Pull kprobes updates from Masami Hiramatsu:
- Skip negative return code check for snprintf in eprobe
- Add recursive call test cases for kprobe unit test
- Add 'char' type to probe events to show it as the character instead
of value
- Update kselftest kprobe-event testcase to ignore '__pfx_' symbols
- Fix kselftest to check filter on eprobe event correctly
- Add filter on eprobe to the README file in tracefs
- Fix optprobes to check whether there is 'under unoptimizing' optprobe
when optimizing another kprobe correctly
- Fix optprobe to check whether there is 'under unoptimizing' optprobe
when fetching the original instruction correctly
- Fix optprobe to free 'forcibly unoptimized' optprobe correctly
* tag 'probes-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/eprobe: no need to check for negative ret value for snprintf
test_kprobes: Add recursed kprobe test case
tracing/probe: add a char type to show the character value of traced arguments
selftests/ftrace: Fix probepoint testcase to ignore __pfx_* symbols
selftests/ftrace: Fix eprobe syntax test case to check filter support
tracing/eprobe: Fix to add filter on eprobe description in README file
x86/kprobes: Fix arch_check_optimized_kprobe check within optimized_kprobe range
x86/kprobes: Fix __recover_optprobed_insn check optimizing logic
kprobes: Fix to handle forcibly unoptimized kprobes on freeing_list
Note that the array can be applied to memory type fetchargs, you can not
apply it to registers/stack-entries etc. (for example, '$stack1:x8[8]' is
wrong, but '+8($stack):x8[8]' is OK.)
+
+ Char type can be used to show the character value of traced arguments.
++
String type is a special type, which fetches a "null-terminated" string from
kernel space. This means it will fail and store NULL if the string container
has been paged out. "ustring" type is an alternative of string for user-space.