Date: Thu, 23 Aug 2018 00:15:28 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Michael Gmelin <freebsd@grem.de> Cc: John Baldwin <jhb@FreeBSD.org>, "freebsd-current@freebsd.org" <freebsd-current@freebsd.org>, Matthias Apitz <guru@unixarea.de> Subject: Re: Fatal trap 12: page fault on Acer Chromebook 720 (peppy) Message-ID: <20180822211528.GB2340@kib.kiev.ua> In-Reply-To: <C8BC1622-4F47-4E56-A428-46DAC5CE71B4@grem.de> References: <e82ed552-83b0-5331-3117-6750b8c205f7@FreeBSD.org> <07E28AC5-EBE6-4893-810A-6C03F07925C8@grem.de> <8726bc32-6023-bfe1-7600-5b2c706236f8@FreeBSD.org> <20180819165951.274d61b0@bsd64.grem.de> <20180819161642.GP2340@kib.kiev.ua> <20180820004512.5171fa75@bsd64.grem.de> <20180820150904.GS2340@kib.kiev.ua> <57B6DC4C-16EE-4B7B-B691-CB79D8C40289@grem.de> <20180822154603.GW2340@kib.kiev.ua> <C8BC1622-4F47-4E56-A428-46DAC5CE71B4@grem.de>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Aug 22, 2018 at 10:03:54PM +0200, Michael Gmelin wrote: > > > > On 22. Aug 2018, at 17:46, Konstantin Belousov <kostikbel@gmail.com> wrote: > > > >> On Tue, Aug 21, 2018 at 12:14:35AM +0200, Michael Gmelin wrote: > >> > >> > >>>> On 20. Aug 2018, at 17:09, Konstantin Belousov <kostikbel@gmail.com> wrote: > >>>> > >>>> On Mon, Aug 20, 2018 at 12:45:12AM +0200, Michael Gmelin wrote: > >>>> > >>>> See here for a screenshot (also including the output of "show pte > >>>> 0xfffff80001000000"): > >>>> > >>>> https://gist.github.com/grembo/78d0f2a100dd4f16775b85a118769658#file-ddb1-png > >>> It is too early for ddb routines to register. > >>> Ok can you try the following debugging patch, to verify my guess ? > >>> > >>> diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c > >>> index 18777d23f09..cd05fdb763f 100644 > >>> --- a/sys/amd64/amd64/pmap.c > >>> +++ b/sys/amd64/amd64/pmap.c > >>> @@ -1052,8 +1052,7 @@ create_pagetables(vm_paddr_t *firstaddr) > >>> pd_p = (pd_entry_t *)DMPDkernphys; > >>> for (i = 0; i < (NPDEPG * nkdmpde); i++) > >>> pd_p[i] = (i << PDRSHIFT) | X86_PG_V | PG_PS | pg_g | > >>> - X86_PG_M | X86_PG_A | pg_nx | > >>> - bootaddr_rwx(i << PDRSHIFT); > >>> + X86_PG_M | X86_PG_A | pg_nx | X86_PG_RW; > >>> for (i = 0; i < nkdmpde; i++) > >>> pdp_p[i] = (DMPDkernphys + ptoa(i)) | X86_PG_RW | > >>> X86_PG_V; > >> > >> With this change it boots okay (mptramp_pagetables is 0x1000000, as expected). > > > > Can you apply the following on top of the previous debugging patch and show > > me the line printed ? > > > > diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c > > index 3d70532b7fd..613fa9f2165 100644 > > --- a/sys/amd64/amd64/pmap.c > > +++ b/sys/amd64/amd64/pmap.c > > @@ -2662,6 +2662,7 @@ pmap_pinit0(pmap_t pmap) > > pmap->pm_pcids[i].pm_gen = 1; > > } > > pmap_activate_boot(pmap); > > +printf("bootaddr addr %#lx rwx %#lx btext %#lx _end %#lx brwsection %#lx etext %#lx KERNBASE %#lx\n", 0x1000000UL, bootaddr_rwx(0x1000000UL), (uintptr_t)btext, (uintptr_t)_end, (uintptr_t)brwsection, (uintptr_t)etext, (uintptr_t)KERNBASE); > > } > > > > void > > bootaddr addr 0x1000000 rwx 0 btext 0xffffffff80342000 _end 0xffffffff823cf840 brwsection #ffffffff81a00000 etext 0xffffffff812041e4 KERNBASE 0xffffffff80000000 > Try this, please. Revert all debugging pmap.c patches that I provided before. diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c index 4ca2e07e578..2ee8f862854 100644 --- a/sys/amd64/amd64/mp_machdep.c +++ b/sys/amd64/amd64/mp_machdep.c @@ -87,6 +87,8 @@ __FBSDID("$FreeBSD$"); #define GiB(v) (v ## ULL << 30) +#define AP_BOOTPT_SZ (PAGE_SIZE * 3) + extern struct pcpu __pcpu[]; /* Temporary variables for init_secondary() */ @@ -101,45 +103,78 @@ char *dbg_stack; static int start_ap(int apic_id); +static bool +is_kernel_paddr(vm_paddr_t pa) +{ + + return (pa >= trunc_2mpage(btext - KERNBASE) && + pa < round_page(_end - KERNBASE)); +} + +static bool +is_mpboot_good(vm_paddr_t start, vm_paddr_t end) +{ + + return (start + AP_BOOTPT_SZ <= GiB(4) && + end >= start + AP_BOOTPT_SZ && atop(end) < Maxmem); +} + /* * Calculate usable address in base memory for AP trampoline code. */ void mp_bootaddress(vm_paddr_t *physmap, unsigned int *physmap_idx) { + vm_paddr_t start, end; unsigned int i; bool allocated; alloc_ap_trampoline(physmap, physmap_idx); + /* + * Find a memory region big enough below the 4GB boundary to + * store the initial page tables. Region must be mapped by + * the direct map. + * + * Note that it needs to be aligned to a page boundary. + */ allocated = false; for (i = *physmap_idx; i <= *physmap_idx; i -= 2) { /* - * Find a memory region big enough below the 4GB - * boundary to store the initial page tables. Region - * must be mapped by the direct map. - * - * Note that it needs to be aligned to a page - * boundary. + * First, try to chomp at the start of the physmap region. + * Kernel binary might claim it already. + */ + start = round_page(physmap[i]); + end = trunc_page(physmap[i + 1]); + if (is_mpboot_good(start, end) && + !is_kernel_paddr(start) && !is_kernel_paddr(end - 1)) { + allocated = true; + physmap[i] = start + AP_BOOTPT_SZ; + break; + } + + /* + * Second, try to chomp at the end. Again, check + * against kernel. */ - if (physmap[i] >= GiB(4) || physmap[i + 1] - - round_page(physmap[i]) < PAGE_SIZE * 3 || - atop(physmap[i + 1]) > Maxmem) - continue; - - allocated = true; - mptramp_pagetables = round_page(physmap[i]); - physmap[i] = round_page(physmap[i]) + (PAGE_SIZE * 3); + end = trunc_page(physmap[i + 1]); + start = end - AP_BOOTPT_SZ; + if (start >= physmap[i] && is_mpboot_good(start, end) && + !is_kernel_paddr(start) && !is_kernel_paddr(end - 1)) { + allocated = true; + physmap[i + 1] = start; + break; + } + } + if (allocated) { + mptramp_pagetables = start; if (physmap[i] == physmap[i + 1] && *physmap_idx != 0) { memmove(&physmap[i], &physmap[i + 2], sizeof(*physmap) * (*physmap_idx - i + 2)); *physmap_idx -= 2; } - break; - } - - if (!allocated) { - mptramp_pagetables = trunc_page(boot_address) - (PAGE_SIZE * 3); + } else { + mptramp_pagetables = trunc_page(boot_address) - AP_BOOTPT_SZ; if (bootverbose) printf( "Cannot find enough space for the initial AP page tables, placing them at %#x",
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20180822211528.GB2340>