linux/kernel/trace/trace_probe.c, branch v5.0

tracing: Use the return of str_has_prefix() to remove open coded numbers

2018-12-23T03:52:30Z

There are several locations that compare constants to the beginning of string variables to determine what commands should be done, then the constant length is used to index into the string. This is error prone as the hard coded numbers have to match the size of the constants. Instead, use the len returned from str_has_prefix() and remove the open coded string length sizes. Cc: Joe Perches Acked-by: Masami Hiramatsu (for trace_probe part) Acked-by: Namhyung Kim Signed-off-by: Steven Rostedt (VMware)

tracing: Use str_has_prefix() instead of using fixed sizes

2018-12-23T03:51:54Z

There are several instances of strncmp(str, "const", 123), where 123 is the strlen of the const string to check if "const" is the prefix of str. But this can be error prone. Use str_has_prefix() instead. Acked-by: Namhyung Kim Signed-off-by: Steven Rostedt (VMware)

tracing/kprobes: Use dyn_event framework for kprobe events

2018-12-09T01:54:09Z

Use dyn_event framework for kprobe events. This shows kprobe events on "tracing/dynamic_events" file. User can also define new events via tracing/dynamic_events. Link: http://lkml.kernel.org/r/154140855646.17322.6619219995865980392.stgit@devbox Reviewed-by: Tom Zanussi Tested-by: Tom Zanussi Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: Integrate similar probe argument parsers

2018-12-09T01:54:09Z

Integrate similar argument parsers for kprobes and uprobes events into traceprobe_parse_probe_arg(). Link: http://lkml.kernel.org/r/154140850016.17322.9836787731210512176.stgit@devbox Reviewed-by: Tom Zanussi Tested-by: Tom Zanussi Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing/kprobes: Fix strpbrk() argument order

2018-11-05T14:47:14Z

Fix strpbrk()'s argument order, it must pass acceptable string in 2nd argument. Note that this can cause a kernel panic where it recovers backup character to code->data. Link: http://lkml.kernel.org/r/154108256792.2604.1816052586385217811.stgit@devbox Fixes: a6682814f371 ("tracing/kprobes: Allow kprobe-events to record module symbol") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: probeevent: Fix uninitialized used of offset in parse args

2018-10-12T16:50:22Z

Dan's smatch utility found an uninitialized use of offset in a path in parse_probe_args(). Unless an offset is specifically specified for commands that allow them, it should default to zero. Link: http://lkml.kernel.org/r/20181012134246.5doqaobxunlqqs53@mwanda Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code") Reported-by: Dan Carpenter (smatch) Signed-off-by: Steven Rostedt (VMware)

tracing/kprobes: Allow kprobe-events to record module symbol

2018-10-11T02:19:12Z

Allow kprobe-events to record module symbols. Since data symbols in a non-loaded module doesn't exist, it fails to define such symbol as an argument of kprobe-event. But if the kprobe event is defined on that module, we can defer to resolve the symbol address. Note that if given symbol is not found, the event is kept unavailable. User can enable it but the event is not recorded. Link: http://lkml.kernel.org/r/153547312336.26502.11432902826345374463.stgit@devbox Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: probeevent: Add $argN for accessing function args

2018-10-11T02:19:11Z

Add $argN special fetch variable for accessing function arguments. This allows user to trace the Nth argument easily at the function entry. Note that this returns most probably assignment of registers and stacks. In some case, it may not work well. If you need to access correct registers or stacks you should use perf-probe. Link: http://lkml.kernel.org/r/152465888632.26224.3412465701570253696.stgit@devbox Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: probeevent: Add array type support

2018-10-11T02:19:10Z

Add array type support for probe events. This allows user to get arraied types from memory address. The array type syntax is TYPE[N] Where TYPE is one of types (u8/16/32/64,s8/16/32/64, x8/16/32/64, symbol, string) and N is a fixed value less than 64. The string array type is a bit different from other types. For other base types, [1] is equal to (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not equal to string. The string type itself represents "char array", but string array type represents "char * array". So, for example, +0(%di):string[1] is equal to +0(+0(%di)):string. Link: http://lkml.kernel.org/r/152465891533.26224.6150658225601339931.stgit@devbox Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: probeevent: Add symbol type

2018-10-11T02:19:10Z

Add "symbol" type to probeevent, which is an alias of u32 or u64 (depends on BITS_PER_LONG). This shows the result value in symbol+offset style. This type is only available with kprobe events. Link: http://lkml.kernel.org/r/152465882860.26224.14779072294412467338.stgit@devbox Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)