Add support for calling to and returning from signal handlers in in user-mode threads

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5750 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2013-03-17 00:40:49 +00:00
parent e0769fc6d0
commit c702374d7b
14 changed files with 380 additions and 27 deletions

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@ -161,6 +161,14 @@ struct xcptcontext
uint32_t saved_pc;
uint32_t saved_basepri;
uint32_t saved_xpsr;
# ifdef CONFIG_NUTTX_KERNEL
/* This is the saved address to use when returning from a user-space
* signal handler.
*/
uint32_t sigreturn;
# endif
#endif
#ifdef CONFIG_NUTTX_KERNEL

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@ -54,8 +54,22 @@
* Pro-processor Definitions
****************************************************************************/
/* This is the value used as the argument to the SVC instruction. It is not
* used.
*/
#define SYS_syscall 0x00
/* The SYS_signal_handler_return is executed here... its value is not always
* available in this context and so is assumed to be 7.
*/
#ifndef SYS_signal_handler_return
# define SYS_signal_handler_return (7)
#elif SYS_signal_handler_return != 7
# error "SYS_signal_handler_return was assumed to be 7"
#endif
/****************************************************************************
* Public Types
****************************************************************************/
@ -218,6 +232,18 @@ static inline uintptr_t sys_call6(unsigned int nbr, uintptr_t parm1,
return reg0;
}
/* This inline function is used by user-space code in order to return from
* a signal handler.
*/
#if defined(CONFIG_NUTTX_KERNEL) && !defined(__KERNEL__)
static inline void signal_handler_return(void) noreturn_function;
static inline void signal_handler_return(void)
{
sys_call0(SYS_signal_handler_return);
}
#endif
/****************************************************************************
* Public Variables
****************************************************************************/

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@ -124,6 +124,14 @@ struct xcptcontext
uint32_t saved_primask;
#endif
uint32_t saved_xpsr;
# ifdef CONFIG_NUTTX_KERNEL
/* This is the saved address to use when returning from a user-space
* signal handler.
*/
uint32_t sigreturn;
# endif
#endif
#ifdef CONFIG_NUTTX_KERNEL

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@ -54,8 +54,22 @@
* Pro-processor Definitions
****************************************************************************/
/* This is the value used as the argument to the SVC instruction. It is not
* used.
*/
#define SYS_syscall 0x00
/* The SYS_signal_handler_return is executed here... its value is not always
* available in this context and so is assumed to be 7.
*/
#ifndef SYS_signal_handler_return
# define SYS_signal_handler_return (7)
#elif SYS_signal_handler_return != 7
# error "SYS_signal_handler_return was assumed to be 7"
#endif
/****************************************************************************
* Public Types
****************************************************************************/
@ -218,6 +232,18 @@ static inline uintptr_t sys_call6(unsigned int nbr, uintptr_t parm1,
return reg0;
}
/* This inline function is used by user-space code in order to return from
* a signal handler.
*/
#if defined(CONFIG_NUTTX_KERNEL) && !defined(__KERNEL__)
static inline void signal_handler_return(void) noreturn_function;
static inline void signal_handler_return(void)
{
sys_call0(SYS_signal_handler_return);
}
#endif
/****************************************************************************
* Public Variables
****************************************************************************/

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@ -57,9 +57,9 @@
#ifdef CONFIG_NUTTX_KERNEL
# ifndef CONFIG_SYS_RESERVED
# error "CONFIG_SYS_RESERVED must be defined to the value 6"
# elif CONFIG_SYS_RESERVED != 6
# error "CONFIG_SYS_RESERVED must have the value 6"
# error "CONFIG_SYS_RESERVED must be defined to have the value 8"
# elif CONFIG_SYS_RESERVED != 8
# error "CONFIG_SYS_RESERVED must have the value 8"
# endif
#endif
@ -70,21 +70,21 @@
* int up_saveusercontext(uint32_t *saveregs);
*/
#define SYS_save_context (0)
#define SYS_save_context (0)
/* SYS call 1:
*
* void up_fullcontextrestore(uint32_t *restoreregs) noreturn_function;
*/
#define SYS_restore_context (1)
#define SYS_restore_context (1)
/* SYS call 2:
*
* void up_switchcontext(uint32_t *saveregs, uint32_t *restoreregs);
*/
#define SYS_switch_context (2)
#define SYS_switch_context (2)
#ifdef CONFIG_NUTTX_KERNEL
/* SYS call 3:
@ -92,21 +92,38 @@
* void up_syscall_return(void);
*/
#define SYS_syscall_return (3)
#define SYS_syscall_return (3)
/* SYS call 4:
*
* void up_task_start(main_t taskentry, int argc, FAR char *argv[]) noreturn_function;
* void up_task_start(main_t taskentry, int argc, FAR char *argv[])
* noreturn_function;
*/
#define SYS_task_start (4)
#define SYS_task_start (4)
/* SYS call 5:
*
* void up_pthread_start(pthread_startroutine_t entrypt, pthread_addr_t arg) noreturn_function
* void up_pthread_start(pthread_startroutine_t entrypt, pthread_addr_t arg)
* noreturn_function
*/
#define SYS_pthread_start (5)
#define SYS_pthread_start (5)
/* SYS call 6:
*
* void signal_handler(_sa_sigaction_t sighand, int signo, FAR siginfo_t *info,
* FAR void *ucontext);
*/
#define SYS_signal_handler (6)
/* SYS call 7:
*
* void signal_handler_return(void);
*/
#define SYS_signal_handler_return (7)
#endif
/************************************************************************************

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@ -122,7 +122,7 @@ void up_sigdeliver(void)
irqrestore((uint8_t)regs[REG_BASEPRI]);
/* Deliver the signals */
/* Deliver the signal */
sigdeliver(rtcb);

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@ -344,6 +344,78 @@ int up_svcall(int irq, FAR void *context)
break;
#endif
/* R0=SYS_signal_handler: This a user signal handler callback
*
* void signal_handler(_sa_sigaction_t sighand, int signo,
* FAR siginfo_t *info, FAR void *ucontext);
*
* At this point, the following values are saved in context:
*
* R0 = SYS_signal_handler
* R1 = sighand
* R2 = signo
* R3 = info
* ucontext (on the stack)
*/
#if defined(CONFIG_NUTTX_KERNEL) && !defined(CONFIG_DISABLE_SIGNALS)
case SYS_signal_handler:
{
struct tcb_s *rtcb = sched_self();
/* Remember the caller's return address */
DEBUGASSERT(rtcb->xcp.sigreturn == 0);
rtcb->xcp.sigreturn = regs[REG_PC];
/* Set up to return to the user-space pthread start-up function in
* unprivileged mode.
*/
regs[REG_PC] = (uint32_t)USERSPACE->signal_handler;
regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR;
/* Change the parameter ordering to match the expectation of struct
* userpace_s signal_handler.
*/
regs[REG_R0] = regs[REG_R1]; /* sighand */
regs[REG_R1] = regs[REG_R2]; /* signal */
regs[REG_R2] = regs[REG_R3]; /* info */
/* The last parameter, arg, is trickier. The arg parameter will
* reside at an offset of 4 from the stack pointer.
*/
regs[REG_R3] = *(uint32_t*)(regs[REG_SP+4]);
}
break;
#endif
/* R0=SYS_signal_handler_return: This a user signal handler callback
*
* void signal_handler_return(void);
*
* At this point, the following values are saved in context:
*
* R0 = SYS_signal_handler_return
*/
#if defined(CONFIG_NUTTX_KERNEL) && !defined(CONFIG_DISABLE_SIGNALS)
case SYS_signal_handler_return:
{
struct tcb_s *rtcb = sched_self();
/* Set up to return to the kernel-mode signal dispatching logic. */
DEBUGASSERT(rtcb->xcp.sigreturn != 0);
regs[REG_PC] = rtcb->xcp.sigreturn;
regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR;
}
break;
#endif
/* This is not an architecture-specific system call. If NuttX is built
* as a standalone kernel with a system call interface, then all of the
* additional system calls must be handled as in the default case.
@ -356,7 +428,7 @@ int up_svcall(int irq, FAR void *context)
/* Verify that the SYS call number is within range */
DEBUGASSERT(cmd < SYS_maxsyscall);
DEBUGASSERT(cmd >= CONFIG_SYS_RESERVED && cmd < SYS_maxsyscall);
/* Make sure that there is a no saved syscall return address. We
* cannot yet handle nested system calls.

View File

@ -57,9 +57,9 @@
#ifdef CONFIG_NUTTX_KERNEL
# ifndef CONFIG_SYS_RESERVED
# error "CONFIG_SYS_RESERVED must be defined to the value 6"
# elif CONFIG_SYS_RESERVED != 6
# error "CONFIG_SYS_RESERVED must have the value 6"
# error "CONFIG_SYS_RESERVED must be defined to have the value 8"
# elif CONFIG_SYS_RESERVED != 8
# error "CONFIG_SYS_RESERVED must have the value 8"
# endif
#endif
@ -70,21 +70,21 @@
* int up_saveusercontext(uint32_t *saveregs);
*/
#define SYS_save_context (0)
#define SYS_save_context (0)
/* SYS call 1:
*
* void up_fullcontextrestore(uint32_t *restoreregs) noreturn_function;
*/
#define SYS_restore_context (1)
#define SYS_restore_context (1)
/* SYS call 2:
*
* void up_switchcontext(uint32_t *saveregs, uint32_t *restoreregs);
*/
#define SYS_switch_context (2)
#define SYS_switch_context (2)
#ifdef CONFIG_NUTTX_KERNEL
/* SYS call 3:
@ -92,21 +92,38 @@
* void up_syscall_return(void);
*/
#define SYS_syscall_return (3)
#define SYS_syscall_return (3)
/* SYS call 4:
*
* void up_task_start(main_t taskentry, int argc, FAR char *argv[]) noreturn_function;
* void up_task_start(main_t taskentry, int argc, FAR char *argv[])
* noreturn_function;
*/
#define SYS_task_start (4)
#define SYS_task_start (4)
/* SYS call 5:
*
* void up_pthread_start(pthread_startroutine_t entrypt, pthread_addr_t arg) noreturn_function
* void up_pthread_start(pthread_startroutine_t entrypt, pthread_addr_t arg)
* noreturn_function
*/
#define SYS_pthread_start (5)
#define SYS_pthread_start (5)
/* SYS call 6:
*
* void signal_handler(_sa_sigaction_t sighand, int signo, FAR siginfo_t *info,
* FAR void *ucontext);
*/
#define SYS_signal_handler (6)
/* SYS call 7:
*
* void signal_handler_return(void);
*/
#define SYS_signal_handler_return (7)
#endif
/************************************************************************************

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@ -125,7 +125,7 @@ void up_sigdeliver(void)
irqrestore((uint16_t)regs[REG_PRIMASK]);
#endif
/* Deliver the signals */
/* Deliver the signal */
sigdeliver(rtcb);

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@ -348,6 +348,78 @@ int up_svcall(int irq, FAR void *context)
break;
#endif
/* R0=SYS_signal_handler: This a user signal handler callback
*
* void signal_handler(_sa_sigaction_t sighand, int signo,
* FAR siginfo_t *info, FAR void *ucontext);
*
* At this point, the following values are saved in context:
*
* R0 = SYS_signal_handler
* R1 = sighand
* R2 = signo
* R3 = info
* ucontext (on the stack)
*/
#if defined(CONFIG_NUTTX_KERNEL) && !defined(CONFIG_DISABLE_SIGNALS)
case SYS_signal_handler:
{
struct tcb_s *rtcb = sched_self();
/* Remember the caller's return address */
DEBUGASSERT(rtcb->xcp.sigreturn == 0);
rtcb->xcp.sigreturn = regs[REG_PC];
/* Set up to return to the user-space pthread start-up function in
* unprivileged mode.
*/
regs[REG_PC] = (uint32_t)USERSPACE->signal_handler;
regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR;
/* Change the parameter ordering to match the expectation of struct
* userpace_s signal_handler.
*/
regs[REG_R0] = regs[REG_R1]; /* sighand */
regs[REG_R1] = regs[REG_R2]; /* signal */
regs[REG_R2] = regs[REG_R3]; /* info */
/* The last parameter, arg, is trickier. The arg parameter will
* reside at an offset of 4 from the stack pointer.
*/
regs[REG_R3] = *(uint32_t*)(regs[REG_SP+4]);
}
break;
#endif
/* R0=SYS_signal_handler_return: This a user signal handler callback
*
* void signal_handler_return(void);
*
* At this point, the following values are saved in context:
*
* R0 = SYS_signal_handler_return
*/
#if defined(CONFIG_NUTTX_KERNEL) && !defined(CONFIG_DISABLE_SIGNALS)
case SYS_signal_handler_return:
{
struct tcb_s *rtcb = sched_self();
/* Set up to return to the kernel-mode signal dispatching logic. */
DEBUGASSERT(rtcb->xcp.sigreturn != 0);
regs[REG_PC] = rtcb->xcp.sigreturn;
regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR;
}
break;
#endif
/* This is not an architecture-specific system call. If NuttX is built
* as a standalone kernel with a system call interface, then all of the
* additional system calls must be handled as in the default case.
@ -360,7 +432,7 @@ int up_svcall(int irq, FAR void *context)
/* Verify that the SYS call number is within range */
DEBUGASSERT(cmd < SYS_maxsyscall);
DEBUGASSERT(cmd >= CONFIG_SYS_RESERVED && cmd < SYS_maxsyscall);
/* Make sure that there is a no saved syscall return address. We
* cannot yet handle nested system calls.

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@ -0,0 +1,100 @@
/****************************************************************************
* arch/arm/src/common/up_task_start.c
*
* 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 <nuttx/arch.h>
#include "svcall.h"
#include "up_internal.h"
#if defined(CONFIG_NUTTX_KERNEL) && defined(__KERNEL__) && !defined(CONFIG_DISABLE_SIGNALS)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_signal_handler
*
* Description:
* In this kernel mode build, this function will be called to execute a
* a signal handler in user-space. When the signal is delivered, 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 signal handler by calling this function.
*
* Normally the a user-mode signalling handling stub will also execute
* before the ultimate signal handler is called. See
* libc/signal/signal_handler.c This function is the user-space, signal
* handler trampoline function. It is called from up_signal_handler() in
* user-mode.
*
* Inputs:
* sighand - The address user-space signal handling function
* signo, info, and ucontext - Standard arguments to be passed to the
* signal handling function.
*
* Return:
* None. This function does not return in the normal sense. It returns
* via signal_handler_return (below)
*
****************************************************************************/
void up_signal_handler(_sa_sigaction_t sighand, int signo,
FAR siginfo_t *info, FAR void *ucontext)
{
/* Let sys_call4() do all of the work */
sys_call4(SYS_signal_handler, (uintptr_t)sighand, (uintptr_t)signo,
(uintptr_t)info, (uintptr_t)ucontext);
}
#endif /* CONFIG_NUTTX_KERNEL && __KERNEL__ && !CONFIG_DISABLE_SIGNALS */

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@ -90,7 +90,8 @@ 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);
sys_call3(SYS_task_start, (uintptr_t)taskentry, (uintptr_t)argc,
(uintptr_t)argv);
}
#endif /* CONFIG_NUTTX_KERNEL */

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@ -65,6 +65,9 @@ endif
ifeq ($(CONFIG_NUTTX_KERNEL),y)
CMN_CSRCS += up_mpu.c up_task_start.c up_pthread_start.c
ifneq ($(CONFIG_DISABLE_SIGNALS),y)
CMN_CSRCS += up_signal_handler.c
endif
endif
ifeq ($(CONFIG_NET),y)

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@ -57,6 +57,9 @@ endif
ifeq ($(CONFIG_NUTTX_KERNEL),y)
CMN_CSRCS += up_mpu.c up_task_start.c up_pthread_start.c
ifneq ($(CONFIG_DISABLE_SIGNALS),y)
CMN_CSRCS += up_signal_handler.c
endif
endif
ifeq ($(CONFIG_ELF),y)