From b110c984b1aa4796d93102e000ba32f50b9c7414 Mon Sep 17 00:00:00 2001 From: "chao.an" Date: Tue, 19 Apr 2022 12:33:27 +0800 Subject: [PATCH] arch/armv7-[a|r]: correct the handing of group env switch This PR resolved 2 issues: 1. CURRENT_REGS is not set correctly on swint handling 2. group env is not changed properly Signed-off-by: chao.an --- arch/arm/src/arm/arm_syscall.c | 48 ++++++++++++++++++++++++++---- arch/arm/src/armv7-a/arm_syscall.c | 46 ++++++++++++++++++++++++---- arch/arm/src/armv7-r/arm_syscall.c | 25 ++++++++++++---- 3 files changed, 103 insertions(+), 16 deletions(-) diff --git a/arch/arm/src/arm/arm_syscall.c b/arch/arm/src/arm/arm_syscall.c index 06687dfd49..d12cf751fc 100644 --- a/arch/arm/src/arm/arm_syscall.c +++ b/arch/arm/src/arm/arm_syscall.c @@ -32,6 +32,7 @@ #include #include "arm_internal.h" +#include "group/group.h" /**************************************************************************** * Public Functions @@ -54,10 +55,22 @@ uint32_t *arm_syscall(uint32_t *regs) { uint32_t cmd; - DEBUGASSERT(regs); + /* Nested interrupts are not supported */ + + DEBUGASSERT(CURRENT_REGS == NULL); + + /* Current regs non-zero indicates that we are processing an interrupt; + * CURRENT_REGS is also used to manage interrupt level context switches. + */ + + CURRENT_REGS = regs; + + /* The SYSCALL command is in R0 on entry. Parameters follow in R1..R7 */ cmd = regs[REG_R0]; + /* Handle the SVCall according to the command in R0 */ + switch (cmd) { /* R0=SYS_restore_context: Restore task context @@ -78,8 +91,8 @@ uint32_t *arm_syscall(uint32_t *regs) * set will determine the restored context. */ - regs = (uint32_t *)regs[REG_R1]; - DEBUGASSERT(regs); + CURRENT_REGS = (uint32_t *)regs[REG_R1]; + DEBUGASSERT(CURRENT_REGS); } break; @@ -104,7 +117,7 @@ uint32_t *arm_syscall(uint32_t *regs) { DEBUGASSERT(regs[REG_R1] != 0 && regs[REG_R2] != 0); *(uint32_t **)regs[REG_R1] = regs; - regs = (uint32_t *)regs[REG_R2]; + CURRENT_REGS = (uint32_t *)regs[REG_R2]; } break; @@ -112,12 +125,37 @@ uint32_t *arm_syscall(uint32_t *regs) { svcerr("ERROR: Bad SYS call: 0x%" PRIx32 "\n", regs[REG_R0]); _alert("Syscall from 0x%" PRIx32 "\n", regs[REG_PC]); - CURRENT_REGS = regs; PANIC(); } break; } +#ifdef CONFIG_ARCH_ADDRENV + /* Check for a context switch. If a context switch occurred, then + * CURRENT_REGS will have a different value than it did on entry. If an + * interrupt level context switch has occurred, then establish the correct + * address environment before returning from the interrupt. + */ + + if (regs != CURRENT_REGS) + { + /* Make sure that the address environment for the previously + * running task is closed down gracefully (data caches dump, + * MMU flushed) and set up the address environment for the new + * thread at the head of the ready-to-run list. + */ + + group_addrenv(NULL); + } +#endif + + /* Set CURRENT_REGS to NULL to indicate that we are no longer in an + * interrupt handler. + */ + + regs = (uint32_t *)CURRENT_REGS; + CURRENT_REGS = NULL; + /* Return the last value of curent_regs. This supports context switches * on return from the exception. That capability is only used with the * SYS_context_switch system call. diff --git a/arch/arm/src/armv7-a/arm_syscall.c b/arch/arm/src/armv7-a/arm_syscall.c index 4e0b07bef3..b621d6044f 100644 --- a/arch/arm/src/armv7-a/arm_syscall.c +++ b/arch/arm/src/armv7-a/arm_syscall.c @@ -35,10 +35,11 @@ #include #include -#include "signal/signal.h" -#include "arm.h" #include "addrenv.h" +#include "arm.h" #include "arm_internal.h" +#include "group/group.h" +#include "signal/signal.h" /**************************************************************************** * Private Functions @@ -165,7 +166,13 @@ uint32_t *arm_syscall(uint32_t *regs) /* Nested interrupts are not supported */ - DEBUGASSERT(regs); + DEBUGASSERT(CURRENT_REGS == NULL); + + /* Current regs non-zero indicates that we are processing an interrupt; + * CURRENT_REGS is also used to manage interrupt level context switches. + */ + + CURRENT_REGS = regs; /* The SYSCALL command is in R0 on entry. Parameters follow in R1..R7 */ @@ -262,8 +269,8 @@ uint32_t *arm_syscall(uint32_t *regs) * set will determine the restored context. */ - regs = (uint32_t *)regs[REG_R1]; - DEBUGASSERT(regs); + CURRENT_REGS = (uint32_t *)regs[REG_R1]; + DEBUGASSERT(CURRENT_REGS); } break; @@ -288,7 +295,7 @@ uint32_t *arm_syscall(uint32_t *regs) { DEBUGASSERT(regs[REG_R1] != 0 && regs[REG_R2] != 0); *(uint32_t **)regs[REG_R1] = regs; - regs = (uint32_t *)regs[REG_R2]; + CURRENT_REGS = (uint32_t *)regs[REG_R2]; } break; @@ -529,10 +536,37 @@ uint32_t *arm_syscall(uint32_t *regs) break; } +#ifdef CONFIG_ARCH_ADDRENV + /* Check for a context switch. If a context switch occurred, then + * CURRENT_REGS will have a different value than it did on entry. If an + * interrupt level context switch has occurred, then establish the correct + * address environment before returning from the interrupt. + */ + + if (regs != CURRENT_REGS) + { + /* Make sure that the address environment for the previously + * running task is closed down gracefully (data caches dump, + * MMU flushed) and set up the address environment for the new + * thread at the head of the ready-to-run list. + */ + + group_addrenv(NULL); + } +#endif + + regs = (uint32_t *)CURRENT_REGS; + /* Report what happened */ dump_syscall("Exit", cmd, regs); + /* Set CURRENT_REGS to NULL to indicate that we are no longer in an + * interrupt handler. + */ + + CURRENT_REGS = NULL; + /* Return the last value of curent_regs. This supports context switches * on return from the exception. That capability is only used with the * SYS_context_switch system call. diff --git a/arch/arm/src/armv7-r/arm_syscall.c b/arch/arm/src/armv7-r/arm_syscall.c index 8b76ce65d2..8283583ca8 100644 --- a/arch/arm/src/armv7-r/arm_syscall.c +++ b/arch/arm/src/armv7-r/arm_syscall.c @@ -33,9 +33,10 @@ #include #include -#include "signal/signal.h" +#include "addrenv.h" #include "arm.h" #include "arm_internal.h" +#include "signal/signal.h" /**************************************************************************** * Private Functions @@ -162,7 +163,13 @@ uint32_t *arm_syscall(uint32_t *regs) /* Nested interrupts are not supported */ - DEBUGASSERT(regs); + DEBUGASSERT(CURRENT_REGS == NULL); + + /* Current regs non-zero indicates that we are processing an interrupt; + * CURRENT_REGS is also used to manage interrupt level context switches. + */ + + CURRENT_REGS = regs; /* The SYSCALL command is in R0 on entry. Parameters follow in R1..R7 */ @@ -259,8 +266,8 @@ uint32_t *arm_syscall(uint32_t *regs) * set will determine the restored context. */ - regs = (uint32_t *)regs[REG_R1]; - DEBUGASSERT(regs); + CURRENT_REGS = (uint32_t *)regs[REG_R1]; + DEBUGASSERT(CURRENT_REGS); } break; @@ -285,7 +292,7 @@ uint32_t *arm_syscall(uint32_t *regs) { DEBUGASSERT(regs[REG_R1] != 0 && regs[REG_R2] != 0); *(uint32_t **)regs[REG_R1] = regs; - regs = (uint32_t *)regs[REG_R2]; + CURRENT_REGS = (uint32_t *)regs[REG_R2]; } break; @@ -526,10 +533,18 @@ uint32_t *arm_syscall(uint32_t *regs) break; } + regs = (uint32_t *)CURRENT_REGS; + /* Report what happened */ dump_syscall("Exit", cmd, regs); + /* Set CURRENT_REGS to NULL to indicate that we are no longer in an + * interrupt handler. + */ + + CURRENT_REGS = NULL; + /* Return the last value of curent_regs. This supports context switches * on return from the exception. That capability is only used with the * SYS_context_switch system call.