From dc953df1ba5526814982676f47580c8e1bcdbfeb Mon Sep 17 00:00:00 2001 From: Thiemo Seufer Date: Mon, 21 Feb 2005 10:55:16 +0000 Subject: [PATCH] Fix wchan implementation, based on earlier by from Atsushi Nemoto. Signed-off-by: Thiemo Seufer Signed-off-by: Ralf Baechle --- arch/mips/kernel/process.c | 135 +++++++++++++++++++++---------------- 1 file changed, 77 insertions(+), 58 deletions(-) diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index e4f2f8011387..f99efce556ea 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -211,22 +211,48 @@ long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); } -struct mips_frame_info { +static struct mips_frame_info { + void *func; + int omit_fp; /* compiled without fno-omit-frame-pointer */ int frame_offset; 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 }, }; -static struct mips_frame_info schedule_frame; -static struct mips_frame_info schedule_timeout_frame; -static struct mips_frame_info sleep_on_frame; -static struct mips_frame_info sleep_on_timeout_frame; -static struct mips_frame_info wait_for_completion_frame; + static int mips_frame_info_initialized; -static int __init get_frame_info(struct mips_frame_info *info, void *func) +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 = -1; + info->frame_offset = info->omit_fp ? 0 : -1; for (i = 0; i < 128; i++, ip++) { /* if jal, jalr, jr, stop. */ if (ip->j_format.opcode == jal_op || @@ -247,14 +273,16 @@ static int __init get_frame_info(struct mips_frame_info *info, void *func) /* sw / sd $ra, offset($sp) */ if (ip->i_format.rt == 31) { if (info->pc_offset != -1) - break; + 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) - break; + continue; +//#endif info->frame_offset = ip->i_format.simmediate / sizeof(long); } @@ -272,13 +300,25 @@ static int __init get_frame_info(struct mips_frame_info *info, void *func) static int __init frame_info_init(void) { - mips_frame_info_initialized = - !get_frame_info(&schedule_frame, schedule) && - !get_frame_info(&schedule_timeout_frame, schedule_timeout) && - !get_frame_info(&sleep_on_frame, sleep_on) && - !get_frame_info(&sleep_on_timeout_frame, sleep_on_timeout) && - !get_frame_info(&wait_for_completion_frame, wait_for_completion); - + 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; return 0; } @@ -303,60 +343,39 @@ unsigned long thread_saved_pc(struct task_struct *tsk) /* 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; if (!p || p == current || p->state == TASK_RUNNING) return 0; - if (!mips_frame_info_initialized) + stack_page = (unsigned long)p->thread_info; + if (!stack_page || !mips_frame_info_initialized) return 0; + pc = thread_saved_pc(p); if (!in_sched_functions(pc)) - goto out; - - if (pc >= (unsigned long) sleep_on_timeout) - goto schedule_timeout_caller; - if (pc >= (unsigned long) sleep_on) - goto schedule_caller; - if (pc >= (unsigned long) interruptible_sleep_on_timeout) - goto schedule_timeout_caller; - if (pc >= (unsigned long)interruptible_sleep_on) - goto schedule_caller; - if (pc >= (unsigned long)wait_for_completion) - goto schedule_caller; - goto schedule_timeout_caller; - -schedule_caller: - frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset]; - if (pc >= (unsigned long) sleep_on) - pc = ((unsigned long *)frame)[sleep_on_frame.pc_offset]; - else - pc = ((unsigned long *)frame)[wait_for_completion_frame.pc_offset]; - goto out; + return pc; -schedule_timeout_caller: - /* - * The schedule_timeout frame - */ frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset]; + do { + int i; - /* - * frame now points to sleep_on_timeout's frame - */ - pc = ((unsigned long *)frame)[schedule_timeout_frame.pc_offset]; + if (frame < stack_page || frame > stack_page + THREAD_SIZE - 32) + return 0; - if (in_sched_functions(pc)) { - /* schedule_timeout called by [interruptible_]sleep_on_timeout */ - frame = ((unsigned long *)frame)[schedule_timeout_frame.frame_offset]; - pc = ((unsigned long *)frame)[sleep_on_timeout_frame.pc_offset]; - } - -out: + for (i = ARRAY_SIZE(mfinfo) - 1; i >= 0; i--) { + if (pc >= (unsigned long) mfinfo[i].func) + break; + } + if (i < 0) + break; -#ifdef CONFIG_64BIT - if (current->thread.mflags & MF_32BIT_REGS) /* Kludge for 32-bit ps */ - pc &= 0xffffffffUL; -#endif + if (mfinfo[i].omit_fp) + break; + pc = ((unsigned long *)frame)[mfinfo[i].pc_offset]; + frame = ((unsigned long *)frame)[mfinfo[i].frame_offset]; + } while (in_sched_functions(pc)); return pc; } -- 2.20.1