hi,Greg
thanks for your kind reply :)
I will send out patch V2 later. let me do some explanation here first.
this feature which I am working on is reverted totally by commit fc21c0 in upstream, maybe the author notice the code is buggy.
So I just fix it, not revert this feature here, big change is not accepted in stable kernel tree.
thanks again for your help.
thanks
xinhui
On 2015年05月12日 20:14, Greg KH wrote:
On Wed, May 13, 2015 at 05:03:04PM +0800, Pan Xinhui wrote:
this patch reverts commit 3440a1ca99707f093e9568ba9762764d3162dd8f which causes the regression.
base knowledge: kernel call cp->func using cp->info as its argument. like cp->func(cp->info);
current code is totally wrong, as 1) &softirq is at stack. 2) cp->info don't point to struct call_single_data.
So in remote_softirq_receive,
1) If the caller had left __try_remote_softirq, dereferencing cp->info could not fetch the correct value.
2) And we can't get struct call_single_data *cp anymore.
The list corruption is below.
__local_trigger will add cp->list into softirq_work_list. But no one will delete cp->list on behalf of us.
if we can succeed to raise_softirq_irqoff, we must delete it from softirq_work_list. because we has lost control of pointer cp.
cp is passed in and may be freed later in other places.
Cc: <stable@xxxxxxxxxxxxxxx> # 3.10
Signed-off-by: xinhuix.pan <xinhuix.pan@xxxxxxxxx>
---
include/linux/smp.h | 1 +
kernel/softirq.c | 10 +++++++---
2 files changed, 8 insertions(+), 3 deletions(-)
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