7c8ad3fc64
commit 52862ab33c5d97490f3fa345d6529829e6d6637b upstream. Commit 587164cd, introduced new opal message type (OPAL_MSG_PRD2) and added opal notifier. But I missed to unregister the notifier during module unload path. This results in below call trace if you try to unload and load opal_prd module. Also add new notifier_block for OPAL_MSG_PRD2 message. Sample calltrace (modprobe -r opal_prd; modprobe opal_prd) BUG: Unable to handle kernel data access on read at 0xc0080000192200e0 Faulting instruction address: 0xc00000000018d1cc Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV CPU: 66 PID: 7446 Comm: modprobe Kdump: loaded Tainted: G E 5.14.0prd #759 NIP: c00000000018d1cc LR: c00000000018d2a8 CTR: c0000000000cde10 REGS: c0000003c4c0f0a0 TRAP: 0300 Tainted: G E (5.14.0prd) MSR: 9000000002009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE> CR: 24224824 XER: 20040000 CFAR: c00000000018d2a4 DAR: c0080000192200e0 DSISR: 40000000 IRQMASK: 1 ... NIP notifier_chain_register+0x2c/0xc0 LR atomic_notifier_chain_register+0x48/0x80 Call Trace: 0xc000000002090610 (unreliable) atomic_notifier_chain_register+0x58/0x80 opal_message_notifier_register+0x7c/0x1e0 opal_prd_probe+0x84/0x150 [opal_prd] platform_probe+0x78/0x130 really_probe+0x110/0x5d0 __driver_probe_device+0x17c/0x230 driver_probe_device+0x60/0x130 __driver_attach+0xfc/0x220 bus_for_each_dev+0xa8/0x130 driver_attach+0x34/0x50 bus_add_driver+0x1b0/0x300 driver_register+0x98/0x1a0 __platform_driver_register+0x38/0x50 opal_prd_driver_init+0x34/0x50 [opal_prd] do_one_initcall+0x60/0x2d0 do_init_module+0x7c/0x320 load_module+0x3394/0x3650 __do_sys_finit_module+0xd4/0x160 system_call_exception+0x140/0x290 system_call_common+0xf4/0x258 Fixes: 587164cd593c ("powerpc/powernv: Add new opal message type") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211028165716.41300-1-hegdevasant@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.