Re: [PATCH] pinctrl: mediatek: Free eint data on failure

From: Enric Balletbo i Serra
Date: Fri Aug 21 2020 - 02:56:33 EST

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In reply to: Sean Wang: "Re: [PATCH] pinctrl: mediatek: Free eint data on failure"
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Hi Sean,

On 20/8/20 2:00, Sean Wang wrote:
> On Wed, Aug 19, 2020 at 9:19 AM Enric Balletbo i Serra
> <enric.balletbo@xxxxxxxxxxxxx> wrote:
>>
>> The pinctrl driver can work without the EINT resource, but, if it is
>> expected to have this resource but the mtk_build_eint() function fails
>> after allocating their data (because can't get the resource or can't map
>> the irq), the data is not freed and you end with a NULL pointer
>> dereference. Fix this by freeing the data if mtk_build_eint() fails, so
>> pinctrl still works and doesn't hang.
>>
>> This is noticeable after commit f97dbf48ca43 ("irqchip/mtk-sysirq: Convert
>> to a platform driver") on MT8183 because, due this commit, the pinctrl driver
>> fails to map the irq and spots the following bug:
>>
>> [ 1.947597] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
>> [ 1.956404] Mem abort info:
>> [ 1.959203] ESR = 0x96000004
>> [ 1.962259] EC = 0x25: DABT (current EL), IL = 32 bits
>> [ 1.967565] SET = 0, FnV = 0
>> [ 1.970613] EA = 0, S1PTW = 0
>> [ 1.973747] Data abort info:
>> [ 1.976619] ISV = 0, ISS = 0x00000004
>> [ 1.980447] CM = 0, WnR = 0
>> [ 1.983410] [0000000000000004] user address but active_mm is swapper
>> [ 1.989759] Internal error: Oops: 96000004 [#1] PREEMPT SMP
>> [ 1.995322] Modules linked in:
>> [ 1.998371] CPU: 7 PID: 1 Comm: swapper/0 Not tainted 5.9.0-rc1+ #44
>> [ 2.004715] Hardware name: MediaTek krane sku176 board (DT)
>> [ 2.010280] pstate: 60000005 (nZCv daif -PAN -UAO BTYPE=--)
>> [ 2.015850] pc : mtk_eint_set_debounce+0x48/0x1b8
>> [ 2.020546] lr : mtk_eint_set_debounce+0x34/0x1b8
>> [ 2.025239] sp : ffff80001008baa0
>> [ 2.028544] x29: ffff80001008baa0 x28: ffff0000ff7ff790
>> [ 2.033847] x27: ffff0000f9ec34b0 x26: ffff0000f9ec3480
>> [ 2.039150] x25: ffff0000fa576410 x24: ffff0000fa502800
>> [ 2.044453] x23: 0000000000001388 x22: ffff0000fa635f80
>> [ 2.049755] x21: 0000000000000008 x20: 0000000000000000
>> [ 2.055058] x19: 0000000000000071 x18: 0000000000000001
>> [ 2.060360] x17: 0000000000000000 x16: 0000000000000000
>> [ 2.065662] x15: ffff0000facc8470 x14: ffffffffffffffff
>> [ 2.070965] x13: 0000000000000001 x12: 00000000000000c0
>> [ 2.076267] x11: 0000000000000040 x10: 0000000000000070
>> [ 2.081569] x9 : ffffaec0063d24d8 x8 : ffff0000fa800270
>> [ 2.086872] x7 : 0000000000000000 x6 : 0000000000000011
>> [ 2.092174] x5 : ffff0000fa800248 x4 : ffff0000fa800270
>> [ 2.097476] x3 : ffff8000100c5000 x2 : 0000000000000000
>> [ 2.102778] x1 : 0000000000000000 x0 : 0000000000000000
>> [ 2.108081] Call trace:
>> [ 2.110520] mtk_eint_set_debounce+0x48/0x1b8
>> [ 2.114870] mtk_gpio_set_config+0x5c/0x78
>> [ 2.118958] gpiod_set_config+0x5c/0x78
>> [ 2.122786] gpiod_set_debounce+0x18/0x28
>> [ 2.126789] gpio_keys_probe+0x50c/0x910
>> [ 2.130705] platform_drv_probe+0x54/0xa8
>> [ 2.134705] really_probe+0xe4/0x3b0
>> [ 2.138271] driver_probe_device+0x58/0xb8
>> [ 2.142358] device_driver_attach+0x74/0x80
>> [ 2.146532] __driver_attach+0x58/0xe0
>> [ 2.150274] bus_for_each_dev+0x70/0xc0
>> [ 2.154100] driver_attach+0x24/0x30
>> [ 2.157666] bus_add_driver+0x14c/0x1f0
>> [ 2.161493] driver_register+0x64/0x120
>> [ 2.165319] __platform_driver_register+0x48/0x58
>> [ 2.170017] gpio_keys_init+0x1c/0x28
>> [ 2.173672] do_one_initcall+0x54/0x1b4
>> [ 2.177499] kernel_init_freeable+0x1d0/0x238
>> [ 2.181848] kernel_init+0x14/0x118
>> [ 2.185328] ret_from_fork+0x10/0x34
>> [ 2.188899] Code: a9438ac1 12001266 f94006c3 121e766a (b9400421)
>> [ 2.194991] ---[ end trace 168cf7b3324b6570 ]---
>> [ 2.199611] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
>> [ 2.207260] SMP: stopping secondary CPUs
>> [ 2.211294] Kernel Offset: 0x2ebff4800000 from 0xffff800010000000
>> [ 2.217377] PHYS_OFFSET: 0xffffb50500000000
>> [ 2.221551] CPU features: 0x0240002,2188200c
>> [ 2.225811] Memory Limit: none
>> [ 2.228860] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---
>>
>> Fixes: 89132dd8ffd2 ("pinctrl: mediatek: extend eint build to pinctrl-mtk-common-v2.c")
>> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
>> ---
>>
>> .../pinctrl/mediatek/pinctrl-mtk-common-v2.c | 27 ++++++++++++++-----
>> 1 file changed, 20 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
>> index 2f3dfb56c3fa..4b532e6b9038 100644
>> --- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
>> +++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
>> @@ -355,6 +355,7 @@ int mtk_build_eint(struct mtk_pinctrl *hw, struct platform_device *pdev)
>> {
>> struct device_node *np = pdev->dev.of_node;
>> struct resource *res;
>> + int ret;
>>
>> if (!IS_ENABLED(CONFIG_EINT_MTK))
>> return 0;
>> @@ -369,19 +370,26 @@ int mtk_build_eint(struct mtk_pinctrl *hw, struct platform_device *pdev)
>> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "eint");
>> if (!res) {
>> dev_err(&pdev->dev, "Unable to get eint resource\n");
>> - return -ENODEV;
>> + ret = -ENODEV;
>> + goto err_free_eint;
>> }
>>
>> hw->eint->base = devm_ioremap_resource(&pdev->dev, res);
>> - if (IS_ERR(hw->eint->base))
>> - return PTR_ERR(hw->eint->base);
>> + if (IS_ERR(hw->eint->base)) {
>> + ret = PTR_ERR(hw->eint->base);
>> + goto err_free_eint;
>> + }
>>
>> hw->eint->irq = irq_of_parse_and_map(np, 0);
>> - if (!hw->eint->irq)
>> - return -EINVAL;
>> + if (!hw->eint->irq) {
>> + ret = -EINVAL;
>> + goto err_free_eint;
>> + }
>>
>> - if (!hw->soc->eint_hw)
>> - return -ENODEV;
>> + if (!hw->soc->eint_hw) {
>> + ret = -ENODEV;
>> + goto err_free_eint;
>> + }
>>
>> hw->eint->dev = &pdev->dev;
>> hw->eint->hw = hw->soc->eint_hw;
>> @@ -389,6 +397,11 @@ int mtk_build_eint(struct mtk_pinctrl *hw, struct platform_device *pdev)
>> hw->eint->gpio_xlate = &mtk_eint_xt;
>>
>> return mtk_eint_do_init(hw->eint);
>> +
>
> Similarly, I think we have to call devm_ioremap_release to explicitly
> free resource when a certain failure occurs after
> devm_ioremap_resource, right?
>

Right, I'll do this for the second version.

Thanks,
Enric

>> +err_free_eint:
>> + devm_kfree(hw->dev, hw->eint);
>> + hw->eint = NULL;
>> + return ret;
>> }
>> EXPORT_SYMBOL_GPL(mtk_build_eint);
>>
>> --
>> 2.28.0
>>

Next message: Pavel Machek: "Re: [PATCH 4.14 196/228] RDMA/ipoib: Return void from ipoib_ib_dev_stop()"
Previous message: peterz: "Re: [PATCH 0/9] TRACE_IRQFLAGS wreckage"
In reply to: Sean Wang: "Re: [PATCH] pinctrl: mediatek: Free eint data on failure"
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