From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Jessica Yu <jeyu@redhat.com>, Jiri Kosina <jikos@kernel.org>,
Miroslav Benes <mbenes@suse.cz>, Petr Mladek <pmladek@suse.com>
Cc: linux-kernel@vger.kernel.org, live-patching@vger.kernel.org,
Michael Ellerman <mpe@ellerman.id.au>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
x86@kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-s390@vger.kernel.org, Vojtech Pavlik <vojtech@suse.com>,
Jiri Slaby <jslaby@suse.cz>,
Chris J Arges <chris.j.arges@canonical.com>,
Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH v3 04/15] livepatch/x86: add TIF_PATCH_PENDING thread flag
Date: Thu, 8 Dec 2016 12:08:29 -0600 [thread overview]
Message-ID: <b7bbfce2330e61329056e4567c68be8e4c55fb5b.1481220077.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1481220077.git.jpoimboe@redhat.com>
Add the TIF_PATCH_PENDING thread flag to enable the new livepatch
per-task consistency model for x86_64. The bit getting set indicates
the thread has a pending patch which needs to be applied when the thread
exits the kernel.
The bit is placed in the _TIF_ALLWORK_MASK macro, which results in
exit_to_usermode_loop() calling klp_update_patch_state() when it's set.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
arch/x86/entry/common.c | 9 ++++++---
arch/x86/include/asm/thread_info.h | 4 +++-
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index bdd9cc5..16a51a5 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -21,6 +21,7 @@
#include <linux/context_tracking.h>
#include <linux/user-return-notifier.h>
#include <linux/uprobes.h>
+#include <linux/livepatch.h>
#include <asm/desc.h>
#include <asm/traps.h>
@@ -129,14 +130,13 @@ static long syscall_trace_enter(struct pt_regs *regs)
#define EXIT_TO_USERMODE_LOOP_FLAGS \
(_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
- _TIF_NEED_RESCHED | _TIF_USER_RETURN_NOTIFY)
+ _TIF_NEED_RESCHED | _TIF_USER_RETURN_NOTIFY | _TIF_PATCH_PENDING)
static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags)
{
/*
* In order to return to user mode, we need to have IRQs off with
- * none of _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_USER_RETURN_NOTIFY,
- * _TIF_UPROBE, or _TIF_NEED_RESCHED set. Several of these flags
+ * none of EXIT_TO_USERMODE_LOOP_FLAGS set. Several of these flags
* can be set at any time on preemptable kernels if we have IRQs on,
* so we need to loop. Disabling preemption wouldn't help: doing the
* work to clear some of the flags can sleep.
@@ -163,6 +163,9 @@ static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags)
if (cached_flags & _TIF_USER_RETURN_NOTIFY)
fire_user_return_notifiers();
+ if (cached_flags & _TIF_PATCH_PENDING)
+ klp_update_patch_state(current);
+
/* Disable IRQs and retry */
local_irq_disable();
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 1fe6043..79f4d6a 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -84,6 +84,7 @@ struct thread_info {
#define TIF_SECCOMP 8 /* secure computing */
#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
#define TIF_UPROBE 12 /* breakpointed or singlestepping */
+#define TIF_PATCH_PENDING 13 /* pending live patching update */
#define TIF_NOTSC 16 /* TSC is not accessible in userland */
#define TIF_IA32 17 /* IA32 compatibility process */
#define TIF_NOHZ 19 /* in adaptive nohz mode */
@@ -107,6 +108,7 @@ struct thread_info {
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
#define _TIF_UPROBE (1 << TIF_UPROBE)
+#define _TIF_PATCH_PENDING (1 << TIF_PATCH_PENDING)
#define _TIF_NOTSC (1 << TIF_NOTSC)
#define _TIF_IA32 (1 << TIF_IA32)
#define _TIF_NOHZ (1 << TIF_NOHZ)
@@ -133,7 +135,7 @@ struct thread_info {
(_TIF_SYSCALL_TRACE | _TIF_NOTIFY_RESUME | _TIF_SIGPENDING | \
_TIF_SINGLESTEP | _TIF_NEED_RESCHED | _TIF_SYSCALL_EMU | \
_TIF_SYSCALL_AUDIT | _TIF_USER_RETURN_NOTIFY | _TIF_UPROBE | \
- _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
+ _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ | _TIF_PATCH_PENDING)
/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW \
--
2.7.4
next prev parent reply other threads:[~2016-12-08 18:12 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-08 18:08 [PATCH v3 00/15] livepatch: hybrid consistency model Josh Poimboeuf
2016-12-08 18:08 ` [PATCH v3 01/15] stacktrace/x86: add function for detecting reliable stack traces Josh Poimboeuf
2016-12-16 13:07 ` Petr Mladek
2016-12-16 22:09 ` Josh Poimboeuf
2016-12-19 16:25 ` Miroslav Benes
2016-12-19 17:25 ` Josh Poimboeuf
2016-12-19 18:23 ` Miroslav Benes
2016-12-20 9:39 ` Petr Mladek
2016-12-20 21:21 ` Josh Poimboeuf
2016-12-08 18:08 ` [PATCH v3 02/15] x86/entry: define _TIF_ALLWORK_MASK flags explicitly Josh Poimboeuf
2016-12-16 14:17 ` Petr Mladek
2016-12-16 22:13 ` Josh Poimboeuf
2016-12-19 16:39 ` Miroslav Benes
2017-01-10 8:49 ` Kamalesh Babulal
2016-12-08 18:08 ` [PATCH v3 03/15] livepatch: temporary stubs for klp_patch_pending() and klp_update_patch_state() Josh Poimboeuf
2016-12-16 14:41 ` Petr Mladek
2016-12-16 22:15 ` Josh Poimboeuf
2016-12-08 18:08 ` Josh Poimboeuf [this message]
2016-12-08 18:27 ` [PATCH v3 04/15] livepatch/x86: add TIF_PATCH_PENDING thread flag Andy Lutomirski
2016-12-16 15:39 ` Petr Mladek
2016-12-21 13:54 ` Miroslav Benes
2017-01-11 7:06 ` Kamalesh Babulal
2016-12-08 18:08 ` [PATCH v3 05/15] livepatch/powerpc: " Josh Poimboeuf
2016-12-16 16:00 ` Petr Mladek
2016-12-21 14:30 ` Miroslav Benes
2017-01-10 8:29 ` Kamalesh Babulal
2016-12-08 18:08 ` [PATCH v3 06/15] livepatch/s390: reorganize TIF thread flag bits Josh Poimboeuf
2016-12-21 15:29 ` Miroslav Benes
2016-12-08 18:08 ` [PATCH v3 07/15] livepatch/s390: add TIF_PATCH_PENDING thread flag Josh Poimboeuf
2016-12-08 18:08 ` [PATCH v3 08/15] livepatch: separate enabled and patched states Josh Poimboeuf
2016-12-16 16:21 ` Petr Mladek
2016-12-23 12:54 ` Miroslav Benes
2017-01-10 9:10 ` Kamalesh Babulal
2016-12-08 18:08 ` [PATCH v3 09/15] livepatch: remove unnecessary object loaded check Josh Poimboeuf
2016-12-16 16:26 ` Petr Mladek
2016-12-23 12:58 ` Miroslav Benes
2017-01-10 9:14 ` Kamalesh Babulal
2016-12-08 18:08 ` [PATCH v3 10/15] livepatch: move patching functions into patch.c Josh Poimboeuf
2016-12-16 16:49 ` Petr Mladek
2016-12-23 13:06 ` Miroslav Benes
2017-01-10 9:15 ` Kamalesh Babulal
2016-12-08 18:08 ` [PATCH v3 11/15] livepatch: use kstrtobool() in enabled_store() Josh Poimboeuf
2016-12-16 16:55 ` Petr Mladek
2016-12-16 22:19 ` Josh Poimboeuf
2016-12-23 13:13 ` Miroslav Benes
2016-12-08 18:08 ` [PATCH v3 12/15] livepatch: store function sizes Josh Poimboeuf
2016-12-19 13:10 ` Petr Mladek
2016-12-23 13:40 ` Miroslav Benes
2017-01-11 10:09 ` Kamalesh Babulal
2016-12-08 18:08 ` [PATCH v3 13/15] livepatch: change to a per-task consistency model Josh Poimboeuf
2016-12-20 17:32 ` Petr Mladek
2016-12-21 21:25 ` Josh Poimboeuf
2016-12-22 14:34 ` Petr Mladek
2016-12-22 18:31 ` Josh Poimboeuf
2017-01-10 13:00 ` Petr Mladek
2017-01-10 20:46 ` Josh Poimboeuf
2017-01-11 15:18 ` Petr Mladek
2017-01-11 15:26 ` Josh Poimboeuf
2016-12-23 9:24 ` Miroslav Benes
2016-12-23 10:18 ` Petr Mladek
2017-01-06 20:07 ` Josh Poimboeuf
2017-01-10 10:40 ` Petr Mladek
2017-01-04 13:44 ` Miroslav Benes
2017-01-06 21:01 ` Josh Poimboeuf
2017-01-10 10:45 ` Miroslav Benes
2017-01-05 9:34 ` Miroslav Benes
2017-01-06 21:04 ` Josh Poimboeuf
2016-12-08 18:08 ` [PATCH v3 14/15] livepatch: add /proc/<pid>/patch_state Josh Poimboeuf
2016-12-21 11:20 ` Petr Mladek
2017-01-04 14:50 ` Miroslav Benes
2016-12-08 18:08 ` [PATCH v3 15/15] livepatch: allow removal of a disabled patch Josh Poimboeuf
2016-12-21 14:44 ` Petr Mladek
2017-01-04 14:57 ` Miroslav Benes
2017-01-06 21:04 ` Josh Poimboeuf
2016-12-10 5:46 ` [PATCH v3 00/15] livepatch: hybrid consistency model Balbir Singh
2016-12-10 17:17 ` Josh Poimboeuf
2016-12-11 2:08 ` Balbir Singh
2016-12-12 14:04 ` Josh Poimboeuf
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