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-rw-r--r--tapsets.cxx111
1 files changed, 67 insertions, 44 deletions
diff --git a/tapsets.cxx b/tapsets.cxx
index 14031308..de80d3a2 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -38,6 +38,51 @@ extern "C" {
using namespace std;
+
+// XXX: should standardize to these functions throughout translator
+
+template <typename OUT, typename IN> inline OUT
+lex_cast(IN const & in)
+{
+ stringstream ss;
+ OUT out;
+ if (!(ss << in && ss >> out))
+ throw runtime_error("bad lexical cast");
+ return out;
+}
+
+template <typename OUT, typename IN> inline OUT
+lex_cast_hex(IN const & in)
+{
+ stringstream ss;
+ OUT out;
+ if (!(ss << hex << showbase << in && ss >> out))
+ throw runtime_error("bad lexical cast");
+ return out;
+}
+
+
+// return as quoted string, with at least '"' backslash-escaped
+template <typename IN> inline string
+lex_cast_qstring(IN const & in)
+{
+ stringstream ss;
+ string out, out2;
+ if (!(ss << in && ss >> out))
+ throw runtime_error("bad lexical cast");
+
+ out2 += '"';
+ for (unsigned i=0; i<out.length(); i++)
+ {
+ if (out[i] == '"') // XXX others?
+ out2 += '\\';
+ out2 += out[i];
+ }
+ out2 += '"';
+ return out2;
+}
+
+
// ------------------------------------------------------------------------
// begin/end probes are run right during registration / deregistration
// ------------------------------------------------------------------------
@@ -102,6 +147,8 @@ be_derived_probe::emit_probe_entries (translator_output* o, unsigned j)
// While begin/end probes are executed single-threaded, we
// still code defensively and use a per-cpu context.
o->newline(1) << "struct context* c = & contexts [smp_processor_id()];";
+ o->newline() << "const char* probe_point = "
+ << lex_cast_qstring(*l) << ";";
// A precondition for running a probe handler is that we're in STARTING
// or STOPPING state (not ERROR), and that no one else is already using
@@ -110,16 +157,15 @@ be_derived_probe::emit_probe_entries (translator_output* o, unsigned j)
if (begin) o->line() << "STAP_SESSION_STARTING)";
else o->line() << "STAP_SESSION_STOPPING)";
o->newline(1) << "return;";
- o->newline(-1) << "if (c->busy) {";
- o->newline(1) << "printk (KERN_ERR \"probe reentrancy\");";
+ o->newline(-1) << "if (atomic_inc_return (&c->busy) != 1) {";
+ o->newline(1) << "printk (KERN_ERR \"probe reentrancy (%s vs %s)\", "
+ << "c->probe_point, probe_point);";
o->newline() << "atomic_set (& session_state, STAP_SESSION_ERROR);";
o->newline() << "return;";
o->newline(-1) << "}";
o->newline();
-
- o->newline() << "c->busy ++;";
- o->newline() << "mb ();"; // for smp
o->newline() << "c->last_error = 0;";
+ o->newline() << "c->probe_point = probe_point;";
o->newline() << "c->nesting = 0;";
o->newline() << "c->regs = 0;";
o->newline() << "c->actioncount = 0;";
@@ -132,8 +178,7 @@ be_derived_probe::emit_probe_entries (translator_output* o, unsigned j)
o->newline() << "atomic_set (& session_state, STAP_SESSION_ERROR);";
o->newline(-1) << "}";
- o->newline() << "c->busy --;";
- o->newline() << "mb ();";
+ o->newline() << "atomic_dec (&c->busy);";
o->newline(-1) << "}" << endl;
}
}
@@ -156,27 +201,7 @@ static string TOK_LABEL("label");
static string TOK_RELATIVE("relative");
-// XXX: should standardize to these functions throughout translator
-template <typename OUT, typename IN> inline OUT
-lex_cast(IN const & in)
-{
- stringstream ss;
- OUT out;
- if (!(ss << in && ss >> out))
- throw runtime_error("bad lexical cast");
- return out;
-}
-
-template <typename OUT, typename IN> inline OUT
-lex_cast_hex(IN const & in)
-{
- stringstream ss;
- OUT out;
- if (!(ss << hex << showbase << in && ss >> out))
- throw runtime_error("bad lexical cast");
- return out;
-}
struct
func_info
@@ -1973,7 +1998,6 @@ dwarf_derived_probe::emit_deregistrations (translator_output* o, unsigned proben
void
dwarf_derived_probe::emit_probe_entries (translator_output* o, unsigned probenum)
{
-
// Construct a single entry function, and a struct kprobe pointing into
// the entry function. The entry function will call the probe function.
o->newline();
@@ -1985,22 +2009,23 @@ dwarf_derived_probe::emit_probe_entries (translator_output* o, unsigned probenum
o->line() << "struct kprobe *_ignored";
o->line() << ", struct pt_regs *regs) {";
o->newline(1) << "struct context *c = & contexts [smp_processor_id()];";
- o->newline();
+ o->newline() << "const char* probe_point = "
+ << lex_cast_qstring(*locations[0]) << ";";
// A precondition for running a probe handler is that we're in RUNNING
// state (not ERROR), and that no one else is already using this context.
o->newline() << "if (atomic_read (&session_state) != STAP_SESSION_RUNNING)";
o->newline(1) << "return 0;";
- o->newline(-1) << "if (c->busy) {";
- o->newline(1) << "printk (KERN_ERR \"probe reentrancy\");";
+ o->newline(-1) << "if (atomic_inc_return (&c->busy) != 1) {";
+ o->newline(1) << "printk (KERN_ERR \"probe reentrancy (%s vs %s)\", "
+ << "c->probe_point, probe_point);";
o->newline() << "atomic_set (& session_state, STAP_SESSION_ERROR);";
o->newline() << "return 0;";
o->newline(-1) << "}";
o->newline();
- o->newline() << "c->busy ++;";
- o->newline() << "mb ();"; // for smp
o->newline() << "c->last_error = 0;";
+ o->newline() << "c->probe_point = probe_point;";
o->newline() << "c->nesting = 0;";
o->newline() << "c->regs = regs;";
o->newline() << "c->actioncount = 0;";
@@ -2013,9 +2038,7 @@ dwarf_derived_probe::emit_probe_entries (translator_output* o, unsigned probenum
o->newline() << "atomic_set (& session_state, STAP_SESSION_ERROR);";
o->newline(-1) << "}";
- o->newline() << "c->busy --;";
- o->newline() << "mb ();";
-
+ o->newline() << "atomic_dec (& c->busy);";
o->newline() << "return 0;";
o->newline(-1) << "}" << endl;
@@ -2140,7 +2163,8 @@ timer_derived_probe::emit_probe_entries (translator_output* o, unsigned j)
o->newline() << "void enter_" << j << " (unsigned long val) {";
o->newline(1) << "struct context* c = & contexts [smp_processor_id()];";
-
+ o->newline() << "const char* probe_point = "
+ << lex_cast_qstring(*locations[0]) << ";";
o->newline() << "(void) val;";
// A precondition for running a probe handler is that we're in
@@ -2149,8 +2173,9 @@ timer_derived_probe::emit_probe_entries (translator_output* o, unsigned j)
o->newline() << "if (atomic_read (&session_state) != STAP_SESSION_RUNNING)";
o->newline(1) << "return;";
- o->newline(-1) << "if (c->busy) {";
- o->newline(1) << "printk (KERN_ERR \"probe reentrancy\");";
+ o->newline(-1) << "if (atomic_inc_return (&c->busy) != 1) {";
+ o->newline(1) << "printk (KERN_ERR \"probe reentrancy (%s vs %s)\", "
+ << "c->probe_point, probe_point);";
o->newline() << "atomic_set (& session_state, STAP_SESSION_ERROR);";
o->newline() << "return;";
o->newline(-1) << "}";
@@ -2162,11 +2187,10 @@ timer_derived_probe::emit_probe_entries (translator_output* o, unsigned j)
o->line() << " + _stp_random_pm(" << randomize << ")";
o->line() << ");";
- o->newline() << "c->busy ++;";
- o->newline() << "mb ();"; // for smp
+ o->newline() << "c->probe_point = probe_point;";
o->newline() << "c->last_error = 0;";
o->newline() << "c->nesting = 0;";
- o->newline() << "if (! in_interrupt())";
+ o->newline() << "if (in_interrupt())";
o->newline(1) << "c->regs = 0;";
o->newline(-1) << "else";
o->newline(1) << "c->regs = task_pt_regs (current);";
@@ -2181,8 +2205,7 @@ timer_derived_probe::emit_probe_entries (translator_output* o, unsigned j)
o->newline() << "atomic_set (& session_state, STAP_SESSION_ERROR);";
o->newline(-1) << "}";
- o->newline() << "c->busy --;";
- o->newline() << "mb ();";
+ o->newline() << "atomic_dec (&c->busy);";
o->newline(-1) << "}" << endl;
}
generated by cgit (git 2.34.1) at 2025-08-05 01:02:04 +0000