_interruptcontext.c \
up_prefetchabort.c up_releasepending.c up_releasestack.c \
up_reprioritizertr.c up_schedulesigaction.c \
up_sigdeliver.c up_syscall.c up_unblocktask.c \
up_undefinedinsn.c up_usestack.c up__vfork.c
up_undefinedinsn.c up_usestack.c up_vfork.c
ifeq ($(CONFIG_ELF),y)
CMN_CSRCS += up_elf.c

4
arch/arm/src/kinetis/Make.defs
View File

@ -40,7 +40,7 @@ HEAD_ASRC = kinetis_vectors.S
# Common ARM and Cortex-M3 files
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_switchcontext.S \
up_vfork.S
vfork.S
CMN_CSRCS = up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
up_createstack.c up_mdelay.c up_udelay.c up_exit.c up_initialize.c \
up_memfault.c up_initialstate.c up_interruptcontext.c \
@ -48,7 +48,7 @@ CMN_CSRCS = up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
up_releasestack.c up_reprioritizertr.c up_schedulesigaction.c \
up_releasepending.c up_sigdeliver.c up_unblocktask.c up_usestack.c \
up_doirq.c up_hardfault.c up_svcall.c up_checkstack.c \
up__vfork.c
up_vfork.c
ifeq ($(CONFIG_ARCH_MEMCPY),y)
CMN_ASRCS += up_memcpy.S

4
arch/arm/src/lm3s/Make.defs
View File

@ -36,7 +36,7 @@
HEAD_ASRC = lm3s_vectors.S
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_switchcontext.S \
up_vfork.S
vfork.S
CMN_CSRCS = up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
up_createstack.c up_mdelay.c up_udelay.c up_exit.c \
up_idle.c up_initialize.c up_initialstate.c up_interruptcontext.c \
@ -44,7 +44,7 @@ CMN_CSRCS = up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
up_releasepending.c up_releasestack.c up_reprioritizertr.c \
up_schedulesigaction.c up_sigdeliver.c up_unblocktask.c \
up_usestack.c up_doirq.c up_hardfault.c up_svcall.c \
up__vfork.c
up_vfork.c
ifeq ($(CONFIG_ARCH_MEMCPY),y)
CMN_ASRCS += up_memcpy.S

4
arch/arm/src/lpc17xx/Make.defs
View File

@ -40,14 +40,14 @@ HEAD_ASRC = lpc17_vectors.S
# Common ARM and Cortex-M3 files
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_switchcontext.S \
up_vfork.S
vfork.S
CMN_CSRCS = up_assert.c up_blocktask.c up_copystate.c up_createstack.c \
up_mdelay.c up_udelay.c up_exit.c up_initialize.c up_memfault.c \
up_initialstate.c up_interruptcontext.c up_modifyreg8.c \
up_modifyreg16.c up_modifyreg32.c up_releasepending.c \
up_releasestack.c up_reprioritizertr.c up_schedulesigaction.c \
up_sigdeliver.c up_unblocktask.c up_usestack.c up_doirq.c \
up_hardfault.c up_svcall.c up_checkstack.c up__vfork.c
up_hardfault.c up_svcall.c up_checkstack.c up_vfork.c
ifeq ($(CONFIG_ARCH_MEMCPY),y)
CMN_ASRCS += up_memcpy.S

4
arch/arm/src/lpc214x/Make.defs
View File

@ -36,13 +36,13 @@
HEAD_ASRC = lpc214x_head.S
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_vectors.S \
up_vfork.S
vfork.S
CMN_CSRCS = up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
up_createstack.c up_dataabort.c up_mdelay.c up_udelay.c \
up_exit.c up_idle.c up_initialize.c up_initialstate.c \
up_interruptcontext.c up_prefetchabort.c up_releasepending.c \
up_releasestack.c up_reprioritizertr.c up_syscall.c up_unblocktask.c \
up_undefinedinsn.c up_usestack.c up_lowputs.c up__vfork.c
up_undefinedinsn.c up_usestack.c up_lowputs.c up_vfork.c
ifneq ($(CONFIG_DISABLE_SIGNALS),y)
CMN_CSRCS += up_schedulesigaction.c up_sigdeliver.c

4
arch/arm/src/lpc2378/Make.defs
View File

@ -41,13 +41,13 @@
HEAD_ASRC = lpc23xx_head.S
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_vectors.S \
up_vfork.S
vfork.S
CMN_CSRCS = up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
up_createstack.c up_dataabort.c up_mdelay.c up_udelay.c \
up_exit.c up_idle.c up_initialize.c up_initialstate.c \
up_interruptcontext.c up_prefetchabort.c up_releasepending.c \
up_releasestack.c up_reprioritizertr.c up_syscall.c up_unblocktask.c \
up_undefinedinsn.c up_usestack.c up_lowputs.c up__vfork.c
up_undefinedinsn.c up_usestack.c up_lowputs.c up_vfork.c
ifneq ($(CONFIG_DISABLE_SIGNALS),y)
CMN_CSRCS += up_schedulesigaction.c up_sigdeliver.c

4
arch/arm/src/lpc31xx/Make.defs
View File

@ -36,7 +36,7 @@
HEAD_ASRC = up_head.S
CMN_ASRCS = up_cache.S up_fullcontextrestore.S up_saveusercontext.S \
up_vectors.S up_vectoraddrexcptn.S up_vectortab.S up_vfork.S
up_vectors.S up_vectoraddrexcptn.S up_vectortab.S vfork.S
CMN_CSRCS = up_assert.c up_blocktask.c up_copystate.c up_createstack.c \
up_dataabort.c up_mdelay.c up_udelay.c up_exit.c up_idle.c \
up_initialize.c up_initialstate.c up_interruptcontext.c \
@ -44,7 +44,7 @@ CMN_CSRCS = up_assert.c up_blocktask.c up_copystate.c up_createstack.c \
up_prefetchabort.c up_releasepending.c up_releasestack.c \
up_reprioritizertr.c up_schedulesigaction.c \
up_sigdeliver.c up_syscall.c up_unblocktask.c \
up_undefinedinsn.c up_usestack.c up__vfork.c
up_undefinedinsn.c up_usestack.c up_vfork.c
ifeq ($(CONFIG_PAGING),y)
CMN_CSRCS += up_pginitialize.c up_checkmapping.c up_allocpage.c up_va2pte.c

4
arch/arm/src/lpc43xx/Make.defs
View File

@ -36,7 +36,7 @@
HEAD_ASRC =
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_switchcontext.S
CMN_ASRCS += up_vfork.S
CMN_ASRCS += vfork.S
CMN_CSRCS = up_assert.c up_blocktask.c up_copystate.c
CMN_CSRCS += up_createstack.c up_mdelay.c up_udelay.c up_exit.c
@ -44,7 +44,7 @@ CMN_CSRCS += up_initialize.c up_initialstate.c up_interruptcontext.c
CMN_CSRCS += up_memfault.c up_modifyreg8.c up_modifyreg16.c up_modifyreg32.c
CMN_CSRCS += up_releasepending.c up_releasestack.c up_reprioritizertr.c
CMN_CSRCS += up_schedulesigaction.c up_sigdeliver.c up_unblocktask.c
CMN_CSRCS += up_usestack.c up_doirq.c up_hardfault.c up_svcall.c up__vfork.c
CMN_CSRCS += up_usestack.c up_doirq.c up_hardfault.c up_svcall.c up_vfork.c
ifeq ($(CONFIG_ARMV7M_CMNVECTOR),y)
CMN_ASRCS += up_exception.S

4
arch/arm/src/sam3u/Make.defs
View File

@ -40,14 +40,14 @@ HEAD_ASRC = sam3u_vectors.S
# Common ARM and Cortex-M3 files
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_switchcontext.S \
up_vfork.S
vfork.S
CMN_CSRCS = up_assert.c up_blocktask.c up_copystate.c up_createstack.c \
up_mdelay.c up_udelay.c up_exit.c up_idle.c up_initialize.c \
up_initialstate.c up_interruptcontext.c up_memfault.c up_modifyreg8.c \
up_modifyreg16.c up_modifyreg32.c up_releasepending.c \
up_releasestack.c up_reprioritizertr.c up_schedulesigaction.c \
up_sigdeliver.c up_unblocktask.c up_usestack.c up_doirq.c \
up_hardfault.c up_svcall.c up__vfork.c
up_hardfault.c up_svcall.c up_vfork.c
# Configuration-dependent common files

4
arch/arm/src/stm32/Make.defs
View File

@ -40,7 +40,7 @@ HEAD_ASRC = stm32_vectors.S
endif
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_switchcontext.S \
up_vfork.S
vfork.S
CMN_CSRCS = up_assert.c up_blocktask.c up_copystate.c \
up_createstack.c up_mdelay.c up_udelay.c up_exit.c \
up_initialize.c up_initialstate.c up_interruptcontext.c \
@ -48,7 +48,7 @@ CMN_CSRCS = up_assert.c up_blocktask.c up_copystate.c \
up_releasepending.c up_releasestack.c up_reprioritizertr.c \
up_schedulesigaction.c up_sigdeliver.c up_systemreset.c \
up_unblocktask.c up_usestack.c up_doirq.c up_hardfault.c \
up_svcall.c up__vfork.c
up_svcall.c up_vfork.c
ifeq ($(CONFIG_ARMV7M_CMNVECTOR),y)
CMN_ASRCS += up_exception.S

4
arch/arm/src/str71x/Make.defs
View File

@ -36,13 +36,13 @@
HEAD_ASRC = str71x_head.S
CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_vectors.S \
up_vfork.S
vfork.S
CMN_CSRCS = up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
up_createstack.c up_dataabort.c up_mdelay.c up_udelay.c \
up_exit.c up_idle.c up_initialize.c up_initialstate.c \
up_interruptcontext.c up_prefetchabort.c up_releasepending.c \
up_releasestack.c up_reprioritizertr.c up_syscall.c up_unblocktask.c \
up_undefinedinsn.c up_usestack.c up_lowputs.c up__vfork.c
up_undefinedinsn.c up_usestack.c up_lowputs.c up_vfork.c
ifneq ($(CONFIG_DISABLE_SIGNALS),y)
CMN_CSRCS += up_schedulesigaction.c up_sigdeliver.c

2
include/nuttx/arch.h
View File

@ -1,7 +1,7 @@
/****************************************************************************
* include/nuttx/arch.h
*
* Copyright (C) 2007-2012 Gregory Nutt. All rights reserved.
* Copyright (C) 2007-2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without

26
include/nuttx/sched.h
View File

@ -382,6 +382,32 @@ EXTERN FAR struct streamlist *sched_getstreams(void);
EXTERN FAR struct socketlist *sched_getsockets(void);
#endif /* CONFIG_NSOCKET_DESCRIPTORS */
/* Internal vfork support.The overall sequence is:
*
* 1) User code calls vfork(). vfork() is provided in architecture-specific
* code.
* 2) vfork()and calls task_vforksetup().
* 3) task_vforksetup() allocates and configures the child task's TCB. This
* consists of:
* - Allocation of the child task's TCB.
* - Initialization of file descriptors and streams
* - Configuration of environment variables
* - Setup the intput parameters for the task.
* - Initialization of the TCB (including call to up_initial_state()
* 4) vfork() provides any additional operating context. vfork must:
* - Allocate and initialize the stack
* - Initialize special values in any CPU registers that were not
* already configured by up_initial_state()
* 5) vfork() then calls task_vforkstart()
* 6) task_vforkstart() then executes the child thread.
*
* task_vforkabort() may be called if an error occurs between steps 3 and 6.
*/
FAR _TCB *task_vforksetup(start_t retaddr);
pid_t task_vforkstart(FAR _TCB *child);
void task_vforkabort(FAR _TCB *child, int errcode);
/* sched_foreach will enumerate over each task and provide the
* TCB of each task to a user callback functions. Interrupts
* will be disabled throughout this enumeration!

2
sched/Makefile
View File

@ -45,7 +45,7 @@ MISC_SRCS = os_start.c os_bringup.c errno_getptr.c errno_get.c errno_set.c \
TSK_SRCS = prctl.c task_create.c task_init.c task_setup.c task_activate.c \
task_start.c task_delete.c task_deletecurrent.c task_exithook.c \
task_restart.c exit.c getpid.c sched_addreadytorun.c \
task_restart.c task_vfork.c exit.c getpid.c sched_addreadytorun.c \
sched_removereadytorun.c sched_addprioritized.c sched_mergepending.c \
sched_addblocked.c sched_removeblocked.c sched_free.c sched_gettcb.c \
sched_verifytcb.c sched_releasetcb.c

3
sched/sched_setuptaskfiles.c
View File

@ -200,7 +200,8 @@ static inline void sched_dupsockets(FAR _TCB *tcb)
* tcb - tcb of the new task.
*
* Return Value:
* None
* Zero (OK) is returned on success; A negated errno value is returned on
* failure.
*
* Assumptions:
*

2
sched/task_create.c
View File

@ -169,6 +169,8 @@ static int thread_create(const char *name, uint8_t type, int priority,
ret = task_activate(tcb);
if (ret != OK)
{
/* The TCB was added to the active task list by task_schedsetup() */
dq_rem((FAR dq_entry_t*)tcb, (dq_queue_t*)&g_inactivetasks);
goto errout_with_tcb;
}

266
sched/task_vfork.c Normal file
View File

@ -0,0 +1,266 @@
/****************************************************************************
* sched/task_vfork
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <assert.h>
#include <queue.h>
#include <errno.h>
#include <nuttx/sched.h>
#include "os_internal.h"
#include "env_internal.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: task_vforksetup
*
* Description:
* The vfork() function has the same effect as fork(), except that the
* behavior is undefined if the process created by vfork() either modifies
* any data other than a variable of type pid_t used to store the return
* value from vfork(), or returns 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 functin provides one step in the overall vfork() sequence: It
* Allocates and initializes the child task's TCB. The overall sequence is:
*
* 1) User code calls vfork(). vfork() is provided in architecture-specific
* code.
* 2) vfork()and calls task_vforksetup().
* 3) task_vforksetup() allocates and configures the child task's TCB. This
* consists of:
* - Allocation of the child task's TCB.
* - Initialization of file descriptors and streams
* - Configuration of environment variables
* - Setup the intput parameters for the task.
* - Initialization of the TCB (including call to up_initial_state()
* 4) up_vfork() provides any additional operating context. up_vfork must:
* - Allocate and initialize the stack
* - Initialize special values in any CPU registers that were not
* already configured by up_initial_state()
* 5) up_vfork() then calls task_vforkstart()
* 6) task_vforkstart() then executes the child thread.
*
* Input Paremeters:
* retaddr - The return address from vfork() where the child task
* will be started.
*
* Returned Value:
* Upon successful completion, task_vforksetup() returns a pointer to
* newly allocated and initalized child task's TCB. NULL is returned
* on any failure and the errno is set appropriately.
*
****************************************************************************/
FAR _TCB *task_vforksetup(start_t retaddr)
{
_TCB *parent = (FAR _TCB *)g_readytorun.head;
_TCB *child;
int priority;
int ret;
DEBUGASSERT(retaddr);
/* Allocate a TCB for the child task. */
child = (FAR _TCB*)kzalloc(sizeof(_TCB));
if (!child)
{
set_errno(ENOMEM);
return NULL;
}
/* Associate file descriptors with the new task */
#if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0
ret = sched_setuptaskfiles(child);
if (ret != OK)
{
goto errout_with_tcb;
}
#endif
/* Clone the parent's task environment */
(void)env_dup(child);
/* Mark the type of this thread (this setting will be needed in
* task_schedsetup() when up_initial_state() is called.
*/
child->flags |= TCB_FLAG_TTYPE_TASK;
/* Get the priority of the parent task */
#ifdef CONFIG_PRIORITY_INHERITANCE
priority = parent->base_priority; /* "Normal," unboosted priority */
#else
priority = parent->sched_priority; /* Current priority */
#endif
/* Initialize the task control block. This calls up_initial_state() */
ret = task_schedsetup(child, priority, retaddr, parent->entry.main);
if (ret != OK)
{
goto errout_with_tcb;
}
return child;
errout_with_tcb:
sched_releasetcb(child);
set_errno(-ret);
return NULL;
}
/****************************************************************************
* Name: task_vforkstart
*
* Description:
* The vfork() function has the same effect as fork(), except that the
* behavior is undefined if the process created by vfork() either modifies
* any data other than a variable of type pid_t used to store the return
* value from vfork(), or returns 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 functin provides one step in the overall vfork() sequence: It
* starts execution of the previously initialized TCB. The overall
* sequence is:
*
* 1) User code calls vfork()
* 2) Architecture-specific code provides vfork()and calls task_vforksetup().
* 3) task_vforksetup() allocates and configures the child task's TCB. This
* consists of:
* - Allocation of the child task's TCB.
* - Initialization of file descriptors and streams
* - Configuration of environment variables
* - Setup the intput parameters for the task.
* - Initialization of the TCB (including call to up_initial_state()
* 4) vfork() provides any additional operating context. vfork must:
* - Allocate and initialize the stack
* - Initialize special values in any CPU registers that were not
* already configured by up_initial_state()
* 5) vfork() then calls task_vforkstart()
* 6) task_vforkstart() then executes the child thread.
*
* Input Paremeters:
* retaddr - The return address from vfork() where the child task
* will be started.
*
* Returned Value:
* Upon successful completion, vfork() returns 0 to the child process and
* returns the process ID of the child process to the parent process.
* Otherwise, -1 is returned to the parent, no child process is created,
* and errno is set to indicate the error.
*
****************************************************************************/
pid_t task_vforkstart(FAR _TCB *child)
{
FAR const char *name;
pid_t pid;
int ret;
DEBUGASSERT(child);
/* Setup to pass parameters to the new task */
#if CONFIG_TASK_NAME_SIZE > 0
name = parent->name;
#else
name = "<noname>";
#endif
(void)task_argsetup(child, name, (const char **)NULL);
/* Get the assigned pid before we start the task */
pid = (int)child->pid;
/* Activate the task */
ret = task_activate(child);
if (ret != OK)
{
task_vforkabort(child, -ret);
return ERROR;
}
return pid;
}
/****************************************************************************
* Name: task_vforkabort
*
* Description:
* Recover from any errors after task_vforksetup() was called.
*
* Returned Value:
* None
*
****************************************************************************/
void task_vforkabort(FAR _TCB *child, int errcode)
{
/* The TCB was added to the active task list by task_schedsetup() */
dq_rem((FAR dq_entry_t*)child, (dq_queue_t*)&g_inactivetasks);
/* Release the TCB */
sched_releasetcb(child);
set_errno(errcode);
}