Re: free_task_struct() called too early?
Alan Cox (alan@lxorguk.ukuu.org.uk)
Fri, 10 Aug 2001 23:43:23 +0100 (BST)
> When a process terminates, it appears that the task structure is freed too
> early. There are memory references to the kernel task area (task_struct and
> stack space) after free_task_struct(p) is called.
>
> If I modify the following line in include/asm-i386/processor.h
>
> #define free_task_struct(p) free_pages((unsigned long) (p), 1) to
> #define free_task_struct(p) memset((void*) (p), 0xf, PAGE_SIZE*2);
> free_pages((unsigned long) (p), 1)
> then kernel will boot to init and lockup on when first task terminates.
>
> Has anyone looked into or aware of this issue?
2.4.8pre fixed a case with semaphores on the stack. It might not be the only
one. Your #define is wrong though, if a single free_task_struct path is an
if you will not do what you expect
do { memset(), free_pages } while(0);
would be safer.
I'd like to know if 2.4.8pre8 does it except on module unload (where it is
still buggy)
Alan
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