Add the exception and interrupt handling machanism for basic kvx
support.
Co-developed-by: Clement Leger <clem...@clement-leger.fr>
Signed-off-by: Clement Leger <clem...@clement-leger.fr>
Co-developed-by: Guillaume Thouvenin <gthouve...@kalray.eu>
Signed-off-by: Guillaume Thouvenin <gthouve...@kalray.eu>
Co-developed-by: Julian Vetter <jvet...@kalray.eu>
Signed-off-by: Julian Vetter <jvet...@kalray.eu>
Co-developed-by: Luc Michel <lmic...@kalray.eu>
Signed-off-by: Luc Michel <lmic...@kalray.eu>
Co-developed-by: Marius Gligor <mgli...@kalray.eu>
Signed-off-by: Marius Gligor <mgli...@kalray.eu>
Co-developed-by: Yann Sionneau <ysionn...@kalray.eu>
Signed-off-by: Yann Sionneau <ysionn...@kalray.eu>
---
Notes:
V1 -> V2:
- removed ipi.h headers and driver (moved into ipi driver patch)
arch/kvx/include/asm/break_hook.h | 69 +++++++++
arch/kvx/include/asm/bug.h | 67 ++++++++
arch/kvx/include/asm/dame.h | 31 ++++
arch/kvx/include/asm/hardirq.h | 14 ++
arch/kvx/include/asm/hw_irq.h | 14 ++
arch/kvx/include/asm/irqflags.h | 58 +++++++
arch/kvx/include/asm/stacktrace.h | 44 ++++++
arch/kvx/include/asm/traps.h | 76 ++++++++++
arch/kvx/kernel/dame_handler.c | 113 ++++++++++++++
arch/kvx/kernel/irq.c | 78 ++++++++++
arch/kvx/kernel/traps.c | 243 ++++++++++++++++++++++++++++++
11 files changed, 807 insertions(+)
create mode 100644 arch/kvx/include/asm/break_hook.h
create mode 100644 arch/kvx/include/asm/bug.h
create mode 100644 arch/kvx/include/asm/dame.h
create mode 100644 arch/kvx/include/asm/hardirq.h
create mode 100644 arch/kvx/include/asm/hw_irq.h
create mode 100644 arch/kvx/include/asm/irqflags.h
create mode 100644 arch/kvx/include/asm/stacktrace.h
create mode 100644 arch/kvx/include/asm/traps.h
create mode 100644 arch/kvx/kernel/dame_handler.c
create mode 100644 arch/kvx/kernel/irq.c
create mode 100644 arch/kvx/kernel/traps.c
diff --git a/arch/kvx/include/asm/break_hook.h
b/arch/kvx/include/asm/break_hook.h
new file mode 100644
index 000000000000..333b2c440c81
--- /dev/null
+++ b/arch/kvx/include/asm/break_hook.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#ifndef __ASM_KVX_BREAK_HOOK_H_
+#define __ASM_KVX_BREAK_HOOK_H_
+
+#include <linux/types.h>
+
+#include <asm/sfr_defs.h>
+#include <asm/insns_defs.h>
+
+/*
+ * The following macros define the different causes of break:
+ * We use the `set $vsfr0 = $rXX` instruction which will raise a trap into the
+ * debugger. The trapping instruction is read and decoded to extract the source
+ * register number. The source register number is used to differentiate the
+ * trap cause.
+ */
+#define BREAK_CAUSE_BUG KVX_REG_R1
+#define BREAK_CAUSE_KGDB_DYN KVX_REG_R2
+#define BREAK_CAUSE_KGDB_COMP KVX_REG_R3
+#define BREAK_CAUSE_BKPT KVX_REG_R63
+
+/**
+ * enum break_ret - Break return value
+ * @BREAK_HOOK_HANDLED: Hook handled successfully
+ * @BREAK_HOOK_ERROR: Hook was not handled
+ */
+enum break_ret {
+ BREAK_HOOK_HANDLED = 0,
+ BREAK_HOOK_ERROR = 1,
+};
+
+/*
+ * The following macro assembles a `set` instruction targeting $vsfr0
+ * using the source register whose number is __id.
+ */
+#define KVX_BREAK_INSN(__id) \
+ KVX_INSN_SET_SYLLABLE_0(KVX_INSN_PARALLEL_EOB, KVX_SFR_VSFR0, __id)
+
+#define KVX_BREAK_INSN_SIZE (KVX_INSN_SET_SIZE * KVX_INSN_SYLLABLE_WIDTH)
+
+struct pt_regs;
+
+/**
+ * struct break_hook - Break hook description
+ * @node: List node
+ * @handler: handler called when break matches this hook
+ * @imm: Immediate value expected for break insn
+ * @mode: Hook mode (user/kernel)
+ */
+struct break_hook {
+ struct list_head node;
+ int (*handler)(struct break_hook *brk_hook, struct pt_regs *regs);
+ u8 id;
+ u8 mode;
+};
+
+void kvx_skip_break_insn(struct pt_regs *regs);
+
+void break_hook_register(struct break_hook *brk_hook);
+void break_hook_unregister(struct break_hook *brk_hook);
+
+int break_hook_handler(u64 es, struct pt_regs *regs);
+
+#endif /* __ASM_KVX_BREAK_HOOK_H_ */
diff --git a/arch/kvx/include/asm/bug.h b/arch/kvx/include/asm/bug.h
new file mode 100644
index 000000000000..62f556b00d5a
--- /dev/null
+++ b/arch/kvx/include/asm/bug.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#ifndef _ASM_KVX_BUG_H
+#define _ASM_KVX_BUG_H
+
+#include <linux/compiler.h>
+#include <linux/const.h>
+#include <linux/types.h>
+
+#include <asm/break_hook.h>
+
+#ifdef CONFIG_GENERIC_BUG
+
+#define BUG_INSN KVX_BREAK_INSN(BREAK_CAUSE_BUG)
+
+#define __BUG_ENTRY_ADDR ".dword 1b"
+
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+#define __BUG_ENTRY_LAST_MEMBER flags
+#define __BUG_ENTRY \
+ __BUG_ENTRY_ADDR "\n\t" \
+ ".dword %0\n\t" \
+ ".short %1\n\t"
+#else
+#define __BUG_ENTRY_LAST_MEMBER file
+#define __BUG_ENTRY \
+ __BUG_ENTRY_ADDR "\n\t"
+#endif
+
+#define BUG() \
+do { \
+ __asm__ __volatile__ ( \
+ "1:\n\t" \
+ ".word " __stringify(BUG_INSN) "\n" \
+ ".pushsection __bug_table,\"a\"\n\t" \
+ "2:\n\t" \
+ __BUG_ENTRY \
+ ".fill 1, %2, 0\n\t" \
+ ".popsection" \
+ : \
+ : "i" (__FILE__), "i" (__LINE__), \
+ "i" (sizeof(struct bug_entry) - \
+ offsetof(struct bug_entry, __BUG_ENTRY_LAST_MEMBER))); \
+ unreachable(); \
+} while (0)
+
+#else /* CONFIG_GENERIC_BUG */
+#define BUG() \
+do { \
+ __asm__ __volatile__ (".word " __stringify(BUG_INSN) "\n"); \
+ unreachable(); \
+} while (0)
+#endif /* CONFIG_GENERIC_BUG */
+
+#define HAVE_ARCH_BUG
+
+struct pt_regs;
+
+void die(struct pt_regs *regs, unsigned long ea, const char *str);
+
+#include <asm-generic/bug.h>
+
+#endif /* _ASM_KVX_BUG_H */
diff --git a/arch/kvx/include/asm/dame.h b/arch/kvx/include/asm/dame.h
new file mode 100644
index 000000000000..8befd767bbee
--- /dev/null
+++ b/arch/kvx/include/asm/dame.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#ifndef _ASM_KVX_DAME_H
+#define _ASM_KVX_DAME_H
+
+#include <asm/sfr.h>
+#include <asm/ptrace.h>
+
+static inline void dame_irq_check(struct pt_regs *regs)
+{
+#ifdef CONFIG_SECURE_DAME_HANDLING
+ unsigned long ilr;
+ /* If we are returning to the kernel, no need to check for DAME */
+ if (!user_mode(regs))
+ return;
+
+ /* Else, make sure we do a barrier to trig any pending DAME IRQ */
+ __builtin_kvx_barrier();
+
+ /* Check if we triggered a DAME */
+ ilr = kvx_sfr_get(ILR);
+ if (ilr & KVX_SFR_ILR_IT16_MASK)
+ panic("DAME error encountered while in kernel !!!!\n");
+#endif
+}
+
+#endif /* _ASM_KVX_DAME_H */
diff --git a/arch/kvx/include/asm/hardirq.h b/arch/kvx/include/asm/hardirq.h
new file mode 100644
index 000000000000..f82630f7e4e2
--- /dev/null
+++ b/arch/kvx/include/asm/hardirq.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#ifndef _ASM_KVX_HARDIRQ_H
+#define _ASM_KVX_HARDIRQ_H
+
+#define __ARCH_IRQ_EXIT_IRQS_DISABLED 1
+
+#include <asm-generic/hardirq.h>
+
+#endif /* _ASM_KVX_HARDIRQ_H */
diff --git a/arch/kvx/include/asm/hw_irq.h b/arch/kvx/include/asm/hw_irq.h
new file mode 100644
index 000000000000..f073dba3b1c5
--- /dev/null
+++ b/arch/kvx/include/asm/hw_irq.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * derived from arch/mips/include/asm/ide.h
+ *
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#ifndef _ASM_KVX_HW_IRQ_H
+#define _ASM_KVX_HW_IRQ_H
+
+void kvx_init_core_irq(void);
+
+#endif /* _ASM_KVX_HW_IRQ_H */
diff --git a/arch/kvx/include/asm/irqflags.h b/arch/kvx/include/asm/irqflags.h
new file mode 100644
index 000000000000..681c890b3fcd
--- /dev/null
+++ b/arch/kvx/include/asm/irqflags.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#ifndef _ASM_KVX_IRQFLAGS_H
+#define _ASM_KVX_IRQFLAGS_H
+
+#include <linux/types.h>
+
+#include <asm/sfr.h>
+
+static inline notrace unsigned long arch_local_save_flags(void)
+{
+ return kvx_sfr_get(PS) & (1 << KVX_SFR_PS_IE_SHIFT);
+}
+
+static inline notrace unsigned long arch_local_irq_save(void)
+{
+ unsigned long flags = arch_local_save_flags();
+
+ kvx_sfr_set_field(PS, IE, 0);
+
+ return flags;
+}
+
+static inline notrace void arch_local_irq_restore(unsigned long flags)
+{
+ /* If flags are set, interrupt are enabled), set the IE bit */
+ if (flags)
+ kvx_sfr_set_field(PS, IE, 1);
+ else
+ kvx_sfr_set_field(PS, IE, 0);
+}
+
+static inline notrace void arch_local_irq_enable(void)
+{
+ kvx_sfr_set_field(PS, IE, 1);
+}
+
+static inline notrace void arch_local_irq_disable(void)
+{
+ kvx_sfr_set_field(PS, IE, 0);
+}
+
+static inline notrace bool arch_irqs_disabled_flags(unsigned long flags)
+{
+ return (flags & (1 << KVX_SFR_PS_IE_SHIFT)) == 0;
+}
+
+static inline notrace bool arch_irqs_disabled(void)
+{
+ return arch_irqs_disabled_flags(kvx_sfr_get(PS));
+}
+
+
+#endif /* _ASM_KVX_IRQFLAGS_H */
diff --git a/arch/kvx/include/asm/stacktrace.h
b/arch/kvx/include/asm/stacktrace.h
new file mode 100644
index 000000000000..0feed6bd4424
--- /dev/null
+++ b/arch/kvx/include/asm/stacktrace.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#ifndef _ASM_KVX_STACKTRACE_H
+#define _ASM_KVX_STACKTRACE_H
+
+#include <linux/sched/task_stack.h>
+
+/**
+ * Structure of a frame on the stack
+ */
+struct stackframe {
+ unsigned long fp; /* Next frame pointer */
+ unsigned long ra; /* Return address */
+};
+
+static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp)
+{
+ unsigned long low = (unsigned long) task_stack_page(tsk);
+ unsigned long high = low + THREAD_SIZE;
+
+ if (sp < low || sp >= high)
+ return false;
+
+ return true;
+}
+
+void show_stacktrace(struct task_struct *task, struct pt_regs *regs);
+
+
+void walk_stackframe(struct task_struct *task, struct stackframe *frame,
+ bool (*fn)(unsigned long, void *), void *arg);
+
+static inline void start_stackframe(struct stackframe *frame,
+ unsigned long fp,
+ unsigned long pc)
+{
+ frame->fp = fp;
+ frame->ra = pc;
+}
+#endif /* _ASM_KVX_STACKTRACE_H */
diff --git a/arch/kvx/include/asm/traps.h b/arch/kvx/include/asm/traps.h
new file mode 100644
index 000000000000..77a663968135
--- /dev/null
+++ b/arch/kvx/include/asm/traps.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ * Guillaume Thouvenin
+ * Marius Gligor
+ */
+
+#ifndef _ASM_KVX_TRAPS_H
+#define _ASM_KVX_TRAPS_H
+
+#include <asm/sfr.h>
+
+#define KVX_TRAP_RESET 0x0
+#define KVX_TRAP_OPCODE 0x1
+#define KVX_TRAP_PRIVILEGE 0x2
+#define KVX_TRAP_DMISALIGN 0x3
+#define KVX_TRAP_PSYSERROR 0x4
+#define KVX_TRAP_DSYSERROR 0x5
+#define KVX_TRAP_PDECCERROR 0x6
+#define KVX_TRAP_DDECCERROR 0x7
+#define KVX_TRAP_PPARERROR 0x8
+#define KVX_TRAP_DPARERROR 0x9
+#define KVX_TRAP_PSECERROR 0xA
+#define KVX_TRAP_DSECERROR 0xB
+#define KVX_TRAP_NOMAPPING 0xC
+#define KVX_TRAP_PROTECTION 0xD
+#define KVX_TRAP_WRITETOCLEAN 0xE
+#define KVX_TRAP_ATOMICTOCLEAN 0xF
+#define KVX_TRAP_TPAR 0x10
+#define KVX_TRAP_DOUBLE_ECC 0x11
+#define KVX_TRAP_VSFR 0x12
+#define KVX_TRAP_PL_OVERFLOW 0x13
+
+#define KVX_TRAP_COUNT 0x14
+
+#define KVX_TRAP_SFRI_NOT_BCU 0
+#define KVX_TRAP_SFRI_GET 1
+#define KVX_TRAP_SFRI_IGET 2
+#define KVX_TRAP_SFRI_SET 4
+#define KVX_TRAP_SFRI_WFXL 5
+#define KVX_TRAP_SFRI_WFXM 6
+#define KVX_TRAP_SFRI_RSWAP 7
+
+/* Access type on memory trap */
+#define KVX_TRAP_RWX_FETCH 1
+#define KVX_TRAP_RWX_WRITE 2
+#define KVX_TRAP_RWX_READ 4
+#define KVX_TRAP_RWX_ATOMIC 6
+
+#ifndef __ASSEMBLY__
+
+typedef void (*trap_handler_func) (uint64_t es, uint64_t ea,
+ struct pt_regs *regs);
+
+#define trap_cause(__es) kvx_sfr_field_val(__es, ES, HTC)
+
+#define trap_sfri(__es) \
+ kvx_sfr_field_val((__es), ES, SFRI)
+
+#define trap_gprp(__es) \
+ kvx_sfr_field_val((__es), ES, GPRP)
+
+#define trap_sfrp(__es) \
+ kvx_sfr_field_val((__es), ES, SFRP)
+
+#ifdef CONFIG_MMU
+extern void do_page_fault(uint64_t es, uint64_t ea, struct pt_regs *regs);
+extern void do_writetoclean(uint64_t es, uint64_t ea, struct pt_regs *regs);
+#endif
+
+void user_do_sig(struct pt_regs *regs, int signo, int code, unsigned long
addr);
+
+#endif /* __ASSEMBLY__ */
+
+#endif
diff --git a/arch/kvx/kernel/dame_handler.c b/arch/kvx/kernel/dame_handler.c
new file mode 100644
index 000000000000..ce190bee8211
--- /dev/null
+++ b/arch/kvx/kernel/dame_handler.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#include <linux/of.h>
+#include <linux/bug.h>
+#include <linux/init.h>
+#include <linux/of_irq.h>
+#include <linux/hardirq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/interrupt.h>
+#include <linux/cpuhotplug.h>
+#include <linux/sched/signal.h>
+
+static unsigned int kvx_dame_irq;
+
+static const char *error_str[KVX_SFR_ES_ITI_WIDTH] = {
+ "PSE",
+ "PILSY",
+ "PILDE",
+ "PILPA",
+ "DSE",
+ "DILSY",
+ "DILDE",
+ "DILPA",
+ "DDEE",
+ "DSYE"
+};
+
+static irqreturn_t dame_irq_handler(int irq, void *dev_id)
+{
+ int bit;
+ struct pt_regs *regs = get_irq_regs();
+ unsigned long error_status = kvx_sfr_field_val(regs->es, ES, ITI);
+
+ if (error_status) {
+ pr_err("Memory Error:\n");
+ for_each_set_bit(bit, &error_status, KVX_SFR_ES_ITI_WIDTH)
+ pr_err("- %s\n", error_str[bit]);
+ }
+
+ /*
+ * If the DAME happened in user mode, we can handle it properly
+ * by killing the user process.
+ * Otherwise, if we are in kernel, we are fried...
+ */
+ if (user_mode(regs))
+ force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *) NULL);
+ else
+ die(regs, 0, "DAME error encountered while in kernel !!!!\n");
+
+ return IRQ_HANDLED;
+}
+
+static int kvx_dame_starting_cpu(unsigned int cpu)
+{
+ enable_percpu_irq(kvx_dame_irq, IRQ_TYPE_NONE);
+
+ return 0;
+}
+
+static int kvx_dame_dying_cpu(unsigned int cpu)
+{
+ disable_percpu_irq(kvx_dame_irq);
+
+ return 0;
+}
+
+static int __init dame_handler_init(void)
+{
+ struct device_node *dame_node;
+ int ret;
+
+ dame_node = of_find_compatible_node(NULL, NULL,
+ "kalray,kvx-dame-handler");
+ if (!dame_node) {
+ pr_err("Failed to find dame handler device tree node\n");
+ return -ENODEV;
+ }
+
+ kvx_dame_irq = irq_of_parse_and_map(dame_node, 0);
+ of_node_put(dame_node);
+
+ if (!kvx_dame_irq) {
+ pr_err("Failed to parse dame irq\n");
+ return -ENODEV;
+ }
+
+ ret = request_percpu_irq(kvx_dame_irq, dame_irq_handler, "dame",
+ &kvx_dame_irq);
+ if (ret) {
+ pr_err("Failed to request dame irq\n");
+ return -ENODEV;
+ }
+
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+ "kvx/dame_handler:online",
+ kvx_dame_starting_cpu,
+ kvx_dame_dying_cpu);
+ if (ret <= 0) {
+ pr_err("Failed to setup cpuhp\n");
+ return ret;
+ }
+
+ pr_info("DAME handler registered\n");
+
+ return 0;
+}
+
+core_initcall(dame_handler_init);
diff --git a/arch/kvx/kernel/irq.c b/arch/kvx/kernel/irq.c
new file mode 100644
index 000000000000..5d7c8cfba1dd
--- /dev/null
+++ b/arch/kvx/kernel/irq.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#include <linux/irqdomain.h>
+#include <linux/irqflags.h>
+#include <linux/hardirq.h>
+#include <linux/irqchip.h>
+#include <linux/bitops.h>
+#include <linux/init.h>
+
+#include <asm/dame.h>
+
+#define IT_MASK(__it) (KVX_SFR_ILL_ ## __it ## _MASK)
+#define IT_LEVEL(__it, __level) \
+ (__level##ULL << KVX_SFR_ILL_ ## __it ## _SHIFT)
+
+void do_IRQ(unsigned long hwirq_mask, struct pt_regs *regs)
+{
+ struct pt_regs *old_regs = set_irq_regs(regs);
+ int irq;
+ unsigned int hwirq;
+
+ trace_hardirqs_off();
+
+ irq_enter();
+
+ while (hwirq_mask) {
+ hwirq = __ffs(hwirq_mask);
+ irq = irq_find_mapping(NULL, hwirq);
+ generic_handle_irq(irq);
+ hwirq_mask &= ~BIT_ULL(hwirq);
+ }
+
+ irq_exit();
+ set_irq_regs(old_regs);
+
+ dame_irq_check(regs);
+}
+
+/*
+ * Early Hardware specific Interrupt setup
+ * -Called very early (start_kernel -> setup_arch -> setup_processor)
+ * -Needed for each CPU
+ */
+void kvx_init_core_irq(void)
+{
+ /*
+ * On KVX, Kernel only care about the following IT:
+ * - IT0: Timer 0
+ * - IT2: Watchdog
+ * - IT4: APIC IT 1
+ * - IT24: IPI
+ */
+ uint64_t mask = IT_MASK(IT0) | IT_MASK(IT2) | IT_MASK(IT4) |
+ IT_MASK(IT24);
+
+ /*
+ * Specific priorities for ITs:
+ * - Watchdog has the highest priority: 3
+ * - Timer has priority 2
+ * - APIC entries have lowest priority: 1
+ */
+ uint64_t value = IT_LEVEL(IT0, 0x2) | IT_LEVEL(IT2, 0x3) |
+ IT_LEVEL(IT4, 0x1) | IT_LEVEL(IT24, 0x1);
+
+ kvx_sfr_set_mask(ILL, mask, value);
+
+ /* Set core level to 0 */
+ kvx_sfr_set_field(PS, IL, 0);
+}
+
+void __init init_IRQ(void)
+{
+ irqchip_init();
+}
diff --git a/arch/kvx/kernel/traps.c b/arch/kvx/kernel/traps.c
new file mode 100644
index 000000000000..3a1706b666c2
--- /dev/null
+++ b/arch/kvx/kernel/traps.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ * Guillaume Thouvenin
+ * Marius Gligor
+ */
+
+#include <linux/context_tracking.h>
+#include <linux/sched/task_stack.h>
+#include <linux/sched/debug.h>
+#include <linux/irqflags.h>
+#include <linux/uaccess.h>
+#include <linux/kdebug.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/init.h>
+#include <linux/ptrace.h>
+
+#include <asm/dame.h>
+#include <asm/traps.h>
+#include <asm/ptrace.h>
+#include <asm/break_hook.h>
+#include <asm/stacktrace.h>
+
+int show_unhandled_signals = 1;
+
+static DEFINE_SPINLOCK(die_lock);
+
+static trap_handler_func trap_handler_table[KVX_TRAP_COUNT] = { NULL };
+
+/* Trap names associated to the trap numbers */
+static const char * const trap_name[] = {
+ "RESET",
+ "OPCODE",
+ "PRIVILEGE",
+ "DMISALIGN",
+ "PSYSERROR",
+ "DSYSERROR",
+ "PDECCERROR",
+ "DDECCERROR",
+ "PPARERROR",
+ "DPARERROR",
+ "PSECERROR",
+ "DSECERROR",
+ /* MMU related traps */
+ "NOMAPPING",
+ "PROTECTION",
+ "WRITETOCLEAN",
+ "ATOMICTOCLEAN",
+ "TPAR",
+ "DOUBLE_ECC",
+ "VSFR",
+ "PL_OVERFLOW"
+};
+
+void die(struct pt_regs *regs, unsigned long ea, const char *str)
+{
+ static int die_counter;
+ int ret;
+
+ oops_enter();
+
+ spin_lock_irq(&die_lock);
+ console_verbose();
+ bust_spinlocks(1);
+
+ pr_emerg("%s [#%d]\n", str, ++die_counter);
+ print_modules();
+ show_regs(regs);
+
+ if (!user_mode(regs))
+ show_stacktrace(NULL, regs);
+
+ ret = notify_die(DIE_OOPS, str, regs, ea, 0, SIGSEGV);
+
+ bust_spinlocks(0);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
+ spin_unlock_irq(&die_lock);
+ oops_exit();
+
+ if (in_interrupt())
+ panic("Fatal exception in interrupt");
+ if (panic_on_oops)
+ panic("Fatal exception");
+ if (ret != NOTIFY_STOP)
+ make_task_dead(SIGSEGV);
+}
+
+void user_do_sig(struct pt_regs *regs, int signo, int code, unsigned long addr)
+{
+ struct task_struct *tsk = current;
+
+ if (show_unhandled_signals && unhandled_signal(tsk, signo)
+ && printk_ratelimit()) {
+ pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x%lx",
+ tsk->comm, task_pid_nr(tsk), signo, code, addr);
+ print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
+ pr_cont("\n");
+ show_regs(regs);
+ }
+ if (signo == SIGKILL) {
+ force_sig(signo);
+ return;
+ }
+ force_sig_fault(signo, code, (void __user *) addr);
+}
+
+static void panic_or_kill(uint64_t es, uint64_t ea, struct pt_regs *regs,
+ int signo, int sigcode)
+{
+ if (user_mode(regs)) {
+ user_do_sig(regs, signo, sigcode, ea);
+ return;
+ }
+
+ pr_alert(CUT_HERE "ERROR: TRAP %s received at 0x%.16llx\n",
+ trap_name[trap_cause(es)], regs->spc);
+ die(regs, ea, "Oops");
+ make_task_dead(SIGKILL);
+}
+
+int is_valid_bugaddr(unsigned long pc)
+{
+ /*
+ * Since the bug was reported, this means that the break hook handling
+ * already check the faulting instruction so there is no need for
+ * additionnal check here. This is a BUG for sure.
+ */
+ return 1;
+}
+
+static int bug_break_handler(struct break_hook *brk_hook, struct pt_regs *regs)
+{
+ enum bug_trap_type type;
+
+ type = report_bug(regs->spc, regs);
+ switch (type) {
+ case BUG_TRAP_TYPE_NONE:
+ return BREAK_HOOK_ERROR;
+ case BUG_TRAP_TYPE_WARN:
+ break;
+ case BUG_TRAP_TYPE_BUG:
+ die(regs, regs->spc, "Kernel BUG");
+ break;
+ }
+
+ /* Skip over break insn if we survived ! */
+ kvx_skip_break_insn(regs);
+
+ return BREAK_HOOK_HANDLED;
+}
+
+static struct break_hook bug_break_hook = {
+ .handler = bug_break_handler,
+ .id = BREAK_CAUSE_BUG,
+ .mode = MODE_KERNEL,
+};
+
+#define GEN_TRAP_HANDLER(__name, __sig, __code) \
+static void __name ## _trap_handler(uint64_t es, uint64_t ea, \
+ struct pt_regs *regs) \
+{ \
+ panic_or_kill(es, ea, regs, __sig, __code); \
+}
+
+GEN_TRAP_HANDLER(default, SIGKILL, SI_KERNEL);
+GEN_TRAP_HANDLER(privilege, SIGILL, ILL_PRVREG);
+GEN_TRAP_HANDLER(dmisalign, SIGBUS, BUS_ADRALN);
+GEN_TRAP_HANDLER(syserror, SIGBUS, BUS_ADRERR);
+GEN_TRAP_HANDLER(opcode, SIGILL, ILL_ILLOPC);
+
+static void register_trap_handler(unsigned int trap_nb, trap_handler_func fn)
+{
+
+ if (trap_nb >= KVX_TRAP_COUNT || fn == NULL)
+ panic("Failed to register handler #%d\n", trap_nb);
+
+ trap_handler_table[trap_nb] = fn;
+}
+
+static void do_vsfr_fault(uint64_t es, uint64_t ea, struct pt_regs *regs)
+{
+ if (break_hook_handler(es, regs) == BREAK_HOOK_HANDLED)
+ return;
+
+ panic_or_kill(es, ea, regs, SIGILL, ILL_PRVREG);
+}
+
+void __init trap_init(void)
+{
+ int i;
+
+ break_hook_register(&bug_break_hook);
+
+ for (i = 0; i < KVX_TRAP_COUNT; i++)
+ register_trap_handler(i, default_trap_handler);
+#ifdef CONFIG_MMU
+ register_trap_handler(KVX_TRAP_NOMAPPING, do_page_fault);
+ register_trap_handler(KVX_TRAP_PROTECTION, do_page_fault);
+ register_trap_handler(KVX_TRAP_WRITETOCLEAN, do_writetoclean);
+#endif
+
+ register_trap_handler(KVX_TRAP_PSYSERROR, syserror_trap_handler);
+ register_trap_handler(KVX_TRAP_DSYSERROR, syserror_trap_handler);
+ register_trap_handler(KVX_TRAP_PRIVILEGE, privilege_trap_handler);
+ register_trap_handler(KVX_TRAP_OPCODE, opcode_trap_handler);
+ register_trap_handler(KVX_TRAP_DMISALIGN, dmisalign_trap_handler);
+ register_trap_handler(KVX_TRAP_VSFR, do_vsfr_fault);
+}
+
+/**
+ * trap_handler - trap handler called by _trap_handler routine in
trap_handler.S
+ * This handler will redirect to other trap handlers if present
+ * If not then it will do a generic action
+ * @es: Exception Syndrome register value
+ * @ea: Exception Address register
+ * @regs: pointer to registers saved when trapping
+ */
+void trap_handler(uint64_t es, uint64_t ea, struct pt_regs *regs)
+{
+ enum ctx_state prev_state = exception_enter();
+ int htc = trap_cause(es);
+ trap_handler_func trap_func = trap_handler_table[htc];
+
+ trace_hardirqs_off();
+
+ /* Normal traps number should and must be between 0 and 15 included */
+ if (unlikely(htc >= KVX_TRAP_COUNT)) {
+ pr_err("Invalid trap %d !\n", htc);
+ goto done;
+ }
+
+ /* If irqs were enabled in the preempted context, reenable them */
+ if (regs->sps & KVX_SFR_PS_IE_MASK)
+ local_irq_enable();
+
+ trap_func(es, ea, regs);
+
+done:
+ dame_irq_check(regs);
+ exception_exit(prev_state);
+}
--
2.37.2
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