diff options
| -rw-r--r-- | ChangeLog | 10 | ||||
| -rw-r--r-- | NEWS | 2 | ||||
| -rw-r--r-- | stapprobes.5.in | 7 | ||||
| -rw-r--r-- | tapset/ChangeLog | 4 | ||||
| -rw-r--r-- | tapset/utrace.stp | 4 | ||||
| -rw-r--r-- | tapsets.cxx | 32 |
6 files changed, 47 insertions, 12 deletions
@@ -1,5 +1,15 @@ 2008-09-09 Masami Hiramatsu <mhiramat@redhat.com> + * stapprobes.5.in: Added a description about $return. + * NEWS: Ditto. + * tapsets.cxx (utrace_var_expanding_copy_visitor): Change + visit_target_symbol_syscall() to visit_target_symbol_context(). + (utrace_var_expanding_copy_visitor::visit_target_symbol_context): + Handle not only $syscall but also $return. + (utrace_var_expanding_copy_visitor::visit_target_symbol): Ditto. + +2008-09-09 Masami Hiramatsu <mhiramat@redhat.com> + * stapprobes.5.in: Added a description about $argN. * NEWS: Ditto. * tapsets.cxx (utrace_var_expanding_copy_visitor): Added @@ -3,6 +3,8 @@ - Additional context variables are available on user-space syscall probes. - $argN ($arg1, $arg2, ... $arg6) in process(PATH_OR_PID).syscall gives you the argument of the system call. + - $return in process(PATH_OR_PID).syscall.return gives you the return + value of the system call. - Target process mode (stap -c CMD or -x PID) now implicitly restricts all "process.*" probes to the given child process. (It does not affect diff --git a/stapprobes.5.in b/stapprobes.5.in index 6e8c3ff2..36b36156 100644 --- a/stapprobes.5.in +++ b/stapprobes.5.in @@ -427,11 +427,14 @@ context variable, and the first 6 arguments of the system call are available in the .BR $argN (ex. $arg1, $arg2, ...) context variable. - A .B .syscall.return probe gets called when a thread described by PID or PATH returns from a -system call. The system call number is available in the "$syscall" +system call. The system call number is available in the +.BR $syscall +context variable, and the return value of the system call is available +in the +.BR $return context variable. A .B .itrace diff --git a/tapset/ChangeLog b/tapset/ChangeLog index 5a08ac63..3e2ebaf7 100644 --- a/tapset/ChangeLog +++ b/tapset/ChangeLog @@ -1,5 +1,9 @@ 2008-09-09 Masami Hiramatsu <mhiramat@redhat.com> + * utrace.stp: Added _utrace_syscall_return(). + +2008-09-09 Masami Hiramatsu <mhiramat@redhat.com> + * utrace.stp: Added _utrace_syscall_arg(). 2008-09-09 Masami Hiramatsu <mhiramat@redhat.com> diff --git a/tapset/utrace.stp b/tapset/utrace.stp index 2b661573..34cb32c5 100644 --- a/tapset/utrace.stp +++ b/tapset/utrace.stp @@ -12,3 +12,7 @@ function _utrace_syscall_nr:long () %{ function _utrace_syscall_arg:long (n:long) %{ THIS->__retvalue = *__stp_user_syscall_arg(current, CONTEXT->regs, (int)THIS->n); /* pure */ %} + +function _utrace_syscall_return:long () %{ + THIS->__retvalue = *__stp_user_syscall_return_value(current, CONTEXT->regs); /* pure */ +%} diff --git a/tapsets.cxx b/tapsets.cxx index 5941339c..28f945fe 100644 --- a/tapsets.cxx +++ b/tapsets.cxx @@ -5847,7 +5847,7 @@ struct utrace_var_expanding_copy_visitor: public var_expanding_copy_visitor bool target_symbol_seen; void visit_target_symbol_arg (target_symbol* e); - void visit_target_symbol_syscall (target_symbol* e); + void visit_target_symbol_context (target_symbol* e); void visit_target_symbol (target_symbol* e); }; @@ -5978,22 +5978,24 @@ utrace_var_expanding_copy_visitor::visit_target_symbol_arg (target_symbol* e) } void -utrace_var_expanding_copy_visitor::visit_target_symbol_syscall (target_symbol* e) +utrace_var_expanding_copy_visitor::visit_target_symbol_context (target_symbol* e) { + string sname = e->base_name; + if (e->components.size() > 0) { switch (e->components[0].first) { case target_symbol::comp_literal_array_index: - throw semantic_error("utrace target variable '$syscall' may not be used as array", + throw semantic_error("utrace target variable '" + sname + "' may not be used as array", e->tok); break; case target_symbol::comp_struct_member: - throw semantic_error("utrace target variable '$syscall' may not be used as a structure", + throw semantic_error("utrace target variable '" + sname + "' may not be used as a structure", e->tok); break; default: - throw semantic_error ("invalid use of utrace target variable '$syscall'", + throw semantic_error ("invalid use of utrace target variable '" + sname + "'", e->tok); break; } @@ -6001,7 +6003,17 @@ utrace_var_expanding_copy_visitor::visit_target_symbol_syscall (target_symbol* e bool lvalue = is_active_lvalue(e); if (lvalue) - throw semantic_error("utrace '$syscall' variable is read-only", e->tok); + throw semantic_error("utrace '" + sname + "' variable is read-only", e->tok); + + string fname; + if (sname == "$return") + { + if (flags != UDPF_SYSCALL_RETURN) + throw semantic_error ("only \"process(PATH_OR_PID).syscall.return\" support $return.", e->tok); + fname = "_utrace_syscall_return"; + } + else + fname = "_utrace_syscall_nr"; // Remember that we've seen a target variable. target_symbol_seen = true; @@ -6010,7 +6022,7 @@ utrace_var_expanding_copy_visitor::visit_target_symbol_syscall (target_symbol* e // function call for the '$syscall' reference. functioncall* n = new functioncall; n->tok = e->tok; - n->function = "_utrace_syscall_nr"; + n->function = fname; n->referent = 0; // NB: must not resolve yet, to ensure inclusion in session provide <functioncall*> (this, n); @@ -6027,10 +6039,10 @@ utrace_var_expanding_copy_visitor::visit_target_symbol (target_symbol* e) if (e->base_name.substr(0,4) == "$arg") visit_target_symbol_arg(e); - else if (e->base_name == "$syscall") - visit_target_symbol_syscall(e); + else if (e->base_name == "$syscall" || e->base_name == "$return") + visit_target_symbol_context(e); else - throw semantic_error ("invalid target symbol for utrace probe, $syscall or $argN expected", + throw semantic_error ("invalid target symbol for utrace probe, $syscall, $return or $argN expected", e->tok); } |