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); pctldev->num_groups = 0; } diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c index 29ad315..6a70339 100644 --- a/drivers/pinctrl/pinmux.c +++ b/drivers/pinctrl/pinmux.c @@ -836,8 +836,8 @@ void pinmux_generic_free_functions(struct pinctrl_dev *pctldev) void **slot; int i = 0; - indices = devm_kzalloc(pctldev->dev, sizeof(*indices) * - pctldev->num_functions, GFP_KERNEL); + indices = kcalloc(pctldev->num_functions, sizeof(*indices), + GFP_KERNEL); if (!indices) return; @@ -850,6 +850,7 @@ void pinmux_generic_free_functions(struct pinctrl_dev *pctldev) radix_tree_delete(&pctldev->pin_function_tree, indices[i]); devm_kfree(pctldev->dev, function); } + kfree(indices); pctldev->num_functions = 0; } -- 2.8.2 -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.