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
task: 000000007b32abb0 task.stack: 0000000062180000
YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001001111011100001111 Not tainted
r00-03 000000ff0804f70f 000000004072bdc0 000000004016302c 0000000062180aa0
r04-07 00000000407165c0 000000007b41f590 00000000f37bd000 00000000f37c0000
r08-11 000000007b41f590 00000000621806b8 0000000000000001 0000000000000064
r12-15 00000000407435c0 00000000407445c0 00000000f37bd000 0000000000000000
r16-19 fffffff0f0d00b0c 00000000621806b8 000000007b41f590 0000000062180000
r20-23 0000000000000f97 000000000800000f 00000000621806b8 00000000f37c0000
r24-27 00000000f37c0000 000000000800000f 0000000040888100 00000000407165c0
r28-31 000000000b9ba800 0000000062180ce0 0000000062180b40 00000000004ca800
sr00-03 000000000b9ba800 00000000004ca800 0000000000000000 000000000b9ba800
sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000
IASQ: 0000000000000000 0000000000000000 IAOQ: 0000000040163084 0000000040163088
IIR: 03ffe01f ISR: 0000000010240000 IOR: 0000008860180018
CPU: 2 CR30: 0000000062180000 CR31: ffffffffffffffff
ORIG_R28: 0000000062180d30
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@xxxxxxxx>
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 85a92db70afc..19c0c141bc3f 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -587,13 +587,12 @@ void flush_cache_range(struct vm_area_struct *vma,
if (parisc_requires_coherency())
flush_tlb_range(vma, start, end);
- if ((end - start) >= parisc_cache_flush_threshold) {
+ if ((end - start) >= parisc_cache_flush_threshold
+ || vma->vm_mm->context != mfsp(3)) {
flush_cache_all();
return;
}
- BUG_ON(vma->vm_mm->context != mfsp(3));
-
flush_user_dcache_range_asm(start, end);
if (vma->vm_flags & VM_EXEC)
flush_user_icache_range_asm(start, end);
--
John David Anglin dave.anglin@xxxxxxxx
