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.
John David Anglin
authored
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>