From 63077519899721120b61d663a68adced068a459d Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Wed, 8 Feb 2006 01:48:03 +0900 Subject: [PATCH] [MIPS] Rewrite get_wchan and its helper functions using kallsyms_lookup. Implement get_wchan() and frame_info_init() using kallsyms_lookup(). This fixes problem with static sched/lock functions and mfinfo[] maintenance issue. If CONFIG_KALLSYMS was disabled, get_wchan() just returns thread_saved_pc() value. Also unwind stackframe based on "addiu sp,-imm" analysis instead of frame pointer. This fixes problem with functions compiled without -fomit-frame-pointer. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- arch/mips/kernel/process.c | 158 ++++++++++++++++++------------------- 1 file changed, 77 insertions(+), 81 deletions(-) diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 5232fc752935..092679c2dca9 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include @@ -272,46 +273,19 @@ long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) static struct mips_frame_info { void *func; - int omit_fp; /* compiled without fno-omit-frame-pointer */ - int frame_offset; + unsigned long func_size; + int frame_size; int pc_offset; -} schedule_frame, mfinfo[] = { - { schedule, 0 }, /* must be first */ - /* arch/mips/kernel/semaphore.c */ - { __down, 1 }, - { __down_interruptible, 1 }, - /* kernel/sched.c */ -#ifdef CONFIG_PREEMPT - { preempt_schedule, 0 }, -#endif - { wait_for_completion, 0 }, - { interruptible_sleep_on, 0 }, - { interruptible_sleep_on_timeout, 0 }, - { sleep_on, 0 }, - { sleep_on_timeout, 0 }, - { yield, 0 }, - { io_schedule, 0 }, - { io_schedule_timeout, 0 }, -#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT) - { __preempt_spin_lock, 0 }, - { __preempt_write_lock, 0 }, -#endif - /* kernel/timer.c */ - { schedule_timeout, 1 }, -/* { nanosleep_restart, 1 }, */ - /* lib/rwsem-spinlock.c */ - { __down_read, 1 }, - { __down_write, 1 }, -}; +} *schedule_frame, mfinfo[64]; +static int mfinfo_num; -static int mips_frame_info_initialized; static int __init get_frame_info(struct mips_frame_info *info) { int i; void *func = info->func; union mips_instruction *ip = (union mips_instruction *)func; info->pc_offset = -1; - info->frame_offset = info->omit_fp ? 0 : -1; + info->frame_size = 0; for (i = 0; i < 128; i++, ip++) { /* if jal, jalr, jr, stop. */ if (ip->j_format.opcode == jal_op || @@ -320,6 +294,23 @@ static int __init get_frame_info(struct mips_frame_info *info) ip->r_format.func == jr_op))) break; + if (info->func_size && i >= info->func_size / 4) + break; + if ( +#ifdef CONFIG_32BIT + ip->i_format.opcode == addiu_op && +#endif +#ifdef CONFIG_64BIT + ip->i_format.opcode == daddiu_op && +#endif + ip->i_format.rs == 29 && + ip->i_format.rt == 29) { + /* addiu/daddiu sp,sp,-imm */ + if (info->frame_size) + continue; + info->frame_size = - ip->i_format.simmediate; + } + if ( #ifdef CONFIG_32BIT ip->i_format.opcode == sw_op && @@ -327,31 +318,20 @@ static int __init get_frame_info(struct mips_frame_info *info) #ifdef CONFIG_64BIT ip->i_format.opcode == sd_op && #endif - ip->i_format.rs == 29) - { + ip->i_format.rs == 29 && + ip->i_format.rt == 31) { /* sw / sd $ra, offset($sp) */ - if (ip->i_format.rt == 31) { - if (info->pc_offset != -1) - continue; - info->pc_offset = - ip->i_format.simmediate / sizeof(long); - } - /* sw / sd $s8, offset($sp) */ - if (ip->i_format.rt == 30) { -//#if 0 /* gcc 3.4 does aggressive optimization... */ - if (info->frame_offset != -1) - continue; -//#endif - info->frame_offset = - ip->i_format.simmediate / sizeof(long); - } + if (info->pc_offset != -1) + continue; + info->pc_offset = + ip->i_format.simmediate / sizeof(long); } } - if (info->pc_offset == -1 || info->frame_offset == -1) { - printk("Can't analyze prologue code at %p\n", func); + if (info->pc_offset == -1 || info->frame_size == 0) { + if (func == schedule) + printk("Can't analyze prologue code at %p\n", func); info->pc_offset = -1; - info->frame_offset = -1; - return -1; + info->frame_size = 0; } return 0; @@ -359,25 +339,36 @@ static int __init get_frame_info(struct mips_frame_info *info) static int __init frame_info_init(void) { - int i, found; - for (i = 0; i < ARRAY_SIZE(mfinfo); i++) - if (get_frame_info(&mfinfo[i])) - return -1; - schedule_frame = mfinfo[0]; - /* bubble sort */ - do { - struct mips_frame_info tmp; - found = 0; - for (i = 1; i < ARRAY_SIZE(mfinfo); i++) { - if (mfinfo[i-1].func > mfinfo[i].func) { - tmp = mfinfo[i]; - mfinfo[i] = mfinfo[i-1]; - mfinfo[i-1] = tmp; - found = 1; - } - } - } while (found); - mips_frame_info_initialized = 1; + int i; +#ifdef CONFIG_KALLSYMS + char *modname; + char namebuf[KSYM_NAME_LEN + 1]; + unsigned long start, size, ofs; + extern char __sched_text_start[], __sched_text_end[]; + extern char __lock_text_start[], __lock_text_end[]; + + start = (unsigned long)__sched_text_start; + for (i = 0; i < ARRAY_SIZE(mfinfo); i++) { + if (start == (unsigned long)schedule) + schedule_frame = &mfinfo[i]; + if (!kallsyms_lookup(start, &size, &ofs, &modname, namebuf)) + break; + mfinfo[i].func = (void *)(start + ofs); + mfinfo[i].func_size = size; + start += size - ofs; + if (start >= (unsigned long)__lock_text_end) + break; + if (start == (unsigned long)__sched_text_end) + start = (unsigned long)__lock_text_start; + } +#else + mfinfo[0].func = schedule; + schedule_frame = &mfinfo[0]; +#endif + for (i = 0; i < ARRAY_SIZE(mfinfo) && mfinfo[i].func; i++) + get_frame_info(&mfinfo[i]); + + mfinfo_num = i; return 0; } @@ -394,47 +385,52 @@ unsigned long thread_saved_pc(struct task_struct *tsk) if (t->reg31 == (unsigned long) ret_from_fork) return t->reg31; - if (schedule_frame.pc_offset < 0) + if (!schedule_frame || schedule_frame->pc_offset < 0) return 0; - return ((unsigned long *)t->reg29)[schedule_frame.pc_offset]; + return ((unsigned long *)t->reg29)[schedule_frame->pc_offset]; } /* get_wchan - a maintenance nightmare^W^Wpain in the ass ... */ unsigned long get_wchan(struct task_struct *p) { unsigned long stack_page; - unsigned long frame, pc; + unsigned long pc; +#ifdef CONFIG_KALLSYMS + unsigned long frame; +#endif if (!p || p == current || p->state == TASK_RUNNING) return 0; stack_page = (unsigned long)task_stack_page(p); - if (!stack_page || !mips_frame_info_initialized) + if (!stack_page || !mfinfo_num) return 0; pc = thread_saved_pc(p); +#ifdef CONFIG_KALLSYMS if (!in_sched_functions(pc)) return pc; - frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset]; + frame = p->thread.reg29 + schedule_frame->frame_size; do { int i; if (frame < stack_page || frame > stack_page + THREAD_SIZE - 32) return 0; - for (i = ARRAY_SIZE(mfinfo) - 1; i >= 0; i--) { + for (i = mfinfo_num - 1; i >= 0; i--) { if (pc >= (unsigned long) mfinfo[i].func) break; } if (i < 0) break; - if (mfinfo[i].omit_fp) - break; pc = ((unsigned long *)frame)[mfinfo[i].pc_offset]; - frame = ((unsigned long *)frame)[mfinfo[i].frame_offset]; + if (!mfinfo[i].frame_size) + break; + frame += mfinfo[i].frame_size; } while (in_sched_functions(pc)); +#endif return pc; }