4.19-stable review patch. If anyone has any objections, please let me know.
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From: Krzysztof Kozlowski krzk@kernel.org
commit 785c9f411eb2d9a6076d3511c631587d5e676bf3 upstream.
Platform driver driver_override field should not be initialized from const memory because the core later kfree() it. If driver_override is manually set later through sysfs, kfree() of old value leads to:
$ echo "new_value" > /sys/bus/platform/drivers/.../driver_override
kernel BUG at ../mm/slub.c:3960! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM ... (kfree) from [<c058e8c0>] (platform_set_driver_override+0x84/0xac) (platform_set_driver_override) from [<c058e908>] (driver_override_store+0x20/0x34) (driver_override_store) from [<c031f778>] (kernfs_fop_write+0x100/0x1dc) (kernfs_fop_write) from [<c0296de8>] (__vfs_write+0x2c/0x17c) (__vfs_write) from [<c02970c4>] (vfs_write+0xa4/0x188) (vfs_write) from [<c02972e8>] (ksys_write+0x4c/0xac) (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x28)
The clk-exynos5-subcmu driver uses override only for the purpose of creating meaningful names for children devices (matching names of power domains, e.g. DISP, MFC). The driver_override was not developed for this purpose so just switch to default names of devices to fix the issue.
Fixes: b06a532bf1fa ("clk: samsung: Add Exynos5 sub-CMU clock driver") Cc: stable@vger.kernel.org Signed-off-by: Krzysztof Kozlowski krzk@kernel.org Reviewed-by: Geert Uytterhoeven geert+renesas@glider.be Signed-off-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/clk/samsung/clk-exynos5-subcmu.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/clk/samsung/clk-exynos5-subcmu.c +++ b/drivers/clk/samsung/clk-exynos5-subcmu.c @@ -138,12 +138,11 @@ static int __init exynos5_clk_register_s struct platform_device *pdev; int ret;
- pdev = platform_device_alloc(info->pd_name, -1); + pdev = platform_device_alloc("exynos5-subcmu", PLATFORM_DEVID_AUTO); if (!pdev) return -ENOMEM;
pdev->dev.parent = parent; - pdev->driver_override = "exynos5-subcmu"; platform_set_drvdata(pdev, (void *)info); of_genpd_add_device(&genpdspec, &pdev->dev); ret = platform_device_add(pdev);