On Thu, Aug 08, 2019 at 05:47:29PM +0200, Romain Perier wrote: > Le mar. 23 juil. 2019 à 10:15, Romain Perier <romain.perier@xxxxxxxxx> a écrit : > > > > Le lun. 22 juil. 2019 à 19:19, Kees Cook <keescook@xxxxxxxxxxxx> a écrit : > > > > > > On Sun, Jul 21, 2019 at 07:55:33PM +0200, Romain Perier wrote: > > > > Ok, thanks for these explanations. > > > > > > (Reminder: please use inline-context email replies instead of > > > top-posting, this makes threads much easier to read.) > > > > Arf, good point. My bad :) > > > > > > > > > > > Looks good! I wonder if you're able to use Coccinelle to generate the > > > conversion patch? There appear to be just under 400 callers of > > > tasklet_init(), which is a lot to type by hand. :) > > > > Mmmhhh, I did not thought *at all* to coccinelle for this, good idea. > > I am gonna to read some docs about the tool > > > > > > > > Also, have you found any other tasklet users that are NOT using > > > tasklet_init()? The timer_struct conversion had about three ways > > > to do initialization. :( > > > > This is what I was looking before you give me details about the task. > > It seems, there > > is only one way to init a tasklet. I have just re-checked, it seems ok. > > Work is in progress (that's an hobby not full time). I am testing the > build with "allyesconfig". That's good -- I tend to use allmodconfig (since it sort of tests a larger set of functions -- the module init code is more complex than the static init code, IIRC), but I think for this series, you're fine either way. > Do you think it is acceptable to change > drivers/mmc/host/renesas_sdhi_internal_dmac.c to add a pointer to the > "struct device" or to the "host", so > renesas_sdhi_internal_dmac_complete_tasklet_fn() could access "host" > from the tasklet parameter > because currently, it is not possible. > from the tasklet you can access "dma_priv", from "dma_priv" you can > access "priv", then from "priv", you're blocked :) > > > This is what I have done for now : > https://salsa.debian.org/rperier-guest/linux-tree/commit/a0e5735129b4118a1df55b02fead6fa9b7996520 > (separately) > > Then the handler would be something like: > https://salsa.debian.org/rperier-guest/linux-tree/commit/5fe1eaeb45060a7df10d166cc96e0bdcf0024368 > (scroll down to renesas_sdhi_internal_dmac_complete_tasklet_fn() ). I did things like this in a few cases for timer_struct, yes. The only question I have is if "struct device" is what you want or "struct platform_device" is what you want? + priv->dev = &pdev->dev; You're already dereferencing "pdev" to get "dev", and then: + struct platform_device *pdev = container_of(priv->dev, typeof(*pdev), dev); What you really want is the pdev anyway in the handler. Maybe just store that instead? Also, I think you can avoid the "dma_priv" variable with a from_tasklet() that uses dma_priv.dma_complete. Something like: struct renesas_sdhi *priv = from_tasklet(priv, t, dma_priv.dma_complete); The only other gotcha to check is if it's ever possible for the pointer you're storing to change through some other means, which would cause you to be doing a use-after-free in this handler? (I assume not, since dma completion is tied to the device...) -- Kees Cook
