| Message ID | 1550749552-8133-3-git-send-email-krzk@kernel.org (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Commit | 785c9f411eb2d9a6076d3511c631587d5e676bf3 |
| Headers | show |
| Series | clk: samsung: Fix kfree() of const memory on setting driver_override | expand |
On Thu, Feb 21, 2019 at 12:46 PM Krzysztof Kozlowski <krzk@kernel.org> wrote: > 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> Gr{oetje,eeting}s, Geert
Quoting Krzysztof Kozlowski (2019-02-21 03:45:52) > 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> > --- Applied to clk-next
diff --git a/drivers/clk/samsung/clk-exynos5-subcmu.c b/drivers/clk/samsung/clk-exynos5-subcmu.c index d07ef26bd052..8ae44b5db4c2 100644 --- 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_subcmu(struct device *parent, 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);
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> --- drivers/clk/samsung/clk-exynos5-subcmu.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)