Hi Andre, On Thu, May 04, 2017 at 12:57:37AM +0100, Andre Przywara wrote: > When a pinctrl driver gets interrupted during its probe process > (returning -EPROBE_DEFER), the devres system cleans up all allocated > resources. During this process it calls pinmux_generic_free_functions() > and pinctrl_generic_free_groups(), which in turn use managed kmalloc > calls for temporarily allocating some memory. Now those calls seem to > get added to the devres list, but are apparently not covered by the > cleanup process, because this is actually just running and iterating the > existing list. This leads to those mallocs being left with the device, > which the devres manager complains about when the driver eventually gets > probed again: > [ 0.825239] ------------[ cut here ]------------ > [ 0.825256] WARNING: CPU: 1 PID: 89 at drivers/base/dd.c:349 > driver_probe_device+0x2ac/0x2e8 > [ 0.825258] Modules linked in: > [ 0.825262] > [ 0.825270] CPU: 1 PID: 89 Comm: kworker/1:1 Not tainted 4.11.0 #307 > [ 0.825272] Hardware name: Pine64+ (DT) > [ 0.825283] Workqueue: events deferred_probe_work_func > [ 0.825288] task: ffff80007c19c100 task.stack: ffff80007c16c000 > [ 0.825292] PC is at driver_probe_device+0x2ac/0x2e8 > [ 0.825296] LR is at driver_probe_device+0x108/0x2e8 > [ 0.825300] pc : [<ffff000008559234>] lr : [<ffff000008559090>] pstate: > 20000045 > .... > This warning is triggered because the devres list is not empty. In this > case the allocations were using 0 bytes, so no real leaks, but still this > ugly warning. > Looking more closely at these *cleanup* functions, devm_kzalloc() is actually > not needed, because the memory is just allocated temporarily and can be > freed just before returning from this function. > So fix this issue by using the bog standard kcalloc() call instead of > devm_kzalloc() and kfree()ing the memory at the end. > > This fixes above warnings on boot, which can be observed on *some* builds > for the Pine64, where the pinctrl driver gets loaded early, but it missing > resources, so gets deferred and is loaded again (successfully) later. > kernelci caught this as well [1]. > > Signed-off-by: Andre Przywara <andre.przyw...@arm.com> > > [1] > https://storage.kernelci.org/net-next/master/v4.11-rc8-2122-gc08bac03d289/arm64/defconfig/lab-baylibre-seattle/boot-sun50i-a64-pine64-plus.html > --- > Hi, > > not sure this is the right fix, I am open to suggestions. > > Cheers, > Andre. > > drivers/pinctrl/core.c | 5 +++-- > drivers/pinctrl/pinmux.c | 5 +++-- > 2 files changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c > index 32822b0d..5198415 100644 > --- a/drivers/pinctrl/core.c > +++ b/drivers/pinctrl/core.c > @@ -690,8 +690,8 @@ static void pinctrl_generic_free_groups(struct > pinctrl_dev *pctldev) > void **slot; > int i = 0; > > - indices = devm_kzalloc(pctldev->dev, sizeof(*indices) * > - pctldev->num_groups, GFP_KERNEL); > + indices = kcalloc(pctldev->num_groups, sizeof(*indices), > + GFP_KERNEL); > if (!indices) > return; > > @@ -704,6 +704,7 @@ static void pinctrl_generic_free_groups(struct > pinctrl_dev *pctldev) > radix_tree_delete(&pctldev->pin_group_tree, indices[i]); > devm_kfree(pctldev->dev, group); > } > + kfree(indices);
We use devm_kfree for other allocations done here, maybe we can just have the same thing here? We would be consistant, and we would still keep the resource tracking. Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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