perf probe: Do not depend on dwfl_module_addrsym()

Do not depend on dwfl_module_addrsym() because it can fail on user-space
shared libraries.

Actually, same bug was fixed by commit 664fee3 ("perf probe: Do not
use dwfl_module_addrsym if dwarf_diename finds symbol name"), but commit
07d3698 ("perf probe: Fix wrong address verification) reverted to
get actual symbol address from symtab.

This fixes it again by getting symbol address from DIE, and only if the
DIE has only address range, it uses dwfl_module_addrsym().

Fixes: 07d3698 ("perf probe: Fix wrong address verification)
Reported-by: Alexandre Ghiti <[email protected]>
Signed-off-by: Masami Hiramatsu <[email protected]>
Tested-by: Alexandre Ghiti <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sasha Levin <[email protected]>
Link: http://lore.kernel.org/lkml/158281812176.476.14164573830975116234.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: mhiramat

tools/perf/util/probe-finder.c

@@ -637,14 +637,19 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
 		return -EINVAL;
 	}
 
-	/* Try to get actual symbol name from symtab */
-	symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
+	if (dwarf_entrypc(sp_die, &eaddr) == 0) {
+		/* If the DIE has entrypc, use it. */
+		symbol = dwarf_diename(sp_die);
+	} else {
+		/* Try to get actual symbol name and address from symtab */
+		symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
+		eaddr = sym.st_value;
+	}
 	if (!symbol) {
 		pr_warning("Failed to find symbol at 0x%lx\n",
 			   (unsigned long)paddr);
 		return -ENOENT;
 	}
-	eaddr = sym.st_value;
 
 	tp->offset = (unsigned long)(paddr - eaddr);
 	tp->address = (unsigned long)paddr;