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authorLinus Torvalds <torvalds@linux-foundation.org>2020-12-17 13:22:17 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-17 13:22:17 -0800
commit09c0796adf0c793462fda1d7c8c43324551405c7 (patch)
tree90893d337b215482f059dd7e522279b23ffa0961 /kernel/trace/Kconfig
parent312dcaf967219effe0483785f24e4072a5bed9a5 (diff)
parentf6a694665f132cbf6e2222dd2f173dc35330a8aa (diff)
Merge tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt: "The major update to this release is that there's a new arch config option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. Currently, only x86_64 enables it. All the ftrace callbacks now take a struct ftrace_regs instead of a struct pt_regs. If the architecture has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will have enough information to read the arguments of the function being traced, as well as access to the stack pointer. This way, if a user (like live kernel patching) only cares about the arguments, then it can avoid using the heavier weight "regs" callback, that puts in enough information in the struct ftrace_regs to simulate a breakpoint exception (needed for kprobes). A new config option that audits the timestamps of the ftrace ring buffer at most every event recorded. Ftrace recursion protection has been cleaned up to move the protection to the callback itself (this saves on an extra function call for those callbacks). Perf now handles its own RCU protection and does not depend on ftrace to do it for it (saving on that extra function call). New debug option to add "recursed_functions" file to tracefs that lists all the places that triggered the recursion protection of the function tracer. This will show where things need to be fixed as recursion slows down the function tracer. The eval enum mapping updates done at boot up are now offloaded to a work queue, as it caused a noticeable pause on slow embedded boards. Various clean ups and last minute fixes" * tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) tracing: Offload eval map updates to a work queue Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS" ring-buffer: Add rb_check_bpage in __rb_allocate_pages ring-buffer: Fix two typos in comments tracing: Drop unneeded assignment in ring_buffer_resize() tracing: Disable ftrace selftests when any tracer is running seq_buf: Avoid type mismatch for seq_buf_init ring-buffer: Fix a typo in function description ring-buffer: Remove obsolete rb_event_is_commit() ring-buffer: Add test to validate the time stamp deltas ftrace/documentation: Fix RST C code blocks tracing: Clean up after filter logic rewriting tracing: Remove the useless value assignment in test_create_synth_event() livepatch: Use the default ftrace_ops instead of REGS when ARGS is available ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs MAINTAINERS: assign ./fs/tracefs to TRACING tracing: Fix some typos in comments ftrace: Remove unused varible 'ret' ring-buffer: Add recording of ring buffer recursion into recursed_functions ...
Diffstat (limited to 'kernel/trace/Kconfig')
-rw-r--r--kernel/trace/Kconfig68
1 files changed, 68 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 2f8d9cc42c40..d5a19413d4f8 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -31,6 +31,15 @@ config HAVE_DYNAMIC_FTRACE_WITH_REGS
config HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
bool
+config HAVE_DYNAMIC_FTRACE_WITH_ARGS
+ bool
+ help
+ If this is set, then arguments and stack can be found from
+ the pt_regs passed into the function callback regs parameter
+ by default, even without setting the REGS flag in the ftrace_ops.
+ This allows for use of regs_get_kernel_argument() and
+ kernel_stack_pointer().
+
config HAVE_FTRACE_MCOUNT_RECORD
bool
help
@@ -725,6 +734,45 @@ config TRACE_EVAL_MAP_FILE
If unsure, say N.
+config FTRACE_RECORD_RECURSION
+ bool "Record functions that recurse in function tracing"
+ depends on FUNCTION_TRACER
+ help
+ All callbacks that attach to the function tracing have some sort
+ of protection against recursion. Even though the protection exists,
+ it adds overhead. This option will create a file in the tracefs
+ file system called "recursed_functions" that will list the functions
+ that triggered a recursion.
+
+ This will add more overhead to cases that have recursion.
+
+ If unsure, say N
+
+config FTRACE_RECORD_RECURSION_SIZE
+ int "Max number of recursed functions to record"
+ default 128
+ depends on FTRACE_RECORD_RECURSION
+ help
+ This defines the limit of number of functions that can be
+ listed in the "recursed_functions" file, that lists all
+ the functions that caused a recursion to happen.
+ This file can be reset, but the limit can not change in
+ size at runtime.
+
+config RING_BUFFER_RECORD_RECURSION
+ bool "Record functions that recurse in the ring buffer"
+ depends on FTRACE_RECORD_RECURSION
+ # default y, because it is coupled with FTRACE_RECORD_RECURSION
+ default y
+ help
+ The ring buffer has its own internal recursion. Although when
+ recursion happens it wont cause harm because of the protection,
+ but it does cause an unwanted overhead. Enabling this option will
+ place where recursion was detected into the ftrace "recursed_functions"
+ file.
+
+ This will add more overhead to cases that have recursion.
+
config GCOV_PROFILE_FTRACE
bool "Enable GCOV profiling on ftrace subsystem"
depends on GCOV_KERNEL
@@ -795,6 +843,26 @@ config RING_BUFFER_STARTUP_TEST
If unsure, say N
+config RING_BUFFER_VALIDATE_TIME_DELTAS
+ bool "Verify ring buffer time stamp deltas"
+ depends on RING_BUFFER
+ help
+ This will audit the time stamps on the ring buffer sub
+ buffer to make sure that all the time deltas for the
+ events on a sub buffer matches the current time stamp.
+ This audit is performed for every event that is not
+ interrupted, or interrupting another event. A check
+ is also made when traversing sub buffers to make sure
+ that all the deltas on the previous sub buffer do not
+ add up to be greater than the current time stamp.
+
+ NOTE: This adds significant overhead to recording of events,
+ and should only be used to test the logic of the ring buffer.
+ Do not use it on production systems.
+
+ Only say Y if you understand what this does, and you
+ still want it enabled. Otherwise say N
+
config MMIOTRACE_TEST
tristate "Test module for mmiotrace"
depends on MMIOTRACE && m