The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023110609-mulled-exes-50b1@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org>
Date: Tue, 31 Oct 2023 12:24:53 -0400
Subject: [PATCH] tracing: Have trace_event_file have ref counters
The following can crash the kernel:
# cd /sys/kernel/tracing
# echo 'p:sched schedule' > kprobe_events
# exec 5>>events/kprobes/sched/enable
# > kprobe_events
# exec 5>&-
The above commands:
1. Change directory to the tracefs directory
2. Create a kprobe event (doesn't matter what one)
3. Open bash file descriptor 5 on the enable file of the kprobe event
4. Delete the kprobe event (removes the files too)
5. Close the bash file descriptor 5
The above causes a crash!
BUG: kernel NULL pointer dereference, address: 0000000000000028
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 6 PID: 877 Comm: bash Not tainted 6.5.0-rc4-test-00008-g2c6b6b1029d4-dirty #186
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:tracing_release_file_tr+0xc/0x50
What happens here is that the kprobe event creates a trace_event_file
"file" descriptor that represents the file in tracefs to the event. It
maintains state of the event (is it enabled for the given instance?).
Opening the "enable" file gets a reference to the event "file" descriptor
via the open file descriptor. When the kprobe event is deleted, the file is
also deleted from the tracefs system which also frees the event "file"
descriptor.
But as the tracefs file is still opened by user space, it will not be
totally removed until the final dput() is called on it. But this is not
true with the event "file" descriptor that is already freed. If the user
does a write to or simply closes the file descriptor it will reference the
event "file" descriptor that was just freed, causing a use-after-free bug.
To solve this, add a ref count to the event "file" descriptor as well as a
new flag called "FREED". The "file" will not be freed until the last
reference is released. But the FREE flag will be set when the event is
removed to prevent any more modifications to that event from happening,
even if there's still a reference to the event "file" descriptor.
Link: https://lore.kernel.org/linux-trace-kernel/20231031000031.1e705592@gandalf.…
Link: https://lore.kernel.org/linux-trace-kernel/20231031122453.7a48b923@gandalf.…
Cc: stable(a)vger.kernel.org
Cc: Mark Rutland <mark.rutland(a)arm.com>
Fixes: f5ca233e2e66d ("tracing: Increase trace array ref count on enable and filter files")
Reported-by: Beau Belgrave <beaub(a)linux.microsoft.com>
Tested-by: Beau Belgrave <beaub(a)linux.microsoft.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 12207dc6722d..696f8dc4aa53 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -492,6 +492,7 @@ enum {
EVENT_FILE_FL_TRIGGER_COND_BIT,
EVENT_FILE_FL_PID_FILTER_BIT,
EVENT_FILE_FL_WAS_ENABLED_BIT,
+ EVENT_FILE_FL_FREED_BIT,
};
extern struct trace_event_file *trace_get_event_file(const char *instance,
@@ -630,6 +631,7 @@ extern int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...);
* TRIGGER_COND - When set, one or more triggers has an associated filter
* PID_FILTER - When set, the event is filtered based on pid
* WAS_ENABLED - Set when enabled to know to clear trace on module removal
+ * FREED - File descriptor is freed, all fields should be considered invalid
*/
enum {
EVENT_FILE_FL_ENABLED = (1 << EVENT_FILE_FL_ENABLED_BIT),
@@ -643,6 +645,7 @@ enum {
EVENT_FILE_FL_TRIGGER_COND = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT),
EVENT_FILE_FL_PID_FILTER = (1 << EVENT_FILE_FL_PID_FILTER_BIT),
EVENT_FILE_FL_WAS_ENABLED = (1 << EVENT_FILE_FL_WAS_ENABLED_BIT),
+ EVENT_FILE_FL_FREED = (1 << EVENT_FILE_FL_FREED_BIT),
};
struct trace_event_file {
@@ -671,6 +674,7 @@ struct trace_event_file {
* caching and such. Which is mostly OK ;-)
*/
unsigned long flags;
+ atomic_t ref; /* ref count for opened files */
atomic_t sm_ref; /* soft-mode reference counter */
atomic_t tm_ref; /* trigger-mode reference counter */
};
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2539cfc20a97..9aebf904ff97 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4978,6 +4978,20 @@ int tracing_open_file_tr(struct inode *inode, struct file *filp)
if (ret)
return ret;
+ mutex_lock(&event_mutex);
+
+ /* Fail if the file is marked for removal */
+ if (file->flags & EVENT_FILE_FL_FREED) {
+ trace_array_put(file->tr);
+ ret = -ENODEV;
+ } else {
+ event_file_get(file);
+ }
+
+ mutex_unlock(&event_mutex);
+ if (ret)
+ return ret;
+
filp->private_data = inode->i_private;
return 0;
@@ -4988,6 +5002,7 @@ int tracing_release_file_tr(struct inode *inode, struct file *filp)
struct trace_event_file *file = inode->i_private;
trace_array_put(file->tr);
+ event_file_put(file);
return 0;
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 0e1405abf4f7..b7f4ea25a194 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1669,6 +1669,9 @@ extern void event_trigger_unregister(struct event_command *cmd_ops,
char *glob,
struct event_trigger_data *trigger_data);
+extern void event_file_get(struct trace_event_file *file);
+extern void event_file_put(struct trace_event_file *file);
+
/**
* struct event_trigger_ops - callbacks for trace event triggers
*
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f9e3e24d8796..f29e815ca5b2 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -990,13 +990,35 @@ static void remove_subsystem(struct trace_subsystem_dir *dir)
}
}
+void event_file_get(struct trace_event_file *file)
+{
+ atomic_inc(&file->ref);
+}
+
+void event_file_put(struct trace_event_file *file)
+{
+ if (WARN_ON_ONCE(!atomic_read(&file->ref))) {
+ if (file->flags & EVENT_FILE_FL_FREED)
+ kmem_cache_free(file_cachep, file);
+ return;
+ }
+
+ if (atomic_dec_and_test(&file->ref)) {
+ /* Count should only go to zero when it is freed */
+ if (WARN_ON_ONCE(!(file->flags & EVENT_FILE_FL_FREED)))
+ return;
+ kmem_cache_free(file_cachep, file);
+ }
+}
+
static void remove_event_file_dir(struct trace_event_file *file)
{
eventfs_remove_dir(file->ei);
list_del(&file->list);
remove_subsystem(file->system);
free_event_filter(file->filter);
- kmem_cache_free(file_cachep, file);
+ file->flags |= EVENT_FILE_FL_FREED;
+ event_file_put(file);
}
/*
@@ -1369,7 +1391,7 @@ event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
flags = file->flags;
mutex_unlock(&event_mutex);
- if (!file)
+ if (!file || flags & EVENT_FILE_FL_FREED)
return -ENODEV;
if (flags & EVENT_FILE_FL_ENABLED &&
@@ -1403,7 +1425,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
ret = -ENODEV;
mutex_lock(&event_mutex);
file = event_file_data(filp);
- if (likely(file)) {
+ if (likely(file && !(file->flags & EVENT_FILE_FL_FREED))) {
ret = tracing_update_buffers(file->tr);
if (ret < 0) {
mutex_unlock(&event_mutex);
@@ -1683,7 +1705,7 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
mutex_lock(&event_mutex);
file = event_file_data(filp);
- if (file)
+ if (file && !(file->flags & EVENT_FILE_FL_FREED))
print_event_filter(file, s);
mutex_unlock(&event_mutex);
@@ -2902,6 +2924,7 @@ trace_create_new_event(struct trace_event_call *call,
atomic_set(&file->tm_ref, 0);
INIT_LIST_HEAD(&file->triggers);
list_add(&file->list, &tr->events);
+ event_file_get(file);
return file;
}
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 33264e510d16..0c611b281a5b 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -2349,6 +2349,9 @@ int apply_event_filter(struct trace_event_file *file, char *filter_string)
struct event_filter *filter = NULL;
int err;
+ if (file->flags & EVENT_FILE_FL_FREED)
+ return -ENODEV;
+
if (!strcmp(strstrip(filter_string), "0")) {
filter_disable(file);
filter = event_filter(file);
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023110607-destruct-footsore-9353@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org>
Date: Tue, 31 Oct 2023 12:24:53 -0400
Subject: [PATCH] tracing: Have trace_event_file have ref counters
The following can crash the kernel:
# cd /sys/kernel/tracing
# echo 'p:sched schedule' > kprobe_events
# exec 5>>events/kprobes/sched/enable
# > kprobe_events
# exec 5>&-
The above commands:
1. Change directory to the tracefs directory
2. Create a kprobe event (doesn't matter what one)
3. Open bash file descriptor 5 on the enable file of the kprobe event
4. Delete the kprobe event (removes the files too)
5. Close the bash file descriptor 5
The above causes a crash!
BUG: kernel NULL pointer dereference, address: 0000000000000028
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 6 PID: 877 Comm: bash Not tainted 6.5.0-rc4-test-00008-g2c6b6b1029d4-dirty #186
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:tracing_release_file_tr+0xc/0x50
What happens here is that the kprobe event creates a trace_event_file
"file" descriptor that represents the file in tracefs to the event. It
maintains state of the event (is it enabled for the given instance?).
Opening the "enable" file gets a reference to the event "file" descriptor
via the open file descriptor. When the kprobe event is deleted, the file is
also deleted from the tracefs system which also frees the event "file"
descriptor.
But as the tracefs file is still opened by user space, it will not be
totally removed until the final dput() is called on it. But this is not
true with the event "file" descriptor that is already freed. If the user
does a write to or simply closes the file descriptor it will reference the
event "file" descriptor that was just freed, causing a use-after-free bug.
To solve this, add a ref count to the event "file" descriptor as well as a
new flag called "FREED". The "file" will not be freed until the last
reference is released. But the FREE flag will be set when the event is
removed to prevent any more modifications to that event from happening,
even if there's still a reference to the event "file" descriptor.
Link: https://lore.kernel.org/linux-trace-kernel/20231031000031.1e705592@gandalf.…
Link: https://lore.kernel.org/linux-trace-kernel/20231031122453.7a48b923@gandalf.…
Cc: stable(a)vger.kernel.org
Cc: Mark Rutland <mark.rutland(a)arm.com>
Fixes: f5ca233e2e66d ("tracing: Increase trace array ref count on enable and filter files")
Reported-by: Beau Belgrave <beaub(a)linux.microsoft.com>
Tested-by: Beau Belgrave <beaub(a)linux.microsoft.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 12207dc6722d..696f8dc4aa53 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -492,6 +492,7 @@ enum {
EVENT_FILE_FL_TRIGGER_COND_BIT,
EVENT_FILE_FL_PID_FILTER_BIT,
EVENT_FILE_FL_WAS_ENABLED_BIT,
+ EVENT_FILE_FL_FREED_BIT,
};
extern struct trace_event_file *trace_get_event_file(const char *instance,
@@ -630,6 +631,7 @@ extern int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...);
* TRIGGER_COND - When set, one or more triggers has an associated filter
* PID_FILTER - When set, the event is filtered based on pid
* WAS_ENABLED - Set when enabled to know to clear trace on module removal
+ * FREED - File descriptor is freed, all fields should be considered invalid
*/
enum {
EVENT_FILE_FL_ENABLED = (1 << EVENT_FILE_FL_ENABLED_BIT),
@@ -643,6 +645,7 @@ enum {
EVENT_FILE_FL_TRIGGER_COND = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT),
EVENT_FILE_FL_PID_FILTER = (1 << EVENT_FILE_FL_PID_FILTER_BIT),
EVENT_FILE_FL_WAS_ENABLED = (1 << EVENT_FILE_FL_WAS_ENABLED_BIT),
+ EVENT_FILE_FL_FREED = (1 << EVENT_FILE_FL_FREED_BIT),
};
struct trace_event_file {
@@ -671,6 +674,7 @@ struct trace_event_file {
* caching and such. Which is mostly OK ;-)
*/
unsigned long flags;
+ atomic_t ref; /* ref count for opened files */
atomic_t sm_ref; /* soft-mode reference counter */
atomic_t tm_ref; /* trigger-mode reference counter */
};
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2539cfc20a97..9aebf904ff97 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4978,6 +4978,20 @@ int tracing_open_file_tr(struct inode *inode, struct file *filp)
if (ret)
return ret;
+ mutex_lock(&event_mutex);
+
+ /* Fail if the file is marked for removal */
+ if (file->flags & EVENT_FILE_FL_FREED) {
+ trace_array_put(file->tr);
+ ret = -ENODEV;
+ } else {
+ event_file_get(file);
+ }
+
+ mutex_unlock(&event_mutex);
+ if (ret)
+ return ret;
+
filp->private_data = inode->i_private;
return 0;
@@ -4988,6 +5002,7 @@ int tracing_release_file_tr(struct inode *inode, struct file *filp)
struct trace_event_file *file = inode->i_private;
trace_array_put(file->tr);
+ event_file_put(file);
return 0;
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 0e1405abf4f7..b7f4ea25a194 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1669,6 +1669,9 @@ extern void event_trigger_unregister(struct event_command *cmd_ops,
char *glob,
struct event_trigger_data *trigger_data);
+extern void event_file_get(struct trace_event_file *file);
+extern void event_file_put(struct trace_event_file *file);
+
/**
* struct event_trigger_ops - callbacks for trace event triggers
*
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f9e3e24d8796..f29e815ca5b2 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -990,13 +990,35 @@ static void remove_subsystem(struct trace_subsystem_dir *dir)
}
}
+void event_file_get(struct trace_event_file *file)
+{
+ atomic_inc(&file->ref);
+}
+
+void event_file_put(struct trace_event_file *file)
+{
+ if (WARN_ON_ONCE(!atomic_read(&file->ref))) {
+ if (file->flags & EVENT_FILE_FL_FREED)
+ kmem_cache_free(file_cachep, file);
+ return;
+ }
+
+ if (atomic_dec_and_test(&file->ref)) {
+ /* Count should only go to zero when it is freed */
+ if (WARN_ON_ONCE(!(file->flags & EVENT_FILE_FL_FREED)))
+ return;
+ kmem_cache_free(file_cachep, file);
+ }
+}
+
static void remove_event_file_dir(struct trace_event_file *file)
{
eventfs_remove_dir(file->ei);
list_del(&file->list);
remove_subsystem(file->system);
free_event_filter(file->filter);
- kmem_cache_free(file_cachep, file);
+ file->flags |= EVENT_FILE_FL_FREED;
+ event_file_put(file);
}
/*
@@ -1369,7 +1391,7 @@ event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
flags = file->flags;
mutex_unlock(&event_mutex);
- if (!file)
+ if (!file || flags & EVENT_FILE_FL_FREED)
return -ENODEV;
if (flags & EVENT_FILE_FL_ENABLED &&
@@ -1403,7 +1425,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
ret = -ENODEV;
mutex_lock(&event_mutex);
file = event_file_data(filp);
- if (likely(file)) {
+ if (likely(file && !(file->flags & EVENT_FILE_FL_FREED))) {
ret = tracing_update_buffers(file->tr);
if (ret < 0) {
mutex_unlock(&event_mutex);
@@ -1683,7 +1705,7 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
mutex_lock(&event_mutex);
file = event_file_data(filp);
- if (file)
+ if (file && !(file->flags & EVENT_FILE_FL_FREED))
print_event_filter(file, s);
mutex_unlock(&event_mutex);
@@ -2902,6 +2924,7 @@ trace_create_new_event(struct trace_event_call *call,
atomic_set(&file->tm_ref, 0);
INIT_LIST_HEAD(&file->triggers);
list_add(&file->list, &tr->events);
+ event_file_get(file);
return file;
}
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 33264e510d16..0c611b281a5b 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -2349,6 +2349,9 @@ int apply_event_filter(struct trace_event_file *file, char *filter_string)
struct event_filter *filter = NULL;
int err;
+ if (file->flags & EVENT_FILE_FL_FREED)
+ return -ENODEV;
+
if (!strcmp(strstrip(filter_string), "0")) {
filter_disable(file);
filter = event_filter(file);
The patch below does not apply to the 6.5-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.5.y
git checkout FETCH_HEAD
git cherry-pick -x bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023110605-thirty-account-3d1a@gregkh' --subject-prefix 'PATCH 6.5.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org>
Date: Tue, 31 Oct 2023 12:24:53 -0400
Subject: [PATCH] tracing: Have trace_event_file have ref counters
The following can crash the kernel:
# cd /sys/kernel/tracing
# echo 'p:sched schedule' > kprobe_events
# exec 5>>events/kprobes/sched/enable
# > kprobe_events
# exec 5>&-
The above commands:
1. Change directory to the tracefs directory
2. Create a kprobe event (doesn't matter what one)
3. Open bash file descriptor 5 on the enable file of the kprobe event
4. Delete the kprobe event (removes the files too)
5. Close the bash file descriptor 5
The above causes a crash!
BUG: kernel NULL pointer dereference, address: 0000000000000028
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 6 PID: 877 Comm: bash Not tainted 6.5.0-rc4-test-00008-g2c6b6b1029d4-dirty #186
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:tracing_release_file_tr+0xc/0x50
What happens here is that the kprobe event creates a trace_event_file
"file" descriptor that represents the file in tracefs to the event. It
maintains state of the event (is it enabled for the given instance?).
Opening the "enable" file gets a reference to the event "file" descriptor
via the open file descriptor. When the kprobe event is deleted, the file is
also deleted from the tracefs system which also frees the event "file"
descriptor.
But as the tracefs file is still opened by user space, it will not be
totally removed until the final dput() is called on it. But this is not
true with the event "file" descriptor that is already freed. If the user
does a write to or simply closes the file descriptor it will reference the
event "file" descriptor that was just freed, causing a use-after-free bug.
To solve this, add a ref count to the event "file" descriptor as well as a
new flag called "FREED". The "file" will not be freed until the last
reference is released. But the FREE flag will be set when the event is
removed to prevent any more modifications to that event from happening,
even if there's still a reference to the event "file" descriptor.
Link: https://lore.kernel.org/linux-trace-kernel/20231031000031.1e705592@gandalf.…
Link: https://lore.kernel.org/linux-trace-kernel/20231031122453.7a48b923@gandalf.…
Cc: stable(a)vger.kernel.org
Cc: Mark Rutland <mark.rutland(a)arm.com>
Fixes: f5ca233e2e66d ("tracing: Increase trace array ref count on enable and filter files")
Reported-by: Beau Belgrave <beaub(a)linux.microsoft.com>
Tested-by: Beau Belgrave <beaub(a)linux.microsoft.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 12207dc6722d..696f8dc4aa53 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -492,6 +492,7 @@ enum {
EVENT_FILE_FL_TRIGGER_COND_BIT,
EVENT_FILE_FL_PID_FILTER_BIT,
EVENT_FILE_FL_WAS_ENABLED_BIT,
+ EVENT_FILE_FL_FREED_BIT,
};
extern struct trace_event_file *trace_get_event_file(const char *instance,
@@ -630,6 +631,7 @@ extern int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...);
* TRIGGER_COND - When set, one or more triggers has an associated filter
* PID_FILTER - When set, the event is filtered based on pid
* WAS_ENABLED - Set when enabled to know to clear trace on module removal
+ * FREED - File descriptor is freed, all fields should be considered invalid
*/
enum {
EVENT_FILE_FL_ENABLED = (1 << EVENT_FILE_FL_ENABLED_BIT),
@@ -643,6 +645,7 @@ enum {
EVENT_FILE_FL_TRIGGER_COND = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT),
EVENT_FILE_FL_PID_FILTER = (1 << EVENT_FILE_FL_PID_FILTER_BIT),
EVENT_FILE_FL_WAS_ENABLED = (1 << EVENT_FILE_FL_WAS_ENABLED_BIT),
+ EVENT_FILE_FL_FREED = (1 << EVENT_FILE_FL_FREED_BIT),
};
struct trace_event_file {
@@ -671,6 +674,7 @@ struct trace_event_file {
* caching and such. Which is mostly OK ;-)
*/
unsigned long flags;
+ atomic_t ref; /* ref count for opened files */
atomic_t sm_ref; /* soft-mode reference counter */
atomic_t tm_ref; /* trigger-mode reference counter */
};
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2539cfc20a97..9aebf904ff97 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4978,6 +4978,20 @@ int tracing_open_file_tr(struct inode *inode, struct file *filp)
if (ret)
return ret;
+ mutex_lock(&event_mutex);
+
+ /* Fail if the file is marked for removal */
+ if (file->flags & EVENT_FILE_FL_FREED) {
+ trace_array_put(file->tr);
+ ret = -ENODEV;
+ } else {
+ event_file_get(file);
+ }
+
+ mutex_unlock(&event_mutex);
+ if (ret)
+ return ret;
+
filp->private_data = inode->i_private;
return 0;
@@ -4988,6 +5002,7 @@ int tracing_release_file_tr(struct inode *inode, struct file *filp)
struct trace_event_file *file = inode->i_private;
trace_array_put(file->tr);
+ event_file_put(file);
return 0;
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 0e1405abf4f7..b7f4ea25a194 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1669,6 +1669,9 @@ extern void event_trigger_unregister(struct event_command *cmd_ops,
char *glob,
struct event_trigger_data *trigger_data);
+extern void event_file_get(struct trace_event_file *file);
+extern void event_file_put(struct trace_event_file *file);
+
/**
* struct event_trigger_ops - callbacks for trace event triggers
*
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f9e3e24d8796..f29e815ca5b2 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -990,13 +990,35 @@ static void remove_subsystem(struct trace_subsystem_dir *dir)
}
}
+void event_file_get(struct trace_event_file *file)
+{
+ atomic_inc(&file->ref);
+}
+
+void event_file_put(struct trace_event_file *file)
+{
+ if (WARN_ON_ONCE(!atomic_read(&file->ref))) {
+ if (file->flags & EVENT_FILE_FL_FREED)
+ kmem_cache_free(file_cachep, file);
+ return;
+ }
+
+ if (atomic_dec_and_test(&file->ref)) {
+ /* Count should only go to zero when it is freed */
+ if (WARN_ON_ONCE(!(file->flags & EVENT_FILE_FL_FREED)))
+ return;
+ kmem_cache_free(file_cachep, file);
+ }
+}
+
static void remove_event_file_dir(struct trace_event_file *file)
{
eventfs_remove_dir(file->ei);
list_del(&file->list);
remove_subsystem(file->system);
free_event_filter(file->filter);
- kmem_cache_free(file_cachep, file);
+ file->flags |= EVENT_FILE_FL_FREED;
+ event_file_put(file);
}
/*
@@ -1369,7 +1391,7 @@ event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
flags = file->flags;
mutex_unlock(&event_mutex);
- if (!file)
+ if (!file || flags & EVENT_FILE_FL_FREED)
return -ENODEV;
if (flags & EVENT_FILE_FL_ENABLED &&
@@ -1403,7 +1425,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
ret = -ENODEV;
mutex_lock(&event_mutex);
file = event_file_data(filp);
- if (likely(file)) {
+ if (likely(file && !(file->flags & EVENT_FILE_FL_FREED))) {
ret = tracing_update_buffers(file->tr);
if (ret < 0) {
mutex_unlock(&event_mutex);
@@ -1683,7 +1705,7 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
mutex_lock(&event_mutex);
file = event_file_data(filp);
- if (file)
+ if (file && !(file->flags & EVENT_FILE_FL_FREED))
print_event_filter(file, s);
mutex_unlock(&event_mutex);
@@ -2902,6 +2924,7 @@ trace_create_new_event(struct trace_event_call *call,
atomic_set(&file->tm_ref, 0);
INIT_LIST_HEAD(&file->triggers);
list_add(&file->list, &tr->events);
+ event_file_get(file);
return file;
}
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 33264e510d16..0c611b281a5b 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -2349,6 +2349,9 @@ int apply_event_filter(struct trace_event_file *file, char *filter_string)
struct event_filter *filter = NULL;
int err;
+ if (file->flags & EVENT_FILE_FL_FREED)
+ return -ENODEV;
+
if (!strcmp(strstrip(filter_string), "0")) {
filter_disable(file);
filter = event_filter(file);
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To be used by drivers that do per-buffer (e.g: virtio-gpu) uploads (rather
than per-plane uploads), since these type of drivers need to handle buffer
damages instead of frame damages.
The drm_atomic_helper_buffer_damage_iter_init() has the same logic than
drm_atomic_helper_damage_iter_init() but it also takes into account if the
framebuffer attached to plane's state has changed since the last update.
And the drm_atomic_helper_buffer_damage_merged() is just a version of the
drm_atomic_helper_damage_merged() helper, but it uses the iter_init helper
that is mentioned above.
Fixes: 01f05940a9a7 ("drm/virtio: Enable fb damage clips property for the primary plane")
Cc: <stable(a)vger.kernel.org> # v6.4+
Reported-by: nerdopolis <bluescreen_avenger(a)verizon.net>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218115
Suggested-by: Sima Vetter <daniel.vetter(a)ffwll.ch>
Signed-off-by: Javier Martinez Canillas <javierm(a)redhat.com>
---
drivers/gpu/drm/drm_damage_helper.c | 79 ++++++++++++++++++++++++++---
include/drm/drm_damage_helper.h | 7 +++
2 files changed, 80 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/drm_damage_helper.c b/drivers/gpu/drm/drm_damage_helper.c
index aa2325567918..b72062c9d31c 100644
--- a/drivers/gpu/drm/drm_damage_helper.c
+++ b/drivers/gpu/drm/drm_damage_helper.c
@@ -204,7 +204,8 @@ EXPORT_SYMBOL(drm_atomic_helper_dirtyfb);
static void
__drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
const struct drm_plane_state *old_state,
- const struct drm_plane_state *state)
+ const struct drm_plane_state *state,
+ bool buffer_damage)
{
struct drm_rect src;
memset(iter, 0, sizeof(*iter));
@@ -223,7 +224,8 @@ __drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
iter->plane_src.x2 = (src.x2 >> 16) + !!(src.x2 & 0xFFFF);
iter->plane_src.y2 = (src.y2 >> 16) + !!(src.y2 & 0xFFFF);
- if (!iter->clips || !drm_rect_equals(&state->src, &old_state->src)) {
+ if (!iter->clips || !drm_rect_equals(&state->src, &old_state->src) ||
+ (buffer_damage && old_state->fb != state->fb)) {
iter->clips = NULL;
iter->num_clips = 0;
iter->full_update = true;
@@ -243,6 +245,10 @@ __drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
* update). Currently this iterator returns full plane src in case plane src
* changed but that can be changed in future to return damage.
*
+ * Note that this helper is for drivers that do per-plane uploads and expect
+ * to handle frame damages. Drivers that do per-buffer uploads instead should
+ * use @drm_atomic_helper_buffer_damage_iter_init() that handles buffer damages.
+ *
* For the case when plane is not visible or plane update should not happen the
* first call to iter_next will return false. Note that this helper use clipped
* &drm_plane_state.src, so driver calling this helper should have called
@@ -253,10 +259,37 @@ drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
const struct drm_plane_state *old_state,
const struct drm_plane_state *state)
{
- __drm_atomic_helper_damage_iter_init(iter, old_state, state);
+ __drm_atomic_helper_damage_iter_init(iter, old_state, state, false);
}
EXPORT_SYMBOL(drm_atomic_helper_damage_iter_init);
+/**
+ * drm_atomic_helper_buffer_damage_iter_init - Initialize the buffer damage iterator.
+ * @iter: The iterator to initialize.
+ * @old_state: Old plane state for validation.
+ * @state: Plane state from which to iterate the damage clips.
+ *
+ * Initialize an iterator, which clips buffer damage
+ * &drm_plane_state.fb_damage_clips to plane &drm_plane_state.src. This iterator
+ * returns full plane src in case buffer damage is not present because user-space
+ * didn't sent, driver discarded it (it want to do full plane update) or the plane
+ * @state has an attached framebuffer that is different than the one in @state (it
+ * has changed since the last plane update).
+ *
+ * For the case when plane is not visible or plane update should not happen the
+ * first call to iter_next will return false. Note that this helper use clipped
+ * &drm_plane_state.src, so driver calling this helper should have called
+ * drm_atomic_helper_check_plane_state() earlier.
+ */
+void
+drm_atomic_helper_buffer_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
+ const struct drm_plane_state *old_state,
+ const struct drm_plane_state *state)
+{
+ __drm_atomic_helper_damage_iter_init(iter, old_state, state, true);
+}
+EXPORT_SYMBOL(drm_atomic_helper_buffer_damage_iter_init);
+
/**
* drm_atomic_helper_damage_iter_next - Advance the damage iterator.
* @iter: The iterator to advance.
@@ -301,7 +334,8 @@ EXPORT_SYMBOL(drm_atomic_helper_damage_iter_next);
static bool __drm_atomic_helper_damage_merged(const struct drm_plane_state *old_state,
struct drm_plane_state *state,
- struct drm_rect *rect)
+ struct drm_rect *rect,
+ bool buffer_damage)
{
struct drm_atomic_helper_damage_iter iter;
struct drm_rect clip;
@@ -312,7 +346,7 @@ static bool __drm_atomic_helper_damage_merged(const struct drm_plane_state *old_
rect->x2 = 0;
rect->y2 = 0;
- drm_atomic_helper_damage_iter_init(&iter, old_state, state);
+ __drm_atomic_helper_damage_iter_init(&iter, old_state, state, buffer_damage);
drm_atomic_for_each_plane_damage(&iter, &clip) {
rect->x1 = min(rect->x1, clip.x1);
rect->y1 = min(rect->y1, clip.y1);
@@ -336,6 +370,10 @@ static bool __drm_atomic_helper_damage_merged(const struct drm_plane_state *old_
* For details see: drm_atomic_helper_damage_iter_init() and
* drm_atomic_helper_damage_iter_next().
*
+ * Note that this helper is for drivers that do per-plane uploads and expect
+ * to handle frame damages. Drivers that do per-buffer uploads instead should
+ * use @drm_atomic_helper_buffer_damage_merged() that handles buffer damages.
+ *
* Returns:
* True if there is valid plane damage otherwise false.
*/
@@ -343,6 +381,35 @@ bool drm_atomic_helper_damage_merged(const struct drm_plane_state *old_state,
struct drm_plane_state *state,
struct drm_rect *rect)
{
- return __drm_atomic_helper_damage_merged(old_state, state, rect);
+ return __drm_atomic_helper_damage_merged(old_state, state, rect, false);
}
EXPORT_SYMBOL(drm_atomic_helper_damage_merged);
+
+/**
+ * drm_atomic_helper_buffer_damage_merged - Merged buffer damage
+ * @old_state: Old plane state for validation.
+ * @state: Plane state from which to iterate the damage clips.
+ * @rect: Returns the merged buffer damage rectangle
+ *
+ * This function merges any valid buffer damage clips into one rectangle and
+ * returns it in @rect. It checks if the framebuffers attached to @old_state
+ * and @state are the same. If that is not the case then the returned damage
+ * rectangle is the &drm_plane_state.src, since a full update should happen.
+ *
+ * Note that &drm_plane_state.fb_damage_clips == NULL in plane state means that
+ * full plane update should happen. It also ensure helper iterator will return
+ * &drm_plane_state.src as damage.
+ *
+ * For details see: drm_atomic_helper_buffer_damage_iter_init() and
+ * drm_atomic_helper_damage_iter_next().
+ *
+ * Returns:
+ * True if there is valid buffer damage otherwise false.
+ */
+bool drm_atomic_helper_buffer_damage_merged(const struct drm_plane_state *old_state,
+ struct drm_plane_state *state,
+ struct drm_rect *rect)
+{
+ return __drm_atomic_helper_damage_merged(old_state, state, rect, true);
+}
+EXPORT_SYMBOL(drm_atomic_helper_buffer_damage_merged);
diff --git a/include/drm/drm_damage_helper.h b/include/drm/drm_damage_helper.h
index effda42cce31..328bb249d68f 100644
--- a/include/drm/drm_damage_helper.h
+++ b/include/drm/drm_damage_helper.h
@@ -74,11 +74,18 @@ void
drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
const struct drm_plane_state *old_state,
const struct drm_plane_state *new_state);
+void
+drm_atomic_helper_buffer_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
+ const struct drm_plane_state *old_state,
+ const struct drm_plane_state *new_state);
bool
drm_atomic_helper_damage_iter_next(struct drm_atomic_helper_damage_iter *iter,
struct drm_rect *rect);
bool drm_atomic_helper_damage_merged(const struct drm_plane_state *old_state,
struct drm_plane_state *state,
struct drm_rect *rect);
+bool drm_atomic_helper_buffer_damage_merged(const struct drm_plane_state *old_state,
+ struct drm_plane_state *state,
+ struct drm_rect *rect);
#endif
--
2.41.0
From: "Abdul Halim, Mohd Syazwan" <mohd.syazwan.abdul.halim(a)intel.com>
The VT-d spec requires (10.4.4 Global Command Register, TE field) that:
Hardware implementations supporting DMA draining must drain any in-flight
DMA read/write requests queued within the Root-Complex before completing
the translation enable command and reflecting the status of the command
through the TES field in the Global Status register.
Unfortunately, some integrated graphic devices fail to do so after some
kind of power state transition. As the result, the system might stuck in
iommu_disable_translation(), waiting for the completion of TE transition.
Add MTL to the quirk list for those devices and skips TE disabling if the
qurik hits.
Fixes: b1012ca8dc4f ("iommu/vt-d: Skip TE disabling on quirky gfx dedicated iommu")
Cc: stable(a)vger.kernel.org
Signed-off-by: Abdul Halim, Mohd Syazwan <mohd.syazwan.abdul.halim(a)intel.com>
Signed-off-by: Lu Baolu <baolu.lu(a)linux.intel.com>
---
drivers/iommu/intel/iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 061df1b68ff7..22cadcefadaa 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5080,7 +5080,7 @@ static void quirk_igfx_skip_te_disable(struct pci_dev *dev)
ver = (dev->device >> 8) & 0xff;
if (ver != 0x45 && ver != 0x46 && ver != 0x4c &&
ver != 0x4e && ver != 0x8a && ver != 0x98 &&
- ver != 0x9a && ver != 0xa7)
+ ver != 0x9a && ver != 0xa7 && ver != 0x7d)
return;
if (risky_device(dev))
--
2.34.1