linux/tools/testing
Masami Hiramatsu (Google) 25f00e40ce tracing/probes: Support $argN in return probe (kprobe and fprobe)
Support accessing $argN in the return probe events. This will help users to
record entry data in function return (exit) event for simplfing the function
entry/exit information in one event, and record the result values (e.g.
allocated object/initialized object) at function exit.

For example, if we have a function `int init_foo(struct foo *obj, int param)`
sometimes we want to check how `obj` is initialized. In such case, we can
define a new return event like below;

 # echo 'r init_foo retval=$retval param=$arg2 field1=+0($arg1)' >> kprobe_events

Thus it records the function parameter `param` and its result `obj->field1`
(the dereference will be done in the function exit timing) value at once.

This also support fprobe, BTF args and'$arg*'. So if CONFIG_DEBUG_INFO_BTF
is enabled, we can trace both function parameters and the return value
by following command.

 # echo 'f target_function%return $arg* $retval' >> dynamic_events

Link: https://lore.kernel.org/all/170952365552.229804.224112990211602895.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-03-07 00:27:34 +09:00
..
crypto/chacha20-s390
cxl cxl/test: Add support for qos_class checking 2024-02-16 23:20:34 -08:00
fault-injection
ktest
kunit kunit: tool: add test for parsing attributes 2023-12-18 13:21:15 -07:00
memblock mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
nvdimm tools/testing/nvdimm: Disable "missing prototypes / declarations" warnings 2024-01-22 10:41:59 -08:00
radix-tree maple_tree: fix warning comparing pointer to 0 2023-12-20 14:48:12 -08:00
scatterlist
selftests tracing/probes: Support $argN in return probe (kprobe and fprobe) 2024-03-07 00:27:34 +09:00
vsock vsock/test: two tests to check credit update logic 2023-12-15 10:37:35 +00:00