From bd1488bdabb2aa6fcd76a187b1cd0de4f311fbad Mon Sep 17 00:00:00 2001 From: patacongo Date: Wed, 6 Mar 2013 19:56:32 +0000 Subject: [PATCH] Fix some bad syscall dispatching log. This change is not testable until these is a tested NuttX kernel build. git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5713 42af7a65-404d-4744-a932-0658087f49c3 --- arch/arm/include/armv6-m/irq.h | 8 +- arch/arm/include/armv7-m/irq.h | 8 +- arch/arm/src/armv6-m/svcall.h | 19 ++- arch/arm/src/armv6-m/up_svcall.c | 220 ++++++++++--------------- arch/arm/src/armv7-m/svcall.h | 21 ++- arch/arm/src/armv7-m/up_svcall.c | 217 ++++++++++-------------- arch/arm/src/sam3u/sam3u_userspace.c | 4 + arch/mips/include/mips32/irq.h | 10 +- arch/mips/include/mips32/syscall.h | 28 +++- arch/mips/src/mips32/up_swint0.c | 216 +++++++++--------------- arch/mips/src/pic32mx/pic32mx-config.h | 16 +- 11 files changed, 344 insertions(+), 423 deletions(-) diff --git a/arch/arm/include/armv6-m/irq.h b/arch/arm/include/armv6-m/irq.h index 68f8c75d4d..f4bfea33f7 100644 --- a/arch/arm/include/armv6-m/irq.h +++ b/arch/arm/include/armv6-m/irq.h @@ -147,11 +147,11 @@ #ifndef __ASSEMBLY__ struct xcptcontext { +#ifndef CONFIG_DISABLE_SIGNALS /* The following function pointer is non-zero if there * are pending signals to be processed. */ -#ifndef CONFIG_DISABLE_SIGNALS void *sigdeliver; /* Actual type is sig_deliver_t */ /* These are saved copies of LR, PRIMASK, and xPSR used during @@ -163,6 +163,12 @@ struct xcptcontext uint32_t saved_xpsr; #endif +#ifdef CONFIG_NUTTX_KERNEL + /* The following holds the return address from a system call */ + + uint32_t sysreturn; +#endif + /* Register save area */ uint32_t regs[XCPTCONTEXT_REGS]; diff --git a/arch/arm/include/armv7-m/irq.h b/arch/arm/include/armv7-m/irq.h index 8acec4c07a..d815aba303 100644 --- a/arch/arm/include/armv7-m/irq.h +++ b/arch/arm/include/armv7-m/irq.h @@ -106,11 +106,11 @@ #ifndef __ASSEMBLY__ struct xcptcontext { +#ifndef CONFIG_DISABLE_SIGNALS /* The following function pointer is non-zero if there * are pending signals to be processed. */ -#ifndef CONFIG_DISABLE_SIGNALS void *sigdeliver; /* Actual type is sig_deliver_t */ /* These are saved copies of LR, PRIMASK, and xPSR used during @@ -126,6 +126,12 @@ struct xcptcontext uint32_t saved_xpsr; #endif +#ifdef CONFIG_NUTTX_KERNEL + /* The following holds the return address from a system call */ + + uint32_t sysreturn; +#endif + /* Register save area */ uint32_t regs[XCPTCONTEXT_REGS]; diff --git a/arch/arm/src/armv6-m/svcall.h b/arch/arm/src/armv6-m/svcall.h index 38c672ff65..46a3856311 100644 --- a/arch/arm/src/armv6-m/svcall.h +++ b/arch/arm/src/armv6-m/svcall.h @@ -51,15 +51,15 @@ ************************************************************************************/ /* Configuration ********************************************************************/ -/* This logic uses three system calls {0,1,2} for context switching. The first three - * syscall values must be reserved. +/* This logic uses three system calls {0,1,2} for context switching and one for the + * syscall return. The first four syscall values must be reserved. */ #ifdef CONFIG_NUTTX_KERNEL # ifndef CONFIG_SYS_RESERVED -# error "CONFIG_SYS_RESERVED must be defined to the value 3" -# elif CONFIG_SYS_RESERVED != 3 -# error "CONFIG_SYS_RESERVED must have the value 3" +# 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" # endif #endif @@ -86,6 +86,15 @@ #define SYS_switch_context (2) +#ifdef CONFIG_NUTTX_KERNEL +/* SYS call 3: + * + * void up_syscall_return(void); + */ + +#define SYS_syscall_return (3) +#endif + /************************************************************************************ * Inline Functions ************************************************************************************/ diff --git a/arch/arm/src/armv6-m/up_svcall.c b/arch/arm/src/armv6-m/up_svcall.c index 60dde4bf57..e8aa977bd3 100644 --- a/arch/arm/src/armv6-m/up_svcall.c +++ b/arch/arm/src/armv6-m/up_svcall.c @@ -52,6 +52,8 @@ #endif #include "svcall.h" +#include "exc_return.h" +#include "os_internal.h" #include "up_internal.h" /**************************************************************************** @@ -59,29 +61,15 @@ ****************************************************************************/ /* Configuration ************************************************************/ -#undef SYSCALL_INTERRUPTIBLE -#if defined(CONFIG_NUTTX_KERNEL) -# if CONFIG_ARCH_INTERRUPTSTACK > 3 -# warning "CONFIG_ARCH_INTERRUPTSTACK and CONFIG_NUTTX_KERNEL are incompatible" -# warning "options as currently implemented. Interrupts will have to be disabled" -# warning "during SYScall processing to avoid un-handled nested interrupts" -# else -# define SYSCALL_INTERRUPTIBLE 1 -# endif -#endif - /* Debug ********************************************************************/ /* Debug output from this file may interfere with context switching! To get * debug output you must enabled the following in your NuttX configuration: * - * CONFIG_DEBUG and CONFIG_DEBUG_SCHED - * - * And you must explicitly define DEBUG_SVCALL below: + * CONFIG_DEBUG and CONFIG_DEBUG_SYSCALL */ -#undef DEBUG_SVCALL /* Define to debug SVCall */ -#ifdef DEBUG_SVCALL -# define svcdbg(format, arg...) slldbg(format, ##arg) +#ifdef CONFIG_DEBUG_SYSCALL +# define svcdbg(format, arg...) lldbg(format, ##arg) #else # define svcdbg(x...) #endif @@ -102,121 +90,29 @@ * Name: dispatch_syscall * * Description: - * Dispatch a system call to the appropriate handling logic. + * Call the stub function corresponding to the system call. * ****************************************************************************/ #ifdef CONFIG_NUTTX_KERNEL -static inline void dispatch_syscall(uint32_t *regs) +static void dispatch_syscall(void) naked_function; +static void dispatch_syscall(void) { - uint32_t cmd = regs[REG_R0]; - FAR struct tcb_s *rtcb = sched_self(); - uintptr_t ret = (uintptr_t)ERROR; - - /* Verify the the SYS call number is within range */ - - if (cmd < SYS_maxsyscall) - { - /* Report error and return ERROR */ - - slldbg("ERROR: Bad SYS call: %d\n", cmd); - } - else - { - /* The index into the syscall table is offset by the number of architecture- - * specific reserved entries at the beginning of the SYS call number space. - */ - - int index = cmd - CONFIG_SYS_RESERVED; - - /* Enable interrupts while the SYSCALL executes */ - -#ifdef SYSCALL_INTERRUPTIBLE - irqenable(); -#endif - - /* Call the correct stub for each SYS call, based on the number of parameters */ - - svcdbg("Calling stub%d at %p\n", index, g_stubloopkup[index].stub0); - - switch (g_stubnparms[index]) - { - /* No parameters */ - - case 0: - ret = g_stublookup[index].stub0(); - break; - - /* Number of parameters: 1 */ - - case 1: - ret = g_stublookup[index].stub1(regs[REG_R1]); - break; - - /* Number of parameters: 2 */ - - case 2: - ret = g_stublookup[index].stub2(regs[REG_R1], regs[REG_R2]); - break; - - /* Number of parameters: 3 */ - - case 3: - ret = g_stublookup[index].stub3(regs[REG_R1], regs[REG_R2], - regs[REG_R3]); - break; - - /* Number of parameters: 4 */ - - case 4: - ret = g_stublookup[index].stub4(regs[REG_R1], regs[REG_R2], - regs[REG_R3], regs[REG_R4]); - break; - - /* Number of parameters: 5 */ - - case 5: - ret = g_stublookup[index].stub5(regs[REG_R1], regs[REG_R2], - regs[REG_R3], regs[REG_R4], - regs[REG_R5]); - break; - - /* Number of parameters: 6 */ - - case 6: - ret = g_stublookup[index].stub6(regs[REG_R1], regs[REG_R2], - regs[REG_R3], regs[REG_R4], - regs[REG_R5], regs[REG_R6]); - break; - - /* Unsupported number of paramters. Report error and return ERROR */ - - default: - slldbg("ERROR: Bad SYS call %d number parameters %d\n", - cmd, g_stubnparms[index]); - break; - } - -#ifdef SYSCALL_INTERRUPTIBLE - irqdisable(); -#endif - } - - /* Set up the return value. First, check if a context switch occurred. - * In this case, regs will no longer be the same as current_regs. In - * the case of a context switch, we will have to save the return value - * in the TCB where it can be returned later when the task is restarted. - */ - - if (regs != current_regs) - { - regs = rtcb->xcp.regs; - } - - /* Then return the result in R0 */ - - svcdbg("Return value regs: %p value: %d\n", regs, ret); - regs[REG_R0] = (uint32_t)ret; + __asm__ __volatile__ + ( + " push {r4-r6}\n" /* Save R4, R5 and R6 */ + " mov r6, r14\n" /* Save LR in R6 */ + " ldr r4, =g_stublookup\n" /* Get the base of the stub lookup table */ + " lsl r3, r0, #2\n" /* Get the offset of the stub for this syscall */ + " ldr r3, [r4, r3]\n" /* Load the entry of the stub for this syscall */ + " blx r3\n" /* Call the stub */ + " mov r14, r6\n" /* Restore R14 */ + " pop {r4-r6}\n" /* Restore R4, R5, and R6 */ + " mov r2, r0\n" /* Save the return value in R0 in R2 for now */ + " mov r0, #3\n" /* R0=SYS_syscall_return */ + " svc 0" /* Return from the syscall */ + ::: + ); } #endif @@ -309,7 +205,7 @@ int up_svcall(int irq, FAR void *context) * * At this point, the following values are saved in context: * - * R0 = 1 + * R0 = SYS_switch_context * R1 = saveregs * R2 = restoreregs * @@ -327,17 +223,81 @@ int up_svcall(int irq, FAR void *context) } break; + /* R0=SYS_syscall_return: This a switch context command: + * + * void up_sycall_return(void); + * + * At this point, the following values are saved in context: + * + * R0 = SYS_syscall_return + * + * We need to restore the saved return address and return in + * unprivileged thread mode. + */ + +#ifdef CONFIG_NUTTX_KERNEL + case SYS_syscall_return: + { + struct tcb_s *rtcb = sched_self(); + + /* Make sure that we got here from a privileged thread and + * that there is a saved syscall return address. + */ + + DEBUGASSERT(rtcb->xcp.sysreturn != NULL && + regs[REG_EXC_RETURN] == EXC_RETURN_PRIVTHR); + + /* Setup to return to the saved syscall return address in + * unprivileged mode. + */ + + current_regs[REG_PC] = rtcb->xcp.sysreturn; + current_regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR; + rtcb->sysreturn = NULL; + + /* The return value must be in R0-R1. dispatch_syscall() temporarily + * moved the value to R2. + */ + + current_regs[REG_R0] = current_regs[REG_R2]; + } + 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. */ default: + { #ifdef CONFIG_NUTTX_KERNEL - dispatch_syscall(regs); + FAR struct tcb_s *rtcb = sched_self(); + + /* Verify the the SYS call number is within range */ + + DEBUGASSERT(current_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. + */ + + DEBUGASSERT(rtcb->xcp.sysreturn == NULL && + regs[REG_EXC_RETURN] == EXC_RETURN_UNPRIVTHR); + + /* Setup to return to dispatch_syscall in privileged mode. */ + + rtcb->sysreturn = regs[REG_PC] + regs[REG_PC] = (uint32_t)dispatch_syscall; + current_regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; + + /* Offset R0 to account for the reserved values */ + + current_regs[REG_R0] -= CONFIG_SYS_RESERVED; #else - slldbg("ERROR: Bad SYS call: %d\n", regs[REG_R0]); + slldbg("ERROR: Bad SYS call: %d\n", regs[REG_R0]); #endif + } break; } diff --git a/arch/arm/src/armv7-m/svcall.h b/arch/arm/src/armv7-m/svcall.h index 6758297999..13b9935a02 100644 --- a/arch/arm/src/armv7-m/svcall.h +++ b/arch/arm/src/armv7-m/svcall.h @@ -1,7 +1,7 @@ /************************************************************************************ * arch/arm/src/armv7-m/svcall.h * - * Copyright (C) 2011 Gregory Nutt. All rights reserved. + * Copyright (C) 2011, 2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without @@ -51,15 +51,15 @@ ************************************************************************************/ /* Configuration ********************************************************************/ -/* This logic uses three system calls {0,1,2} for context switching. The first three - * syscall values must be reserved. +/* This logic uses three system calls {0,1,2} for context switching and one for the + * syscall return. The first four syscall values must be reserved. */ #ifdef CONFIG_NUTTX_KERNEL # ifndef CONFIG_SYS_RESERVED -# error "CONFIG_SYS_RESERVED must be defined to the value 3" -# elif CONFIG_SYS_RESERVED != 3 -# error "CONFIG_SYS_RESERVED must have the value 3" +# 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" # endif #endif @@ -86,6 +86,15 @@ #define SYS_switch_context (2) +#ifdef CONFIG_NUTTX_KERNEL +/* SYS call 3: + * + * void up_syscall_return(void); + */ + +#define SYS_syscall_return (3) +#endif + /************************************************************************************ * Inline Functions ************************************************************************************/ diff --git a/arch/arm/src/armv7-m/up_svcall.c b/arch/arm/src/armv7-m/up_svcall.c index 9fa5a0b821..48ab00ebaa 100644 --- a/arch/arm/src/armv7-m/up_svcall.c +++ b/arch/arm/src/armv7-m/up_svcall.c @@ -52,6 +52,8 @@ #endif #include "svcall.h" +#include "exc_return.h" +#include "os_internal.h" #include "up_internal.h" /**************************************************************************** @@ -59,29 +61,15 @@ ****************************************************************************/ /* Configuration ************************************************************/ -#undef SYSCALL_INTERRUPTIBLE -#if defined(CONFIG_NUTTX_KERNEL) -# if CONFIG_ARCH_INTERRUPTSTACK > 3 -# warning "CONFIG_ARCH_INTERRUPTSTACK and CONFIG_NUTTX_KERNEL are incompatible" -# warning "options as currently implemented. Interrupts will have to be disabled" -# warning "during SYScall processing to avoid un-handled nested interrupts" -# else -# define SYSCALL_INTERRUPTIBLE 1 -# endif -#endif - /* Debug ********************************************************************/ /* Debug output from this file may interfere with context switching! To get * debug output you must enabled the following in your NuttX configuration: * - * CONFIG_DEBUG and CONFIG_DEBUG_SCHED - * - * And you must explicitly define DEBUG_SVCALL below: + * CONFIG_DEBUG and CONFIG_DEBUG_SYSCALL */ -#undef DEBUG_SVCALL /* Define to debug SVCall */ -#ifdef DEBUG_SVCALL -# define svcdbg(format, arg...) slldbg(format, ##arg) +#ifdef CONFIG_DEBUG_SYSCALL +# define svcdbg(format, arg...) lldbg(format, ##arg) #else # define svcdbg(x...) #endif @@ -102,121 +90,28 @@ * Name: dispatch_syscall * * Description: - * Dispatch a system call to the appropriate handling logic. + * Call the stub function corresponding to the system call. * ****************************************************************************/ #ifdef CONFIG_NUTTX_KERNEL -static inline void dispatch_syscall(uint32_t *regs) +static void dispatch_syscall(void) naked_function; +static void dispatch_syscall(void) { - uint32_t cmd = regs[REG_R0]; - FAR struct tcb_s *rtcb = sched_self(); - uintptr_t ret = (uintptr_t)ERROR; - - /* Verify the the SYS call number is within range */ - - if (cmd < SYS_maxsyscall) - { - /* Report error and return ERROR */ - - slldbg("ERROR: Bad SYS call: %d\n", cmd); - } - else - { - /* The index into the syscall table is offset by the number of architecture- - * specific reserved entries at the beginning of the SYS call number space. - */ - - int index = cmd - CONFIG_SYS_RESERVED; - - /* Enable interrupts while the SYSCALL executes */ - -#ifdef SYSCALL_INTERRUPTIBLE - irqenable(); -#endif - - /* Call the correct stub for each SYS call, based on the number of parameters */ - - svcdbg("Calling stub%d at %p\n", index, g_stubloopkup[index].stub0); - - switch (g_stubnparms[index]) - { - /* No parameters */ - - case 0: - ret = g_stublookup[index].stub0(); - break; - - /* Number of parameters: 1 */ - - case 1: - ret = g_stublookup[index].stub1(regs[REG_R1]); - break; - - /* Number of parameters: 2 */ - - case 2: - ret = g_stublookup[index].stub2(regs[REG_R1], regs[REG_R2]); - break; - - /* Number of parameters: 3 */ - - case 3: - ret = g_stublookup[index].stub3(regs[REG_R1], regs[REG_R2], - regs[REG_R3]); - break; - - /* Number of parameters: 4 */ - - case 4: - ret = g_stublookup[index].stub4(regs[REG_R1], regs[REG_R2], - regs[REG_R3], regs[REG_R4]); - break; - - /* Number of parameters: 5 */ - - case 5: - ret = g_stublookup[index].stub5(regs[REG_R1], regs[REG_R2], - regs[REG_R3], regs[REG_R4], - regs[REG_R5]); - break; - - /* Number of parameters: 6 */ - - case 6: - ret = g_stublookup[index].stub6(regs[REG_R1], regs[REG_R2], - regs[REG_R3], regs[REG_R4], - regs[REG_R5], regs[REG_R6]); - break; - - /* Unsupported number of paramters. Report error and return ERROR */ - - default: - slldbg("ERROR: Bad SYS call %d number parameters %d\n", - cmd, g_stubnparms[index]); - break; - } - -#ifdef SYSCALL_INTERRUPTIBLE - irqdisable(); -#endif - } - - /* Set up the return value. First, check if a context switch occurred. - * In this case, regs will no longer be the same as current_regs. In - * the case of a context switch, we will have to save the return value - * in the TCB where it can be returned later when the task is restarted. - */ - - if (regs != current_regs) - { - regs = rtcb->xcp.regs; - } - - /* Then return the result in R0 */ - - svcdbg("Return value regs: %p value: %d\n", regs, ret); - regs[REG_R0] = (uint32_t)ret; + __asm__ __volatile__ + ( + " push {r4, r5}\n" /* Save R4 and R5 */ + " mov r5, r14\n" /* Save LR in R5 */ + " ldr r4, =g_stublookup\n" /* Get the base of the stub lookup table */ + " ldr r4, [r4, r0, lsl #2]\n" /* Load the entry of the stub for this syscall */ + " blx r4\n" /* Call the stub */ + " mov r14, r5\n" /* Restore R14 */ + " pop {r4, r5}\n" /* Restore R4 and R5 */ + " mov r2, r0\n" /* Save the return value in R0 in R2 for now */ + " mov r0, #3\n" /* R0=SYS_syscall_return */ + " svc 0" /* Return from the syscall */ + ::: + ); } #endif @@ -327,17 +222,81 @@ int up_svcall(int irq, FAR void *context) } break; + /* R0=SYS_syscall_return: This a switch context command: + * + * void up_sycall_return(void); + * + * At this point, the following values are saved in context: + * + * R0 = SYS_syscall_return + * + * We need to restore the saved return address and return in + * unprivileged thread mode. + */ + +#ifdef CONFIG_NUTTX_KERNEL + case SYS_syscall_return: + { + struct tcb_s *rtcb = sched_self(); + + /* Make sure that we got here from a privileged thread and + * that there is a saved syscall return address. + */ + + DEBUGASSERT(rtcb->xcp.sysreturn != NULL && + regs[REG_EXC_RETURN] == EXC_RETURN_PRIVTHR); + + /* Setup to return to the saved syscall return address in + * unprivileged mode. + */ + + current_regs[REG_PC] = rtcb->xcp.sysreturn; + current_regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR; + rtcb->sysreturn = NULL; + + /* The return value must be in R0-R1. dispatch_syscall() temporarily + * moved the value to R2. + */ + + current_regs[REG_R0] = current_regs[REG_R2]; + } + 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. */ default: + { #ifdef CONFIG_NUTTX_KERNEL - dispatch_syscall(regs); + FAR struct tcb_s *rtcb = sched_self(); + + /* Verify the the SYS call number is within range */ + + DEBUGASSERT(current_regs[REG_R0] < SYS_maxsyscall); + + /* Make sure that we got here from a unprivileged thread and that + * there is a no saved syscall return address. + */ + + DEBUGASSERT(rtcb->xcp.sysreturn == NULL && + regs[REG_EXC_RETURN] == EXC_RETURN_UNPRIVTHR); + + /* Setup to return to dispatch_syscall in privileged mode. */ + + rtcb->sysreturn = regs[REG_PC] + regs[REG_PC] = (uint32_t)dispatch_syscall; + current_regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; + + /* Offset R0 to account for the reserved values */ + + current_regs[REG_R0] -= CONFIG_SYS_RESERVED; #else - slldbg("ERROR: Bad SYS call: %d\n", regs[REG_R0]); + slldbg("ERROR: Bad SYS call: %d\n", regs[REG_R0]); #endif + } break; } diff --git a/arch/arm/src/sam3u/sam3u_userspace.c b/arch/arm/src/sam3u/sam3u_userspace.c index e59cc56190..28f45afce3 100644 --- a/arch/arm/src/sam3u/sam3u_userspace.c +++ b/arch/arm/src/sam3u/sam3u_userspace.c @@ -38,6 +38,10 @@ ****************************************************************************/ #include + +#include +#include + #include #ifdef CONFIG_NUTTX_KERNEL diff --git a/arch/mips/include/mips32/irq.h b/arch/mips/include/mips32/irq.h index 01a50029f2..22fa6c75e0 100644 --- a/arch/mips/include/mips32/irq.h +++ b/arch/mips/include/mips32/irq.h @@ -1,7 +1,7 @@ /**************************************************************************** * arch/mips/include/mips32/irq.h * - * Copyright (C) 2011 Gregory Nutt. All rights reserved. + * Copyright (C) 2011, 2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without @@ -310,11 +310,11 @@ struct xcptcontext { +#ifndef CONFIG_DISABLE_SIGNALS /* The following function pointer is non-NULL if there are pending signals * to be processed. */ -#ifndef CONFIG_DISABLE_SIGNALS void *sigdeliver; /* Actual type is sig_deliver_t */ /* These additional register save locations are used to implement the @@ -325,6 +325,12 @@ struct xcptcontext uint32_t saved_status; /* Status with interrupts disabled. */ #endif +#ifdef CONFIG_NUTTX_KERNEL + /* The following holds the return address from a system call */ + + uint32_t sysreturn; +#endif + /* Register save area */ uint32_t regs[XCPTCONTEXT_REGS]; diff --git a/arch/mips/include/mips32/syscall.h b/arch/mips/include/mips32/syscall.h index d91eed9932..349fba9bd5 100644 --- a/arch/mips/include/mips32/syscall.h +++ b/arch/mips/include/mips32/syscall.h @@ -1,7 +1,7 @@ /**************************************************************************** * arch/mips/include/mips32/syscall.h * - * Copyright (C) 2011-2012 Gregory Nutt. All rights reserved. + * Copyright (C) 2011-2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without @@ -57,15 +57,17 @@ #define SYS_syscall 0x00 /* Configuration ********************************************************************/ -/* This logic uses three system calls {0,1,2} for context switching. The first three - * syscall values must be reserved. +/* SYS call 1 and 2 are defined for internal use by the PIC32MX port (see + * arch/mips/include/mips32/syscall.h). In addition, SYS call 3 is the return from + * a SYS call in kernel mode. The first four syscall values must, therefore, be + * reserved (0 is not used). */ - + #ifdef CONFIG_NUTTX_KERNEL # ifndef CONFIG_SYS_RESERVED -# error "CONFIG_SYS_RESERVED must be defined to the value 2" -# elif CONFIG_SYS_RESERVED != 2 -# error "CONFIG_SYS_RESERVED must have the value 2" +# 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" # endif #endif @@ -148,6 +150,8 @@ /* Context switching system calls ***************************************************/ +/* SYS call 0: (not used) */ + /* SYS call 1: * * void up_fullcontextrestore(uint32_t *restoreregs) noreturn_function; @@ -166,6 +170,16 @@ #define up_switchcontext(saveregs, restoreregs) \ (void)sys_call2(SYS_switch_context, (uintptr_t)saveregs, (uintptr_t)restoreregs) +#ifdef CONFIG_NUTTX_KERNEL +/* SYS call 3: + * + * void up_syscall_return(void); + */ + +#define SYS_syscall_return (3) +#define up_syscall_return() (void)sys_call0(SYS_syscall_return) + +#endif #endif /* __ASSEMBLY__ */ /**************************************************************************** diff --git a/arch/mips/src/mips32/up_swint0.c b/arch/mips/src/mips32/up_swint0.c index fc03de58bb..068bd45abf 100644 --- a/arch/mips/src/mips32/up_swint0.c +++ b/arch/mips/src/mips32/up_swint0.c @@ -57,29 +57,15 @@ ****************************************************************************/ /* Configuration ************************************************************/ -#undef SYSCALL_INTERRUPTIBLE -#if defined(CONFIG_NUTTX_KERNEL) -# if CONFIG_ARCH_INTERRUPTSTACK > 3 -# warning "CONFIG_ARCH_INTERRUPTSTACK and CONFIG_NUTTX_KERNEL are incompatible" -# warning "options as currently implemented. Interrupts will have to be disabled" -# warning "during SYScall processing to avoid un-handled nested interrupts" -# else -# define SYSCALL_INTERRUPTIBLE 1 -# endif -#endif - /* Debug ********************************************************************/ /* Debug output from this file may interfere with context switching! To get * debug output you must enabled the following in your NuttX configuration: * - * CONFIG_DEBUG and CONFIG_DEBUG_SCHED - * - * And you must explicitly define DEBUG_SWINT0 below: + * CONFIG_DEBUG and CONFIG_DEBUG_SYSCALL */ -#undef DEBUG_SWINT0 /* Define to debug SWInt */ -#ifdef DEBUG_SWINT0 -# define swidbg(format, arg...) slldbg(format, ##arg) +#ifdef CONFIG_DEBUG_SYSCALL +# define swidbg(format, arg...) lldbg(format, ##arg) #else # define swidbg(x...) #endif @@ -100,7 +86,7 @@ * Name: up_registerdump ****************************************************************************/ -#ifdef DEBUG_SWINT0 +#ifdef CONFIG_DEBUG_SYSCALL static void up_registerdump(const uint32_t *regs) { swidbg("MFLO:%08x MFHI:%08x EPC:%08x STATUS:%08x\n", @@ -132,125 +118,27 @@ static void up_registerdump(const uint32_t *regs) * Name: dispatch_syscall * * Description: - * Dispatch a system call to the appropriate handling logic. + * Call the stub function corresponding to the system call. * ****************************************************************************/ #ifdef CONFIG_NUTTX_KERNEL -static inline void dispatch_syscall(uint32_t *regs) +static void dispatch_syscall(void) naked_function; +static void dispatch_syscall(void) { - uint32_t cmd = regs[REG_A0]; - FAR struct tcb_s *rtcb = sched_self(); - uintptr_t ret = (uintptr_t)ERROR; +# error "Missing logic" - /* Verify the the SYS call number is within range */ - - if (cmd < SYS_maxsyscall) - { - /* Report error and return ERROR */ - - slldbg("ERROR: Bad SYS call: %d\n", cmd); - } - else - { - /* The index into the syscall table is offset by the number of - * architecture-specific reserved entries at the beginning of the - * SYS call number space. - */ - - int index = cmd - CONFIG_SYS_RESERVED; - - /* Enable interrupts while the SYSCALL executes */ - -#ifdef SYSCALL_INTERRUPTIBLE - irqenable(); -#endif - - /* Call the correct stub for each SYS call, based on the number of - * parameters: $5=parm1, $6=parm2, $7=parm3, $8=parm4, $9=parm5, and - * $10=parm6. - */ - - swidbg("Calling stub%d at %p\n", index, g_stubloopkup[index].stub0); - - switch (g_stubnparms[index]) - { - /* No parameters */ - - case 0: - ret = g_stublookup[index].stub0(); - break; - - /* Number of parameters: 1 */ - - case 1: - ret = g_stublookup[index].stub1(regs[REG_A1]); - break; - - /* Number of parameters: 2 */ - - case 2: - ret = g_stublookup[index].stub2(regs[REG_A1], regs[REG_A2]); - break; - - /* Number of parameters: 3 */ - - case 3: - ret = g_stublookup[index].stub3(regs[REG_A1], regs[REG_A2], - regs[REG_A3]); - break; - - /* Number of parameters: 4 */ - - case 4: - ret = g_stublookup[index].stub4(regs[REG_A1], regs[REG_A2], - regs[REG_A3], regs[REG_T0]); - break; - - /* Number of parameters: 5 */ - - case 5: - ret = g_stublookup[index].stub5(regs[REG_A1], regs[REG_A2], - regs[REG_A3], regs[REG_T0], - regs[REG_T1]); - break; - - /* Number of parameters: 6 */ - - case 6: - ret = g_stublookup[index].stub6(regs[REG_A1], regs[REG_A2], - regs[REG_A3], regs[REG_T0], - regs[REG_T1], regs[REG_T2]); - break; - - /* Unsupported number of paramters. Report error and return ERROR */ - - default: - slldbg("ERROR: Bad SYS call %d number parameters %d\n", - cmd, g_stubnparms[index]); - break; - } - -#ifdef SYSCALL_INTERRUPTIBLE - irqdisable(); -#endif - } - - /* Set up the return vaue. First, check if a context switch occurred. - * In this case, regs will no longer be the same as current_regs. In - * the case of a context switch, we will have to save the return value - * in the TCB where it can be returned later when the task is restarted. - */ - - if (regs != current_regs) - { - regs = rtcb->xcp.regs; - } - - /* Then return the result in v0 */ - - swidbg("Return value regs: %p value: %d\n", regs, ret); - regs[REG_v0] = (uint32_t)ret; +/* Refer to arch/arm/src/armv7-m/up_svcall.h for how this is done for ARM */ +/* __asm__ __volatile__ */ +/* ( +/* Save registers */ +/* Get the base of the stub lookup table */ +/* Get the offset of the stub for this syscall */ +/* Load the entry of the stub for this syscall */ +/* Call the stub */ +/* Restore regsisters */ +/* Return from the syscall */ +/* ); */ } #endif @@ -279,7 +167,7 @@ int up_swint0(int irq, FAR void *context) * arguments depending on the system call. */ -#ifdef DEBUG_SWINT0 +#ifdef CONFIG_DEBUG_SYSCALL swidbg("Entry: regs: %p cmd: %d\n", regs, regs[REG_R4]); up_registerdump(regs); #endif @@ -334,23 +222,81 @@ int up_swint0(int irq, FAR void *context) } break; + /* R0=SYS_syscall_return: This a switch context command: + * + * void up_sycall_return(void); + * + * At this point, the following values are saved in context: + * + * R0 = SYS_syscall_return + * + * We need to restore the saved return address and return in + * unprivileged thread mode. + */ + +#ifdef CONFIG_NUTTX_KERNEL + case SYS_syscall_return: + { + struct tcb_s *rtcb = sched_self(); + + /* Make sure that we got here from a privileged thread and + * that there is a saved syscall return address. + */ + +#error "Missing logic -- need to test for privileged mode" + DEBUGASSERT(rtcb->xcp.sysreturn != NULL && ???); + + /* Setup to return to the saved syscall return address in + * unprivileged mode. + */ + + current_regs[REG_EPC] = rtcb->xcp.sysreturn; +#error "Missing logic -- need to set for unprivileged mode" + rtcb->sysreturn = NULL; + } + break; +#endif + /* This is not an architecture-specify 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. */ default: + { #ifdef CONFIG_NUTTX_KERNEL - dispatch_syscall(regs); + FAR struct tcb_s *rtcb = sched_self(); + + /* Verify the the SYS call number is within range */ + + DEBUGASSERT(current_regs[REG_A0] < SYS_maxsyscall); + + /* Make sure that we got here from an unprivileged thread and that + * there is a no saved syscall return address. + */ + +#error "Missing logic -- Need to set unprivileged mode" + DEBUGASSERT(rtcb->xcp.sysreturn == NULL && ???); + + /* Setup to return to dispatch_syscall in privileged mode. */ + + rtcb->sysreturn = regs[REG_EPC] + regs[REG_EPC] = (uint32_t)dispatch_syscall; +#error "Missing logic -- Need to set privileged mode" + + /* Offset R0 to account for the reserved values */ + + current_regs[REG_R0] -= CONFIG_SYS_RESERVED; #else - slldbg("ERROR: Bad SYS call: %d\n", regs[REG_A0]); + slldbg("ERROR: Bad SYS call: %d\n", regs[REG_A0]); #endif + } break; } /* Report what happened. That might difficult in the case of a context switch */ -#ifdef DEBUG_SWINT0 +#ifdef CONFIG_DEBUG_SYSCALL if (regs != current_regs) { swidbg("SWInt Return: Context switch!\n"); diff --git a/arch/mips/src/pic32mx/pic32mx-config.h b/arch/mips/src/pic32mx/pic32mx-config.h index 4dd0a150e6..d64caf5fba 100644 --- a/arch/mips/src/pic32mx/pic32mx-config.h +++ b/arch/mips/src/pic32mx/pic32mx-config.h @@ -1,7 +1,7 @@ /************************************************************************************ * arch/mips/src/pic32mx/pic32mx-config.h * - * Copyright (C) 2011-2012 Gregory Nutt. All rights reserved. + * Copyright (C) 2011-2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without @@ -485,15 +485,17 @@ #endif /* SYS calls ************************************************************************/ -/* SYS call 0 and 1 are defined for internal use by the PIC32MX port (see - * arch/mips/include/mips32/syscall.h +/* SYS call 1 and 2 are defined for internal use by the PIC32MX port (see + * arch/mips/include/mips32/syscall.h). In addition, SYS call 3 is the return from + * a SYS call in kernel mode. The first four syscall values must, therefore, be + * reserved (0 is not used). */ #ifdef CONFIG_NUTTX_KERNEL -# if !defined(CONFIG_SYS_RESERVED) || CONFIG_SYS_RESERVED < 2 -# error "CONFIG_SYS_RESERVED must be defined to be 2 for a kernel build" -# elif CONFIG_SYS_RESERVED > 2 -# warning "CONFIG_SYS_RESERVED should be defined to be 2 for a kernel build" +# if !defined(CONFIG_SYS_RESERVED) || CONFIG_SYS_RESERVED < 4 +# error "CONFIG_SYS_RESERVED must be defined to be 4 for a kernel build" +# elif CONFIG_SYS_RESERVED > 4 +# warning "CONFIG_SYS_RESERVED should be defined to be 4 for a kernel build" # endif #endif