On Tue, Sep 06, 2022 at 10:50:42AM -0700, Dionna Amalie Glaze wrote: > > > > It really helps this kind of stuff if you can post the *actual* error. > > I assume this was a page fault, so there should have been some other > > stuff before the RIP:... > > > > I posted the error on August 15th. I was bumping in my last post > since I confirmed with Tom Lendacky that it wasn't AMD's patches at > fault. > Here's a new dump below that matches the disassembly: > > [ 0.043137] Faking a node at [mem 0x0000000000000000-0x000000403fffffff] > [ 0.044018] NODE_DATA(0) allocated [mem 0x403fffc000-0x403fffffff] > [ 0.044922] Zone ranges: > [ 0.045250] DMA [mem 0x0000000000001000-0x0000000000ffffff] > [ 0.046039] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] > [ 0.046828] Normal [mem 0x0000000100000000-0x000000403fffffff] > [ 0.047657] Movable zone start for each node > [ 0.048201] Early memory node ranges > [ 0.048674] node 0: [mem 0x0000000000001000-0x000000000009ffff] > [ 0.049474] node 0: [mem 0x0000000000100000-0x000000000080cfff > [ 0.050274] node 0: [mem 0x000000000080f000-0x00000000beceefff] > [ 0.051074] node 0: [mem 0x00000000befff000-0x00000000bfbb0fff] > [ 0.051874] node 0: [mem 0x00000000bfbb2000-0x00000000bffdbfff] > [ 0.052674] node 0: [mem 0x0000000100000000-0x000000403fffffff] > [ 0.053530] Initmem setup node 0 [mem 0x0000000000001000-0x000000403fffffff] > PANIC: Unsupported exit-code 0x404 in early #VC exception (IP: > 0xfffffffface0cdd0) > [ 0.056667] CPU: 0 PID: 0 Comm: swapper Not tainted > 5.17.0-rc6-173762-gffb12b02c6d7-dirty #1 > [ 0.057744] Hardware name: Google Google Compute Engine/Google > Compute Engine, BIOS Google 01/01/2011 > [ 0.058920] RIP: 0010:memmap_init_range+0x11d/0x188 > [ 0.059686] Code: 77 16 f6 42 10 02 74 10 48 03 42 08 48 c1 e8 0c > 48 89 c3 e9 3a ff ff ff 48 89 df 48 c1 e7 06 48 03 3d a4 1e 65 ff 48 > 8d 47 08 <c7> 47 34 01 00 00 00 48 c7 47 38 00 00 00 00 c7 47 30 ff ff > ff ff > [ 0.062121] RSP: 0000:ffffffffac603dc0 EFLAGS: 00010082 ORIG_RAX: > 0000000000000404 > [ 0.063087] RAX: ffffda1ac0000048 RBX: 0000000000000001 RCX: 0000000000000000 > [ 0.063998] RDX: 0300000000000000 RSI: 0000000000000000 RDI: ffffda1ac000004 > [ 0.064944] RBP: 0000000000000000 R08: 0000000000001000 R09: 0000000000000000 > [ 0.065873] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 > [ 0.066782] R13: 00000000000000a0 R14: 0000000000000000 R15: 0000000000000000 > [ 0.067695] FS: 0000000000000000(0000) GS:ffffffffacd88000(0000) > knlGS:0000000000000000 > [ 0.068727] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 0.069488] CR2: ffffda1ac0000074 CR3: 00080020b680c000 CR4: 00000000000606b0 > [ 0.070397] Call Trace: > [ 0.070710] <TASK> > [ 0.070976] ? free_area_init+0x724/0x7d4 > [ 0.071486] ? zone_sizes_init+0x52/0x6c > [ 0.071986] ? setup_arch+0xa55/0xb77 > [ 0.072453] ? start_kernel+0x64/0x65f > [ 0.072931] ? secondary_startup_64_no_verify+0xd6/0xdb > [ 0.073598] </TASK> > > Note this is a crash in SEV-SNP, but I assume we'd get the same #VE in TDX. > > > Another thing that's really nice is to do the disassembly of the "Code:" > > or share disassembly of memmap_init_range. > > 0000000000000172 <memmap_init_range>: > 172: 41 56 push %r14 > 174: 89 f0 mov %esi,%eax > 176: 45 89 ce mov %r9d,%r14d > 179: 41 55 push %r13 > 17b: 4c 8d 2c 39 lea (%rcx,%rdi,1),%r13 > 17f: 41 54 push %r12 > 181: 49 89 d4 mov %rdx,%r12 > 184: 49 8d 55 ff lea -0x1(%r13),%rdx > 188: 48 3b 15 00 00 00 00 cmp 0x0(%rip),%rdx # 18f > <memmap_init_range+0x1d> > 18f: 55 push %rbp > 190: 53 push %rbx > 191: 48 89 cb mov %rcx,%rbx > 194: 76 07 jbe 19d <memmap_init_range+0x2b> > 196: 48 89 15 00 00 00 00 mov %rdx,0x0(%rip) # 19d > <memmap_init_range+0x2b> > 19d: 4c 89 e5 mov %r12,%rbp > 1a0: ba 03 00 00 00 mov $0x3,%edx > 1a5: 48 c1 e0 3a shl $0x3a,%rax > 1a9: 48 c1 e5 38 shl $0x38,%rbp > 1ad: 48 c1 e2 38 shl $0x38,%rdx > 1b1: 48 21 d5 and %rdx,%rbp > 1b4: 48 09 c5 or %rax,%rbp > 1b7: 49 39 dd cmp %rbx,%r13 > 1ba: 0f 86 31 01 00 00 jbe 2f1 <memmap_init_range+0x17f> > 1c0: 45 85 f6 test %r14d,%r14d > 1c3: 0f 85 b4 00 00 00 jne 27d <memmap_init_range+0x10b> > 1c9: 49 83 fc 03 cmp $0x3,%r12 > 1cd: 0f 94 c1 sete %cl > 1d0: 22 0d 00 00 00 00 and 0x0(%rip),%cl # 1d6 > <memmap_init_range+0x64> > 1d6: 0f 84 a1 00 00 00 je 27d <memmap_init_range+0x10b> > 1dc: 48 8b 15 00 00 00 00 mov 0x0(%rip),%rdx # 1e3 > <memmap_init_range+0x71> > 1e3: 48 85 d2 test %rdx,%rdx > 1e6: 74 10 je 1f8 <memmap_init_range+0x86> > 1e8: 48 8b 42 08 mov 0x8(%rdx),%rax > 1ec: 48 03 02 add (%rdx),%rax > 1ef: 48 c1 e8 0c shr $0xc,%rax > 1f3: 48 39 d8 cmp %rbx,%rax > 1f6: 77 55 ja 24d <memmap_init_range+0xdb> > 1f8: 48 8b 05 00 00 00 00 mov 0x0(%rip),%rax # 1ff > <memmap_init_range+0x8d> > 1ff: 4c 6b 05 00 00 00 00 imul $0x18,0x0(%rip),%r8 # > 207 <memmap_init_range+0x95> > 206: 18 > 207: 31 f6 xor %esi,%esi > 209: 48 89 05 00 00 00 00 mov %rax,0x0(%rip) # 210 > <memmap_init_range+0x9e> > 210: 49 01 c0 add %rax,%r8 > 213: 48 89 c7 mov %rax,%rdi > 216: 4c 39 c0 cmp %r8,%rax > 219: 73 26 jae 241 <memmap_init_range+0xcf> > 21b: 48 8b 57 08 mov 0x8(%rdi),%rdx > 21f: 48 03 17 add (%rdi),%rdx > 222: 48 83 c0 18 add $0x18,%rax > 226: 48 c1 ea 0c shr $0xc,%rdx > 22a: 48 39 da cmp %rbx,%rdx > 22d: 76 0e jbe 23d <memmap_init_range+0xcb> > 22f: 40 84 f6 test %sil,%sil > 232: 74 19 je 24d <memmap_init_range+0xdb> > 234: 48 89 3d 00 00 00 00 mov %rdi,0x0(%rip) # 23b > <memmap_init_range+0xc9> > 23b: eb 10 jmp 24d <memmap_init_range+0xdb> > 23d: 89 ce mov %ecx,%esi > 23f: eb d2 jmp 213 <memmap_init_range+0xa1> > 241: 40 84 f6 test %sil,%sil > 244: 74 07 je 24d <memmap_init_range+0xdb> > 246: 48 89 05 00 00 00 00 mov %rax,0x0(%rip) # 24d > <memmap_init_range+0xdb> > 24d: 48 8b 15 00 00 00 00 mov 0x0(%rip),%rdx # 254 > <memmap_init_range+0xe2> > 254: 48 8b 02 mov (%rdx),%rax > 257: 48 8d 88 ff 0f 00 00 lea 0xfff(%rax),%rcx > 25e: 48 c1 e9 0c shr $0xc,%rcx > 262: 48 39 d9 cmp %rbx,%rcx > 265: 77 16 ja 27d <memmap_init_range+0x10b> > 267: f6 42 10 02 testb $0x2,0x10(%rdx) > 26b: 74 10 je 27d <memmap_init_range+0x10b> > 26d: 48 03 42 08 add 0x8(%rdx),%rax > 271: 48 c1 e8 0c shr $0xc,%rax > 275: 48 89 c3 mov %rax,%rbx > 278: e9 3a ff ff ff jmp 1b7 <memmap_init_range+0x45> > 27d: 48 89 df mov %rbx,%rdi > 280: 48 c1 e7 06 shl $0x6,%rdi > 284: 48 03 3d 00 00 00 00 add 0x0(%rip),%rdi # 28b > <memmap_init_range+0x119> > 28b: 48 8d 47 08 lea 0x8(%rdi),%rax > 28f: c7 47 34 01 00 00 00 movl $0x1,0x34(%rdi) # Here's > where the crash RIP is. > 296: 48 c7 47 38 00 00 00 movq $0x0,0x38(%rdi) > 29d: 00 > 29e: c7 47 30 ff ff ff ff movl $0xffffffff,0x30(%rdi) > 2a5: 48 c7 47 28 00 00 00 movq $0x0,0x28(%rdi) > 2ac: 00 > 2ad: 48 c7 47 20 00 00 00 movq $0x0,0x20(%rdi) > 2b4: 00 > 2b5: 48 c7 47 18 00 00 00 movq $0x0,0x18(%rdi) > 2bc: 00 > 2bd: 48 89 2f mov %rbp,(%rdi) > 2c0: 48 89 47 08 mov %rax,0x8(%rdi) > 2c4: 48 89 47 10 mov %rax,0x10(%rdi) > 2c8: 41 83 fe 01 cmp $0x1,%r14d > 2cc: 75 05 jne 2d3 <memmap_init_range+0x161> > 2ce: 48 0f ba 2f 0c btsq $0xc,(%rdi) > 2d3: f7 c3 ff 01 00 00 test $0x1ff,%ebx > 2d9: 75 0e jne 2e9 <memmap_init_range+0x177> > 2db: 8b 74 24 38 mov 0x38(%rsp),%esi > 2df: e8 00 00 00 00 call 2e4 <memmap_init_range+0x172> > 2e4: e8 00 00 00 00 call 2e9 <memmap_init_range+0x177> > 2e9: 48 ff c3 inc %rbx > 2ec: e9 c6 fe ff ff jmp 1b7 <memmap_init_range+0x45> > 2f1: 5b pop %rbx > 2f2: 5d pop %rbp > 2f3: 41 5c pop %r12 > 2f5: 41 5d pop %r13 > 2f7: 41 5e pop %r14 > 2f9: c3 ret > > > Even nicer would be to give > > an faddr2line of the RIP value and track down which C code was actually > > at fault. > > arch_atomic_set > arch/x86/include/asm/atomic.h:41 > > of INIT_LIST_HEAD in __init_single_page, called from memmap_init_range. Looks like the first access to the memory map fails, although I think it's not in INIT_LIST_HEAD() but rather in init_page_count(). I'd start with making sure that page_alloc::memmap_alloc() actually returns accepted memory. If you build kernel with CONFIG_DEBUG_VM=y the memory map will poisoned in this function, so my guess is it'd crash there. > -- > -Dionna Glaze, PhD (she/her) -- Sincerely yours, Mike.
