From: Tycho Andersen <tycho@docker.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, kernel-hardening@lists.openwall.com,
Marco Benatto <marco.antonio.780@gmail.com>,
Juerg Haefliger <juerg.haefliger@canonical.com>,
Tycho Andersen <tycho@docker.com>,
x86@kernel.org
Subject: [PATCH v6 02/11] x86: always set IF before oopsing from page fault
Date: Thu, 7 Sep 2017 11:36:00 -0600 [thread overview]
Message-ID: <20170907173609.22696-3-tycho@docker.com> (raw)
In-Reply-To: <20170907173609.22696-1-tycho@docker.com>
Oopsing might kill the task, via rewind_stack_do_exit() at the bottom, and
that might sleep:
Aug 23 19:30:27 xpfo kernel: [ 38.302714] BUG: sleeping function called from invalid context at ./include/linux/percpu-rwsem.h:33
Aug 23 19:30:27 xpfo kernel: [ 38.303837] in_atomic(): 0, irqs_disabled(): 1, pid: 1970, name: lkdtm_xpfo_test
Aug 23 19:30:27 xpfo kernel: [ 38.304758] CPU: 3 PID: 1970 Comm: lkdtm_xpfo_test Tainted: G D 4.13.0-rc5+ #228
Aug 23 19:30:27 xpfo kernel: [ 38.305813] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1ubuntu1 04/01/2014
Aug 23 19:30:27 xpfo kernel: [ 38.306926] Call Trace:
Aug 23 19:30:27 xpfo kernel: [ 38.307243] dump_stack+0x63/0x8b
Aug 23 19:30:27 xpfo kernel: [ 38.307665] ___might_sleep+0xec/0x110
Aug 23 19:30:27 xpfo kernel: [ 38.308139] __might_sleep+0x45/0x80
Aug 23 19:30:27 xpfo kernel: [ 38.308593] exit_signals+0x21/0x1c0
Aug 23 19:30:27 xpfo kernel: [ 38.309046] ? blocking_notifier_call_chain+0x11/0x20
Aug 23 19:30:27 xpfo kernel: [ 38.309677] do_exit+0x98/0xbf0
Aug 23 19:30:27 xpfo kernel: [ 38.310078] ? smp_reader+0x27/0x40 [lkdtm]
Aug 23 19:30:27 xpfo kernel: [ 38.310604] ? kthread+0x10f/0x150
Aug 23 19:30:27 xpfo kernel: [ 38.311045] ? read_user_with_flags+0x60/0x60 [lkdtm]
Aug 23 19:30:27 xpfo kernel: [ 38.311680] rewind_stack_do_exit+0x17/0x20
To be safe, let's just always enable irqs.
The particular case I'm hitting is:
Aug 23 19:30:27 xpfo kernel: [ 38.278615] __bad_area_nosemaphore+0x1a9/0x1d0
Aug 23 19:30:27 xpfo kernel: [ 38.278617] bad_area_nosemaphore+0xf/0x20
Aug 23 19:30:27 xpfo kernel: [ 38.278618] __do_page_fault+0xd1/0x540
Aug 23 19:30:27 xpfo kernel: [ 38.278620] ? irq_work_queue+0x9b/0xb0
Aug 23 19:30:27 xpfo kernel: [ 38.278623] ? wake_up_klogd+0x36/0x40
Aug 23 19:30:27 xpfo kernel: [ 38.278624] trace_do_page_fault+0x3c/0xf0
Aug 23 19:30:27 xpfo kernel: [ 38.278625] do_async_page_fault+0x14/0x60
Aug 23 19:30:27 xpfo kernel: [ 38.278627] async_page_fault+0x28/0x30
When a fault is in kernel space which has been triggered by XPFO.
Signed-off-by: Tycho Andersen <tycho@docker.com>
CC: x86@kernel.org
---
arch/x86/mm/fault.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 2a1fa10c6a98..7572ad4dae70 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -864,6 +864,12 @@ no_context(struct pt_regs *regs, unsigned long error_code,
/* Executive summary in case the body of the oops scrolled away */
printk(KERN_DEFAULT "CR2: %016lx\n", address);
+ /*
+ * We're about to oops, which might kill the task. Make sure we're
+ * allowed to sleep.
+ */
+ flags |= X86_EFLAGS_IF;
+
oops_end(flags, regs, sig);
}
--
2.11.0
next prev parent reply other threads:[~2017-09-07 17:37 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-07 17:35 [PATCH v6 00/11] Add support for eXclusive Page Frame Ownership Tycho Andersen
2017-09-07 17:35 ` [PATCH v6 01/11] mm: add MAP_HUGETLB support to vm_mmap Tycho Andersen
2017-09-08 7:42 ` Christoph Hellwig
2017-09-07 17:36 ` Tycho Andersen [this message]
2017-09-07 17:36 ` [PATCH v6 03/11] mm, x86: Add support for eXclusive Page Frame Ownership (XPFO) Tycho Andersen
2017-09-07 18:33 ` Ralph Campbell
2017-09-07 18:50 ` Tycho Andersen
2017-09-08 7:51 ` Christoph Hellwig
2017-09-08 14:58 ` Tycho Andersen
2017-09-09 15:35 ` Laura Abbott
2017-09-11 15:03 ` Tycho Andersen
2017-09-11 7:24 ` Yisheng Xie
2017-09-11 14:50 ` Tycho Andersen
2017-09-11 16:03 ` Juerg Haefliger
2017-09-11 16:59 ` Tycho Andersen
2017-09-12 8:05 ` Yisheng Xie
2017-09-12 14:36 ` Tycho Andersen
2017-09-12 18:13 ` Tycho Andersen
2017-09-14 6:15 ` Yisheng Xie
2017-09-20 23:46 ` Dave Hansen
2017-09-21 0:02 ` Tycho Andersen
2017-09-21 0:04 ` Dave Hansen
2017-09-11 18:32 ` Tycho Andersen
2017-09-11 21:54 ` Marco Benatto
2017-09-20 15:48 ` Dave Hansen
2017-09-20 22:34 ` Tycho Andersen
2017-09-20 23:21 ` Dave Hansen
2017-09-21 0:09 ` Tycho Andersen
2017-09-21 0:27 ` Dave Hansen
2017-09-21 1:37 ` Tycho Andersen
2017-11-10 1:09 ` Tycho Andersen
2017-11-13 22:20 ` Dave Hansen
2017-11-13 22:46 ` Dave Hansen
2017-11-15 0:33 ` [kernel-hardening] " Tycho Andersen
2017-11-15 0:37 ` Dave Hansen
2017-11-15 0:42 ` Tycho Andersen
2017-11-15 3:44 ` Matthew Wilcox
2017-11-15 7:00 ` Dave Hansen
2017-11-15 14:58 ` Matthew Wilcox
2017-11-15 16:20 ` [kernel-hardening] " Tycho Andersen
2017-11-15 21:34 ` Matthew Wilcox
2017-09-21 0:03 ` Dave Hansen
2017-09-21 0:28 ` Dave Hansen
2017-09-21 1:04 ` Tycho Andersen
2017-09-07 17:36 ` [PATCH v6 04/11] swiotlb: Map the buffer if it was unmapped by XPFO Tycho Andersen
2017-09-07 18:10 ` Christoph Hellwig
2017-09-07 18:44 ` Tycho Andersen
2017-09-08 7:13 ` Christoph Hellwig
2017-09-07 17:36 ` [PATCH v6 05/11] arm64/mm: Add support for XPFO Tycho Andersen
2017-09-08 7:53 ` Christoph Hellwig
2017-09-08 17:24 ` Tycho Andersen
2017-09-14 10:41 ` Julien Grall
2017-09-14 11:29 ` Juergen Gross
2017-09-14 18:22 ` [kernel-hardening] " Mark Rutland
2017-09-18 21:27 ` Tycho Andersen
2017-09-07 17:36 ` [PATCH v6 06/11] xpfo: add primitives for mapping underlying memory Tycho Andersen
2017-09-07 17:36 ` [PATCH v6 07/11] arm64/mm, xpfo: temporarily map dcache regions Tycho Andersen
2017-09-14 18:25 ` Mark Rutland
2017-09-18 21:29 ` Tycho Andersen
2017-09-07 17:36 ` [PATCH v6 08/11] arm64/mm: Add support for XPFO to swiotlb Tycho Andersen
2017-09-07 17:36 ` [PATCH v6 09/11] arm64/mm: disable section/contiguous mappings if XPFO is enabled Tycho Andersen
2017-09-09 15:38 ` Laura Abbott
2017-09-07 17:36 ` [PATCH v6 10/11] mm: add a user_virt_to_phys symbol Tycho Andersen
2017-09-08 7:55 ` Christoph Hellwig
2017-09-08 15:44 ` Kees Cook
2017-09-11 7:36 ` Christoph Hellwig
2017-09-14 18:34 ` [kernel-hardening] " Mark Rutland
2017-09-18 20:56 ` Tycho Andersen
2017-09-07 17:36 ` [PATCH v6 11/11] lkdtm: Add test for XPFO Tycho Andersen
2017-09-07 19:08 ` Kees Cook
2017-09-10 0:57 ` kbuild test robot
2017-09-11 10:34 ` [PATCH v6 00/11] Add support for eXclusive Page Frame Ownership Yisheng Xie
2017-09-11 15:02 ` Tycho Andersen
2017-09-12 7:07 ` Yisheng Xie
2017-09-12 7:40 ` Juerg Haefliger
2017-09-12 8:11 ` Yisheng Xie
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