From: Khalid Aziz <khalid.aziz@oracle.com>
To: juergh@gmail.com, tycho@tycho.ws, jsteckli@amazon.de,
ak@linux.intel.com, torvalds@linux-foundation.org,
liran.alon@oracle.com, keescook@google.com,
konrad.wilk@oracle.com
Cc: Tycho Andersen <tycho@docker.com>,
deepa.srinivasan@oracle.com, chris.hyser@oracle.com,
tyhicks@canonical.com, dwmw@amazon.co.uk,
andrew.cooper3@citrix.com, jcm@redhat.com,
boris.ostrovsky@oracle.com, kanth.ghatraju@oracle.com,
joao.m.martins@oracle.com, jmattson@google.com,
pradeep.vincent@oracle.com, john.haxby@oracle.com,
tglx@linutronix.de, kirill.shutemov@linux.intel.com, hch@lst.de,
steven.sistare@oracle.com, kernel-hardening@lists.openwall.com,
linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org,
Khalid Aziz <khalid.aziz@oracle.com>
Subject: [RFC PATCH v7 02/16] x86: always set IF before oopsing from page fault
Date: Thu, 10 Jan 2019 14:09:34 -0700 [thread overview]
Message-ID: <46b0f1a61dabf6440d461c063a32573b96f3a5ce.1547153058.git.khalid.aziz@oracle.com> (raw)
In-Reply-To: <cover.1547153058.git.khalid.aziz@oracle.com>
In-Reply-To: <cover.1547153058.git.khalid.aziz@oracle.com>
From: Tycho Andersen <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
Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
---
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 71d4b9d4d43f..ba51652fbd33 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -748,6 +748,12 @@ 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);
}
--
2.17.1
next prev parent reply other threads:[~2019-01-10 21:11 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-10 21:09 [RFC PATCH v7 00/16] Add support for eXclusive Page Frame Ownership Khalid Aziz
2019-01-10 21:09 ` [RFC PATCH v7 01/16] mm: add MAP_HUGETLB support to vm_mmap Khalid Aziz
2019-01-10 21:09 ` Khalid Aziz [this message]
2019-01-10 21:09 ` [RFC PATCH v7 03/16] mm, x86: Add support for eXclusive Page Frame Ownership (XPFO) Khalid Aziz
2019-01-10 21:09 ` [RFC PATCH v7 04/16] swiotlb: Map the buffer if it was unmapped by XPFO Khalid Aziz
2019-01-23 14:16 ` Konrad Rzeszutek Wilk
2019-01-10 21:09 ` [RFC PATCH v7 05/16] arm64/mm: Add support for XPFO Khalid Aziz
2019-01-10 21:09 ` Khalid Aziz
2019-01-23 14:20 ` Konrad Rzeszutek Wilk
2019-01-23 14:20 ` Konrad Rzeszutek Wilk
2019-02-12 15:45 ` Khalid Aziz
2019-02-12 15:45 ` Khalid Aziz
2019-01-23 14:24 ` Konrad Rzeszutek Wilk
2019-01-23 14:24 ` Konrad Rzeszutek Wilk
2019-02-12 15:52 ` Khalid Aziz
2019-02-12 15:52 ` Khalid Aziz
2019-02-12 20:01 ` Laura Abbott
2019-02-12 20:01 ` Laura Abbott
2019-02-12 20:34 ` Khalid Aziz
2019-02-12 20:34 ` Khalid Aziz
2019-01-10 21:09 ` [RFC PATCH v7 06/16] xpfo: add primitives for mapping underlying memory Khalid Aziz
2019-01-10 21:09 ` [RFC PATCH v7 07/16] arm64/mm, xpfo: temporarily map dcache regions Khalid Aziz
2019-01-10 21:09 ` Khalid Aziz
2019-01-11 14:54 ` Tycho Andersen
2019-01-11 14:54 ` Tycho Andersen
2019-01-11 18:28 ` Khalid Aziz
2019-01-11 18:28 ` Khalid Aziz
2019-01-11 19:50 ` Tycho Andersen
2019-01-11 19:50 ` Tycho Andersen
2019-01-23 14:56 ` Konrad Rzeszutek Wilk
2019-01-23 14:56 ` Konrad Rzeszutek Wilk
2019-01-10 21:09 ` [RFC PATCH v7 08/16] arm64/mm: disable section/contiguous mappings if XPFO is enabled Khalid Aziz
2019-01-10 21:09 ` Khalid Aziz
2019-01-10 21:09 ` [RFC PATCH v7 09/16] mm: add a user_virt_to_phys symbol Khalid Aziz
2019-01-10 21:09 ` Khalid Aziz
2019-01-23 15:03 ` Konrad Rzeszutek Wilk
2019-01-23 15:03 ` Konrad Rzeszutek Wilk
2019-01-10 21:09 ` [RFC PATCH v7 10/16] lkdtm: Add test for XPFO Khalid Aziz
2019-01-10 21:09 ` [RFC PATCH v7 11/16] mm, x86: omit TLB flushing by default for XPFO page table modifications Khalid Aziz
2019-01-10 21:09 ` [RFC PATCH v7 12/16] xpfo, mm: remove dependency on CONFIG_PAGE_EXTENSION Khalid Aziz
2019-01-16 15:01 ` Julian Stecklina
2019-01-10 21:09 ` [RFC PATCH v7 13/16] xpfo, mm: optimize spinlock usage in xpfo_kunmap Khalid Aziz
2019-01-10 21:09 ` [RFC PATCH v7 14/16] EXPERIMENTAL: xpfo, mm: optimize spin lock usage in xpfo_kmap Khalid Aziz
2019-01-17 0:18 ` Laura Abbott
2019-01-17 15:14 ` Khalid Aziz
2019-01-10 21:09 ` [RFC PATCH v7 15/16] xpfo, mm: Fix hang when booting with "xpfotlbflush" Khalid Aziz
2019-01-10 21:09 ` [RFC PATCH v7 16/16] xpfo, mm: Defer TLB flushes for non-current CPUs (x86 only) Khalid Aziz
2019-01-10 23:07 ` [RFC PATCH v7 00/16] Add support for eXclusive Page Frame Ownership Kees Cook
2019-01-10 23:07 ` Kees Cook
2019-01-11 0:20 ` Khalid Aziz
2019-01-11 0:44 ` Andy Lutomirski
2019-01-11 0:44 ` Andy Lutomirski
2019-01-11 21:45 ` Khalid Aziz
2019-01-10 23:40 ` Dave Hansen
2019-01-11 9:59 ` Peter Zijlstra
2019-01-11 18:21 ` Khalid Aziz
2019-01-11 20:42 ` Dave Hansen
2019-01-11 21:06 ` Andy Lutomirski
2019-01-11 21:06 ` Andy Lutomirski
2019-01-11 23:25 ` Khalid Aziz
2019-01-11 23:23 ` Khalid Aziz
2019-01-16 1:28 ` Laura Abbott
2019-01-16 14:56 ` Julian Stecklina
2019-01-16 15:16 ` Khalid Aziz
2019-01-17 23:38 ` Laura Abbott
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