[PATCH] remoteproc: make rproc_class constant
Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the rproc_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.
Cc: Greg Kroah-Hartman
Suggested-by: Greg Kroah-Hartman
Signed-off-by: Ricardo B. Marliere
---
drivers/remoteproc/remoteproc_internal.h | 2 +-
drivers/remoteproc/remoteproc_sysfs.c| 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/remoteproc/remoteproc_internal.h
b/drivers/remoteproc/remoteproc_internal.h
index f62a82d71dfa..0cd09e67ac14 100644
--- a/drivers/remoteproc/remoteproc_internal.h
+++ b/drivers/remoteproc/remoteproc_internal.h
@@ -72,7 +72,7 @@ void rproc_init_debugfs(void);
void rproc_exit_debugfs(void);
/* from remoteproc_sysfs.c */
-extern struct class rproc_class;
+extern const struct class rproc_class;
int rproc_init_sysfs(void);
void rproc_exit_sysfs(void);
diff --git a/drivers/remoteproc/remoteproc_sysfs.c
b/drivers/remoteproc/remoteproc_sysfs.c
index 8c7ea8922638..138e752c5e4e 100644
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -254,7 +254,7 @@ static const struct attribute_group *rproc_devgroups[] = {
NULL
};
-struct class rproc_class = {
+const struct class rproc_class = {
.name = "remoteproc",
.dev_groups = rproc_devgroups,
};
---
base-commit: 8b46dc5cfa5ffea279aed0fc05dc4b1c39a51517
change-id: 20240305-class_cleanup-remoteproc2-f1212934f990
Best regards,
--
Ricardo B. Marliere
[PATCH] rpmsg: core: make rpmsg_class constant
Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the rpmsg_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.
Cc: Greg Kroah-Hartman
Suggested-by: Greg Kroah-Hartman
Signed-off-by: Ricardo B. Marliere
---
drivers/rpmsg/rpmsg_char.c | 2 +-
drivers/rpmsg/rpmsg_core.c | 16 +---
drivers/rpmsg/rpmsg_ctrl.c | 2 +-
drivers/rpmsg/rpmsg_internal.h | 2 +-
4 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 1cb8d7474428..d7a342510902 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -423,7 +423,7 @@ static struct rpmsg_eptdev
*rpmsg_chrdev_eptdev_alloc(struct rpmsg_device *rpdev
init_waitqueue_head(&eptdev->readq);
device_initialize(dev);
- dev->class = rpmsg_class;
+ dev->class = &rpmsg_class;
dev->parent = parent;
dev->groups = rpmsg_eptdev_groups;
dev_set_drvdata(dev, eptdev);
diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 4295c01a2861..0fa08266404d 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -20,7 +20,9 @@
#include "rpmsg_internal.h"
-struct class *rpmsg_class;
+const struct class rpmsg_class = {
+ .name = "rpmsg",
+};
EXPORT_SYMBOL(rpmsg_class);
/**
@@ -715,16 +717,16 @@ static int __init rpmsg_init(void)
{
int ret;
- rpmsg_class = class_create("rpmsg");
- if (IS_ERR(rpmsg_class)) {
- pr_err("failed to create rpmsg class\n");
- return PTR_ERR(rpmsg_class);
+ ret = class_register(&rpmsg_class);
+ if (ret) {
+ pr_err("failed to register rpmsg class\n");
+ return ret;
}
ret = bus_register(&rpmsg_bus);
if (ret) {
pr_err("failed to register rpmsg bus: %d\n", ret);
- class_destroy(rpmsg_class);
+ class_destroy(&rpmsg_class);
}
return ret;
}
@@ -733,7 +735,7 @@ postcore_initcall(rpmsg_init);
static void __exit rpmsg_fini(void)
{
bus_unregister(&rpmsg_bus);
- class_destroy(rpmsg_class);
+ class_destroy(&rpmsg_class);
}
module_exit(rpmsg_fini);
diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
index c312794ba4b3..28f57945ccd9 100644
--- a/drivers/rpmsg/rpmsg_ctrl.c
+++ b/drivers/rpmsg/rpmsg_ctrl.c
@@ -150,7 +150,7 @@ static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev)
dev = &ctrldev->dev;
device_initialize(dev);
dev->parent = &rpdev->dev;
- dev->class = rpmsg_class;
+ dev->class = &rpmsg_class;
mutex_init(&ctrldev->ctrl_lock);
cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
index b950d6f790a3..a3ba768138f1 100644
--- a/drivers/rpmsg/rpmsg_internal.h
+++ b/drivers/rpmsg/rpmsg_internal.h
@@ -18,7 +18,7 @@
#define to_rpmsg_device(d) container_of(d, struct rpmsg_device, dev)
#define to_rpmsg_driver(d) container_of(d, struct rpmsg_driver, drv)
-extern struct class *rpmsg_class;
+extern const struct class rpmsg_class;
/**
* struct rpmsg_device_ops - indirection table for the rpmsg_device operations
---
base-commit: b03aa6d4e9a74c4289929b6cf3c6bcc80270682d
change-id: 20240305-class_cleanup-remoteproc-2b53e26b2817
Best regards,
--
Ricardo B. Marliere
[PATCH] dax: constify the struct device_type usage
Since commit aed65af1cc2f ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the
dax_mapping_type variable to be a constant structure as well, placing it
into read-only memory which can not be modified at runtime.
Cc: Greg Kroah-Hartman
Signed-off-by: Ricardo B. Marliere
---
drivers/dax/bus.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 1ff1ab5fa105..e265ba019785 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -763,7 +763,7 @@ static const struct attribute_group
*dax_mapping_attribute_groups[] = {
NULL,
};
-static struct device_type dax_mapping_type = {
+static const struct device_type dax_mapping_type = {
.release = dax_mapping_release,
.groups = dax_mapping_attribute_groups,
};
---
base-commit: b401b621758e46812da61fa58a67c3fd8d91de0d
change-id: 20240219-device_cleanup-dax-d82fd0c67ffd
Best regards,
--
Ricardo B. Marliere
[PATCH] virtio: make virtio_bus const
Now that the driver core can properly handle constant struct bus_type,
move the virtio_bus variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Cc: Greg Kroah-Hartman
Suggested-by: Greg Kroah-Hartman
Signed-off-by: Ricardo B. Marliere
---
drivers/virtio/virtio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index f4080692b351..a68e6556f71b 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -353,7 +353,7 @@ static void virtio_dev_remove(struct device *_d)
of_node_put(dev->dev.of_node);
}
-static struct bus_type virtio_bus = {
+static const struct bus_type virtio_bus = {
.name = "virtio",
.match = virtio_dev_match,
.dev_groups = virtio_dev_groups,
---
base-commit: 41b9fb381a486360b2daaec0c7480f8e3ff72bc7
change-id: 20240204-bus_cleanup-virtio-9f076c3cb068
Best regards,
--
Ricardo B. Marliere
[PATCH] vdpa: make vdpa_bus const
Now that the driver core can properly handle constant struct bus_type,
move the vdpa_bus variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Cc: Greg Kroah-Hartman
Suggested-by: Greg Kroah-Hartman
Signed-off-by: Ricardo B. Marliere
---
drivers/vdpa/vdpa.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index d0695680b282..c73c06102e7e 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -115,7 +115,7 @@ static const struct attribute_group vdpa_dev_group = {
};
__ATTRIBUTE_GROUPS(vdpa_dev);
-static struct bus_type vdpa_bus = {
+static const struct bus_type vdpa_bus = {
.name = "vdpa",
.dev_groups = vdpa_dev_groups,
.match = vdpa_dev_match,
---
base-commit: 41b9fb381a486360b2daaec0c7480f8e3ff72bc7
change-id: 20240204-bus_cleanup-vdpa-8e19b86329f6
Best regards,
--
Ricardo B. Marliere
[PATCH] rpmsg: core: make rpmsg_bus const
Now that the driver core can properly handle constant struct bus_type,
move the rpmsg_bus variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Cc: Greg Kroah-Hartman
Suggested-by: Greg Kroah-Hartman
Signed-off-by: Ricardo B. Marliere
---
drivers/rpmsg/rpmsg_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 8abc7d022ff7..4295c01a2861 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -605,7 +605,7 @@ static void rpmsg_dev_remove(struct device *dev)
rpmsg_destroy_ept(rpdev->ept);
}
-static struct bus_type rpmsg_bus = {
+static const struct bus_type rpmsg_bus = {
.name = "rpmsg",
.match = rpmsg_dev_match,
.dev_groups = rpmsg_dev_groups,
---
base-commit: 80255b24efbe83a6a01600484b6959259a30ded5
change-id: 20240204-bus_cleanup-rpmsg-1a5f6ab69a24
Best regards,
--
Ricardo B. Marliere
[PATCH] nvdimm: make nvdimm_bus_type const
Now that the driver core can properly handle constant struct bus_type,
move the nvdimm_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Cc: Greg Kroah-Hartman
Suggested-by: Greg Kroah-Hartman
Signed-off-by: Ricardo B. Marliere
---
drivers/nvdimm/bus.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index ef3d0f83318b..508aed017ddc 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -271,7 +271,7 @@ EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);
-static struct bus_type nvdimm_bus_type = {
+static const struct bus_type nvdimm_bus_type = {
.name = "nd",
.uevent = nvdimm_bus_uevent,
.match = nvdimm_bus_match,
---
base-commit: a085a5eb6594a3ebe5c275e9c2c2d341f686c23c
change-id: 20240204-bus_cleanup-nvdimm-91771693bd4d
Best regards,
--
Ricardo B. Marliere
[PATCH] device-dax: make dax_bus_type const
Now that the driver core can properly handle constant struct bus_type,
move the dax_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Cc: Greg Kroah-Hartman
Suggested-by: Greg Kroah-Hartman
Signed-off-by: Ricardo B. Marliere
---
drivers/dax/bus.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 1659b787b65f..fe0a415c854d 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -222,7 +222,7 @@ static void dax_bus_remove(struct device *dev)
dax_drv->remove(dev_dax);
}
-static struct bus_type dax_bus_type = {
+static const struct bus_type dax_bus_type = {
.name = "dax",
.uevent = dax_bus_uevent,
.match = dax_bus_match,
---
base-commit: 73bf93edeeea866b0b6efbc8d2595bdaaba7f1a5
change-id: 20240204-bus_cleanup-dax-52c34f72615f
Best regards,
--
Ricardo B. Marliere
[PATCH v3 3/3] tracing: convert __trace_seq_init to use WARN_ON_ONCE
The initialization of trace_seq buffers is done elsewhere and therefore
__trace_seq_init should yield a warning if it has to actually initialize
the buffer.
Suggested-by: Steven Rostedt
Signed-off-by: Ricardo B. Marliere
---
kernel/trace/trace_seq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index 741b2f3d76c0..3c7a7d903b54 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -32,7 +32,7 @@
*/
static inline void __trace_seq_init(struct trace_seq *s)
{
- if (unlikely(!s->seq.size))
+ if (WARN_ON_ONCE(!s->seq.size))
trace_seq_init(s);
}
--
2.43.0
[PATCH v3 2/3] tracing: add trace_seq_reset function
Currently, trace_seq_init may be called many times with the intent of
resetting the buffer. Add a function trace_seq_reset that does that and
replace the relevant occurrences to use it instead.
Suggested-by: Steven Rostedt
Signed-off-by: Ricardo B. Marliere
---
include/linux/trace_seq.h| 11 +++
include/trace/trace_events.h | 2 +-
kernel/trace/trace.c | 10 +-
kernel/trace/trace_output.c | 2 +-
kernel/trace/trace_seq.c | 2 +-
5 files changed, 19 insertions(+), 8 deletions(-)
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
index 9ec229dfddaa..d3fa41001813 100644
--- a/include/linux/trace_seq.h
+++ b/include/linux/trace_seq.h
@@ -29,6 +29,17 @@ trace_seq_init(struct trace_seq *s)
s->readpos = 0;
}
+static inline void
+trace_seq_reset(struct trace_seq *s)
+{
+ if (WARN_ON_ONCE(!s->seq.size))
+ seq_buf_init(&s->seq, s->buffer, TRACE_SEQ_BUFFER_SIZE);
+ else
+ seq_buf_clear(&s->seq);
+ s->full = 0;
+ s->readpos = 0;
+}
+
/**
* trace_seq_used - amount of actual data written to buffer
* @s: trace sequence descriptor
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index c2f9cabf154d..2bc79998e5ab 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -227,7 +227,7 @@ trace_raw_output_##call(struct trace_iterator *iter, int
flags, \
\
field = (typeof(field))entry; \
\
- trace_seq_init(p); \
+ trace_seq_reset(p); \
return trace_output_call(iter, #call, print); \
} \
static struct trace_event_functions trace_event_type_funcs_##call = { \
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9eddf8168df2..9827700d0164 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2928,7 +2928,7 @@ static void output_printk(struct trace_event_buffer
*fbuffer)
event = &fbuffer->trace_file->event_call->event;
raw_spin_lock_irqsave(&tracepoint_iter_lock, flags);
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
iter->ent = fbuffer->entry;
event_call->event.funcs->trace(iter, 0, event);
trace_seq_putc(&iter->seq, 0);
@@ -6925,7 +6925,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
if (sret != -EBUSY)
goto out;
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
if (iter->trace->read) {
sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
@@ -6998,7 +6998,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
/* Now copy what we have to the user */
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
if (iter->seq.readpos >= trace_seq_used(&iter->seq))
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
/*
* If there was nothing to send to user, in spite of consuming trace
@@ -7130,7 +7130,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
spd.partial[i].offset = 0;
spd.partial[i].len = trace_seq_used(&iter->seq);
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
}
trace_access_unlock(iter->cpu_file);
@@ -10282,7 +10282,7 @@ trace_printk_seq(struct trace_seq *s)
printk(KERN_TRACE "%s", s->buffer);
- trace_seq_init(s);
+ trace_seq_reset(s);
}
void trace_init_global_iter(struct trace_iterator *iter)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 3e7fa44dc2b2..c949e7736618 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -308,7 +308,7 @@ int trace_raw_output_prep(struct trace_iterator *iter,
return TRACE_TYPE_UNHANDLED;
}
- trace_seq_init(p);
+ trace_seq_reset(p);
trace_seq_printf(s, "%s: ", trace_event_name(event));
return trace_handle_return(s);
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index c158d65a8a88..741b2f3d76c0 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -59,7 +59,7 @@ int trace_print_seq(struct seq_file *m, struct trace_seq *s)
* do something else with the contents.
*/
if (!ret)
- trace_seq_init(s);
+ trace_seq_reset(s);
return ret;
}
--
2.43.0
[PATCH v3 1/3] tracing: initialize trace_seq buffers
In order to extend trace_seq into being dynamic, the struct trace_seq
will no longer be valid if simply set to zero. Call trace_seq_init() for
all trace_seq when they are first created.
Suggested-by: Steven Rostedt
Signed-off-by: Ricardo B. Marliere
---
kernel/trace/trace.c | 14 ++
1 file changed, 14 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 46dbe22121e9..9eddf8168df2 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4889,6 +4889,9 @@ __tracing_open(struct inode *inode, struct file *file,
bool snapshot)
mutex_unlock(&trace_types_lock);
+ trace_seq_init(&iter->seq);
+ trace_seq_init(&iter->tmp_seq);
+
return iter;
fail:
@@ -6770,6 +6773,7 @@ static int tracing_open_pipe(struct inode *inode, struct
file *filp)
}
trace_seq_init(&iter->seq);
+ trace_seq_init(&iter->tmp_seq);
iter->trace = tr->current_trace;
if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
@@ -6947,6 +6951,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
trace_iterator_reset(iter);
cpumask_clear(iter->started);
trace_seq_init(&iter->seq);
+ trace_seq_init(&iter->tmp_seq);
trace_event_read_lock();
trace_access_lock(iter->cpu_file);
@@ -8277,6 +8282,9 @@ static int tracing_buffers_open(struct inode *inode,
struct file *filp)
if (ret < 0)
trace_array_put(tr);
+ trace_seq_init(&info->iter.seq);
+ trace_seq_init(&info->iter.tmp_seq);
+
return ret;
}
@@ -10300,6 +10308,9 @@ void trace_init_global_iter(struct trace_iterator *iter)
iter->temp_size = STATIC_TEMP_BUF_SIZE;
iter->fmt = static_fmt_buf;
iter->fmt_size = STATIC_FMT_BUF_SIZE;
+
+ trace_seq_init(&iter->seq);
+ trace_seq_init(&iter->tmp_seq);
}
void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
@@ -10712,6 +10723,9 @@ void __init early_trace_init(void)
tracepoint_printk = 0;
else
static_key_enable(&tracepoint_printk_key.key);
+
+ trace_seq_init(&tracepoint_print_iter->seq);
+ trace_seq_init(&tracepoint_print_iter->tmp_seq);
}
tracer_alloc_buffers();
--
2.43.0
[PATCH v3 0/3] tracing: add trace_seq_reset function
This series is a prerequisite for a later effort of making trace_seq more flexible about its buffer size. To achieve that, initializing and resetting the buffers need to be differentiated. Changes in v3: - Reordered commits so it doesn't produce a failing build in-between. - Improved changelogs. Changes in v2: - Added a WARN_ON_ONCE to __trace_seq_init to catch possible misuses. - Properly initialized trace_seq buffers. Ricardo B. Marliere (3): tracing: initialize trace_seq buffers tracing: add trace_seq_reset function tracing: convert __trace_seq_init to use WARN_ON_ONCE include/linux/trace_seq.h| 11 +++ include/trace/trace_events.h | 2 +- kernel/trace/trace.c | 24 +++- kernel/trace/trace_output.c | 2 +- kernel/trace/trace_seq.c | 4 ++-- 5 files changed, 34 insertions(+), 9 deletions(-) -- 2.43.0
Re: Re: [PATCH v2 2/3] tracing: initialize trace_seq buffers
Hi Steve,
On 25 Jan 15:44, Steven Rostedt wrote:
> On Thu, 25 Jan 2024 17:16:21 -0300
> "Ricardo B. Marliere" wrote:
>
> > Now that trace_seq_reset have been created, correct the places where the
> > buffers need to be initialized.
>
> This patch would need to come first. You don't ever want to intentionally
> create a broken kernel.
Indeed, sorry for the lack of attention.
>
> Also, the change log should be:
>
> In order to extend trace_seq into being dynamic, the struct trace_seq
> will no longer be valid if simply set to zero. Call trace_seq_init() for
> all trace_seq when they are first created.
Ack.
>
> >
> > Suggested-by: Steven Rostedt
> > Signed-off-by: Ricardo B. Marliere
> > ---
> > kernel/trace/trace.c | 14 ++
> > 1 file changed, 14 insertions(+)
> >
>
> You also need to initialize iter.seq in ftrace_dump()
Thanks a lot for reviewing, I will send a v3.
- Ricardo
>
> -- Steve
>
> > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> > index d4c55d3e21c2..9827700d0164 100644
> > --- a/kernel/trace/trace.c
> > +++ b/kernel/trace/trace.c
> > @@ -4889,6 +4889,9 @@ __tracing_open(struct inode *inode, struct file
> > *file, bool snapshot)
> >
> > mutex_unlock(&trace_types_lock);
> >
> > + trace_seq_init(&iter->seq);
> > + trace_seq_init(&iter->tmp_seq);
> > +
> > return iter;
> >
> > fail:
> > @@ -6770,6 +6773,7 @@ static int tracing_open_pipe(struct inode *inode,
> > struct file *filp)
> > }
> >
> > trace_seq_init(&iter->seq);
> > + trace_seq_init(&iter->tmp_seq);
> > iter->trace = tr->current_trace;
> >
> > if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
> > @@ -6947,6 +6951,7 @@ tracing_read_pipe(struct file *filp, char __user
> > *ubuf,
> > trace_iterator_reset(iter);
> > cpumask_clear(iter->started);
> > trace_seq_init(&iter->seq);
> > + trace_seq_init(&iter->tmp_seq);
> >
> > trace_event_read_lock();
> > trace_access_lock(iter->cpu_file);
> > @@ -8277,6 +8282,9 @@ static int tracing_buffers_open(struct inode *inode,
> > struct file *filp)
> > if (ret < 0)
> > trace_array_put(tr);
> >
> > + trace_seq_init(&info->iter.seq);
> > + trace_seq_init(&info->iter.tmp_seq);
> > +
> > return ret;
> > }
> >
> > @@ -10300,6 +10308,9 @@ void trace_init_global_iter(struct trace_iterator
> > *iter)
> > iter->temp_size = STATIC_TEMP_BUF_SIZE;
> > iter->fmt = static_fmt_buf;
> > iter->fmt_size = STATIC_FMT_BUF_SIZE;
> > +
> > + trace_seq_init(&iter->seq);
> > + trace_seq_init(&iter->tmp_seq);
> > }
> >
> > void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
> > @@ -10712,6 +10723,9 @@ void __init early_trace_init(void)
> > tracepoint_printk = 0;
> > else
> > static_key_enable(&tracepoint_printk_key.key);
> > +
> > + trace_seq_init(&tracepoint_print_iter->seq);
> > + trace_seq_init(&tracepoint_print_iter->tmp_seq);
> > }
> > tracer_alloc_buffers();
> >
>
[PATCH v2 3/3] tracing: convert __trace_seq_init to use WARN_ON_ONCE
The initialization of trace_seq buffers are done elsewhere and therefore
__trace_seq_init should yield a warning if it has to actually initialize
the buffer.
Suggested-by: Steven Rostedt
Signed-off-by: Ricardo B. Marliere
---
kernel/trace/trace_seq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index 741b2f3d76c0..3c7a7d903b54 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -32,7 +32,7 @@
*/
static inline void __trace_seq_init(struct trace_seq *s)
{
- if (unlikely(!s->seq.size))
+ if (WARN_ON_ONCE(!s->seq.size))
trace_seq_init(s);
}
--
2.43.0
[PATCH v2 2/3] tracing: initialize trace_seq buffers
Now that trace_seq_reset have been created, correct the places where the
buffers need to be initialized.
Suggested-by: Steven Rostedt
Signed-off-by: Ricardo B. Marliere
---
kernel/trace/trace.c | 14 ++
1 file changed, 14 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d4c55d3e21c2..9827700d0164 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4889,6 +4889,9 @@ __tracing_open(struct inode *inode, struct file *file,
bool snapshot)
mutex_unlock(&trace_types_lock);
+ trace_seq_init(&iter->seq);
+ trace_seq_init(&iter->tmp_seq);
+
return iter;
fail:
@@ -6770,6 +6773,7 @@ static int tracing_open_pipe(struct inode *inode, struct
file *filp)
}
trace_seq_init(&iter->seq);
+ trace_seq_init(&iter->tmp_seq);
iter->trace = tr->current_trace;
if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
@@ -6947,6 +6951,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
trace_iterator_reset(iter);
cpumask_clear(iter->started);
trace_seq_init(&iter->seq);
+ trace_seq_init(&iter->tmp_seq);
trace_event_read_lock();
trace_access_lock(iter->cpu_file);
@@ -8277,6 +8282,9 @@ static int tracing_buffers_open(struct inode *inode,
struct file *filp)
if (ret < 0)
trace_array_put(tr);
+ trace_seq_init(&info->iter.seq);
+ trace_seq_init(&info->iter.tmp_seq);
+
return ret;
}
@@ -10300,6 +10308,9 @@ void trace_init_global_iter(struct trace_iterator *iter)
iter->temp_size = STATIC_TEMP_BUF_SIZE;
iter->fmt = static_fmt_buf;
iter->fmt_size = STATIC_FMT_BUF_SIZE;
+
+ trace_seq_init(&iter->seq);
+ trace_seq_init(&iter->tmp_seq);
}
void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
@@ -10712,6 +10723,9 @@ void __init early_trace_init(void)
tracepoint_printk = 0;
else
static_key_enable(&tracepoint_printk_key.key);
+
+ trace_seq_init(&tracepoint_print_iter->seq);
+ trace_seq_init(&tracepoint_print_iter->tmp_seq);
}
tracer_alloc_buffers();
--
2.43.0
[PATCH v2 1/3] tracing: add trace_seq_reset function
Currently, trace_seq_init may be called many times with the intent of
resetting the buffer. Add a function trace_seq_reset that does that and
replace the relevant occurrences to use it instead.
Suggested-by: Steven Rostedt
Signed-off-by: Ricardo B. Marliere
---
include/linux/trace_seq.h| 11 +++
include/trace/trace_events.h | 2 +-
kernel/trace/trace.c | 10 +-
kernel/trace/trace_output.c | 2 +-
kernel/trace/trace_seq.c | 2 +-
5 files changed, 19 insertions(+), 8 deletions(-)
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
index 9ec229dfddaa..d3fa41001813 100644
--- a/include/linux/trace_seq.h
+++ b/include/linux/trace_seq.h
@@ -29,6 +29,17 @@ trace_seq_init(struct trace_seq *s)
s->readpos = 0;
}
+static inline void
+trace_seq_reset(struct trace_seq *s)
+{
+ if (WARN_ON_ONCE(!s->seq.size))
+ seq_buf_init(&s->seq, s->buffer, TRACE_SEQ_BUFFER_SIZE);
+ else
+ seq_buf_clear(&s->seq);
+ s->full = 0;
+ s->readpos = 0;
+}
+
/**
* trace_seq_used - amount of actual data written to buffer
* @s: trace sequence descriptor
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index c2f9cabf154d..2bc79998e5ab 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -227,7 +227,7 @@ trace_raw_output_##call(struct trace_iterator *iter, int
flags, \
\
field = (typeof(field))entry; \
\
- trace_seq_init(p); \
+ trace_seq_reset(p); \
return trace_output_call(iter, #call, print); \
} \
static struct trace_event_functions trace_event_type_funcs_##call = { \
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 46dbe22121e9..d4c55d3e21c2 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2928,7 +2928,7 @@ static void output_printk(struct trace_event_buffer
*fbuffer)
event = &fbuffer->trace_file->event_call->event;
raw_spin_lock_irqsave(&tracepoint_iter_lock, flags);
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
iter->ent = fbuffer->entry;
event_call->event.funcs->trace(iter, 0, event);
trace_seq_putc(&iter->seq, 0);
@@ -6921,7 +6921,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
if (sret != -EBUSY)
goto out;
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
if (iter->trace->read) {
sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
@@ -6993,7 +6993,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
/* Now copy what we have to the user */
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
if (iter->seq.readpos >= trace_seq_used(&iter->seq))
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
/*
* If there was nothing to send to user, in spite of consuming trace
@@ -7125,7 +7125,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
spd.partial[i].offset = 0;
spd.partial[i].len = trace_seq_used(&iter->seq);
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
}
trace_access_unlock(iter->cpu_file);
@@ -10274,7 +10274,7 @@ trace_printk_seq(struct trace_seq *s)
printk(KERN_TRACE "%s", s->buffer);
- trace_seq_init(s);
+ trace_seq_reset(s);
}
void trace_init_global_iter(struct trace_iterator *iter)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 3e7fa44dc2b2..c949e7736618 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -308,7 +308,7 @@ int trace_raw_output_prep(struct trace_iterator *iter,
return TRACE_TYPE_UNHANDLED;
}
- trace_seq_init(p);
+ trace_seq_reset(p);
trace_seq_printf(s, "%s: ", trace_event_name(event));
return trace_handle_return(s);
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index c158d65a8a88..741b2f3d76c0 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -59,7 +59,7 @@ int trace_print_seq(struct seq_file *m, struct trace_seq *s)
* do something else with the contents.
*/
if (!ret)
- trace_seq_init(s);
+ trace_seq_reset(s);
return ret;
}
--
2.43.0
[PATCH v2 0/3] add trace_seq_reset function
This series is a prerequisite for a later effort of making trace_seq more flexible about its buffer size. To achieve that, initializing and resetting the buffers need to be differentiated. Ricardo B. Marliere (3): tracing: add trace_seq_reset function tracing: initialize trace_seq buffers tracing: convert __trace_seq_init to use WARN_ON_ONCE include/linux/trace_seq.h| 11 +++ include/trace/trace_events.h | 2 +- kernel/trace/trace.c | 24 +++- kernel/trace/trace_output.c | 2 +- kernel/trace/trace_seq.c | 4 ++-- 5 files changed, 34 insertions(+), 9 deletions(-) -- 2.43.0
Re: [PATCH] tracing: add trace_seq_reset function
On 22 Jan 17:10, Steven Rostedt wrote:
> On Mon, 22 Jan 2024 15:22:25 -0300
> "Ricardo B. Marliere" wrote:
>
> > Currently, trace_seq_init may be called many times with the intent of
> > resetting the buffer. Add a function trace_seq_reset that does that and
> > replace the relevant occurrences to use it instead.
> >
>
> Hi Ricardo!
>
> It's also OK to add to the commit log that the goal of this is to later
> extend trace_seq to be more flexible in the size of the buffer it holds. To
> do that, we need to differentiate between initializing a trace_seq and just
> resetting it.
>
Hi, Steve
Certainly. I also forgot to add your Suggested-by.
>
> > Signed-off-by: Ricardo B. Marliere
> > ---
> > include/linux/trace_seq.h| 8
> > include/trace/trace_events.h | 2 +-
> > kernel/trace/trace.c | 8
> > kernel/trace/trace_seq.c | 2 +-
> > 4 files changed, 14 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
> > index 9ec229dfddaa..c28e0ccb50bd 100644
> > --- a/include/linux/trace_seq.h
> > +++ b/include/linux/trace_seq.h
> > @@ -29,6 +29,14 @@ trace_seq_init(struct trace_seq *s)
> > s->readpos = 0;
> > }
> >
> > +static inline void
> > +trace_seq_reset(struct trace_seq *s)
> > +{
> > + seq_buf_clear(&s->seq);
> > + s->full = 0;
> > + s->readpos = 0;
> > +}
> > +
> > /**
> > * trace_seq_used - amount of actual data written to buffer
> > * @s: trace sequence descriptor
> > diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
> > index c2f9cabf154d..2bc79998e5ab 100644
> > --- a/include/trace/trace_events.h
> > +++ b/include/trace/trace_events.h
> > @@ -227,7 +227,7 @@ trace_raw_output_##call(struct trace_iterator *iter,
> > int flags, \
> > \
> > field = (typeof(field))entry; \
> > \
> > - trace_seq_init(p); \
> > + trace_seq_reset(p); \
> > return trace_output_call(iter, #call, print); \
>
> Note, p = &iter->tmp_seq
>
> where it has never been initialized. To do this, we need to add:
>
> trace_seq_init(&iter->tmp_seq);
>
> where ever iter is created. You need to look at all the locations where
> iter is created ("iter =") and differentiate where it is first used from
> just passing pointers around.
>
> The iter = kzalloc() will be easy, but for example, both seq and tmp_seq
> need to be initialized in tracing_buffers_open().
That makes sense, I will work on a v2.
>
> Perhaps we need a:
>
> if (WARN_ON_ONCE(!s->seq.size))
> seq_buf_init(&s->seq, s->buffer, TRACE_SEQ_BUFFER_SIZE);
> else
> seq_buf_clear(&s->seq);
>
>
> in the trace_seq_reset() to catch any place that doesn't have it
> initialized yet.
But that would be temporary, right? Kind of a "trace_seq_init_or_reset".
If that's the case it would be best to simply work out all the places
instead. Would the current tests [1] cover everything or should
something else be made to make sure no place was missing from the patch?
Thanks for reviewing!
- Ricardo
--
[1] https://github.com/rostedt/ftrace-ktests
[PATCH] tracing: add trace_seq_reset function
Currently, trace_seq_init may be called many times with the intent of
resetting the buffer. Add a function trace_seq_reset that does that and
replace the relevant occurrences to use it instead.
Signed-off-by: Ricardo B. Marliere
---
include/linux/trace_seq.h| 8
include/trace/trace_events.h | 2 +-
kernel/trace/trace.c | 8
kernel/trace/trace_seq.c | 2 +-
4 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
index 9ec229dfddaa..c28e0ccb50bd 100644
--- a/include/linux/trace_seq.h
+++ b/include/linux/trace_seq.h
@@ -29,6 +29,14 @@ trace_seq_init(struct trace_seq *s)
s->readpos = 0;
}
+static inline void
+trace_seq_reset(struct trace_seq *s)
+{
+ seq_buf_clear(&s->seq);
+ s->full = 0;
+ s->readpos = 0;
+}
+
/**
* trace_seq_used - amount of actual data written to buffer
* @s: trace sequence descriptor
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index c2f9cabf154d..2bc79998e5ab 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -227,7 +227,7 @@ trace_raw_output_##call(struct trace_iterator *iter, int
flags, \
\
field = (typeof(field))entry; \
\
- trace_seq_init(p); \
+ trace_seq_reset(p); \
return trace_output_call(iter, #call, print); \
} \
static struct trace_event_functions trace_event_type_funcs_##call = { \
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 46dbe22121e9..9147f3717b9a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6946,7 +6946,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
/* reset all but tr, trace, and overruns */
trace_iterator_reset(iter);
cpumask_clear(iter->started);
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
trace_event_read_lock();
trace_access_lock(iter->cpu_file);
@@ -6993,7 +6993,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
/* Now copy what we have to the user */
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
if (iter->seq.readpos >= trace_seq_used(&iter->seq))
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
/*
* If there was nothing to send to user, in spite of consuming trace
@@ -7125,7 +7125,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
spd.partial[i].offset = 0;
spd.partial[i].len = trace_seq_used(&iter->seq);
- trace_seq_init(&iter->seq);
+ trace_seq_reset(&iter->seq);
}
trace_access_unlock(iter->cpu_file);
@@ -10274,7 +10274,7 @@ trace_printk_seq(struct trace_seq *s)
printk(KERN_TRACE "%s", s->buffer);
- trace_seq_init(s);
+ trace_seq_reset(s);
}
void trace_init_global_iter(struct trace_iterator *iter)
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index c158d65a8a88..741b2f3d76c0 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -59,7 +59,7 @@ int trace_print_seq(struct seq_file *m, struct trace_seq *s)
* do something else with the contents.
*/
if (!ret)
- trace_seq_init(s);
+ trace_seq_reset(s);
return ret;
}
--
2.43.0
