Date: Tue, 5 Jun 2018 16:11:35 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Michael Gmelin <freebsd@grem.de> Cc: "freebsd-current@freebsd.org" <freebsd-current@freebsd.org>, Matthias Apitz <guru@unixarea.de>, jhb@freebsd.org Subject: Re: Fatal trap 12: page fault on Acer Chromebook 720 (peppy) Message-ID: <20180605131135.GH2450@kib.kiev.ua> In-Reply-To: <20180604231756.2ed2adb9@bsd64.grem.de> References: <20180603144840.44bfea41@bsd64.grem.de> <20180603132110.GP3789@kib.kiev.ua> <20180603165500.361ec894@bsd64.grem.de> <20180603150423.GQ3789@kib.kiev.ua> <20180603215020.452a81d8@bsd64.grem.de> <20180603205340.GS3789@kib.kiev.ua> <20180604004632.56ca6afa@bsd64.grem.de> <20180604110654.GA2450@kib.kiev.ua> <20180604231756.2ed2adb9@bsd64.grem.de>
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On Mon, Jun 04, 2018 at 11:17:56PM +0200, Michael Gmelin wrote: > > > On Mon, 4 Jun 2018 14:06:55 +0300 > Konstantin Belousov <kostikbel@gmail.com> wrote: > > > On Mon, Jun 04, 2018 at 12:46:32AM +0200, Michael Gmelin wrote: > > > > > > > > > On Sun, 3 Jun 2018 23:53:40 +0300 > > > Konstantin Belousov <kostikbel@gmail.com> wrote: > > > > > > > On Sun, Jun 03, 2018 at 09:50:20PM +0200, Michael Gmelin wrote: > > > > > > > > > > > > > > > On Sun, 3 Jun 2018 18:04:23 +0300 > > > > > Konstantin Belousov <kostikbel@gmail.com> wrote: > > > > > > > > > > > On Sun, Jun 03, 2018 at 04:55:00PM +0200, Michael Gmelin > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > On Sun, 3 Jun 2018 16:21:10 +0300 > > > > > > > Konstantin Belousov <kostikbel@gmail.com> wrote: > > > > > > > > > > > > > > > On Sun, Jun 03, 2018 at 02:48:40PM +0200, Michael Gmelin > > > > > > > > wrote: > > > > > > > > > Hi, > > > > > > > > > > > > > > > > > > After upgrading CURRENT to r333992 (from something at > > > > > > > > > least a year old, quite some changes in mp_machdep.c > > > > > > > > > since), this machine crashes on boot: > > > > > > > > > > > > > > > > > > Copyright (c) 1992-2018 The FreeBSD Project. > > > > > > > > > Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, > > > > > > > > > 1992, 1993, 1994 The Regents of the University of > > > > > > > > > California. All rights reserved. FreeBSD is a registered > > > > > > > > > trademark of The FreeBSD Foundation. FreeBSD > > > > > > > > > 12.0-CURRENT #1 r333992: Tue May 22 00:31:04 CEST 2018 > > > > > > > > > root@flimsy:/usr/obj/usr/src/amd64.amd64/sys/flimsy > > > > > > > > > amd64 FreeBSD clang version 6.0.0 > > > > > > > > > (tags/RELEASE_600/final 326565) (based on LLVM 6.0.0) > > > > > > > > > WARNING: WITNESS option enabled, expect reduced > > > > > > > > > performance. VT(vga): resolution 640x480 CPU: Intel(R) > > > > > > > > > Celeron(R) 2955U @ 1.40GHz (1396.80-MHz K8-class CPU) > > > > > > > > > Origin="GenuineIntel" Id=0x40651 Family=0x6 > > > > > > > > > Model=0x45 Stepping=1 > > > > > > > > > Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA, > > > > > > > > > CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE> > > > > > > > > > Features2=0x4ddaebbf<SSE3,PCLMULQDQ,DTES64,MON,DS_CPL,VMX,EST,TM2,SSSE3,SDBG,CX16, > > > > > > > > > xTPR,PDCM,PCID,SSE4.1,SSE4.2,MOVBE,POPCNT,TSCDLT,XSAVE,OSXSAVE,RDRAND> > > > > > > > > > AMD Features=0x2c100800<SYSCALL,NX,Page1GB,RDTSCP,LM> > > > > > > > > > AMD Features2=0x21<LAHF,ABM> Structured Extended > > > > > > > > > Features=0x2603<FSGSBASE,TSCADJ,ERMS,INVPCID,NFPUSG> > > > > > > > > > XSAVE Features=0x1<XSAVEOPT> VT-x: (disabled in BIOS) > > > > > > > > > PAT,HLT,MTF,PAUSE,EPT,UG,VPID TSC: P-state invariant, > > > > > > > > > performance statistics real memory = 4301258752 (4102 > > > > > > > > > MB) avail memory = 1907572736 (1819 MB) Event timer > > > > > > > > > "LAPIC" quality 600 ACPI APIC Table: <CORE > > > > > > > > > COREBOOT> > > > > > > > > What does this mean ? Did you flashed coreboot ? > > > > > > > > > > > > > > This machine comes with it by default (my model was > > > > > > > delivered with SeaBIOS 20131018_145217-build121-m2). So I > > > > > > > didn't flash anything (didn't feel like bricking it). > > > > > > > > > > > > > > > > > > > > > > > > kernel trap 12 with interrupts disabled > > > > > > > > > > > > > > > > > > Fatal trap 12: page fault while in kernel mode > > > > > > > > > cpuid = 0; apic id = 00 > > > > > > > > > fault virtual address = 0xfffff80001000000 > > > > > > > > > fault code = supervisor write data, > > > > > > > > > protection violation instruction pointer = > > > > > > > > > 0x20:Oxffffffff8102955f stack pointer = > > > > > > > > > 0x28:0xffffffff82a79be0 frame pointer = > > > > > > > > > 0x28:0xffffffff82a79c10 code segment = base > > > > > > > > > Ox0, limit Oxfffff, type Ox1b = DPL 0, pres 1, long 1, > > > > > > > > > def32 0, gran 1 processor eflags = resume, IOPL > > > > > > > > > = 0 current process = 0 () > > > > > > > > > [ thread pid 0 tid 0 ] > > > > > > > > > Stopped at native_start_all_aps+0x08f: movq > > > > > > > > > %rax,(%rsi) > > > > > > > > Look up the source line number for this address. > > > > > > > > > > > > > > > > > > > > > > I guess that's sys/amd64/amd64/support.S line 854 (in > > > > > > > rdmsr), called by native_start_all_aps. Any additional > > > > > > > hints how I can track it down? > > > > > > Why did you decided that this is rdmsr_safe() ? First, > > > > > > native_start_all_aps() does not call rdmsr, second the ddb > > > > > > report clearly indicates that the fault occured acessing DMAP > > > > > > in native_start_all_aps(). > > > > > > > > > > > > Just look up the source line by the address > > > > > > native_start_all_aps+0x08f. > > > > > > > > > > Okay, according to kgbd this should be here: > > > > > > > > > > https://svnweb.freebsd.org/base/head/sys/amd64/amd64/mp_machdep.c?revision=333368&view=markup#l369 > > > > > > > > > > 364 > > > > > 365 /* Create the initial 1GB replicated page tables */ > > > > > 366 for (i = 0; i < 512; i++) { > > > > > 367 /* Each slot of the level 4 pages points to the > > > > > same level 3 page */ 368 pt4[i] = > > > > > (u_int64_t)(uintptr_t)(mptramp_pagetables + PAGE_SIZE); 369 > > > > > pt4[i] |= PG_V | PG_RW | PG_U; 370 > > > > > 371 /* Each slot of the level 3 pages points to the > > > > > same level 2 page */ 372 pt3[i] = > > > > > (u_int64_t)(uintptr_t)(mptramp_pagetables + (2 * PAGE_SIZE)); > > > > > 373 pt3[i] |= PG_V | PG_RW | PG_U; 374 > > > > > 375 /* The level 2 page slots are mapped with 2MB > > > > > pages for 1GB. */ 376 pt2[i] = i * (2 * 1024 * 1024); > > > > > 377 pt2[i] |= PG_V | PG_RW | PG_PS | PG_U; > > > > > 378 } > > > > > > > > > > -m > > > > You have fault on write due to read-only mapping of the portion of > > > > the direct map, which maps the kernel text. It is consistent with > > > > the faulting address. It is not clear if it is something new on > > > > your machine, or before the kernel text was silently corrupted, > > > > since ro protection is somewhat recent. > > > > > > > > It seems that mp_bootaddress() selected the bad place for the > > > > bootstrap page tables. Even more, we do not include the kernel > > > > text into the physmem[] array, so it is not clear how did it > > > > happen. This code was also changed recently. > > > > > > > > Can you add the print of the physmap[] array somewhere before the > > > > panic, to see what is the kernel idea of the available memory ? > > > > It should be already done if you have serial console and set > > > > debug.late_console tunable to 0. > > > > > > This is a sad little machine without any kind of serial console. > > > > > > Physmap looks like this after calling getmemsize(): > > > > > > [0]: 0x10000 > > > [1]: 0x30000 > > > [2]: 0x40000 > > > [3]: 0x9e000 > > > [4]: 0x100000 > > > [5]: 0xf00000 > > > [6]: 0x1003000 > > > [7]: 0x7bf7a000 > > > > > > Physical memory chunks logged in cpu_startup are: > > > > > > 0x0000000000010000 - 0x000000000002ffff, 141072 bytes (32 pages) > > > 0x0000000000040000 - 0x000000000009dfff, 385024 bytes (94 pages) > > These two chunks reports are consistent with the physmap[0-1, 2-3]. > > > > > 0x0000000000100000 - 0x00000000001fffff, 1048576 bytes (256 pages) > > > 0x0000000002c00000 - 0x0000000075467fff, 1921417216 bytes (469096 > > > pages) 0x0000000100000000 - 0x00000001005e7fff, 6193152 bytes (1512 > > > pages) > > But these three looks completely unrelated to the rest of the physmap, > > perhaps except the physmap[4]. We allocate boot pages from the top > > of the last physmap chunk, but I am certain that we do not consume > > that much memory for boot to make physmap[7] from the last reported > > address. > > > > Are you sure that there are no typos in the values above ? > > Double checked the numbers. I changed it a bit more, > so that debug output appears all on one page. Please see here for the > results: > > https://gist.github.com/grembo/cebb9f7e2a98c37a51bee1e508f7d890 Ok, I have a guess what is going on. Does the result of the quirks end up as hw.physmem tunable passed to kernel ? It seems that there is physmap[] element pointing outside the DMAP-mapped region. Perhaps print the dmap limit too, to see whether I am on the right track. Try the following change. It lacks i386 bits. diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c index e5c69ed91fa..bd6bbf04006 100644 --- a/sys/amd64/amd64/machdep.c +++ b/sys/amd64/amd64/machdep.c @@ -1254,7 +1254,7 @@ getmemsize(caddr_t kmdp, u_int64_t first) * in real mode mode (e.g. SMP bare metal). */ if (init_ops.mp_bootaddress) - init_ops.mp_bootaddress(physmap, &physmap_idx); + init_ops.mp_bootaddress(physmap, &physmap_idx, first); /* * Maxmem isn't the "maximum memory", it's one larger than the diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c index 30146142087..292a6cefa91 100644 --- a/sys/amd64/amd64/mp_machdep.c +++ b/sys/amd64/amd64/mp_machdep.c @@ -103,7 +103,8 @@ static int start_ap(int apic_id); * Calculate usable address in base memory for AP trampoline code. */ void -mp_bootaddress(vm_paddr_t *physmap, unsigned int *physmap_idx) +mp_bootaddress(vm_paddr_t *physmap, unsigned int *physmap_idx, + vm_paddr_t dmap_limit) { unsigned int i; bool allocated; @@ -117,8 +118,9 @@ mp_bootaddress(vm_paddr_t *physmap, unsigned int *physmap_idx) * store the initial page tables. Note that it needs to be * aligned to a page boundary. */ - if (physmap[i] >= GiB(4) || - (physmap[i + 1] - round_page(physmap[i])) < (PAGE_SIZE * 3)) + if (physmap[i] >= GiB(4) || physmap[i + 1] - + round_page(physmap[i]) < PAGE_SIZE * 3 || + physmap[i + 1] - PAGE_SIZE * 3 > dmap_limit) continue; allocated = true; diff --git a/sys/amd64/include/smp.h b/sys/amd64/include/smp.h index 2ecfe62cf9f..24f0580fe51 100644 --- a/sys/amd64/include/smp.h +++ b/sys/amd64/include/smp.h @@ -58,7 +58,7 @@ void invlpg_pcid_handler(void); void invlrng_invpcid_handler(void); void invlrng_pcid_handler(void); int native_start_all_aps(void); -void mp_bootaddress(vm_paddr_t *, unsigned int *); +void mp_bootaddress(vm_paddr_t *, unsigned int *, vm_paddr_t); #endif /* !LOCORE */ #endif /* SMP */ diff --git a/sys/x86/include/init.h b/sys/x86/include/init.h index 880cabaa949..58bbe0a5fd6 100644 --- a/sys/x86/include/init.h +++ b/sys/x86/include/init.h @@ -41,7 +41,7 @@ struct init_ops { void (*early_clock_source_init)(void); void (*early_delay)(int); void (*parse_memmap)(caddr_t, vm_paddr_t *, int *); - void (*mp_bootaddress)(vm_paddr_t *, unsigned int *); + void (*mp_bootaddress)(vm_paddr_t *, unsigned int *, vm_paddr_t); int (*start_all_aps)(void); void (*msi_init)(void); };
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