[PATCH 12/19] csky: Debug and Ptrace GDB
From: Guo Ren
Date: Sun Mar 18 2018 - 15:54:02 EST
Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
---
arch/csky/include/uapi/asm/ptrace.h | 97 +++++++++++
arch/csky/kernel/dumpstack.c | 65 +++++++
arch/csky/kernel/ptrace.c | 339 ++++++++++++++++++++++++++++++++++++
3 files changed, 501 insertions(+)
create mode 100644 arch/csky/include/uapi/asm/ptrace.h
create mode 100644 arch/csky/kernel/dumpstack.c
create mode 100644 arch/csky/kernel/ptrace.c
diff --git a/arch/csky/include/uapi/asm/ptrace.h b/arch/csky/include/uapi/asm/ptrace.h
new file mode 100644
index 0000000..b8516b2
--- /dev/null
+++ b/arch/csky/include/uapi/asm/ptrace.h
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#ifndef _CSKY_PTRACE_H
+#define _CSKY_PTRACE_H
+
+#define REGNO_SR 32
+#define REGNO_PC 33
+
+#ifndef __ASSEMBLY__
+
+/* this struct defines the way the registers are stored on the
+ stack during a system call. */
+struct pt_regs {
+ unsigned long pc;
+ long orig_a0;
+ unsigned long sr;
+ long a0; // ABIV2: r0, ABIV1: r2
+ long a1; // ABIV2: r1, ABIV1: r3
+ long a2; // ABIV2: r2, ABIV1: r4
+ long a3; // ABIV2: r3, ABIV1: r5
+ // ABIV2: r4 ~ r13, ABIV1: r6 ~ r14, r1.
+ long regs[10];
+ long r15;
+#if defined(__CSKYABIV2__)
+ // r16~r31;
+ long exregs[16];
+ long rhi;
+ long rlo;
+#endif
+};
+
+/*
+ * Switch stack for switch_to after push pt_regs.
+ *
+ * ABI_CSKYV2: r4 ~ r11, r15 ~ r17, r26 ~ r30;
+ * ABI_CSKYV1: r8 ~ r14, r15;
+ */
+struct switch_stack {
+#if defined(__CSKYABIV2__)
+ unsigned long r4;
+ unsigned long r5;
+ unsigned long r6;
+ unsigned long r7;
+ unsigned long r8;
+ unsigned long r9;
+ unsigned long r10;
+ unsigned long r11;
+#else
+ unsigned long r8;
+ unsigned long r9;
+ unsigned long r10;
+ unsigned long r11;
+ unsigned long r12;
+ unsigned long r13;
+ unsigned long r14;
+#endif
+ unsigned long r15;
+#if defined(__CSKYABIV2__)
+ unsigned long r16;
+ unsigned long r17;
+ unsigned long r26;
+ unsigned long r27;
+ unsigned long r28;
+ unsigned long r29;
+ unsigned long r30;
+#endif
+};
+
+#define PTRACE_GETREGS 12
+#define PTRACE_SETREGS 13
+#define PTRACE_GETFPREGS 14
+#define PTRACE_SETFPREGS 15
+#define PTRACE_GET_THREAD_AREA 25
+
+#define CSKY_GREG_NUM 35
+#define CSKY_FREG_NUM_HI 72
+#define CSKY_FREG_NUM_LO 40
+#define CSKY_FCR_NUM 74
+
+#ifdef __KERNEL__
+
+#define PS_S 0x80000000 /* Supervisor Mode */
+
+#define arch_has_single_step() (1)
+#define current_pt_regs() \
+ (struct pt_regs *)((char *)current_thread_info() + THREAD_SIZE) - 1
+#define current_user_stack_pointer() rdusp()
+
+#define user_mode(regs) (!((regs)->sr & PS_S))
+#define instruction_pointer(regs) ((regs)->pc)
+#define profile_pc(regs) instruction_pointer(regs)
+
+void show_regs(struct pt_regs *);
+
+#endif /* __KERNEL__ */
+#endif /* __ASSEMBLY__ */
+#endif /* _CSKY_PTRACE_H */
diff --git a/arch/csky/kernel/dumpstack.c b/arch/csky/kernel/dumpstack.c
new file mode 100644
index 0000000..d4be08a
--- /dev/null
+++ b/arch/csky/kernel/dumpstack.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#include <linux/ptrace.h>
+
+int kstack_depth_to_print = 48;
+
+void show_trace(unsigned long *stack)
+{
+ unsigned long *endstack;
+ unsigned long addr;
+ int i;
+
+ pr_info("Call Trace:");
+ addr = (unsigned long)stack + THREAD_SIZE - 1;
+ endstack = (unsigned long *)(addr & -THREAD_SIZE);
+ i = 0;
+ while (stack + 1 <= endstack) {
+ addr = *stack++;
+ /*
+ * If the address is either in the text segment of the
+ * kernel, or in the region which contains vmalloc'ed
+ * memory, it *may* be the address of a calling
+ * routine; if so, print it so that someone tracing
+ * down the cause of the crash will be able to figure
+ * out the call path that was taken.
+ */
+ if (__kernel_text_address(addr)) {
+#ifndef CONFIG_KALLSYMS
+ if (i % 5 == 0)
+ pr_cont("\n ");
+#endif
+ pr_cont(" [<%08lx>] %pS\n", addr, (void *)addr);
+ i++;
+ }
+ }
+ pr_cont("\n");
+}
+
+void show_stack(struct task_struct *task, unsigned long *stack)
+{
+ unsigned long *p;
+ unsigned long *endstack;
+ int i;
+
+ if (!stack) {
+ if (task)
+ stack = (unsigned long *)task->thread.esp0;
+ else
+ stack = (unsigned long *)&stack;
+ }
+ endstack = (unsigned long *)(((unsigned long)stack + THREAD_SIZE - 1) & -THREAD_SIZE);
+
+ pr_info("Stack from %08lx:", (unsigned long)stack);
+ p = stack;
+ for (i = 0; i < kstack_depth_to_print; i++) {
+ if (p + 1 > endstack)
+ break;
+ if (i % 8 == 0)
+ pr_cont("\n ");
+ pr_cont(" %08lx", *p++);
+ }
+ pr_cont("\n");
+ show_trace(stack);
+}
+
diff --git a/arch/csky/kernel/ptrace.c b/arch/csky/kernel/ptrace.c
new file mode 100644
index 0000000..9aee8b5
--- /dev/null
+++ b/arch/csky/kernel/ptrace.c
@@ -0,0 +1,339 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/signal.h>
+#include <linux/uaccess.h>
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/asm-offsets.h>
+
+#include <abi/regdef.h>
+
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+/* sets the trace bits. */
+#define TRACE_MODE_SI 1 << 14
+#define TRACE_MODE_RUN 0
+#define TRACE_MODE_JMP 0x3 << 14
+#define TRACE_MODE_MASK ~(0x3 << 14)
+
+/*
+ * PT_xxx is the stack offset at which the register is saved.
+ * Notice that usp has no stack-slot and needs to be treated
+ * specially (see get_reg/put_reg below).
+ */
+static int regoff[] = PTRACE_REGOFF_ABI;
+
+/*
+ * Get contents of register REGNO in task TASK.
+ */
+static long get_reg(struct task_struct *task, int regno)
+{
+ unsigned long *addr;
+
+ if (regno == REGNO_USP)
+ addr = &task->thread.usp;
+ else if ((regno < sizeof(regoff)/sizeof(regoff[0])) && (regoff[regno] != -1))
+ addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
+ else
+ return 0;
+ return *addr;
+}
+
+/*
+ * Write contents of register REGNO in task TASK.
+ */
+static int put_reg(struct task_struct *task, int regno,
+ unsigned long data)
+{
+ unsigned long *addr;
+
+ if (regno == REGNO_USP)
+ addr = &task->thread.usp;
+ else if ((regno < sizeof(regoff) / sizeof(regoff[0])) && (regoff[regno] != -1))
+ addr = (unsigned long *) (task->thread.esp0 + regoff[regno]);
+ else
+ return -1;
+ *addr = data;
+ return 0;
+}
+/*
+ * Make sure the single step bit is not set.
+ */
+static void singlestep_disable(struct task_struct *child)
+{
+ unsigned long tmp;
+ tmp = (get_reg(child, REGNO_SR) & TRACE_MODE_MASK) | TRACE_MODE_RUN;
+ put_reg(child, REGNO_SR, tmp);
+}
+
+
+static void singlestep_enable(struct task_struct *child)
+{
+ unsigned long tmp;
+ tmp = (get_reg(child, REGNO_SR) & TRACE_MODE_MASK) | TRACE_MODE_SI;
+ put_reg(child, REGNO_SR, tmp);
+}
+
+/*
+ * Make sure the single step bit is set.
+ */
+void user_enable_single_step(struct task_struct *child)
+{
+ if (child->thread.esp0 == 0) return;
+ singlestep_enable(child);
+}
+
+void user_disable_single_step(struct task_struct *child)
+{
+ if (child->thread.esp0 == 0) return;
+ singlestep_disable(child);
+}
+
+int ptrace_getfpregs(struct task_struct *child, void __user *data)
+{
+
+ if (!access_ok(VERIFY_WRITE, data, sizeof(struct user_cskyfp_struct)))
+ return -EIO;
+
+ if(raw_copy_to_user(data, &child->thread.fcr,
+ sizeof(struct user_cskyfp_struct)))
+ return -EFAULT;
+
+ return 0;
+}
+
+int ptrace_setfpregs(struct task_struct *child, void __user *data)
+{
+ if (!access_ok(VERIFY_READ, data, sizeof(struct user_cskyfp_struct)))
+ return -EIO;
+
+ if(raw_copy_from_user(&child->thread.fcr, data,
+ sizeof(struct user_cskyfp_struct)))
+ return -EFAULT;
+ return 0;
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure the single step bit is not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+ singlestep_disable(child);
+}
+
+/*
+ * Handle the requests of ptrace system call.
+ *
+ * INPUT:
+ * child - process being traced.
+ * request - request type.
+ * addr - address of data that this request to read from or write to.
+ * data - address of data that this request to read to or write from.
+ *
+ * RETURN:
+ * 0 - success
+ * others - fail
+ */
+long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
+ unsigned long data)
+{
+ unsigned long tmp = 0, ret = 0;
+ int i;
+
+ switch (request) {
+ /* read the word at location addr in the USER area. */
+ case PTRACE_PEEKUSR:
+ if (addr & 3)
+ goto out_eio;
+ addr >>= 2; /* temporary hack. */
+
+ if (addr >= 0 && addr <= CSKY_GREG_NUM) {
+ tmp = get_reg(child, addr);
+ }else if(addr >= CSKY_FREG_NUM_LO && addr < CSKY_FREG_NUM_HI) {
+ tmp = child->thread.fp[addr - CSKY_FREG_NUM_LO];
+ }else if(addr >= CSKY_FREG_NUM_HI && addr < CSKY_FCR_NUM) {
+ tmp = (&(child->thread.fcr))[addr - CSKY_FREG_NUM_HI];
+ } else
+ break;
+ ret = put_user(tmp,(long unsigned int *) data);
+ break;
+
+ case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
+ if (addr & 3)
+ goto out_eio;
+ addr >>= 2; /* temporary hack. */
+
+ if (addr >= 0 && addr <= CSKY_GREG_NUM) {
+ if (put_reg(child, addr, data)) /*** should protect 'psr'? ***/
+ goto out_eio;
+ }else if(addr >= CSKY_FREG_NUM_LO && addr < CSKY_FREG_NUM_HI) {
+ child->thread.fp[addr - CSKY_FREG_NUM_LO] = data;
+ }else if(addr >= CSKY_FREG_NUM_HI && addr <= CSKY_FCR_NUM) {
+ (&(child->thread.fcr))[addr - CSKY_FREG_NUM_HI] = data;
+ }else
+ goto out_eio;
+ break;
+ case PTRACE_GETREGS: /* Get all gp regs from the child. */
+ for (i = 0; i <= CSKY_GREG_NUM; i++) {
+ tmp = get_reg(child, i);
+ ret = put_user(tmp, (unsigned long *)data);
+ if (ret)
+ break;
+ data += sizeof(long);
+ }
+ break;
+ case PTRACE_SETREGS: /* Set all gp regs in the child. */
+ for (i = 0; i <= CSKY_GREG_NUM; i++) {
+ ret = get_user(tmp, (unsigned long *)data);
+ if (ret)
+ break;
+ put_reg(child, i, tmp);
+ data += sizeof(long);
+ }
+ break;
+
+ case PTRACE_GETFPREGS:
+ ret = ptrace_getfpregs(child, (void __user *) data);
+ break;
+
+ case PTRACE_SETFPREGS:
+ ret = ptrace_setfpregs(child, (void __user *) data);
+ break;
+
+ case PTRACE_GET_THREAD_AREA:
+ ret = put_user(task_thread_info(child)->tp_value,
+ (long unsigned int *) data);
+ break;
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+ return ret;
+out_eio:
+ return -EIO;
+}
+
+/*
+ * If process's system calls is traces, do some corresponding handles in this
+ * fuction before entering system call function and after exiting system call
+ * fuction.
+ */
+asmlinkage void syscall_trace(int why, struct pt_regs * regs)
+{
+ long saved_why;
+ /*
+ * Save saved_why, why is used to denote syscall entry/exit;
+ * why = 0:entry, why = 1: exit
+ */
+ saved_why = regs->regs[SYSTRACE_SAVENUM];
+ regs->regs[SYSTRACE_SAVENUM] = why;
+
+ /* the 0x80 provides a way for the tracing parent to distinguish
+ between a syscall stop and SIGTRAP delivery */
+ ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
+ ? 0x80 : 0));
+ /*
+ * this isn't the same as continuing with a signal, but it will do
+ * for normal use. strace only continues with a signal if the
+ * stopping signal is not SIGTRAP. -brl
+ */
+ if (current->exit_code) {
+ send_sig(current->exit_code, current, 1);
+ current->exit_code = 0;
+ }
+
+ regs->regs[SYSTRACE_SAVENUM] = saved_why;
+ return;
+}
+
+void show_regs(struct pt_regs *fp)
+{
+ unsigned long *sp;
+ unsigned char *tp;
+ int i;
+
+ pr_info("\nCURRENT PROCESS:\n\n");
+ pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
+
+ if (current->mm) {
+ pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
+ (int) current->mm->start_code,
+ (int) current->mm->end_code,
+ (int) current->mm->start_data,
+ (int) current->mm->end_data,
+ (int) current->mm->end_data,
+ (int) current->mm->brk);
+ pr_info("USER-STACK=%08x KERNEL-STACK=%08x\n\n",
+ (int) current->mm->start_stack,
+ (int) (((unsigned long) current) + 2 * PAGE_SIZE));
+ }
+
+ pr_info("PC: 0x%08lx\n", (long)fp->pc);
+ pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
+ pr_info("PSR: 0x%08lx\n", (long)fp->sr);
+
+ pr_info("a0: 0x%08lx a1: 0x%08lx a2: 0x%08lx a3: 0x%08lx\n",
+ fp->a0, fp->a1, fp->a2, fp->a3);
+#if defined(__CSKYABIV2__)
+ pr_info("r4: 0x%08lx r5: 0x%08lx r6: 0x%08lx r7: 0x%08lx\n",
+ fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
+ pr_info("r8: 0x%08lx r9: 0x%08lx r10: 0x%08lx r11: 0x%08lx\n",
+ fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
+ pr_info("r12 0x%08lx r13: 0x%08lx r15: 0x%08lx\n",
+ fp->regs[8], fp->regs[9], fp->r15);
+ pr_info("r16:0x%08lx r17: 0x%08lx r18: 0x%08lx r19: 0x%08lx\n",
+ fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
+ pr_info("r20 0x%08lx r21: 0x%08lx r22: 0x%08lx r23: 0x%08lx\n",
+ fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
+ pr_info("r24 0x%08lx r25: 0x%08lx r26: 0x%08lx r27: 0x%08lx\n",
+ fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
+ pr_info("r28 0x%08lx r29: 0x%08lx r30: 0x%08lx r31: 0x%08lx\n",
+ fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->exregs[15]);
+ pr_info("hi 0x%08lx lo: 0x%08lx \n",
+ fp->rhi, fp->rlo);
+#else
+ pr_info("r6: 0x%08lx r7: 0x%08lx r8: 0x%08lx r9: 0x%08lx\n",
+ fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
+ pr_info("r10: 0x%08lx r11: 0x%08lx r12: 0x%08lx r13: 0x%08lx\n",
+ fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
+ pr_info("r14 0x%08lx r1: 0x%08lx r15: 0x%08lx\n",
+ fp->regs[8], fp->regs[9], fp->r15);
+#endif
+
+ pr_info("\nCODE:");
+ tp = ((unsigned char *) fp->pc) - 0x20;
+ tp += ((int)tp % 4) ? 2 : 0;
+ for (sp = (unsigned long *) tp, i = 0; (i < 0x40); i += 4) {
+ if ((i % 0x10) == 0)
+ pr_cont("\n%08x: ", (int) (tp + i));
+ pr_cont("%08x ", (int) *sp++);
+ }
+ pr_cont("\n");
+
+ pr_info("\nKERNEL STACK:");
+ tp = ((unsigned char *) fp) - 0x40;
+ for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
+ if ((i % 0x10) == 0)
+ pr_cont("\n%08x: ", (int) (tp + i));
+ pr_cont("%08x ", (int) *sp++);
+ }
+ pr_cont("\n");
+
+ return;
+}
+
--
2.7.4