13d57093c1
In testing James' patch to drivers/parisc/pdc_stable.c, I hit the BUG statement in flush_cache_range() during a system shutdown: kernel BUG at arch/parisc/kernel/cache.c:595! CPU: 2 PID: 6532 Comm: kworker/2:0 Not tainted 4.13.0-rc2+ #1 Workqueue: events free_ioctx IAOQ[0]: flush_cache_range+0x144/0x148 IAOQ[1]: flush_cache_page+0x0/0x1a8 RP(r2): flush_cache_range+0xec/0x148 Backtrace: [<00000000402910ac>] unmap_page_range+0x84/0x880 [<00000000402918f4>] unmap_single_vma+0x4c/0x60 [<0000000040291a18>] zap_page_range_single+0x110/0x160 [<0000000040291c34>] unmap_mapping_range+0x174/0x1a8 [<000000004026ccd8>] truncate_pagecache+0x50/0xa8 [<000000004026cd84>] truncate_setsize+0x54/0x70 [<000000004033d534>] put_aio_ring_file+0x44/0xb0 [<000000004033d5d8>] aio_free_ring+0x38/0x140 [<000000004033d714>] free_ioctx+0x34/0xa8 [<00000000401b0028>] process_one_work+0x1b8/0x4d0 [<00000000401b04f4>] worker_thread+0x1b4/0x648 [<00000000401b9128>] kthread+0x1b0/0x208 [<0000000040150020>] end_fault_vector+0x20/0x28 [<0000000040639518>] nf_ip_reroute+0x50/0xa8 [<0000000040638ed0>] nf_ip_route+0x10/0x78 [<0000000040638c90>] xfrm4_mode_tunnel_input+0x180/0x1f8 CPU: 2 PID: 6532 Comm: kworker/2:0 Not tainted 4.13.0-rc2+ #1 Workqueue: events free_ioctx Backtrace: [<0000000040163bf0>] show_stack+0x20/0x38 [<0000000040688480>] dump_stack+0xa8/0x120 [<0000000040163dc4>] die_if_kernel+0x19c/0x2b0 [<0000000040164d0c>] handle_interruption+0xa24/0xa48 This patch modifies flush_cache_range() to handle non current contexts. In as much as this occurs infrequently, the simplest approach is to flush the entire cache when this happens. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org # 4.9+ Signed-off-by: Helge Deller <deller@gmx.de>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.