From 256ff9a480238dfd1d30b7dfb3d61835991b3ee7 Mon Sep 17 00:00:00 2001 From: patacongo Date: Thu, 14 Mar 2013 22:44:06 +0000 Subject: Switch to user-mode before starting a new task git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5742 42af7a65-404d-4744-a932-0658087f49c3 --- nuttx/arch/arm/src/armv6-m/svcall.h | 13 +++- nuttx/arch/arm/src/armv6-m/up_initialstate.c | 23 ++----- nuttx/arch/arm/src/armv6-m/up_svcall.c | 55 ++++++++++++---- nuttx/arch/arm/src/armv7-m/svcall.h | 13 +++- nuttx/arch/arm/src/armv7-m/up_initialstate.c | 57 ++--------------- nuttx/arch/arm/src/armv7-m/up_svcall.c | 59 +++++++++++++---- nuttx/arch/arm/src/common/up_task_start.c | 96 ++++++++++++++++++++++++++++ nuttx/arch/arm/src/lpc17xx/Make.defs | 2 +- nuttx/arch/arm/src/sam3u/Make.defs | 40 ++++++------ 9 files changed, 238 insertions(+), 120 deletions(-) create mode 100644 nuttx/arch/arm/src/common/up_task_start.c (limited to 'nuttx/arch/arm/src') diff --git a/nuttx/arch/arm/src/armv6-m/svcall.h b/nuttx/arch/arm/src/armv6-m/svcall.h index 46a385631..f453cad55 100644 --- a/nuttx/arch/arm/src/armv6-m/svcall.h +++ b/nuttx/arch/arm/src/armv6-m/svcall.h @@ -57,9 +57,9 @@ #ifdef CONFIG_NUTTX_KERNEL # ifndef CONFIG_SYS_RESERVED -# error "CONFIG_SYS_RESERVED must be defined to the value 4" -# elif CONFIG_SYS_RESERVED != 4 -# error "CONFIG_SYS_RESERVED must have the value 4" +# error "CONFIG_SYS_RESERVED must be defined to the value 5" +# elif CONFIG_SYS_RESERVED != 5 +# error "CONFIG_SYS_RESERVED must have the value 5" # endif #endif @@ -93,6 +93,13 @@ */ #define SYS_syscall_return (3) + +/* SYS call 3: + * + * void up_task_start(main_t taskentry, int argc, FAR char *argv[]) noreturn_function; + */ + +#define SYS_task_start (4) #endif /************************************************************************************ diff --git a/nuttx/arch/arm/src/armv6-m/up_initialstate.c b/nuttx/arch/arm/src/armv6-m/up_initialstate.c index 3e7e3a48f..646d148c1 100644 --- a/nuttx/arch/arm/src/armv6-m/up_initialstate.c +++ b/nuttx/arch/arm/src/armv6-m/up_initialstate.c @@ -126,26 +126,13 @@ void up_initial_state(struct tcb_s *tcb) #endif #endif /* CONFIG_PIC */ - /* Set privileged- or unprivileged-mode, depending on how NuttX is - * configured and what kind of thread is being started. + /* All tasks start via a stub function in kernel space. So all + * tasks must start in privileged thread mode. If CONFIG_NUTTX_KERNEL + * is defined, then that stub function will switch to unprivileged + * mode before transferring control to the user task. */ -#ifdef CONFIG_NUTTX_KERNEL - if ((tcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_KERNEL) - { - /* It is a normal task or a pthread. Set user mode */ - - xcp->regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR; - } - else - { - /* If the kernel build is not selected -OR- if this is a kernel - * thread, then start it in privileged thread mode. - */ - - xcp->regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; - } -#endif /* CONFIG_NUTTX_KERNEL */ + xcp->regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; /* Enable or disable interrupts, based on user configuration */ diff --git a/nuttx/arch/arm/src/armv6-m/up_svcall.c b/nuttx/arch/arm/src/armv6-m/up_svcall.c index b1bf1e4ec..f36e92297 100644 --- a/nuttx/arch/arm/src/armv6-m/up_svcall.c +++ b/nuttx/arch/arm/src/armv6-m/up_svcall.c @@ -232,9 +232,9 @@ int up_svcall(int irq, FAR void *context) } break; - /* R0=SYS_syscall_return: This a switch context command: + /* R0=SYS_syscall_return: This a syscall return command: * - * void up_sycall_return(void); + * void up_syscall_return(void); * * At this point, the following values are saved in context: * @@ -260,15 +260,48 @@ int up_svcall(int irq, FAR void *context) * unprivileged mode. */ - current_regs[REG_PC] = rtcb->xcp.sysreturn; - current_regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR; - rtcb->xcp.sysreturn = 0; + regs[REG_PC] = rtcb->xcp.sysreturn; + regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR; + rtcb->xcp.sysreturn = 0; /* The return value must be in R0-R1. dispatch_syscall() temporarily * moved the value to R2. */ - current_regs[REG_R0] = current_regs[REG_R2]; + regs[REG_R0] = regs[REG_R2]; + } + break; +#endif + + /* R0=SYS_task_start: This a user task start + * + * void up_task_start(main_t taskentry, int argc, FAR char *argv[]) noreturn_function; + * + * At this point, the following values are saved in context: + * + * R0 = SYS_task_start + * R1 = taskentry + * R2 = argc + * R3 = argv + */ + +#ifdef CONFIG_NUTTX_KERNEL + case SYS_task_start: + { + /* Set up to return to the user-space task start-up function in + * unprivileged mode. + */ + + regs[REG_PC] = (uint32_t)USERSPACE->task_startup; + regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR; + + /* Change the paramter ordering to match the expection of struct + * userpace_s task_startup: + */ + + regs[REG_R0] = regs[REG_R1]; /* Task entry */ + regs[REG_R1] = regs[REG_R2]; /* argc */ + regs[REG_R2] = regs[REG_R3]; /* argv */ } break; #endif @@ -285,7 +318,7 @@ int up_svcall(int irq, FAR void *context) /* Verify the the SYS call number is within range */ - DEBUGASSERT(current_regs[REG_R0] < SYS_maxsyscall); + DEBUGASSERT(regs[REG_R0] < SYS_maxsyscall); /* Make sure that we got here from an unprivileged thread and that * there is a no saved syscall return address. @@ -296,13 +329,13 @@ int up_svcall(int irq, FAR void *context) /* Setup to return to dispatch_syscall in privileged mode. */ - rtcb->xcp.sysreturn = regs[REG_PC]; - regs[REG_PC] = (uint32_t)dispatch_syscall; - current_regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; + rtcb->xcp.sysreturn = regs[REG_PC]; + regs[REG_PC] = (uint32_t)dispatch_syscall; + regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; /* Offset R0 to account for the reserved values */ - current_regs[REG_R0] -= CONFIG_SYS_RESERVED; + regs[REG_R0] -= CONFIG_SYS_RESERVED; #else slldbg("ERROR: Bad SYS call: %d\n", regs[REG_R0]); #endif diff --git a/nuttx/arch/arm/src/armv7-m/svcall.h b/nuttx/arch/arm/src/armv7-m/svcall.h index 13b9935a0..f6b068f86 100644 --- a/nuttx/arch/arm/src/armv7-m/svcall.h +++ b/nuttx/arch/arm/src/armv7-m/svcall.h @@ -57,9 +57,9 @@ #ifdef CONFIG_NUTTX_KERNEL # ifndef CONFIG_SYS_RESERVED -# error "CONFIG_SYS_RESERVED must be defined to the value 4" -# elif CONFIG_SYS_RESERVED != 4 -# error "CONFIG_SYS_RESERVED must have the value 4" +# error "CONFIG_SYS_RESERVED must be defined to the value 5" +# elif CONFIG_SYS_RESERVED != 5 +# error "CONFIG_SYS_RESERVED must have the value 5" # endif #endif @@ -93,6 +93,13 @@ */ #define SYS_syscall_return (3) + +/* SYS call 3: + * + * void up_task_start(main_t taskentry, int argc, FAR char *argv[]) noreturn_function; + */ + +#define SYS_task_start (4) #endif /************************************************************************************ diff --git a/nuttx/arch/arm/src/armv7-m/up_initialstate.c b/nuttx/arch/arm/src/armv7-m/up_initialstate.c index 6f9abcd31..41828af5b 100644 --- a/nuttx/arch/arm/src/armv7-m/up_initialstate.c +++ b/nuttx/arch/arm/src/armv7-m/up_initialstate.c @@ -126,63 +126,20 @@ void up_initial_state(struct tcb_s *tcb) #endif #endif /* CONFIG_PIC */ -#ifdef CONFIG_ARMV7M_CMNVECTOR - /* Set privileged- or unprivileged-mode, depending on how NuttX is - * configured and what kind of thread is being started. - * - * If the kernel build is not selected, then all threads run in - * privileged thread mode. - * - * If FPU support is not configured, set the bit that indicates that - * the context does not include the volatile FP registers. + /* All tasks start via a stub function in kernel space. So all + * tasks must start in privileged thread mode. If CONFIG_NUTTX_KERNEL + * is defined, then that stub function will switch to unprivileged + * mode before transferring control to the user task. */ - xcp->regs[REG_EXC_RETURN] = EXC_RETURN_BASE | EXC_RETURN_THREAD_MODE; + xcp->regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; -#ifndef CONFIG_ARCH_FPU - - xcp->regs[REG_EXC_RETURN] |= EXC_RETURN_STD_CONTEXT; - -#else +#if defined(CONFIG_ARMV7M_CMNVECTOR) && defined(CONFIG_ARCH_FPU) xcp->regs[REG_FPSCR] = 0; // XXX initial FPSCR should be configurable xcp->regs[REG_FPReserved] = 0; -#endif /* CONFIG_ARCH_FPU */ - -#ifdef CONFIG_NUTTX_KERNEL - if ((tcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_KERNEL) - { - /* It is a normal task or a pthread. Set user mode */ - - xcp->regs[REG_EXC_RETURN] |= EXC_RETURN_PROCESS_STACK; - } -#endif /* CONFIG_NUTTX_KERNEL */ - -#else /* CONFIG_ARMV7M_CMNVECTOR */ - - /* Set privileged- or unprivileged-mode, depending on how NuttX is - * configured and what kind of thread is being started. - * - * If the kernel build is not selected, then all threads run in - * privileged thread mode. - */ - -#ifdef CONFIG_NUTTX_KERNEL - if ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_KERNEL) - { - /* It is a kernel thread.. set privileged thread mode */ - - xcp->regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; - } - else - { - /* It is a normal task or a pthread. Set user mode */ - - xcp->regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR; - } -#endif /* CONFIG_NUTTX_KERNEL */ -#endif /* CONFIG_ARMV7M_CMNVECTOR */ +#endif /* CONFIG_ARMV7M_CMNVECTOR && CONFIG_ARCH_FPU */ /* Enable or disable interrupts, based on user configuration */ diff --git a/nuttx/arch/arm/src/armv7-m/up_svcall.c b/nuttx/arch/arm/src/armv7-m/up_svcall.c index 8321cd3bb..8f7efc1da 100644 --- a/nuttx/arch/arm/src/armv7-m/up_svcall.c +++ b/nuttx/arch/arm/src/armv7-m/up_svcall.c @@ -237,9 +237,9 @@ int up_svcall(int irq, FAR void *context) } break; - /* R0=SYS_syscall_return: This a switch context command: + /* R0=SYS_syscall_return: This a syscall return command: * - * void up_sycall_return(void); + * void up_syscall_return(void); * * At this point, the following values are saved in context: * @@ -256,23 +256,54 @@ int up_svcall(int irq, FAR void *context) /* Make sure that there is a saved syscall return address. */ - svcdbg("sysreturn: %08x excreturn: %08x\n", - rtcb->xcp.sysreturn, rtcb->xcp.excreturn); DEBUGASSERT(rtcb->xcp.sysreturn != 0); /* Setup to return to the saved syscall return address in * the original mode. */ - current_regs[REG_PC] = rtcb->xcp.sysreturn; - current_regs[REG_EXC_RETURN] = rtcb->xcp.excreturn; - rtcb->xcp.sysreturn = 0; + regs[REG_PC] = rtcb->xcp.sysreturn; + regs[REG_EXC_RETURN] = rtcb->xcp.excreturn; + rtcb->xcp.sysreturn = 0; /* The return value must be in R0-R1. dispatch_syscall() temporarily * moved the value for R0 into R2. */ - current_regs[REG_R0] = current_regs[REG_R2]; + regs[REG_R0] = regs[REG_R2]; + } + break; +#endif + + /* R0=SYS_task_start: This a user task start + * + * void up_task_start(main_t taskentry, int argc, FAR char *argv[]) noreturn_function; + * + * At this point, the following values are saved in context: + * + * R0 = SYS_task_start + * R1 = taskentry + * R2 = argc + * R3 = argv + */ + +#ifdef CONFIG_NUTTX_KERNEL + case SYS_task_start: + { + /* Set up to return to the user-space task start-up function in + * unprivileged mode. + */ + + regs[REG_PC] = (uint32_t)USERSPACE->task_startup; + regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR; + + /* Change the paramter ordering to match the expection of struct + * userpace_s task_startup: + */ + + regs[REG_R0] = regs[REG_R1]; /* Task entry */ + regs[REG_R1] = regs[REG_R2]; /* argc */ + regs[REG_R2] = regs[REG_R3]; /* argv */ } break; #endif @@ -289,7 +320,7 @@ int up_svcall(int irq, FAR void *context) /* Verify that the SYS call number is within range */ - DEBUGASSERT(current_regs[REG_R0] < SYS_maxsyscall); + DEBUGASSERT(regs[REG_R0] < SYS_maxsyscall); /* Make sure that we got here that there is a no saved syscall * return address. We cannot yet handle nested system calls. @@ -299,15 +330,15 @@ int up_svcall(int irq, FAR void *context) /* Setup to return to dispatch_syscall in privileged mode. */ - rtcb->xcp.sysreturn = regs[REG_PC]; - rtcb->xcp.excreturn = current_regs[REG_EXC_RETURN]; + rtcb->xcp.sysreturn = regs[REG_PC]; + rtcb->xcp.excreturn = regs[REG_EXC_RETURN]; - current_regs[REG_PC] = (uint32_t)dispatch_syscall; - current_regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; + regs[REG_PC] = (uint32_t)dispatch_syscall; + regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; /* Offset R0 to account for the reserved values */ - current_regs[REG_R0] -= CONFIG_SYS_RESERVED; + regs[REG_R0] -= CONFIG_SYS_RESERVED; #else slldbg("ERROR: Bad SYS call: %d\n", regs[REG_R0]); #endif diff --git a/nuttx/arch/arm/src/common/up_task_start.c b/nuttx/arch/arm/src/common/up_task_start.c new file mode 100644 index 000000000..c006f9595 --- /dev/null +++ b/nuttx/arch/arm/src/common/up_task_start.c @@ -0,0 +1,96 @@ +/**************************************************************************** + * arch/arm/src/common/up_task_start.c + * + * Copyright (C) 2013 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt + * + * 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 +#include + +#include "svcall.h" +#include "up_internal.h" + +#ifdef CONFIG_NUTTX_KERNEL + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: up_task_start + * + * Description: + * In this kernel mode build, this function will be called to execute a + * task in user-space. When the task is first started, a kernel-mode + * stub will first run to perform some housekeeping functions. This + * kernel-mode stub will then be called transfer control to the user-mode + * task. + * + * Normally the a user-mode start-up stub will also execute before the + * task actually starts. See libc/sched/task_startup.c + * + * Input Parameters: + * taskentry - The user-space entry point of the task. + * argc - The number of parameters being passed. + * argv - The parameters being passed. These lie in kernel-space memory + * and will have to be reallocated in user-space memory. + * + * Returned Value: + * This function should not return. It should call the user-mode start-up + * stub and that stub should call exit if/when the user task terminates. + * + ****************************************************************************/ + +void up_task_start(main_t taskentry, int argc, FAR char *argv[]) +{ + /* Let sys_call3() do all of the work */ + + sys_call3(SYS_task_start, (uintptr_t)taskentry, (uintptr_t)argc, (uintptr_t)argv); +} + +#endif /* CONFIG_NUTTX_KERNEL */ diff --git a/nuttx/arch/arm/src/lpc17xx/Make.defs b/nuttx/arch/arm/src/lpc17xx/Make.defs index 679e51a5f..82ce2c4b6 100644 --- a/nuttx/arch/arm/src/lpc17xx/Make.defs +++ b/nuttx/arch/arm/src/lpc17xx/Make.defs @@ -64,7 +64,7 @@ CMN_ASRCS += up_memcpy.S endif ifeq ($(CONFIG_NUTTX_KERNEL),y) -CMN_CSRCS += up_mpu.c +CMN_CSRCS += up_mpu.c up_task_start.c endif ifeq ($(CONFIG_NET),y) diff --git a/nuttx/arch/arm/src/sam3u/Make.defs b/nuttx/arch/arm/src/sam3u/Make.defs index 1255af237..918d40148 100644 --- a/nuttx/arch/arm/src/sam3u/Make.defs +++ b/nuttx/arch/arm/src/sam3u/Make.defs @@ -35,28 +35,28 @@ # The start-up, "head", file -HEAD_ASRC = sam3u_vectors.S +HEAD_ASRC = sam3u_vectors.S # Common ARM and Cortex-M3 files -CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_switchcontext.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 +CMN_ASRCS = up_saveusercontext.S up_fullcontextrestore.S up_switchcontext.S +CMN_ASRCS += vfork.S +CMN_CSRCS = up_assert.c up_blocktask.c up_copystate.c up_createstack.c +CMN_CSRCS += up_mdelay.c up_udelay.c up_exit.c up_idle.c up_initialize.c +CMN_CSRCS += up_initialstate.c up_interruptcontext.c up_memfault.c up_modifyreg8.c +CMN_CSRCS += up_modifyreg16.c up_modifyreg32.c up_releasepending.c +CMN_CSRCS += up_releasestack.c up_reprioritizertr.c up_schedulesigaction.c +CMN_CSRCS += up_sigdeliver.c up_unblocktask.c up_usestack.c up_doirq.c +CMN_CSRCS += up_hardfault.c up_svcall.c up_vfork.c # Configuration-dependent common files ifeq ($(CONFIG_ARCH_MEMCPY),y) -CMN_ASRCS += up_memcpy.S +CMN_ASRCS += up_memcpy.S endif ifeq ($(CONFIG_NUTTX_KERNEL),y) -CMN_CSRCS += up_mpu.c +CMN_CSRCS += up_mpu.c up_task_start.c endif ifeq ($(CONFIG_ELF),y) @@ -65,25 +65,25 @@ endif # Required SAM3U files -CHIP_ASRCS = -CHIP_CSRCS = sam3u_allocateheap.c sam3u_clockconfig.c sam3u_gpioirq.c \ - sam3u_irq.c sam3u_lowputc.c sam3u_pio.c sam3u_serial.c \ - sam3u_start.c sam3u_timerisr.c +CHIP_ASRCS = +CHIP_CSRCS = sam3u_allocateheap.c sam3u_clockconfig.c sam3u_gpioirq.c +CHIP_CSRCS += sam3u_irq.c sam3u_lowputc.c sam3u_pio.c sam3u_serial.c +CHIP_CSRCS += sam3u_start.c sam3u_timerisr.c # Configuration-dependent SAM3U files ifeq ($(CONFIG_NUTTX_KERNEL),y) -CHIP_CSRCS += sam3u_userspace.c sam3u_mpuinit.c +CHIP_CSRCS += sam3u_userspace.c sam3u_mpuinit.c endif ifeq ($(CONFIG_SAM3U_DMA),y) -CHIP_CSRCS += sam3u_dmac.c +CHIP_CSRCS += sam3u_dmac.c endif ifeq ($(CONFIG_SAM3U_HSMCI),y) -CHIP_CSRCS += sam3u_hsmci.c +CHIP_CSRCS += sam3u_hsmci.c endif ifeq ($(CONFIG_SAM3U_SPI),y) -CHIP_CSRCS += sam3u_spi.c +CHIP_CSRCS += sam3u_spi.c endif -- cgit v1.2.3