--- /dev/null
+/*
+ * arch/ubicom32/kernel/stacktrace.c
+ * Ubicom32 architecture stack back trace implementation.
+ *
+ * (C) Copyright 2009, Ubicom, Inc.
+ *
+ * This file is part of the Ubicom32 Linux Kernel Port.
+ *
+ * The Ubicom32 Linux Kernel Port is free software: you can redistribute
+ * it and/or modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * The Ubicom32 Linux Kernel Port is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with the Ubicom32 Linux Kernel Port. If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Ubicom32 implementation derived from (with many thanks):
+ * arch/m68knommu
+ * arch/blackfin
+ * arch/parisc
+ */
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <linux/module.h>
+#include <asm/stacktrace.h>
+#include <asm/thread.h>
+#include <asm/ip5000.h>
+
+/*
+ * These symbols are filled in by the linker.
+ */
+extern unsigned long _stext;
+extern unsigned long _etext;
+
+extern unsigned long __ocm_text_run_begin;
+extern unsigned long __data_begin;
+
+/*
+ * stacktrace_iterate()
+ * Walk the stack looking for call and calli instructions on an aligned
+ * boundary.
+ *
+ * Trace must point to the top of the current stack frame.
+ */
+unsigned long stacktrace_iterate(unsigned long **trace,
+ unsigned long stext,
+ unsigned long etext,
+ unsigned long ocm_stext,
+ unsigned long ocm_etext,
+ unsigned long sstack,
+ unsigned long estack)
+{
+ unsigned int thread_trap_en, instruction;
+ unsigned long address;
+ unsigned int limit = 0;
+ unsigned long result = 0;
+ unsigned long *sp = *trace;
+
+ /*
+ * Exclude the current thread from being monitored for traps.
+ */
+ asm volatile(
+ " thread_get_self_mask d15 \n\t"
+ /* save current trap status */
+ " and.4 %0, MT_TRAP_EN, d15 \n\t"
+ " not.4 d15, d15 \n\t"
+ /* disable trap */
+ " and.4 MT_TRAP_EN, MT_TRAP_EN, d15 \n\t"
+ " pipe_flush 0 \n\t"
+ : "=r" (thread_trap_en)
+ :
+ : "d15", "cc"
+ );
+
+ while (limit++ < 256) {
+ /*
+ * See if we have a valid stack.
+ */
+ if (!between((unsigned long)sp, sstack, estack)) {
+#ifdef TRAP_DEBUG_STACK_TRACE
+ printk(KERN_EMERG "stack address is out of range - "
+ "sp: %x, sstack: %x, estack: %x\n",
+ (unsigned int)sp, (unsigned int)sstack,
+ (unsigned int)estack);
+#endif
+ result = 0;
+ *trace = 0;
+ break;
+ }
+
+ /*
+ * Get the value off the stack and back up 4 bytes to what
+ * should be the address of a call or calli.
+ */
+ address = (*sp++) - 4;
+
+ /*
+ * If the address is not within the text segment, skip this
+ * value.
+ */
+ if (!between(address, stext, etext) &&
+ !between(address, ocm_stext, ocm_etext)) {
+#ifdef TRAP_DEBUG_STACK_TRACE
+ printk(KERN_EMERG "not a text address - "
+ "address: %08x, stext: %08x, etext: %08x\n"
+ "ocm_stext: %08x, ocm_etext: %08x\n",
+ (unsigned int)address,
+ (unsigned int)stext,
+ (unsigned int)etext,
+ (unsigned int)ocm_stext,
+ (unsigned int)ocm_etext);
+#endif
+ continue;
+
+ }
+
+ /*
+ * If the address is not on an aligned boundary it can not be a
+ * return address.
+ */
+ if (address & 0x3) {
+ continue;
+ }
+
+ /*
+ * Read the probable instruction.
+ */
+ instruction = *(unsigned int *)address;
+
+ /*
+ * Is this a call instruction?
+ */
+ if ((instruction & 0xF8000000) == (u32_t)(0x1B << 27)) {
+#ifdef TRAP_DEBUG_STACK_TRACE
+ printk(KERN_EMERG "call inst. result: %x, "
+ "test: %x\n", (unsigned int)address,
+ (unsigned int)instruction);
+#endif
+ *trace = sp;
+ result = address;
+ break;
+ }
+
+ /*
+ * Is this a calli instruction?
+ */
+ if ((instruction & 0xF8000000) == (u32_t)(0x1E << 27)) {
+#ifdef TRAP_DEBUG_STACK_TRACE
+ printk(KERN_EMERG "calli inst. result: %x, "
+ "test: %x\n", (unsigned int)address,
+ (unsigned int)instruction);
+#endif
+ *trace = sp;
+ result = address;
+ break;
+ }
+ }
+
+ /*
+ * Restore the current thread to be monitored for traps.
+ */
+ if (thread_trap_en) {
+ asm volatile(
+ " thread_get_self_mask d15 \n\t"
+ " or.4 MT_TRAP_EN, MT_TRAP_EN, d15 \n\t"
+ :
+ :
+ : "d15", "cc"
+ );
+ }
+ return result;
+}
+
+#ifdef CONFIG_STACKTRACE
+/*
+ * stacktrace_save_entries()
+ * Save stack back trace information into the provided trace structure.
+ */
+void stacktrace_save_entries(struct task_struct *tsk,
+ struct stack_trace *trace,
+ unsigned long sp)
+{
+ unsigned long code_start = (unsigned long)&_stext;
+ unsigned long code_end = (unsigned long)&_etext;
+ unsigned long ocm_code_start = (unsigned long)&__ocm_text_run_begin;
+ unsigned long ocm_code_end = (unsigned long)&__data_begin;
+ unsigned long stack_end = (unsigned long)(tsk->stack + THREAD_SIZE - 8);
+ unsigned long stack = (unsigned long)sp;
+ unsigned int idx = 0;
+ unsigned long *handle;
+ int skip = trace->skip;
+
+ handle = (unsigned long *)stack;
+ while (idx < trace->max_entries) {
+ if (skip) {
+ skip--;
+ continue;
+ }
+ trace->entries[idx] = stacktrace_iterate(&handle,
+ code_start, code_end,
+ ocm_code_start, ocm_code_end,
+ (unsigned long)stack, stack_end);
+ if (trace->entries[idx] == 0) {
+ break;
+ }
+ idx++;
+ }
+}
+
+/*
+ * save_stack_trace()
+ * Save the specified amount of the kernel stack trace information
+ * for the current task.
+ */
+void save_stack_trace(struct stack_trace *trace)
+{
+ unsigned long sp = 0;
+ asm volatile (
+ " move.4 %0, SP \n\t"
+ : "=r" (sp)
+ );
+ stacktrace_save_entries(current, trace, sp);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+/*
+ * save_stack_trace_tsk()
+ * Save the specified amount of the kernel stack trace information
+ * for the specified task.
+ *
+ * Note: We assume the specified task is not currently running.
+ */
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+ stacktrace_save_entries(tsk, trace, tsk->thread.sp);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+#endif /* CONFIG_STACKTRACE */
projects / openwrt / svn-archive / archive.git / blobdiff