trace_seq: Increase the buffer size to almost two pages

Now that trace_marker can hold more than 1KB string, and can write as much
as the ring buffer can hold, the trace_seq is not big enough to hol

trace_seq: Increase the buffer size to almost two pages

Now that trace_marker can hold more than 1KB string, and can write as much
as the ring buffer can hold, the trace_seq is not big enough to hold
writes:

~# a="1234567890"
~# cnt=4080
~# s=""
~# while [ $cnt -gt 10 ]; do
~# s="${s}${a}"
~# cnt=$((cnt-10))
~# done
~# echo $s > trace_marker
~# cat trace
# tracer: nop
#
# entries-in-buffer/entries-written: 2/2 #P:8
#
# _-----=> irqs-off/BH-disabled
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / _-=> migrate-disable
# |||| / delay
# TASK-PID CPU# ||||| TIMESTAMP FUNCTION
# | | | ||||| | |
<...>-860 [002] ..... 105.543465: tracing_mark_write[LINE TOO BIG]
<...>-860 [002] ..... 105.543496: tracing_mark_write: 789012345678901234567890

By increasing the trace_seq buffer to almost two pages, it can now print
out the first line.

This also subtracts the rest of the trace_seq fields from the buffer, so
that the entire trace_seq is now PAGE_SIZE aligned.

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

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tracing: Move readpos from seq_buf to trace_seq

To make seq_buf more lightweight as a string buf, move the readpos member
from seq_buf to its container, trace_seq. That puts the responsibility
of m

tracing: Move readpos from seq_buf to trace_seq

To make seq_buf more lightweight as a string buf, move the readpos member
from seq_buf to its container, trace_seq. That puts the responsibility
of maintaining the readpos entirely in the tracing code. If some future
users want to package up the readpos with a seq_buf, we can define a
new struct then.

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Kees Cook <[email protected]>
Cc: Justin Stitt <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

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tracing: Fix kernel-doc warnings in trace_seq.c

Fix kernel-doc warning:

kernel/trace/trace_seq.c:142: warning: Function parameter or member
'args' not described in 'trace_seq_vprintf'

Link: https:

tracing: Fix kernel-doc warnings in trace_seq.c

Fix kernel-doc warning:

kernel/trace/trace_seq.c:142: warning: Function parameter or member
'args' not described in 'trace_seq_vprintf'

Link: https://lkml.kernel.org/r/[email protected]

Cc: <[email protected]>
Signed-off-by: Gaosheng Cui <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

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tracing: Acquire buffer from temparary trace sequence

there is one dwc3 trace event declare as below,
DECLARE_EVENT_CLASS(dwc3_log_event,
TP_PROTO(u32 event, struct dwc3 *dwc),
TP_ARGS(event, dwc)

tracing: Acquire buffer from temparary trace sequence

there is one dwc3 trace event declare as below,
DECLARE_EVENT_CLASS(dwc3_log_event,
TP_PROTO(u32 event, struct dwc3 *dwc),
TP_ARGS(event, dwc),
TP_STRUCT__entry(
__field(u32, event)
__field(u32, ep0state)
__dynamic_array(char, str, DWC3_MSG_MAX)
),
TP_fast_assign(
__entry->event = event;
__entry->ep0state = dwc->ep0state;
),
TP_printk("event (%08x): %s", __entry->event,
dwc3_decode_event(__get_str(str), DWC3_MSG_MAX,
__entry->event, __entry->ep0state))
);
the problem is when trace function called, it will allocate up to
DWC3_MSG_MAX bytes from trace event buffer, but never fill the buffer
during fast assignment, it only fill the buffer when output function are
called, so this means if output function are not called, the buffer will
never used.

add __get_buf(len) which acquiree buffer from iter->tmp_seq when trace
output function called, it allow user write string to acquired buffer.

the mentioned dwc3 trace event will changed as below,
DECLARE_EVENT_CLASS(dwc3_log_event,
TP_PROTO(u32 event, struct dwc3 *dwc),
TP_ARGS(event, dwc),
TP_STRUCT__entry(
__field(u32, event)
__field(u32, ep0state)
),
TP_fast_assign(
__entry->event = event;
__entry->ep0state = dwc->ep0state;
),
TP_printk("event (%08x): %s", __entry->event,
dwc3_decode_event(__get_buf(DWC3_MSG_MAX), DWC3_MSG_MAX,
__entry->event, __entry->ep0state))
);.

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Masami Hiramatsu <[email protected]>
Signed-off-by: Linyu Yuan <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

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tracing: Fix various typos in comments

Fix ~59 single-word typos in the tracing code comments, and fix
the grammar in a handful of places.

Link: https://lore.kernel.org/r/20210322224546.GA1981273@g

tracing: Fix various typos in comments

Fix ~59 single-word typos in the tracing code comments, and fix
the grammar in a handful of places.

Link: https://lore.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]

Reviewed-by: Randy Dunlap <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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tracing: Remove unused TRACE_SEQ_BUF_USED

This macro isn't used from commit 3a161d99c43c ("tracing: Create
seq_buf layer in trace_seq"). so no needs to keep it.

Link: http://lkml.kernel.org/r/15795

tracing: Remove unused TRACE_SEQ_BUF_USED

This macro isn't used from commit 3a161d99c43c ("tracing: Create
seq_buf layer in trace_seq"). so no needs to keep it.

Link: http://lkml.kernel.org/r/[email protected]

Signed-off-by: Alex Shi <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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tracing: Fix indentation issue

There is a declaration that is indented one level too deeply, remove
the extraneous tab.

Link: http://lkml.kernel.org/r/[email protected]

tracing: Fix indentation issue

There is a declaration that is indented one level too deeply, remove
the extraneous tab.

Link: http://lkml.kernel.org/r/[email protected]

Signed-off-by: Colin Ian King <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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tracing: Use seq_buf_hex_dump() to dump buffers

Without this, buffers can be printed with __print_array macro that has
no formatting options and can be hard to read. The other way is to
mimic format

tracing: Use seq_buf_hex_dump() to dump buffers

Without this, buffers can be printed with __print_array macro that has
no formatting options and can be hard to read. The other way is to
mimic formatting capability with multiple calls of trace event with one
call per row which gives performance impact and different timestamp in
each row.

Link: http://lkml.kernel.org/r/[email protected]

Signed-off-by: Piotr Maziarz <[email protected]>
Signed-off-by: Cezary Rojewski <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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tracing: Add SPDX License format tags to tracing files

Add the SPDX License header to ease license compliance management.

Signed-off-by: Steven Rostedt (VMware) <[email protected]>

tracing: use %*pb[l] to print bitmaps including cpumasks and nodemasks

printk and friends can now format bitmaps using '%*pb[l]'. cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr

tracing: use %*pb[l] to print bitmaps including cpumasks and nodemasks

printk and friends can now format bitmaps using '%*pb[l]'. cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.

Signed-off-by: Tejun Heo <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

tracing: Use trace_seq_used() and seq_buf_used() instead of len

As the seq_buf->len will soon be +1 size when there's an overflow, we
must use trace_seq_used() or seq_buf_used() methods to get the r

tracing: Use trace_seq_used() and seq_buf_used() instead of len

As the seq_buf->len will soon be +1 size when there's an overflow, we
must use trace_seq_used() or seq_buf_used() methods to get the real
length. This will prevent buffer overflow issues if just the len
of the seq_buf descriptor is used to copy memory.

Link: http://lkml.kernel.org/r/[email protected]

Reported-by: Petr Mladek <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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tracing: Convert seq_buf_path() to be like seq_path()

Rewrite seq_buf_path() like it is done in seq_path() and allow
it to accept any escape character instead of just "\n".

Making seq_buf_path() li

tracing: Convert seq_buf_path() to be like seq_path()

Rewrite seq_buf_path() like it is done in seq_path() and allow
it to accept any escape character instead of just "\n".

Making seq_buf_path() like seq_path() will help prevent problems
when converting seq_file to use the seq_buf logic.

Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]

Tested-by: Jiri Kosina <[email protected]>
Acked-by: Jiri Kosina <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

show more ...

tracing: Create seq_buf layer in trace_seq

Create a seq_buf layer that trace_seq sits on. The seq_buf will not
be limited to page size. This will allow other usages of seq_buf
instead of a hard set

tracing: Create seq_buf layer in trace_seq

Create a seq_buf layer that trace_seq sits on. The seq_buf will not
be limited to page size. This will allow other usages of seq_buf
instead of a hard set PAGE_SIZE one that trace_seq has.

Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]

Tested-by: Jiri Kosina <[email protected]>
Acked-by: Jiri Kosina <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

show more ...

tracing: Remove return values of most trace_seq_*() functions

The trace_seq_printf() and friends are used to store strings into a buffer
that can be passed around from function to function. If the t

tracing: Remove return values of most trace_seq_*() functions

The trace_seq_printf() and friends are used to store strings into a buffer
that can be passed around from function to function. If the trace_seq buffer
fills up, it will not print any more. The return values were somewhat
inconsistant and using trace_seq_has_overflowed() was a better way to know
if the write to the trace_seq buffer succeeded or not.

Now that all users have removed reading the return value of the printf()
type functions, they can safely return void and keep future users of them
from reading the inconsistent values as well.

Link: http://lkml.kernel.org/r/[email protected]

Signed-off-by: Steven Rostedt <[email protected]>

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tracing: Fix trace_seq_bitmask() to start at current position

In trace_seq_bitmask() it calls bitmap_scnprintf() not from the current
position of the trace_seq buffer (s->buffer + s->len), but inste

tracing: Fix trace_seq_bitmask() to start at current position

In trace_seq_bitmask() it calls bitmap_scnprintf() not from the current
position of the trace_seq buffer (s->buffer + s->len), but instead from
the beginning of the buffer (s->buffer).

Luckily, the only user of this "ipi_raise tracepoint" uses it as the
first parameter, and as such, the start of the temp buffer in
include/trace/ftrace.h (see __get_bitmask()).

Reported-by: Petr Mladek <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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tracing: Remove trace_seq_reserve()

trace_seq_reserve() has no users in the kernel, it just wastes space.
Remove it.

Cc: Eduard - Gabriel Munteanu <[email protected]>
Signed-off-by: Steve

tracing: Remove trace_seq_reserve()

trace_seq_reserve() has no users in the kernel, it just wastes space.
Remove it.

Cc: Eduard - Gabriel Munteanu <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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tracing: Make trace_seq_putmem_hex() more robust

Currently trace_seq_putmem_hex() can only take as a parameter a pointer
to something that is 8 bytes or less, otherwise it will overflow the
buffer.

tracing: Make trace_seq_putmem_hex() more robust

Currently trace_seq_putmem_hex() can only take as a parameter a pointer
to something that is 8 bytes or less, otherwise it will overflow the
buffer. This is protected by a macro that encompasses the call to
trace_seq_putmem_hex() that has a BUILD_BUG_ON() for the variable before
it is passed in. This is not very robust and if trace_seq_putmem_hex() ever
gets used outside that macro it will cause issues.

Instead of only being able to produce a hex output of memory that is for
a single word, change it to be more robust and allow any size input.

Signed-off-by: Steven Rostedt <[email protected]>

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tracing: Clean up trace_seq.c

For using trace_seq_*() functions in NMI context, I posted a patch to move
it to the lib/ directory. This caused Andrew Morton to take a look at the code.
He went throu

tracing: Clean up trace_seq.c

For using trace_seq_*() functions in NMI context, I posted a patch to move
it to the lib/ directory. This caused Andrew Morton to take a look at the code.
He went through and gave a lot of comments about missing kernel doc,
inconsistent types for the save variable, mix match of EXPORT_SYMBOL_GPL()
and EXPORT_SYMBOL() as well as missing EXPORT_SYMBOL*()s. There were
a few comments about the way variables were being compared (int vs uint).

All these were good review comments and should be implemented regardless of
if trace_seq.c should be moved to lib/ or not.

Signed-off-by: Steven Rostedt <[email protected]>

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tracing: Move the trace_seq_* functions into its own trace_seq.c file

The trace_seq_*() functions are a nice utility that allows users to manipulate
buffers with printf() like formats. It has its ow

tracing: Move the trace_seq_* functions into its own trace_seq.c file

The trace_seq_*() functions are a nice utility that allows users to manipulate
buffers with printf() like formats. It has its own trace_seq.h header in
include/linux and should be in its own file. Being tied with trace_output.c
is rather awkward.

Signed-off-by: Steven Rostedt <[email protected]>

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