Messages in this thread | | | Date | Fri, 18 Jan 2008 16:48:44 -0500 | From | Jeff Layton <> | Subject | Re: [PATCH 1/4] SUNRPC: spin svc_rqst initialization to its own function |
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On Fri, 18 Jan 2008 15:59:43 -0500 "J. Bruce Fields" <bfields@fieldses.org> wrote:
> On Mon, Jan 14, 2008 at 09:05:15AM -0500, Jeff Layton wrote: > > Move the initialzation in __svc_create_thread that happens prior to > > thread creation to a new function. Export the function to allow > > services to have better control over the svc_rqst structs. > > > > Also rearrange the rqstp initialization to prevent NULL pointer > > dereferences in svc_exit_thread in case allocations fail. > > Those NULL dereferences are from the > > list_del(&rqstp->rq_all); > > ? OK, make sense. Thanks! > > --b. >
Sorry, I didn't explain that well...
This was the problem that Neil pointed out with the existing code. If the rqstp kzalloc succeeds, but the later kmallocs in __svc_create_thread fail, we goto here:
out_thread: svc_exit_thread(rqstp);
svc_exit_thread does this:
struct svc_pool *pool = rqstp->rq_pool;
...and then later:
spin_lock_bh(&pool->sp_lock);
...but rq_pool is set after the kmallocs, so if they fail rq_pool will be NULL, and we'll oops in that spin_lock_bh().
The fix is to move the kmallocs closer to the bottom in the new svc_prepare_thread function.
Thanks, -- Jeff Layton <jlayton@redhat.com>
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