linux/kernel/trace/ring_buffer.c, branch v5.6

ring-buffer: Remove abandoned macro RB_MISSED_FLAGS

2020-01-21T23:38:02Z

This macro isn't used since commit d325c402964e ("ring-buffer: Remove unused function ring_buffer_page_len()"), so better to remove it. Link: http://lkml.kernel.org/r/1579586080-45300-1-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi Signed-off-by: Steven Rostedt (VMware)

ring-buffer: Fix kernel doc for rb_update_event()

2020-01-14T21:27:51Z

rb_update_event has changed without the kernel-doc update. Signed-off-by: Steven Rostedt (VMware)

ring-bufer: kernel-doc warning fixes

2020-01-14T21:23:34Z

Also fixes a couple of typos Link: http://lkml.kernel.org/r/1401992525-10417-1-git-send-email-fabf@skynet.be Cc: Andrew Morton Signed-off-by: Fabian Frederick [ Found this deep in the abyss of my INBOX ] Signed-off-by: Steven Rostedt (VMware)

tracing: Make struct ring_buffer less ambiguous

2020-01-13T18:19:38Z

As there's two struct ring_buffers in the kernel, it causes some confusion. The other one being the perf ring buffer. It was agreed upon that as neither of the ring buffers are generic enough to be used globally, they should be renamed as: perf's ring_buffer -> perf_buffer ftrace's ring_buffer -> trace_buffer This implements the changes to the ring buffer that ftrace uses. Link: https://lore.kernel.org/r/20191213140531.116b3200@gandalf.local.home Signed-off-by: Steven Rostedt (VMware)

Fix up for "printk: Drop pr_warning definition"

2019-12-06T09:02:35Z

Link: http://lkml.kernel.org/r/20191206092503.303d6a57@canb.auug.org.au Cc: Linux Next Mailing List Cc: Linux Kernel Mailing List Cc: "Steven Rostedt (VMware)" Cc: Kefeng Wang Cc: Linus Torvalds Signed-off-by: Stephen Rothwell Signed-off-by: Petr Mladek

tracing: Do not create directories if lockdown is in affect

2019-12-04T13:27:15Z

If lockdown is disabling tracing on boot up, it prevents the tracing files from even bering created. But when that happens, there's several places that will give a warning that the files were not created as that is usually a sign of a bug. Add in strategic locations where a check is made to see if tracing is disabled by lockdown, and if it is, do not go further, and fail silently (but print that tracing is disabled by lockdown, without doing a WARN_ON()). Cc: Matthew Garrett Fixes: 17911ff38aa5 ("tracing: Add locked_down checks to the open calls of files created for tracefs") Signed-off-by: Steven Rostedt (VMware)

ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS

2019-05-28T13:36:19Z

Commit c19fa94a8fed ("Add HAVE_64BIT_ALIGNED_ACCESS") added the config for architectures that required 64bit aligned access for all 64bit words. As the ftrace ring buffer stores data on 4 byte alignment, this config option was used to force it to store data on 8 byte alignment to make sure the data being stored and written directly into the ring buffer was 8 byte aligned as it would cause issues trying to write an 8 byte word on a 4 not 8 byte aligned memory location. But with the removal of the metag architecture, which was the only architecture to use this, there is no architecture supported by Linux that requires 8 byte aligne access for all 8 byte words (4 byte alignment is good enough). Removing this config can simplify the code a bit. Signed-off-by: Steven Rostedt (VMware)

Merge tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2019-05-15T23:05:47Z

Pull tracing updates from Steven Rostedt: "The major changes in this tracing update includes: - Removal of non-DYNAMIC_FTRACE from 32bit x86 - Removal of mcount support from x86 - Emulating a call from int3 on x86_64, fixes live kernel patching - Consolidated Tracing Error logs file Minor updates: - Removal of klp_check_compiler_support() - kdb ftrace dumping output changes - Accessing and creating ftrace instances from inside the kernel - Clean up of #define if macro - Introduction of TRACE_EVENT_NOP() to disable trace events based on config options And other minor fixes and clean ups" * tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits) x86: Hide the int3_emulate_call/jmp functions from UML livepatch: Remove klp_check_compiler_support() ftrace/x86: Remove mcount support ftrace/x86_32: Remove support for non DYNAMIC_FTRACE tracing: Simplify "if" macro code tracing: Fix documentation about disabling options using trace_options tracing: Replace kzalloc with kcalloc tracing: Fix partial reading of trace event's id file tracing: Allow RCU to run between postponed startup tests tracing: Fix white space issues in parse_pred() function tracing: Eliminate const char[] auto variables ring-buffer: Fix mispelling of Calculate tracing: probeevent: Fix to make the type of $comm string tracing: probeevent: Do not accumulate on ret variable tracing: uprobes: Re-enable $comm support for uprobe events ftrace/x86_64: Emulate call function while updating in breakpoint handler x86_64: Allow breakpoints to emulate call instructions x86_64: Add gap to int3 to allow for call emulation tracing: kdb: Allow ftdump to skip all but the last few entries tracing: Add trace_total_entries() / trace_total_entries_cpu() ...

trace: Fix preempt_enable_no_resched() abuse

2019-04-26T15:45:03Z

Unless the very next line is schedule(), or implies it, one must not use preempt_enable_no_resched(). It can cause a preemption to go missing and thereby cause arbitrary delays, breaking the PREEMPT=y invariant. Link: http://lkml.kernel.org/r/20190423200318.GY14281@hirez.programming.kicks-ass.net Cc: Waiman Long Cc: Linus Torvalds Cc: Ingo Molnar Cc: Will Deacon Cc: Thomas Gleixner Cc: the arch/x86 maintainers Cc: Davidlohr Bueso Cc: Tim Chen Cc: huang ying Cc: Roman Gushchin Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: stable@vger.kernel.org Fixes: 2c2d7329d8af ("tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()") Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Steven Rostedt (VMware)

ring-buffer: Fix ring buffer size in rb_write_something()

2019-04-02T22:24:06Z

'cnt' should be used to calculate ring buffer size rather than data->cnt Link: http://lkml.kernel.org/r/1537704693-184237-1-git-send-email-yuehaibing@huawei.com Signed-off-by: YueHaibing Signed-off-by: Steven Rostedt (VMware)