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2020-11-18ftrace/documentation: Fix RST C code blocksSteven Rostedt (VMware)1-0/+6
Some C code in the ftrace-users.rst document is missing RST C block annotation, which has to be added. Link: https://lore.kernel.org/r/20201116173502.392a769c@canb.auug.org.au Acked-by: Jonathan Corbet <corbet@lwn.net> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Add recording of functions that caused recursionSteven Rostedt (VMware)1-2/+4
This adds CONFIG_FTRACE_RECORD_RECURSION that will record to a file "recursed_functions" all the functions that caused recursion while a callback to the function tracer was running. Link: https://lkml.kernel.org/r/20201106023548.102375687@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Guo Ren <guoren@kernel.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: x86@kernel.org Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-csky@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: live-patching@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Reverse what the RECURSION flag means in the ftrace_opsSteven Rostedt (VMware)1-22/+60
Now that all callbacks are recursion safe, reverse the meaning of the RECURSION flag and rename it from RECURSION_SAFE to simply RECURSION. Now only callbacks that request to have recursion protecting it will have the added trampoline to do so. Also remove the outdated comment about "PER_CPU" when determining to use the ftrace_ops_assist_func. Link: https://lkml.kernel.org/r/20201028115613.742454631@goodmis.org Link: https://lkml.kernel.org/r/20201106023547.904270143@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: linux-doc@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15docs: trace-uses.rst: remove bogus c-domain tagsMauro Carvalho Chehab1-6/+6
There are some c-domain tags that are wrong. While this won't cause problems with Sphinx < 3.0, this cause troubles with newer versions, as the C parser won't recognize the contents of the tag, and will drop it from the output. Let's just place them at literal blocks. Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2019-11-13tracing: Use CONFIG_PREEMPTIONSebastian Andrzej Siewior1-1/+1
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Add additional header output for PREEMPT_RT. Link: http://lkml.kernel.org/r/20191015191821.11479-34-bigeasy@linutronix.de Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-04ftrace: Introduce PERMANENT ftrace_ops flagMiroslav Benes1-0/+8
Livepatch uses ftrace for redirection to new patched functions. It means that if ftrace is disabled, all live patched functions are disabled as well. Toggling global 'ftrace_enabled' sysctl thus affect it directly. It is not a problem per se, because only administrator can set sysctl values, but it still may be surprising. Introduce PERMANENT ftrace_ops flag to amend this. If the FTRACE_OPS_FL_PERMANENT is set on any ftrace ops, the tracing cannot be disabled by disabling ftrace_enabled. Equally, a callback with the flag set cannot be registered if ftrace_enabled is disabled. Link: http://lkml.kernel.org/r/20191016113316.13415-2-mbenes@suse.cz Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-06-15docs: Fix some broken referencesMauro Carvalho Chehab1-1/+1
As we move stuff around, some doc references are broken. Fix some of them via this script: ./scripts/documentation-file-ref-check --fix Manually checked if the produced result is valid, removing a few false-positives. Acked-by: Takashi Iwai <tiwai@suse.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27linux-next: ftrace/docs: Fix spelling typos in ftrace-users.rstMasanari Iida1-2/+2
This patch corrects some spelling typo in ftrace-users.rst Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-03-07trace doc: add ftrace-uses.rst to doc treeChangbin Du1-11/+12
Add ftrace-uses.rst into Sphinx TOC tree. Few format issues are fixed. Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Changbin Du <changbin.du@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-12-21docs: ftrace-uses.rst fix varios code-block directivesMarkus Heiser1-30/+30
ftrace-uses.rst is not yet included into any toctree, but since it is a .rst file, it is parsed by the Sphinx build. Thats, why we see some WARNINGS: - trace/ftrace-uses.rst:53: WARNING: Definition list ends without a blank line; unexpected unindent. - trace/ftrace-uses.rst:89: WARNING: Inline emphasis start-string without end-string. - trace/ftrace-uses.rst:89: WARNING: Inline emphasis start-string without end-strin Fixing the code-block directives results in a less noisy build, but the 'not included' WARNING will be stay: - trace/ftrace-uses.rst: WARNING: document isn't included in any toctree Signed-off-by: Markus Heiser <markus.heiser@darmarit.de> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-11-05ftrace/docs: Add documentation on how to use ftrace from within the kernelSteven Rostedt1-0/+293
With the coming removal of jprobes, using ftrace callbacks is one of the utilities that replace the jprobes functionality. Having a document that explains how to use ftrace as such will help in the transition from jprobes to ftrace. This document is for kernel developers that require attaching a callback to a function within the kernel. Link: http://lkml.kernel.org/r/150724519527.5014.10207042218696587159.stgit@devbox Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> [jc: fixed one formatting issue that broke the docs build] Signed-off-by: Jonathan Corbet <corbet@lwn.net>