diff options
Diffstat (limited to 'target/linux/ubicom32/files/arch/ubicom32/kernel/stacktrace.c')
| -rw-r--r-- | target/linux/ubicom32/files/arch/ubicom32/kernel/stacktrace.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/target/linux/ubicom32/files/arch/ubicom32/kernel/stacktrace.c b/target/linux/ubicom32/files/arch/ubicom32/kernel/stacktrace.c new file mode 100644 index 000000000..2a10e3f4f --- /dev/null +++ b/target/linux/ubicom32/files/arch/ubicom32/kernel/stacktrace.c @@ -0,0 +1,244 @@ +/* + * 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 */ |