| Message ID | 20231019101017.425284-4-herve.codina@bootlin.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix i2c mux module refcount issues | expand |
On Thu, Oct 19, 2023 at 12:10:16PM +0200, Herve Codina wrote: > i2c-mux-gpmux uses the pair of_find_i2c_adapter_by_node() / > i2c_put_adapter(). These pair alone is not correct to properly lock the > I2C parent adapter. > > Indeed, i2c_put_adapter() decrements the module refcount while > of_find_i2c_adapter_by_node() does not increment it. This leads to an > underflow of the parent module refcount. > > Use the dedicated function, of_get_i2c_adapter_by_node(), to handle > correctly the module refcount. > > Fixes: ac8498f0ce53 ("i2c: i2c-mux-gpmux: new driver") > Signed-off-by: Herve Codina <herve.codina@bootlin.com> > Acked-by: Peter Rosin <peda@axentia.se> > --- > drivers/i2c/muxes/i2c-mux-gpmux.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Hi, This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him a patch that has triggered this response. He used to manually respond to these common problems, but in order to save his sanity (he kept writing the same thing over and over, yet to different people), I was created. Hopefully you will not take offence and will fix the problem in your patch and resubmit it so that it can be accepted into the Linux kernel tree. You are receiving this message because of the following common error(s) as indicated below: - You have marked a patch with a "Fixes:" tag for a commit that is in an older released kernel, yet you do not have a cc: stable line in the signed-off-by area at all, which means that the patch will not be applied to any older kernel releases. To properly fix this, please follow the documented rules in the Documentation/process/stable-kernel-rules.rst file for how to resolve this. If you wish to discuss this problem further, or you have questions about how to resolve this issue, please feel free to respond to this email and Greg will reply once he has dug out from the pending patches received from other developers. thanks, greg k-h's patch email bot
On Thu, 19 Oct 2023 12:10:16 +0200 Herve Codina <herve.codina@bootlin.com> wrote: > i2c-mux-gpmux uses the pair of_find_i2c_adapter_by_node() / > i2c_put_adapter(). These pair alone is not correct to properly lock the > I2C parent adapter. > > Indeed, i2c_put_adapter() decrements the module refcount while > of_find_i2c_adapter_by_node() does not increment it. This leads to an > underflow of the parent module refcount. > > Use the dedicated function, of_get_i2c_adapter_by_node(), to handle > correctly the module refcount. > > Fixes: ac8498f0ce53 ("i2c: i2c-mux-gpmux: new driver") > Signed-off-by: Herve Codina <herve.codina@bootlin.com> > Acked-by: Peter Rosin <peda@axentia.se> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > drivers/i2c/muxes/i2c-mux-gpmux.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/i2c/muxes/i2c-mux-gpmux.c b/drivers/i2c/muxes/i2c-mux-gpmux.c > index baccf4bfaf02..8305661e1253 100644 > --- a/drivers/i2c/muxes/i2c-mux-gpmux.c > +++ b/drivers/i2c/muxes/i2c-mux-gpmux.c > @@ -52,7 +52,7 @@ static struct i2c_adapter *mux_parent_adapter(struct device *dev) > dev_err(dev, "Cannot parse i2c-parent\n"); > return ERR_PTR(-ENODEV); > } > - parent = of_find_i2c_adapter_by_node(parent_np); > + parent = of_get_i2c_adapter_by_node(parent_np); > of_node_put(parent_np); > if (!parent) > return ERR_PTR(-EPROBE_DEFER);
diff --git a/drivers/i2c/muxes/i2c-mux-gpmux.c b/drivers/i2c/muxes/i2c-mux-gpmux.c index baccf4bfaf02..8305661e1253 100644 --- a/drivers/i2c/muxes/i2c-mux-gpmux.c +++ b/drivers/i2c/muxes/i2c-mux-gpmux.c @@ -52,7 +52,7 @@ static struct i2c_adapter *mux_parent_adapter(struct device *dev) dev_err(dev, "Cannot parse i2c-parent\n"); return ERR_PTR(-ENODEV); } - parent = of_find_i2c_adapter_by_node(parent_np); + parent = of_get_i2c_adapter_by_node(parent_np); of_node_put(parent_np); if (!parent) return ERR_PTR(-EPROBE_DEFER);
i2c-mux-gpmux uses the pair of_find_i2c_adapter_by_node() / i2c_put_adapter(). These pair alone is not correct to properly lock the I2C parent adapter. Indeed, i2c_put_adapter() decrements the module refcount while of_find_i2c_adapter_by_node() does not increment it. This leads to an underflow of the parent module refcount. Use the dedicated function, of_get_i2c_adapter_by_node(), to handle correctly the module refcount. Fixes: ac8498f0ce53 ("i2c: i2c-mux-gpmux: new driver") Signed-off-by: Herve Codina <herve.codina@bootlin.com> Acked-by: Peter Rosin <peda@axentia.se> --- drivers/i2c/muxes/i2c-mux-gpmux.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)