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authorThiemo Seufer <ths@networkno.de>2005-02-21 10:55:16 +0000
committerRalf Baechle <ralf@linux-mips.org>2005-10-29 19:30:40 +0100
commitdc953df1ba5526814982676f47580c8e1bcdbfeb (patch)
tree83adba634d22f0788edbd944586b6f2d2a95bde7 /arch/mips/kernel
parent4e6a05fe5f87efd58da16fbf61e1f6329575fcfd (diff)
Fix wchan implementation, based on earlier by from Atsushi Nemoto.
Signed-off-by: Thiemo Seufer <ths@networkno.de> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel')
-rw-r--r--arch/mips/kernel/process.c135
1 files changed, 77 insertions, 58 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index e4f2f801138..f99efce556e 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, &regs, 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;
}