diff options
| -rw-r--r-- | runtime/uprobes2/uprobes.c | 3 | ||||
| -rw-r--r-- | stapprobes.3stap.in | 42 |
2 files changed, 37 insertions, 8 deletions
diff --git a/runtime/uprobes2/uprobes.c b/runtime/uprobes2/uprobes.c index 9ea05349..07ad3984 100644 --- a/runtime/uprobes2/uprobes.c +++ b/runtime/uprobes2/uprobes.c @@ -2239,7 +2239,8 @@ static u32 uprobe_report_exit(enum utrace_resume_action action, } } up_read(&uproc->rwsem); - if (utask->state == UPTASK_TRAMPOLINE_HIT) + if (utask->state == UPTASK_TRAMPOLINE_HIT || + utask->state == UPTASK_BP_HIT) uprobe_decref_process(uproc); } diff --git a/stapprobes.3stap.in b/stapprobes.3stap.in index e60a8fe4..b3066611 100644 --- a/stapprobes.3stap.in +++ b/stapprobes.3stap.in @@ -412,10 +412,14 @@ contain wildcards, or the probe will not be registered. Also, statement probes must be run under guru-mode only. - .SS USER-SPACE -Early prototype support for user-space probing is available in the -form of a non-symbolic probe point: +Support for user-space probing is available for kernels +that are configured with the utrace extensions. See +.SAMPLE +http://people.redhat.com/roland/utrace/ +.ESAMPLE +.PP +There are several forms. First, a non-symbolic probe point: .SAMPLE process(PID).statement(ADDRESS).absolute .ESAMPLE @@ -427,7 +431,8 @@ no $variables. The target PID parameter must identify a running process, and ADDRESS should identify a valid instruction address. All threads of that process will be probed. .PP -Additional user-space probing is available in the following forms: +Second, non-symbolic user-kernel interface events handled by +utrace may be probed: .SAMPLE process(PID).begin process("PATH").begin @@ -451,7 +456,6 @@ process(PID).insn process("PATH").insn process(PID).insn.block process("PATH").insn.block -process("PATH").mark("LABEL") .ESAMPLE .PP A @@ -490,6 +494,15 @@ probe gets called for every single-stepped instruction of the process described A .B .insn.block probe gets called for every block-stepped instruction of the process described by PID or PATH. + +.PP +Third, symbolic static instrumentation compiled into programs and +shared libraries may be +probed: +.SAMPLE +process("PATH").mark("LABEL") +.ESAMPLE +.PP A .B .mark probe gets called via a static probe which is defined in the @@ -501,14 +514,29 @@ for probes with 2 arguments, and so on. The arguments of the probe are available in the context variables $arg1, $arg2, ... An alternative to using the STAP_PROBE macros is to use the dtrace script to create custom macros. + .PP -Note that +Finally, full symbolic source-level probes in user-space programs +and shared libraries are supported. These are exactly analogous +to the symbolic DWARF-based kernel/module probes described above, +and expose similar contextual $-variables. +.SAMPLE +process("PATH").function("NAME") +process("PATH").statement("*@FILE.c:123") +process("PATH").function("*").return +process("PATH").function("myfun").label("foo") +.ESAMPLE + +.PP +Note that for all process probes, .I PATH names refer to executables that are searched the same way shells do: relative to the working directory if they contain a "/" character, otherwise in .BR $PATH . If a process probe is specified without a PID or PATH, all user -threads are probed. +threads are probed. PATH may sometimes name a shared library +in which case all processes that map that shared library may be +probed. .SS PROCFS |