ftrace: Cleanup ftrace_dyn_arch_init()

Most of ARCHs use empty ftrace_dyn_arch_init(), introduce a weak common
ftrace_dyn_arch_init() to cleanup them.

Link: https://lkml.kernel.org/r/20210909090216

ftrace: Cleanup ftrace_dyn_arch_init()

Most of ARCHs use empty ftrace_dyn_arch_init(), introduce a weak common
ftrace_dyn_arch_init() to cleanup them.

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

Acked-by: Heiko Carstens <[email protected]> (s390)
Acked-by: Helge Deller <[email protected]> (parisc)
Signed-off-by: Weizhao Ouyang <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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microblaze: function_graph: Simplify with function_graph_enter()

The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack,

microblaze: function_graph: Simplify with function_graph_enter()

The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().

Have microblaze use the new code, and remove the shadow stack management as well as
having to set up the trace structure.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.

Cc: Michal Simek <[email protected]>
Cc: [email protected]
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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ftrace: Add return address pointer to ftrace_ret_stack

Storing this value will help prevent unwinders from getting out of sync
with the function graph tracer ret_stack. Now instead of needing a
sta

ftrace: Add return address pointer to ftrace_ret_stack

Storing this value will help prevent unwinders from getting out of sync
with the function graph tracer ret_stack. Now instead of needing a
stateful iterator, they can compare the return address pointer to find
the right ret_stack entry.

Note that an array of 50 ftrace_ret_stack structs is allocated for every
task. So when an arch implements this, it will add either 200 or 400
bytes of memory usage per task (depending on whether it's a 32-bit or
64-bit platform).

Signed-off-by: Josh Poimboeuf <[email protected]>
Acked-by: Steven Rostedt <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Byungchul Park <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Nilay Vaish <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/a95cfcc39e8f26b89a430c56926af0bb217bc0a1.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <[email protected]>

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microblaze: ftrace: Add call to ftrace_graph_is_dead() in function graph code

ftrace_stop() is going away as it disables parts of function tracing
that affects users that should not be affected. But

microblaze: ftrace: Add call to ftrace_graph_is_dead() in function graph code

ftrace_stop() is going away as it disables parts of function tracing
that affects users that should not be affected. But ftrace_graph_stop()
is built on ftrace_stop(). Here's another example of killing all of
function tracing because something went wrong with function graph
tracing.

Instead of disabling all users of function tracing on function graph
error, disable only function graph tracing. To do this, the arch code
must call ftrace_graph_is_dead() before it implements function graph.

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

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

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ftrace: Do not pass data to ftrace_dyn_arch_init

As the data parameter is not really used by any ftrace_dyn_arch_init,
remove that from ftrace_dyn_arch_init. This also removes the addr
local variabl

ftrace: Do not pass data to ftrace_dyn_arch_init

As the data parameter is not really used by any ftrace_dyn_arch_init,
remove that from ftrace_dyn_arch_init. This also removes the addr
local variable from ftrace_init which is now unused.

Note the documentation was imprecise as it did not suggest to set
(*data) to 0.

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

Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: [email protected]
Signed-off-by: Jiri Slaby <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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ftrace: Pass retval through return in ftrace_dyn_arch_init()

No architecture uses the "data" parameter in ftrace_dyn_arch_init() in any
way, it just sets the value to 0. And this is used as a return

ftrace: Pass retval through return in ftrace_dyn_arch_init()

No architecture uses the "data" parameter in ftrace_dyn_arch_init() in any
way, it just sets the value to 0. And this is used as a return value
in the caller -- ftrace_init, which just checks the retval against
zero.

Note there is also "return 0" in every ftrace_dyn_arch_init. So it is
enough to check the retval and remove all the indirect sets of data on
all archs.

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

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

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microblaze: Fix coding style issues

Fix coding style issues reported by checkpatch.pl.

Signed-off-by: Michal Simek <[email protected]>

microblaze: Fix ftrace

- Do not trace idle loop which takes a lot time
- Fix cache handling in generic ftrace code
- Do not trace lib functions ashldi3, ashrdi3, lshrdi3
Functions are called from

microblaze: Fix ftrace

- Do not trace idle loop which takes a lot time
- Fix cache handling in generic ftrace code
- Do not trace lib functions ashldi3, ashrdi3, lshrdi3
Functions are called from generic ftrace code which
can't be traced

Signed-off-by: Michal Simek <[email protected]>

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microblaze: Fix ftrace_update_ftrace_func panic

The Microblaze dynamic ftrace code assumes a call ordering that is not met
in all scenarios. Specifically, executing a command similar to:

echo 105

microblaze: Fix ftrace_update_ftrace_func panic

The Microblaze dynamic ftrace code assumes a call ordering that is not met
in all scenarios. Specifically, executing a command similar to:

echo 105 > /sys/kernel/debug/tracing/set_ftrace_pid

before any other tracing-related commands results in a kernel panic:

BUG: failure at arch/microblaze/kernel/ftrace.c:198/ftrace_update_ftrace_func()!

Recoding ftrace_update_ftrace_func() to use &ftrace_caller directly eliminates
the need to capture its address elsewhere (and thus rely on a particular call
sequence).

Signed-off-by: Steven J. Magnani <[email protected]>
Signed-off-by: Michal Simek <[email protected]>

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microblaze: ftrace: Add dynamic function graph tracer

This patch add support for dynamic function graph tracer.

There is one my expactation that I can do flush_icache after
all code modification. O

microblaze: ftrace: Add dynamic function graph tracer

This patch add support for dynamic function graph tracer.

There is one my expactation that I can do flush_icache after
all code modification. On microblaze is this safer than do
flush for every entry. For icache is used name flush but
correct should be invalidation - this will be fix in upcomming
new cache implementaion and WB support.

Signed-off-by: Michal Simek <[email protected]>

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microblaze: ftrace: add function graph support

For more information look at Documentation/trace folder.

Signed-off-by: Michal Simek <[email protected]>

microblaze: ftrace: Add dynamic trace support

With dynamic function tracer, by default, _mcount is defined as an
"empty" function, it returns directly without any more action. When
enabling it in us

microblaze: ftrace: Add dynamic trace support

With dynamic function tracer, by default, _mcount is defined as an
"empty" function, it returns directly without any more action. When
enabling it in user-space, it will jump to a real tracing
function(ftrace_caller), and do the real job for us.

Differ from the static function tracer, dynamic function tracer provides
two functions ftrace_make_call()/ftrace_make_nop() to enable/disable the
tracing of some indicated kernel functions(set_ftrace_filter).

In the kernel version, there is only one "_mcount" string for every
kernel function, so, we just need to match this one in mcount_regex of
scripts/recordmcount.pl.

For more information please look at code and Documentation/trace folder.

Steven ACK that scripts/recordmcount.pl part.

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

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