Messages in this thread Patch in this message | | | From | Shawn Wang <> | Subject | [PATCH] x86/resctrl: Clear the staged configs when destroying schemata list | Date | Tue, 27 Sep 2022 10:54:29 +0800 |
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Array staged_config in struct rdt_domain still maintains the original value when resctrl is unmounted. If resctrl is mounted with cdp option and then remounted without cdp option, field have_new_ctrl in staged_config[CDP_CODE] and staged_config[CDP_DATA] will still be true. Since resctrl_arch_update_domains() traverses all resctrl_conf_type, it will continue to update CDP_CODE and CDP_DATA configurations, which can cause overflow problem.
The problem can be reproduced by the following commands: # A system with 16 usable closids and mba disabled mount -t resctrl resctrl -o cdp /sys/fs/resctrl mkdir /sys/fs/resctrl/p{1..7} umount /sys/fs/resctrl/ mount -t resctrl resctrl /sys/fs/resctrl mkdir /sys/fs/resctrl/p{1..8}
dmesg will generate the following error: [ 6180.939345] unchecked MSR access error: WRMSR to 0xca0 (tried to write 0x00000000000007ff) at rIP: 0xffffffff82249142 (cat_wrmsr+0x32/0x60) [ 6180.951983] Call Trace: [ 6180.954516] <IRQ> [ 6180.956619] __flush_smp_call_function_queue+0x11d/0x170 [ 6180.962028] __sysvec_call_function+0x24/0xd0 [ 6180.966485] sysvec_call_function+0x89/0xc0 [ 6180.970760] </IRQ> [ 6180.972947] <TASK> [ 6180.975131] asm_sysvec_call_function+0x16/0x20 [ 6180.979757] RIP: 0010:cpuidle_enter_state+0xcd/0x400 [ 6180.984821] Code: 49 89 c5 0f 1f 44 00 00 31 ff e8 1e e5 77 ff 45 84 ff 74 12 9c 58 f6 c4 02 0f 85 13 03 00 00 31 ff e8 67 70 7d ff fb 45 85 f6 <0f> 88 75 01 00 00 49 63 c6 4c 2b 2c 24 48 8d 14 40 48 8d 14 90 49 [ 6181.003710] RSP: 0018:ffffffff83a03e48 EFLAGS: 00000202 [ 6181.009028] RAX: ffff943400800000 RBX: 0000000000000001 RCX: 000000000000001f [ 6181.016261] RDX: 0000000000000000 RSI: ffffffff83795059 RDI: ffffffff837c101e [ 6181.023490] RBP: ffff9434c9352000 R08: 0000059f1cb1a05e R09: 0000000000000008 [ 6181.030717] R10: 0000000000000001 R11: 0000000000005c66 R12: ffffffff83bbf3a0 [ 6181.037944] R13: 0000059f1cb1a05e R14: 0000000000000001 R15: 0000000000000000 [ 6181.045202] ? cpuidle_enter_state+0xb2/0x400 [ 6181.049678] cpuidle_enter+0x24/0x40 [ 6181.053370] do_idle+0x1dd/0x260 [ 6181.056713] cpu_startup_entry+0x14/0x20 [ 6181.060753] rest_init+0xbb/0xc0 [ 6181.064097] arch_call_rest_init+0x5/0xa [ 6181.068137] start_kernel+0x668/0x691 [ 6181.071914] secondary_startup_64_no_verify+0xe0/0xeb [ 6181.077086] </TASK>
We fix this issue by clearing the staged configs when destroying schemata list.
Signed-off-by: Shawn Wang <shawnwang@linux.alibaba.com> Suggested-by: Xin Hao <xhao@linux.alibaba.com> --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index f276aff521e8..b4a817ae83ab 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2127,8 +2127,15 @@ static int schemata_list_create(void) static void schemata_list_destroy(void) { struct resctrl_schema *s, *tmp; + struct rdt_domain *dom; list_for_each_entry_safe(s, tmp, &resctrl_schema_all, list) { + /* + * Clear staged_config on each domain before schemata list is + * destroyed. + */ + list_for_each_entry(dom, &s->res->domains, list) + memset(dom->staged_config, 0, sizeof(dom->staged_config)); list_del(&s->list); kfree(s); } -- 2.27.0
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