From 71ce3e3c495897125681f2adfe13033aff1a3a58 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 4 Jan 2018 13:41:55 -0800 Subject: [PATCH 040/103] kaiser: Set _PAGE_NX only if supported This resolves a crash if loaded under qemu + haxm under windows. See https://www.spinics.net/lists/kernel/msg2689835.html for details. Here is a boot log (the log is from chromeos-4.4, but Tao Wu says that the same log is also seen with vanilla v4.4.110-rc1). [ 0.712750] Freeing unused kernel memory: 552K [ 0.721821] init: Corrupted page table at address 57b029b332e0 [ 0.722761] PGD 80000000bb238067 PUD bc36a067 PMD bc369067 PTE 45d2067 [ 0.722761] Bad pagetable: 000b [#1] PREEMPT SMP [ 0.722761] Modules linked in: [ 0.722761] CPU: 1 PID: 1 Comm: init Not tainted 4.4.96 #31 [ 0.722761] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014 [ 0.722761] task: ffff8800bc290000 ti: ffff8800bc28c000 task.ti: ffff8800bc28c000 [ 0.722761] RIP: 0010:[] [] __clear_user+0x42/0x67 [ 0.722761] RSP: 0000:ffff8800bc28fcf8 EFLAGS: 00010202 [ 0.722761] RAX: 0000000000000000 RBX: 00000000000001a4 RCX: 00000000000001a4 [ 0.722761] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000057b029b332e0 [ 0.722761] RBP: ffff8800bc28fd08 R08: ffff8800bc290000 R09: ffff8800bb2f4000 [ 0.722761] R10: ffff8800bc290000 R11: ffff8800bb2f4000 R12: 000057b029b332e0 [ 0.722761] R13: 0000000000000000 R14: 000057b029b33340 R15: ffff8800bb1e2a00 [ 0.722761] FS: 0000000000000000(0000) GS:ffff8800bfb00000(0000) knlGS:0000000000000000 [ 0.722761] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 0.722761] CR2: 000057b029b332e0 CR3: 00000000bb2f8000 CR4: 00000000000006e0 [ 0.722761] Stack: [ 0.722761] 000057b029b332e0 ffff8800bb95fa80 ffff8800bc28fd18 ffffffff83f4120c [ 0.722761] ffff8800bc28fe18 ffffffff83e9e7a1 ffff8800bc28fd68 0000000000000000 [ 0.722761] ffff8800bc290000 ffff8800bc290000 ffff8800bc290000 ffff8800bc290000 [ 0.722761] Call Trace: [ 0.722761] [] clear_user+0x2e/0x30 [ 0.722761] [] load_elf_binary+0xa7f/0x18f7 [ 0.722761] [] search_binary_handler+0x86/0x19c [ 0.722761] [] do_execveat_common.isra.26+0x909/0xf98 [ 0.722761] [] ? rest_init+0x87/0x87 [ 0.722761] [] do_execve+0x23/0x25 [ 0.722761] [] run_init_process+0x2b/0x2d [ 0.722761] [] kernel_init+0x6d/0xda [ 0.722761] [] ret_from_fork+0x3f/0x70 [ 0.722761] [] ? rest_init+0x87/0x87 [ 0.722761] Code: 86 84 be 12 00 00 00 e8 87 0d e8 ff 66 66 90 48 89 d8 48 c1 eb 03 4c 89 e7 83 e0 07 48 89 d9 be 08 00 00 00 31 d2 48 85 c9 74 0a <48> 89 17 48 01 f7 ff c9 75 f6 48 89 c1 85 c9 74 09 88 17 48 ff [ 0.722761] RIP [] __clear_user+0x42/0x67 [ 0.722761] RSP [ 0.722761] ---[ end trace def703879b4ff090 ]--- [ 0.722761] BUG: sleeping function called from invalid context at /mnt/host/source/src/third_party/kernel/v4.4/kernel/locking/rwsem.c:21 [ 0.722761] in_atomic(): 0, irqs_disabled(): 1, pid: 1, name: init [ 0.722761] CPU: 1 PID: 1 Comm: init Tainted: G D 4.4.96 #31 [ 0.722761] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014 [ 0.722761] 0000000000000086 dcb5d76098c89836 ffff8800bc28fa30 ffffffff83f34004 [ 0.722761] ffffffff84839dc2 0000000000000015 ffff8800bc28fa40 ffffffff83d57dc9 [ 0.722761] ffff8800bc28fa68 ffffffff83d57e6a ffffffff84a53640 0000000000000000 [ 0.722761] Call Trace: [ 0.722761] [] dump_stack+0x4d/0x63 [ 0.722761] [] ___might_sleep+0x13a/0x13c [ 0.722761] [] __might_sleep+0x9f/0xa6 [ 0.722761] [] down_read+0x20/0x31 [ 0.722761] [] __blocking_notifier_call_chain+0x35/0x63 [ 0.722761] [] blocking_notifier_call_chain+0x14/0x16 [ 0.800374] usb 1-1: new full-speed USB device number 2 using uhci_hcd [ 0.722761] [] profile_task_exit+0x1a/0x1c [ 0.802309] [] do_exit+0x39/0xe7f [ 0.802309] [] ? vprintk_default+0x1d/0x1f [ 0.802309] [] ? printk+0x57/0x73 [ 0.802309] [] oops_end+0x80/0x85 [ 0.802309] [] pgtable_bad+0x8a/0x95 [ 0.802309] [] __do_page_fault+0x8c/0x352 [ 0.802309] [] ? file_has_perm+0xc4/0xe5 [ 0.802309] [] do_page_fault+0xc/0xe [ 0.802309] [] page_fault+0x22/0x30 [ 0.802309] [] ? __clear_user+0x42/0x67 [ 0.802309] [] ? __clear_user+0x23/0x67 [ 0.802309] [] clear_user+0x2e/0x30 [ 0.802309] [] load_elf_binary+0xa7f/0x18f7 [ 0.802309] [] search_binary_handler+0x86/0x19c [ 0.802309] [] do_execveat_common.isra.26+0x909/0xf98 [ 0.802309] [] ? rest_init+0x87/0x87 [ 0.802309] [] do_execve+0x23/0x25 [ 0.802309] [] run_init_process+0x2b/0x2d [ 0.802309] [] kernel_init+0x6d/0xda [ 0.802309] [] ret_from_fork+0x3f/0x70 [ 0.802309] [] ? rest_init+0x87/0x87 [ 0.830559] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 [ 0.830559] [ 0.831305] Kernel Offset: 0x2c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 0.831305] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 The crash part of this problem may be solved with the following patch (thanks to Hugh for the hint). There is still another problem, though - with this patch applied, the qemu session aborts with "VCPU Shutdown request", whatever that means. Cc: lepton Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/kaiser.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c index b6b0f3a..d8376b4 100644 --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -413,7 +413,8 @@ pgd_t kaiser_set_shadow_pgd(pgd_t *pgdp, pgd_t pgd) * get out to userspace running on the kernel CR3, * userspace will crash instead of running. */ - pgd.pgd |= _PAGE_NX; + if (__supported_pte_mask & _PAGE_NX) + pgd.pgd |= _PAGE_NX; } } else if (!pgd.pgd) { /* -- 2.7.4