From 931ffab0783e9e073e66f78a2577483bc2ef8e45 Mon Sep 17 00:00:00 2001 From: Gregory Nutt Date: Thu, 11 Sep 2014 18:43:30 -0600 Subject: Fix logic for returning from exceptions to user-mode contexts --- nuttx/arch/arm/src/armv7-a/arm_syscall.c | 11 +++- nuttx/arch/arm/src/armv7-a/arm_vectors.S | 92 +++++++++++++++++++------------- 2 files changed, 65 insertions(+), 38 deletions(-) diff --git a/nuttx/arch/arm/src/armv7-a/arm_syscall.c b/nuttx/arch/arm/src/armv7-a/arm_syscall.c index a312d9636..eeb8c1fdd 100644 --- a/nuttx/arch/arm/src/armv7-a/arm_syscall.c +++ b/nuttx/arch/arm/src/armv7-a/arm_syscall.c @@ -414,9 +414,18 @@ uint32_t *arm_syscall(uint32_t *regs) break; } +#if defined(CONFIG_DEBUG_SYSCALL) /* Report what happened */ - svcdbg("SYSCALL Return: %d \n", regs[REG_R0]); + svcdbg("SYSCALL Exit: regs: %p: %d\n", regs); + svcdbg(" R0: %08x %08x %08x %08x %08x %08x %08x %08x\n", + regs[REG_R0], regs[REG_R1], regs[REG_R2], regs[REG_R3], + regs[REG_R4], regs[REG_R5], regs[REG_R6], regs[REG_R7]); + svcdbg(" R8: %08x %08x %08x %08x %08x %08x %08x %08x\n", + regs[REG_R8], regs[REG_R9], regs[REG_R10], regs[REG_R11], + regs[REG_R12], regs[REG_R13], regs[REG_R14], regs[REG_R15]); + svcdbg("CPSR: %08x\n", regs[REG_CPSR]); +#endif /* Return the last value of curent_regs. This supports context switchs * on return from the exception. That capability is not used here, diff --git a/nuttx/arch/arm/src/armv7-a/arm_vectors.S b/nuttx/arch/arm/src/armv7-a/arm_vectors.S index a8a9f38ca..f272460d2 100644 --- a/nuttx/arch/arm/src/armv7-a/arm_vectors.S +++ b/nuttx/arch/arm/src/armv7-a/arm_vectors.S @@ -201,11 +201,11 @@ arm_vectorirq: /* Restore the CPSR, SVC mode registers and return */ - ldr r1, [r0, #(4*REG_CPSR)] /* Setup the return SPSR */ - msr spsr, r1 /* Establish the return mode SPSR */ + ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the return SPSR */ + msr spsr, r1 /* Set the return mode SPSR */ #ifdef CONFIG_BUILD_KERNEL - /* Did we enter from user mode? If so then we need to restore the + /* Are we leaving in user mode? If so then we need to restore the * values of USER mode r13(sp) and r14(lr). */ @@ -217,9 +217,12 @@ arm_vectorirq: * is not in the register list). */ - add r1, r0, #(4*REG_R13) /* R1=address of R13/R14 storage */ - ldmia r1, {r13, r14}^ /* Restore to user mode USER R13/R14 */ - ldmia r0, {r0-R12,r15}^ /* Return */ + mov r13, r0 /* (SVC) R13=Register storage area */ + ldmia r13, {r0-R12} /* Restore common R0-R12 */ + add r14, r13, #(4*REG_R13) /* (SVC) R14=address of R13/R14 storage */ + ldmia r14, {r13, r14}^ /* Restore user mode R13/R14 */ + add r14, r13, #(4*REG_R15) /* (SVC) R14=address of R15 storage */ + ldmia r14, {r15}^ /* Return */ .Lirqleavesvc: #endif @@ -327,11 +330,11 @@ arm_vectorsvc: /* Restore the CPSR, SVC mode registers and return */ - ldr r1, [r0, #(4*REG_CPSR)] /* Setup the SVC mode SPSR */ - msr spsr, r1 /* Establish the return mode SPSR */ + ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the return SPSR */ + msr spsr, r1 /* Set the return mode SPSR */ #ifdef CONFIG_BUILD_KERNEL - /* Did we enter from user mode? If so then we need to restore the + /* Are we leaving in user mode? If so then we need to restore the * values of USER mode r13(sp) and r14(lr). */ @@ -343,9 +346,12 @@ arm_vectorsvc: * is not in the register list). */ - add r1, r0, #(4*REG_R13) /* R1=address of R13/R14 storage */ - ldmia r1, {r13, r14}^ /* Restore to user mode USER R13/R14 */ - ldmia r0, {r0-R12,r15}^ /* Return */ + mov r13, r0 /* (SVC) R13=Register storage area */ + ldmia r13, {r0-R12} /* Restore common R0-R12 */ + add r14, r13, #(4*REG_R13) /* (SVC) R14=address of R13/R14 storage */ + ldmia r14, {r13, r14}^ /* Restore user mode R13/R14 */ + add r14, r13, #(4*REG_R15) /* (SVC) R14=address of R15 storage */ + ldmia r14, {r15}^ /* Return */ .Lleavesvcsvc: #endif @@ -468,11 +474,11 @@ arm_vectordata: /* Restore the CPSR, SVC mode registers and return */ - ldr r1, [r0, #(4*REG_CPSR)] /* Setup the SVC mode SPSR */ - msr spsr_cxsf, r1 /* Establish the return mode SPSR */ + ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the return SPSR */ + msr spsr_cxsf, r1 /* Set the return mode SPSR */ #ifdef CONFIG_BUILD_KERNEL - /* Did we enter from user mode? If so then we need to restore the + /* Are we leaving in user mode? If so then we need to restore the * values of USER mode r13(sp) and r14(lr). */ @@ -484,9 +490,12 @@ arm_vectordata: * is not in the register list). */ - add r1, r0, #(4*REG_R13) /* R1=address of R13/R14 storage */ - ldmia r1, {r13, r14}^ /* Restore to user mode USER R13/R14 */ - ldmia r0, {r0-R12,r15}^ /* Return */ + mov r13, r0 /* (SVC) R13=Register storage area */ + ldmia r13, {r0-R12} /* Restore common R0-R12 */ + add r14, r13, #(4*REG_R13) /* (SVC) R14=address of R13/R14 storage */ + ldmia r14, {r13, r14}^ /* Restore user mode R13/R14 */ + add r14, r13, #(4*REG_R15) /* (SVC) R14=address of R15 storage */ + ldmia r14, {r15}^ /* Return */ .Ldabtleavesvc: #endif @@ -611,11 +620,11 @@ arm_vectorprefetch: /* Restore the CPSR, SVC mode registers and return */ - ldr r1, [r0, #(4*REG_CPSR)] /* Setup the SVC mode SPSR */ - msr spsr_cxsf, r1 /* Establish the return mode SPSR */ + ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the return SPSR */ + msr spsr_cxsf, r1 /* Set the return mode SPSR */ #ifdef CONFIG_BUILD_KERNEL - /* Did we enter from user mode? If so then we need to restore the + /* Are we leaving in user mode? If so then we need to restore the * values of USER mode r13(sp) and r14(lr). */ @@ -627,9 +636,12 @@ arm_vectorprefetch: * is not in the register list). */ - add r1, r0, #(4*REG_R13) /* R1=address of R13/R14 storage */ - ldmia r1, {r13, r14}^ /* Restore to user mode USER R13/R14 */ - ldmia r0, {r0-R12,r15}^ /* Return */ + mov r13, r0 /* (SVC) R13=Register storage area */ + ldmia r13, {r0-R12} /* Restore common R0-R12 */ + add r14, r13, #(4*REG_R13) /* (SVC) R14=address of R13/R14 storage */ + ldmia r14, {r13, r14}^ /* Restore user mode R13/R14 */ + add r14, r13, #(4*REG_R15) /* (SVC) R14=address of R15 storage */ + ldmia r14, {r15}^ /* Return */ .Lpabtleavesvc: #endif @@ -749,11 +761,11 @@ arm_vectorundefinsn: /* Restore the CPSR, SVC mode registers and return */ - ldr r1, [r0, #(4*REG_CPSR)] /* Setup the SVC mode SPSR */ - msr spsr_cxsf, r1 /* Establish the return mode SPSR */ + ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the return SPSR */ + msr spsr_cxsf, r1 /* Set the return mode SPSR */ #ifdef CONFIG_BUILD_KERNEL - /* Did we enter from user mode? If so then we need to restore the + /* Are we leaving in user mode? If so then we need to restore the * values of USER mode r13(sp) and r14(lr). */ @@ -765,9 +777,12 @@ arm_vectorundefinsn: * is not in the register list). */ - add r1, r0, #(4*REG_R13) /* R1=address of R13/R14 storage */ - ldmia r1, {r13, r14}^ /* Restore to user mode USER R13/R14 */ - ldmia r0, {r0-R12,r15}^ /* Return */ + mov r13, r0 /* (SVC) R13=Register storage area */ + ldmia r13, {r0-R12} /* Restore common R0-R12 */ + add r14, r13, #(4*REG_R13) /* (SVC) R14=address of R13/R14 storage */ + ldmia r14, {r13, r14}^ /* Restore user mode R13/R14 */ + add r14, r13, #(4*REG_R15) /* (SVC) R14=address of R15 storage */ + ldmia r14, {r15}^ /* Return */ .Lundefleavesvc: #endif @@ -826,7 +841,7 @@ arm_vectorfiq: #ifdef CONFIG_BUILD_KERNEL /* Did we enter from user mode? If so then we need get the values of - * USER mode r13(sp) and r14(lr). + * USER mode rr13(sp) and r14(lr). */ and r1, r4, #PSR_MODE_MASK /* Interrupted mode */ @@ -897,11 +912,11 @@ arm_vectorfiq: /* Restore the CPSR, SVC mode registers and return */ - ldr r1, [r0, #(4*REG_CPSR)] /* Setup the SVC mode SPSR */ - msr spsr, r1 /* Establish the return mode SPSR */ + ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the return SPSR */ + msr spsr, r1 /* Set the return mode SPSR */ #ifdef CONFIG_BUILD_KERNEL - /* Did we enter from user mode? If so then we need to restore the + /* Are we leaving in user mode? If so then we need to restore the * values of USER mode r13(sp) and r14(lr). */ @@ -913,9 +928,12 @@ arm_vectorfiq: * is not in the register list). */ - add r1, r0, #(4*REG_R13) /* R1=address of R13/R14 storage */ - ldmia r1, {r13, r14}^ /* Restore to user mode USER R13/R14 */ - ldmia r0, {r0-R12,r15}^ /* Return */ + mov r13, r0 /* (SVC) R13=Register storage area */ + ldmia r13, {r0-R12} /* Restore common R0-R12 */ + add r14, r13, #(4*REG_R13) /* (SVC) R14=address of R13/R14 storage */ + ldmia r14, {r13, r14}^ /* Restore user mode R13/R14 */ + add r14, r13, #(4*REG_R15) /* (SVC) R14=address of R15 storage */ + ldmia r14, {r15}^ /* Return */ .Lfiqleavesvc: #endif -- cgit v1.2.3