From b2b336288ce9e92a21efe7dcd314f604bc97be29 Mon Sep 17 00:00:00 2001
From: Mark Wielaard <mjw@redhat.com>
Date: Thu, 2 Apr 2009 18:42:38 +0200
Subject: PR6580: Implement symname, symdata and modname context functions.

This adds a couple of the suggested context/stack revamp functions
from PR6580. In particular it replaces the symbolname() function that
sneaked in with the pr6866 branch merge with the suggested symname().

* runtime/sym.c (_stp_mod_sec_lookup): Make section optional.
  (_stp_symbol_snprint): Provide a way to get optional module info.
* tapset/context-symbols.stp: Replace symbolname() with symname(),
  add modname() and symdata().
  (probemod): Implement pc based fallback.
* tapset/context-unwind.stp (caller): Adjust for _stp_symbol_snprint
  change.
* testsuite/systemtap.context/usymbols.exp: Use new symname.
* testsuite/buildok/modname.stp: New test.
* testsuite/buildok/symdata.stp: Likewise.
* testsuite/buildok/symname.stp: Likewise.
---
 tapset/context-symbols.stp | 60 ++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 53 insertions(+), 7 deletions(-)

(limited to 'tapset/context-symbols.stp')

diff --git a/tapset/context-symbols.stp b/tapset/context-symbols.stp
index 4c200aa8..66d9fea2 100644
--- a/tapset/context-symbols.stp
+++ b/tapset/context-symbols.stp
@@ -66,7 +66,7 @@ function probefunc:string () %{ /* pure */
 #else
 		((unsigned long)REG_IP(CONTEXT->regs) >= (unsigned long)PAGE_OFFSET)) {
 #endif
-		_stp_symbol_snprint(THIS->__retvalue, MAXSTRINGLEN, REG_IP(CONTEXT->regs), current);
+		_stp_symbol_snprint(THIS->__retvalue, MAXSTRINGLEN, REG_IP(CONTEXT->regs), current, 0);
        	         if (THIS->__retvalue[0] == '.')  /* powerpc symbol has a dot*/
        	         	strlcpy(THIS->__retvalue,THIS->__retvalue + 1,MAXSTRINGLEN);
 	} else {
@@ -89,13 +89,59 @@ function probemod:string () %{ /* pure */
 		while (*ptr != '"' && --len && *ptr)
 			*dst++ = *ptr++;
 		*dst = 0;
-	} else {
-		/* XXX: need a PC- and symbol-table-based fallback. */
-		THIS->__retvalue[0] = '\0';
-	}
+	} else if (CONTEXT->regs) {
+		struct _stp_module *m;
+		m = _stp_mod_sec_lookup (REG_IP(CONTEXT->regs), current, NULL);
+		if (m && m->name)
+			strlcpy (THIS->__retvalue, m->name, MAXSTRINGLEN);
+		else
+			strlcpy (THIS->__retvalue, "<unknown>", MAXSTRINGLEN);
+	} else
+		strlcpy (THIS->__retvalue, "<unknown>", MAXSTRINGLEN);
 %}
 
-function symbolname:string (addr:long) %{ /* pure */
+/**
+ * sfunction modname - Return the kernel module name loaded at the address.
+ * @addr: The address.
+ *
+ * Description: Returns the module name associated with the given
+ * address if known. If not known it will return the string "<unknown>".
+ * If the address was not in a kernel module, but in the kernel itself,
+ * then the string "kernel" will be returned.
+ */
+function modname:string (addr: long) %{ /* pure */
+	struct _stp_module *m;
+	m = _stp_mod_sec_lookup (THIS->addr, current, NULL);
+	if (m && m->name)
+          strlcpy (THIS->__retvalue, m->name, MAXSTRINGLEN);
+	else
+	  strlcpy (THIS->__retvalue, "<unknown>", MAXSTRINGLEN);
+%}
+
+/**
+ * sfunction symname - Return the symbol associated with the given address.
+ * @addr: The address to translate.
+ *
+ * Description: Returns the (function) symbol name associated with the
+ * given address if known. If not known it will return the hex string
+ * representation of addr.
+ */
+function symname:string (addr: long) %{ /* pure */
+	 _stp_symbol_snprint(THIS->__retvalue, MAXSTRINGLEN, THIS->addr,
+			     current, 0);
+%}
+
+/**
+ * sfunction symdata - Return the symbol and module offset for the address.
+ * @addr: The address to translate.
+ *
+ * Description: Returns the (function) symbol name associated with the
+ * given address if known, plus the module name (between brackets) and
+ * the offset inside the module, plus the size of the symbol function.
+ * If any element is not known it will be ommitted and if the symbol name
+ * is unknown it will return the hex string for the given address.
+ */
+function symdata:string (addr: long) %{ /* pure */
 	 _stp_symbol_snprint(THIS->__retvalue, MAXSTRINGLEN, THIS->addr,
-	                     current);
+			     current, 1);
 %}
-- 
cgit