sravan/linux-tkg
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

linux 6.1.y: misc_additions: Get rid of Bluetooth: fix deadlock for RFCOMM sk state change and x86/split_lock: Add sysctl to control the misery mode. The latter will be added to community patches instead and we'll now pass split_lock_detect=off by default to the command line. We'll see how the situation pans out and adapt as needed.

Browse Source
This commit is contained in:
Tk-Glitch
2022-12-16 14:00:36 +01:00
parent d0d6f02944
commit 367925c322
2 changed files with 237 additions and 406 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
customization.cfg
View File

@@ -241,7 +241,7 @@ _aggressive_ondemand="true"
_tcp_cong_alg=""
# You can pass a default set of kernel command line options here - example: "intel_pstate=passive nowatchdog amdgpu.ppfeaturemask=0xfffd7fff mitigations=off"
_custom_commandline="intel_pstate=passive"
_custom_commandline="intel_pstate=passive split_lock_detect=off"
# Selection of Clearlinux patches
_clear_patches="true"

625
linux-tkg-patches/6.1/0012-misc-additions.patch
View File

@@ -64,422 +64,253 @@ index 2c7171e0b0010..85de313ddec29 100644
select CPU_FREQ_GOV_PERFORMANCE
help
From 430daaab3c78de6bd82f10cfb5a0f016c6e583f6 Mon Sep 17 00:00:00 2001
From: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Date: Mon, 4 Oct 2021 14:07:34 -0400
Subject: [PATCH] Bluetooth: fix deadlock for RFCOMM sk state change
From 0c079d3f88df5f8286cd5c91b54bdac7c819be85 Mon Sep 17 00:00:00 2001
From: Matthew Auld <matthew.auld@intel.com>
Date: Tue, 6 Dec 2022 16:11:41 +0000
Subject: [PATCH] drm/i915: improve the catch-all evict to handle lock
contention
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Syzbot reports the following task hang [1]:
The catch-all evict can fail due to object lock contention, since it
only goes as far as trylocking the object, due to us already holding the
vm->mutex. Doing a full object lock here can deadlock, since the
vm->mutex is always our inner lock. Add another execbuf pass which drops
the vm->mutex and then tries to grab the object will the full lock,
before then retrying the eviction. This should be good enough for now to
fix the immediate regression with userspace seeing -ENOSPC from execbuf
due to contended object locks during GTT eviction.
INFO: task syz-executor255:8499 blocked for more than 143 seconds.
Not tainted 5.14.0-rc7-syzkaller #0
Testcase: igt@gem_ppgtt@shrink-vs-evict-*
Fixes: 7e00897be8bf ("drm/i915: Add object locking to i915_gem_evict_for_node and i915_gem_evict_something, v2.")
References: https://gitlab.freedesktop.org/drm/intel/-/issues/7627
References: https://gitlab.freedesktop.org/drm/intel/-/issues/7570
References: https://bugzilla.mozilla.org/show_bug.cgi?id=1779558
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Mani Milani <mani@chromium.org>
Cc: <stable@vger.kernel.org> # v5.18+
Call Trace:
context_switch kernel/sched/core.c:4681 [inline]
__schedule+0x93a/0x26f0 kernel/sched/core.c:5938
schedule+0xd3/0x270 kernel/sched/core.c:6017
__lock_sock+0x13d/0x260 net/core/sock.c:2644
lock_sock_nested+0xf6/0x120 net/core/sock.c:3185
lock_sock include/net/sock.h:1612 [inline]
rfcomm_sk_state_change+0xb4/0x390 net/bluetooth/rfcomm/sock.c:73
__rfcomm_dlc_close+0x1b6/0x8a0 net/bluetooth/rfcomm/core.c:489
rfcomm_dlc_close+0x1ea/0x240 net/bluetooth/rfcomm/core.c:520
__rfcomm_sock_close+0xac/0x260 net/bluetooth/rfcomm/sock.c:220
rfcomm_sock_shutdown+0xe9/0x210 net/bluetooth/rfcomm/sock.c:931
rfcomm_sock_release+0x5f/0x140 net/bluetooth/rfcomm/sock.c:951
__sock_release+0xcd/0x280 net/socket.c:649
sock_close+0x18/0x20 net/socket.c:1314
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
exit_task_work include/linux/task_work.h:32 [inline]
do_exit+0xbd4/0x2a60 kernel/exit.c:825
do_group_exit+0x125/0x310 kernel/exit.c:922
get_signal+0x47f/0x2160 kernel/signal.c:2808
arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865
handle_signal_work kernel/entry/common.c:148 [inline]
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
Showing all locks held in the system:
1 lock held by khungtaskd/1653:
#0: ffffffff8b97c280 (rcu_read_lock){....}-{1:2}, at:
debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446
1 lock held by krfcommd/4781:
#0: ffffffff8d306528 (rfcomm_mutex){+.+.}-{3:3}, at:
rfcomm_process_sessions net/bluetooth/rfcomm/core.c:1979 [inline]
#0: ffffffff8d306528 (rfcomm_mutex){+.+.}-{3:3}, at:
rfcomm_run+0x2ed/0x4a20 net/bluetooth/rfcomm/core.c:2086
2 locks held by in:imklog/8206:
#0: ffff8880182ce5f0 (&f->f_pos_lock){+.+.}-{3:3}, at:
__fdget_pos+0xe9/0x100 fs/file.c:974
#1: ffff8880b9c51a58 (&rq->__lock){-.-.}-{2:2}, at:
raw_spin_rq_lock_nested kernel/sched/core.c:460 [inline]
#1: ffff8880b9c51a58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock
kernel/sched/sched.h:1307 [inline]
#1: ffff8880b9c51a58 (&rq->__lock){-.-.}-{2:2}, at: rq_lock
kernel/sched/sched.h:1610 [inline]
#1: ffff8880b9c51a58 (&rq->__lock){-.-.}-{2:2}, at:
__schedule+0x233/0x26f0 kernel/sched/core.c:5852
4 locks held by syz-executor255/8499:
#0: ffff888039a83690 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at:
inode_lock include/linux/fs.h:774 [inline]
#0: ffff888039a83690 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at:
__sock_release+0x86/0x280 net/socket.c:648
#1:
ffff88802fa31120 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0},
at: lock_sock include/net/sock.h:1612 [inline]
#1:
ffff88802fa31120 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0},
at: rfcomm_sock_shutdown+0x54/0x210 net/bluetooth/rfcomm/sock.c:928
#2: ffffffff8d306528 (rfcomm_mutex){+.+.}-{3:3}, at:
rfcomm_dlc_close+0x34/0x240 net/bluetooth/rfcomm/core.c:507
#3: ffff888141bd6d28 (&d->lock){+.+.}-{3:3}, at:
__rfcomm_dlc_close+0x162/0x8a0 net/bluetooth/rfcomm/core.c:487
==================================================================
The task hangs because of a deadlock that occurs when lock_sock() is
called in rfcomm_sk_state_change(). One such call stack is:
rfcomm_sock_shutdown():
lock_sock();
__rfcomm_sock_close():
rfcomm_dlc_close():
__rfcomm_dlc_close():
rfcomm_dlc_lock();
rfcomm_sk_state_change():
lock_sock();
lock_sock() has to be called when the sk state is changed because the
lock is not always held when rfcomm_sk_state_change() is
called. However, besides the recursive deadlock, there is also an
issue of a lock hierarchy inversion between rfcomm_dlc_lock() and
lock_sock() if the socket is locked in rfcomm_sk_state_change().
To avoid these issues, we can instead schedule the sk state change in
the global workqueue. This is already the implicit assumption about
how sk state changes happen. For example, in rfcomm_sock_shutdown(),
the call to __rfcomm_sock_close() is followed by
bt_sock_wait_state().
Additionally, the call to rfcomm_sock_kill() inside
rfcomm_sk_state_change() should be removed. The socket shouldn't be
killed here because only rfcomm_sock_release() calls sock_orphan(),
which it already follows up with a call to rfcomm_sock_kill().
Fixes: b7ce436a5d79 ("Bluetooth: switch to lock_sock in RFCOMM")
Link: https://syzkaller.appspot.com/bug?extid=7d51f807c81b190a127d [1]
Reported-by: syzbot+7d51f807c81b190a127d@syzkaller.appspotmail.com
Tested-by: syzbot+7d51f807c81b190a127d@syzkaller.appspotmail.com
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Revision 1 of https://patchwork.freedesktop.org/series/111686/
---
include/net/bluetooth/rfcomm.h | 3 +++
net/bluetooth/rfcomm/core.c | 2 ++
net/bluetooth/rfcomm/sock.c | 34 ++++++++++++++++++++++------------
3 files changed, 27 insertions(+), 12 deletions(-)
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 25 +++++++++++--
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 2 +-
drivers/gpu/drm/i915/i915_gem_evict.c | 37 ++++++++++++++-----
drivers/gpu/drm/i915/i915_gem_evict.h | 4 +-
drivers/gpu/drm/i915/i915_vma.c | 2 +-
.../gpu/drm/i915/selftests/i915_gem_evict.c | 4 +-
6 files changed, 56 insertions(+), 18 deletions(-)
diff --git a/include/net/bluetooth/rfcomm.h b/include/net/bluetooth/rfcomm.h
index 99d26879b02a53..a92799fc5e74d0 100644
--- a/include/net/bluetooth/rfcomm.h
+++ b/include/net/bluetooth/rfcomm.h
@@ -171,6 +171,7 @@ struct rfcomm_dlc {
struct rfcomm_session *session;
struct sk_buff_head tx_queue;
struct timer_list timer;
+ struct work_struct state_change_work;
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 845023c14eb36f..094e92ed28db4f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -741,25 +741,44 @@ static int eb_reserve(struct i915_execbuffer *eb)
*
* Defragmenting is skipped if all objects are pinned at a fixed location.
*/
- for (pass = 0; pass <= 2; pass++) {
+ for (pass = 0; pass <= 3; pass++) {
int pin_flags = PIN_USER | PIN_VALIDATE;
struct mutex lock;
unsigned long state;
@@ -186,6 +187,7 @@ struct rfcomm_dlc {
u8 sec_level;
u8 role_switch;
u32 defer_setup;
+ int err;
if (pass == 0)
pin_flags |= PIN_NONBLOCK;
uint mtu;
uint cfc;
@@ -310,6 +312,7 @@ struct rfcomm_pinfo {
u8 role_switch;
};
if (pass >= 1)
- unpinned = eb_unbind(eb, pass == 2);
+ unpinned = eb_unbind(eb, pass >= 2);
+void __rfcomm_sk_state_change(struct work_struct *work);
int rfcomm_init_sockets(void);
void rfcomm_cleanup_sockets(void);
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index 7324764384b677..c6494e85cd68b2 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -289,6 +289,7 @@ static void rfcomm_dlc_clear_state(struct rfcomm_dlc *d)
d->flags = 0;
d->mscex = 0;
d->sec_level = BT_SECURITY_LOW;
+ d->err = 0;
d->mtu = RFCOMM_DEFAULT_MTU;
d->v24_sig = RFCOMM_V24_RTC | RFCOMM_V24_RTR | RFCOMM_V24_DV;
@@ -306,6 +307,7 @@ struct rfcomm_dlc *rfcomm_dlc_alloc(gfp_t prio)
timer_setup(&d->timer, rfcomm_dlc_timeout, 0);
skb_queue_head_init(&d->tx_queue);
+ INIT_WORK(&d->state_change_work, __rfcomm_sk_state_change);
mutex_init(&d->lock);
refcount_set(&d->refcnt, 1);
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 4bf4ea6cbb5eee..4850dafbaa05fb 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -61,19 +61,22 @@ static void rfcomm_sk_data_ready(struct rfcomm_dlc *d, struct sk_buff *skb)
rfcomm_dlc_throttle(d);
if (pass == 2) {
err = mutex_lock_interruptible(&eb->context->vm->mutex);
if (!err) {
- err = i915_gem_evict_vm(eb->context->vm, &eb->ww);
+ err = i915_gem_evict_vm(eb->context->vm, &eb->ww, NULL);
mutex_unlock(&eb->context->vm->mutex);
}
if (err)
return err;
}
-static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err)
+void __rfcomm_sk_state_change(struct work_struct *work)
{
+ struct rfcomm_dlc *d = container_of(work, struct rfcomm_dlc,
+ state_change_work);
struct sock *sk = d->owner, *parent;
if (!sk)
return;
- BT_DBG("dlc %p state %ld err %d", d, d->state, err);
-
lock_sock(sk);
+ rfcomm_dlc_lock(d);
- if (err)
- sk->sk_err = err;
+ BT_DBG("dlc %p state %ld err %d", d, d->state, d->err);
+ if (pass == 3) {
+retry:
+ err = mutex_lock_interruptible(&eb->context->vm->mutex);
+ if (!err) {
+ struct drm_i915_gem_object *busy_bo = NULL;
+
+ if (d->err)
+ sk->sk_err = d->err;
sk->sk_state = d->state;
@@ -91,15 +94,22 @@ static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err)
sk->sk_state_change(sk);
}
+ rfcomm_dlc_unlock(d);
release_sock(sk);
+ sock_put(sk);
+ err = i915_gem_evict_vm(eb->context->vm, &eb->ww, &busy_bo);
+ mutex_unlock(&eb->context->vm->mutex);
+ if (err && busy_bo) {
+ err = i915_gem_object_lock(busy_bo, &eb->ww);
+ i915_gem_object_put(busy_bo);
+ if (!err)
+ goto retry;
+ }
- if (parent && sock_flag(sk, SOCK_ZAPPED)) {
- /* We have to drop DLC lock here, otherwise
- * rfcomm_sock_destruct() will dead lock. */
- rfcomm_dlc_unlock(d);
- rfcomm_sock_kill(sk);
- rfcomm_dlc_lock(d);
- }
+static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err)
+{
+ struct sock *sk = d->owner;
+
+ if (!sk)
+ return;
+
+ d->err = err;
+ sock_hold(sk);
+ if (!schedule_work(&d->state_change_work))
+ sock_put(sk);
}
/* ---- Socket functions ---- */
From 727209376f4998bc84db1d5d8af15afea846a92b Mon Sep 17 00:00:00 2001
From: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Date: Mon, 24 Oct 2022 17:02:54 -0300
Subject: x86/split_lock: Add sysctl to control the misery mode
Commit b041b525dab9 ("x86/split_lock: Make life miserable for split lockers")
changed the way the split lock detector works when in "warn" mode;
basically, it not only shows the warn message, but also intentionally
introduces a slowdown through sleeping plus serialization mechanism
on such task. Based on discussions in [0], seems the warning alone
wasn't enough motivation for userspace developers to fix their
applications.
This slowdown is enough to totally break some proprietary (aka.
unfixable) userspace[1].
Happens that originally the proposal in [0] was to add a new mode
which would warns + slowdown the "split locking" task, keeping the
old warn mode untouched. In the end, that idea was discarded and
the regular/default "warn" mode now slows down the applications. This
is quite aggressive with regards proprietary/legacy programs that
basically are unable to properly run in kernel with this change.
While it is understandable that a malicious application could DoS
by split locking, it seems unacceptable to regress old/proprietary
userspace programs through a default configuration that previously
worked. An example of such breakage was reported in [1].
Add a sysctl to allow controlling the "misery mode" behavior, as per
Thomas suggestion on [2]. This way, users running legacy and/or
proprietary software are allowed to still execute them with a decent
performance while still observing the warning messages on kernel log.
[0] https://lore.kernel.org/lkml/20220217012721.9694-1-tony.luck@intel.com/
[1] https://github.com/doitsujin/dxvk/issues/2938
[2] https://lore.kernel.org/lkml/87pmf4bter.ffs@tglx/
[ dhansen: minor changelog tweaks, including clarifying the actual
problem ]
Fixes: b041b525dab9 ("x86/split_lock: Make life miserable for split lockers")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Andre Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/all/20221024200254.635256-1-gpiccoli%40igalia.com
---
Documentation/admin-guide/sysctl/kernel.rst | 23 +++++++++++
arch/x86/kernel/cpu/intel.c | 63 ++++++++++++++++++++++++-----
2 files changed, 76 insertions(+), 10 deletions(-)
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 98d1b198b2b4c..c2c64c1b706ff 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -1314,6 +1314,29 @@ watchdog work to be queued by the watchdog timer function, otherwise the NMI
watchdog — if enabled — can detect a hard lockup condition.
+split_lock_mitigate (x86 only)
+==============================
+
+On x86, each "split lock" imposes a system-wide performance penalty. On larger
+systems, large numbers of split locks from unprivileged users can result in
+denials of service to well-behaved and potentially more important users.
+
+The kernel mitigates these bad users by detecting split locks and imposing
+penalties: forcing them to wait and only allowing one core to execute split
+locks at a time.
+
+These mitigations can make those bad applications unbearably slow. Setting
+split_lock_mitigate=0 may restore some application performance, but will also
+increase system exposure to denial of service attacks from split lock users.
+
+= ===================================================================
+0 Disable the mitigation mode - just warns the split lock on kernel log
+ and exposes the system to denials of service from the split lockers.
+1 Enable the mitigation mode (this is the default) - penalizes the split
+ lockers with intentional performance degradation.
+= ===================================================================
+
+
stack_erasing
=============
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 2d7ea5480ec33..4278996504833 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -1034,8 +1034,32 @@ static const struct {
static struct ratelimit_state bld_ratelimit;
+static unsigned int sysctl_sld_mitigate = 1;
static DEFINE_SEMAPHORE(buslock_sem);
+#ifdef CONFIG_PROC_SYSCTL
+static struct ctl_table sld_sysctls[] = {
+ {
+ .procname = "split_lock_mitigate",
+ .data = &sysctl_sld_mitigate,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_douintvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ {}
+};
+
+static int __init sld_mitigate_sysctl_init(void)
+{
+ register_sysctl_init("kernel", sld_sysctls);
+ return 0;
+ }
+ if (err)
+ return err;
+ }
+
+late_initcall(sld_mitigate_sysctl_init);
+#endif
+
static inline bool match_option(const char *arg, int arglen, const char *opt)
list_for_each_entry(ev, &eb->unbound, bind_link) {
err = eb_reserve_vma(eb, ev, pin_flags);
if (err)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index 73d9eda1d6b7a6..c83d98e1dc5da0 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -369,7 +369,7 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)
if (vma == ERR_PTR(-ENOSPC)) {
ret = mutex_lock_interruptible(&ggtt->vm.mutex);
if (!ret) {
- ret = i915_gem_evict_vm(&ggtt->vm, &ww);
+ ret = i915_gem_evict_vm(&ggtt->vm, &ww, NULL);
mutex_unlock(&ggtt->vm.mutex);
}
if (ret)
diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
index f025ee4fa52618..a4b4d9b7d26c7a 100644
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -416,6 +416,11 @@ int i915_gem_evict_for_node(struct i915_address_space *vm,
* @vm: Address space to cleanse
* @ww: An optional struct i915_gem_ww_ctx. If not NULL, i915_gem_evict_vm
* will be able to evict vma's locked by the ww as well.
+ * @busy_bo: Optional pointer to struct drm_i915_gem_object. If not NULL, then
+ * in the event i915_gem_evict_vm() is unable to trylock an object for eviction,
+ * then @busy_bo will point to it. -EBUSY is also returned. The caller must drop
+ * the vm->mutex, before trying again to acquire the contended lock. The caller
+ * also owns a reference to the object.
*
* This function evicts all vmas from a vm.
*
@@ -425,7 +430,8 @@ int i915_gem_evict_for_node(struct i915_address_space *vm,
* To clarify: This is for freeing up virtual address space, not for freeing
* memory in e.g. the shrinker.
*/
-int i915_gem_evict_vm(struct i915_address_space *vm, struct i915_gem_ww_ctx *ww)
+int i915_gem_evict_vm(struct i915_address_space *vm, struct i915_gem_ww_ctx *ww,
+ struct drm_i915_gem_object **busy_bo)
{
int len = strlen(opt), ratelimit;
@@ -1146,12 +1170,20 @@ static void split_lock_init(void)
split_lock_verify_msr(sld_state != sld_off);
int ret = 0;
@@ -457,15 +463,22 @@ int i915_gem_evict_vm(struct i915_address_space *vm, struct i915_gem_ww_ctx *ww)
* the resv is shared among multiple objects, we still
* need the object ref.
*/
- if (dying_vma(vma) ||
+ if (!i915_gem_object_get_rcu(vma->obj) ||
(ww && (dma_resv_locking_ctx(vma->obj->base.resv) == &ww->ctx))) {
__i915_vma_pin(vma);
list_add(&vma->evict_link, &locked_eviction_list);
continue;
}
-static void __split_lock_reenable(struct work_struct *work)
+static void __split_lock_reenable_unlock(struct work_struct *work)
{
sld_update_msr(true);
up(&buslock_sem);
}
+static DECLARE_DELAYED_WORK(sl_reenable_unlock, __split_lock_reenable_unlock);
+
+static void __split_lock_reenable(struct work_struct *work)
+{
+ sld_update_msr(true);
- if (!i915_gem_object_trylock(vma->obj, ww))
+ if (!i915_gem_object_trylock(vma->obj, ww)) {
+ if (busy_bo) {
+ *busy_bo = vma->obj; /* holds ref */
+ ret = -EBUSY;
+ break;
+ }
+static DECLARE_DELAYED_WORK(sl_reenable, __split_lock_reenable);
+
/*
* If a CPU goes offline with pending delayed work to re-enable split lock
* detection then the delayed work will be executed on some other CPU. That
@@ -1169,10 +1201,9 @@ static int splitlock_cpu_offline(unsigned int cpu)
return 0;
+ i915_gem_object_put(vma->obj);
continue;
+ }
__i915_vma_pin(vma);
list_add(&vma->evict_link, &eviction_list);
@@ -473,25 +486,29 @@ int i915_gem_evict_vm(struct i915_address_space *vm, struct i915_gem_ww_ctx *ww)
if (list_empty(&eviction_list) && list_empty(&locked_eviction_list))
break;
- ret = 0;
/* Unbind locked objects first, before unlocking the eviction_list */
list_for_each_entry_safe(vma, vn, &locked_eviction_list, evict_link) {
__i915_vma_unpin(vma);
- if (ret == 0)
+ if (ret == 0) {
ret = __i915_vma_unbind(vma);
- if (ret != -EINTR) /* "Get me out of here!" */
- ret = 0;
+ if (ret != -EINTR) /* "Get me out of here!" */
+ ret = 0;
+ }
+ if (!dying_vma(vma))
+ i915_gem_object_put(vma->obj);
}
-static DECLARE_DELAYED_WORK(split_lock_reenable, __split_lock_reenable);
-
static void split_lock_warn(unsigned long ip)
{
+ struct delayed_work *work;
int cpu;
if (!current->reported_split_lock)
@@ -1180,14 +1211,26 @@ static void split_lock_warn(unsigned long ip)
current->comm, current->pid, ip);
current->reported_split_lock = 1;
- /* misery factor #1, sleep 10ms before trying to execute split lock */
- if (msleep_interruptible(10) > 0)
- return;
- /* Misery factor #2, only allow one buslocked disabled core at a time */
- if (down_interruptible(&buslock_sem) == -EINTR)
- return;
+ if (sysctl_sld_mitigate) {
+ /*
+ * misery factor #1:
+ * sleep 10ms before trying to execute split lock.
+ */
+ if (msleep_interruptible(10) > 0)
+ return;
+ /*
+ * Misery factor #2:
+ * only allow one buslocked disabled core at a time.
+ */
+ if (down_interruptible(&buslock_sem) == -EINTR)
+ return;
+ work = &sl_reenable_unlock;
+ } else {
+ work = &sl_reenable;
list_for_each_entry_safe(vma, vn, &eviction_list, evict_link) {
__i915_vma_unpin(vma);
- if (ret == 0)
+ if (ret == 0) {
ret = __i915_vma_unbind(vma);
- if (ret != -EINTR) /* "Get me out of here!" */
- ret = 0;
+ if (ret != -EINTR) /* "Get me out of here!" */
+ ret = 0;
+ }
+
cpu = get_cpu();
- schedule_delayed_work_on(cpu, &split_lock_reenable, 2);
+ schedule_delayed_work_on(cpu, work, 2);
/* Disable split lock detection on this CPU to make progress */
sld_update_msr(false);
i915_gem_object_unlock(vma->obj);
+ i915_gem_object_put(vma->obj);
}
} while (ret == 0);
diff --git a/drivers/gpu/drm/i915/i915_gem_evict.h b/drivers/gpu/drm/i915/i915_gem_evict.h
index e593c530f9bd7a..bf0ee0e4fe6088 100644
--- a/drivers/gpu/drm/i915/i915_gem_evict.h
+++ b/drivers/gpu/drm/i915/i915_gem_evict.h
@@ -11,6 +11,7 @@
struct drm_mm_node;
struct i915_address_space;
struct i915_gem_ww_ctx;
+struct drm_i915_gem_object;
int __must_check i915_gem_evict_something(struct i915_address_space *vm,
struct i915_gem_ww_ctx *ww,
@@ -23,6 +24,7 @@ int __must_check i915_gem_evict_for_node(struct i915_address_space *vm,
struct drm_mm_node *node,
unsigned int flags);
int i915_gem_evict_vm(struct i915_address_space *vm,
- struct i915_gem_ww_ctx *ww);
+ struct i915_gem_ww_ctx *ww,
+ struct drm_i915_gem_object **busy_bo);
#endif /* __I915_GEM_EVICT_H__ */
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index f17c09ead7d778..4d06875de14a14 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -1569,7 +1569,7 @@ static int __i915_ggtt_pin(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
* locked objects when called from execbuf when pinning
* is removed. This would probably regress badly.
*/
- i915_gem_evict_vm(vm, NULL);
+ i915_gem_evict_vm(vm, NULL, NULL);
mutex_unlock(&vm->mutex);
}
} while (1);
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_evict.c b/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
index 8c6517d29b8e0c..37068542aafe7f 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
@@ -344,7 +344,7 @@ static int igt_evict_vm(void *arg)
/* Everything is pinned, nothing should happen */
mutex_lock(&ggtt->vm.mutex);
- err = i915_gem_evict_vm(&ggtt->vm, NULL);
+ err = i915_gem_evict_vm(&ggtt->vm, NULL, NULL);
mutex_unlock(&ggtt->vm.mutex);
if (err) {
pr_err("i915_gem_evict_vm on a full GGTT returned err=%d]\n",
@@ -356,7 +356,7 @@ static int igt_evict_vm(void *arg)
for_i915_gem_ww(&ww, err, false) {
mutex_lock(&ggtt->vm.mutex);
- err = i915_gem_evict_vm(&ggtt->vm, &ww);
+ err = i915_gem_evict_vm(&ggtt->vm, &ww, NULL);
mutex_unlock(&ggtt->vm.mutex);
}