Messages in this thread Patch in this message | | | Date | Thu, 9 Jun 2022 12:43:00 +0800 | Subject | Re: [next] arm64: boot failed - next-20220606 | From | Kefeng Wang <> |
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On 2022/6/9 11:44, Kefeng Wang wrote: > > On 2022/6/9 10:49, Vasily Averin wrote: >> Dear ARM developers, >> could you please help me to find the reason of this problem? > Hi, >> mem_cgroup_from_obj(): >> ffff80000836cf40: d503245f bti c >> ffff80000836cf44: d503201f nop >> ffff80000836cf48: d503201f nop >> ffff80000836cf4c: d503233f paciasp >> ffff80000836cf50: d503201f nop >> ffff80000836cf54: d2e00021 mov x1, >> #0x1000000000000 // #281474976710656 >> ffff80000836cf58: 8b010001 add x1, x0, x1 >> ffff80000836cf5c: b25657e4 mov x4, >> #0xfffffc0000000000 // #-4398046511104 >> ffff80000836cf60: d34cfc21 lsr x1, x1, #12 >> ffff80000836cf64: d37ae421 lsl x1, x1, #6 >> ffff80000836cf68: 8b040022 add x2, x1, x4 >> ffff80000836cf6c: f9400443 ldr x3, [x2, #8] >> >> x5 : ffff80000a96f000 x4 : fffffc0000000000 x3 : ffff80000ad5e680 >> x2 : fffffe00002bc240 x1 : 00000200002bc240 x0 : ffff80000af09740 >> >> x0 = 0xffff80000af09740 is an argument of mem_cgroup_from_obj() >> according to System.map it is init_net >> >> This issue is caused by calling virt_to_page() on address of static >> variable init_net. >> Arm64 consider that addresses of static variables are not valid >> virtual addresses. >> On x86_64 the same API works without any problem. >> >> Unfortunately I do not understand the cause of the problem. >> I do not see any bugs in my patch. >> I'm using an existing API, mem_cgroup_from_obj(), to find the memory >> cgroup used >> to account for the specified object. >> In particular, in the current case, I wanted to get the memory cgroup >> of the >> specified network namespace by the name taken from for_each_net(). >> The first object in this list is the static structure unit_net > > root@test:~# cat /proc/kallsyms |grep -w _data > ffff80000a110000 D _data > root@test:~# cat /proc/kallsyms |grep -w _end > ffff80000a500000 B _end > root@test:~# cat /proc/kallsyms |grep -w init_net > ffff80000a4eb980 B init_net > > the init_net is located in data section, on arm64, it is allowed by > vmalloc, see > > map_kernel_segment(pgdp, _data, _end, PAGE_KERNEL, &vmlinux_data, > 0, 0); > > and the arm has same behavior. > > We could let init_net be allocated dynamically, but I think it could > change a lot. > > Any better sugguestion, Catalin?
or add vmalloc check in mem_cgroup_from_obj()?
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 27cebaa53472..fb817e5da5f0 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2860,7 +2860,10 @@ struct mem_cgroup *mem_cgroup_from_obj(void *p) if (mem_cgroup_disabled()) return NULL;
- folio = virt_to_folio(p); + if (unlikely(is_vmalloc_addr(p))) + folio = page_folio(vmalloc_to_page(p)); + else + folio = virt_to_folio(p);
/* * Slab objects are accounted individually, not per-page.
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