Re: 2.5.64-mm1
From: Alex Tomas <hidden>
Date: 2003-03-06 13:46:02
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Andrew Morton (AM) writes:
AM> hm, yes, it does look that way. AM> It could be that any task which travels that path ends up running AM> under lock_kernel() for the rest of its existence, and nobody AM> noticed. Probably, this patch may help us. It checks current->lock_depth after each syscall and prints warning. diff -uNr linux/arch/i386/kernel/entry.S edited/arch/i386/kernel/entry.S
--- linux/arch/i386/kernel/entry.S Thu Mar 6 14:57:38 2003
+++ edited/arch/i386/kernel/entry.S Thu Mar 6 16:40:27 2003@@ -282,6 +282,17 @@ syscall_call: call *sys_call_table(,%eax,4) movl %eax,EAX(%esp) # store the return value + + movl TI_TASK(%ebp), %edx # check current->lock_depth + movl 20(%edx), %ecx + cmpl $0, %ecx + je syscall_exit + cmpl $-1, %ecx + je syscall_exit + + GET_THREAD_INFO(%ebp) + call warn_invalid_lock_depth + syscall_exit: cli # make sure we don't miss an interrupt # setting need_resched or sigpending
diff -uNr linux/arch/i386/kernel/l edited/arch/i386/kernel/l
--- linux/arch/i386/kernel/l Thu Jan 1 03:00:00 1970
+++ edited/arch/i386/kernel/l Thu Mar 6 13:44:03 2003@@ -0,0 +1 @@ +make: *** No rule to make target `bzImage'. Stop.
diff -uNr linux/arch/i386/kernel/process.c edited/arch/i386/kernel/process.c
--- linux/arch/i386/kernel/process.c Thu Mar 6 14:57:25 2003
+++ edited/arch/i386/kernel/process.c Thu Mar 6 16:32:17 2003@@ -714,3 +714,14 @@ return 0; } +asmlinkage void warn_invalid_lock_depth(void) +{ + struct task_struct * tsk = current; + + if (!(tsk->flags & 0x10000000)) { + printk("WARNING: non-zero(%d) lock_depth, pid %u\n", + tsk->lock_depth, tsk->pid); + tsk->flags |= 0x10000000; + } +} + --
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