c855af2f9c
Fix the problem of dev being released twice. ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 75 PID: 15700 at lib/refcount.c:28 refcount_warn_saturate+0xd4/0x150 CPU: 75 PID: 15700 Comm: rmmod Tainted: G E 5.10.0-rc3+ #3 Hardware name: Huawei TaiShan 200 (Model 2280)/BC82AMDDA, BIOS 0.88 07/24/2019 pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--) pc : refcount_warn_saturate+0xd4/0x150 lr : refcount_warn_saturate+0xd4/0x150 sp : ffff2028150cbc00 x29: ffff2028150cbc00 x28: ffff2028150121c0 x27: 0000000000000000 x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000003 x23: 0000000000000000 x22: ffff2028150cbc90 x21: ffff2020038a30a8 x20: ffff2028150cbc90 x19: ffff0020cd938020 x18: 0000000000000010 x17: 0000000000000000 x16: 0000000000000000 x15: ffffffffffffffff x14: ffff2028950cb88f x13: ffff2028150cb89d x12: 0000000000000000 x11: 0000000005f5e0ff x10: ffff2028150cb800 x9 : 00000000ffffffd0 x8 : 75203b776f6c6672 x7 : ffff800011a6f7c8 x6 : 0000000000000001 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 x2 : ffff202ffe2f9dc0 x1 : ffffa02fecf40000 x0 : 0000000000000026 Call trace: refcount_warn_saturate+0xd4/0x150 devm_drm_dev_init_release+0x50/0x70 devm_action_release+0x20/0x30 release_nodes+0x13c/0x218 devres_release_all+0x80/0x170 device_release_driver_internal+0x128/0x1f0 driver_detach+0x6c/0xe0 bus_remove_driver+0x74/0x100 driver_unregister+0x34/0x60 pci_unregister_driver+0x24/0xd8 hibmc_pci_driver_exit+0x14/0xe858 [hibmc_drm] __arm64_sys_delete_module+0x1fc/0x2d0 el0_svc_common.constprop.3+0xa8/0x188 do_el0_svc+0x80/0xa0 el0_sync_handler+0x8c/0xb0 el0_sync+0x15c/0x180 CPU: 75 PID: 15700 Comm: rmmod Tainted: G E 5.10.0-rc3+ #3 Hardware name: Huawei TaiShan 200 (Model 2280)/BC82AMDDA, BIOS 0.88 07/24/2019 Call trace: dump_backtrace+0x0/0x208 show_stack+0x2c/0x40 dump_stack+0xd8/0x10c __warn+0xac/0x128 report_bug+0xcc/0x180 bug_handler+0x24/0x78 call_break_hook+0x80/0xa0 brk_handler+0x28/0x68 do_debug_exception+0x9c/0x148 el1_sync_handler+0x7c/0x128 el1_sync+0x80/0x100 refcount_warn_saturate+0xd4/0x150 devm_drm_dev_init_release+0x50/0x70 devm_action_release+0x20/0x30 release_nodes+0x13c/0x218 devres_release_all+0x80/0x170 device_release_driver_internal+0x128/0x1f0 driver_detach+0x6c/0xe0 bus_remove_driver+0x74/0x100 driver_unregister+0x34/0x60 pci_unregister_driver+0x24/0xd8 hibmc_pci_driver_exit+0x14/0xe858 [hibmc_drm] __arm64_sys_delete_module+0x1fc/0x2d0 el0_svc_common.constprop.3+0xa8/0x188 do_el0_svc+0x80/0xa0 el0_sync_handler+0x8c/0xb0 el0_sync+0x15c/0x180 ---[ end trace 00718630d6e5ff18 ]--- Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/1607941973-32287-1-git-send-email-tiantao6@hisilicon.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.