From: Tom de Vries <tdevries@suse.de>
Date: Thu, 17 Jan 2019 00:08:05 +0000 (+0000)
Subject: [libbacktrace] Handle DW_FORM_GNU_strp_alt
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f2f00d3a04533afd3d02e29bb28afb5203de9078;p=gcc.git

[libbacktrace] Handle DW_FORM_GNU_strp_alt

Handle DW_FORM_GNU_strp_alt which references the .debug_str section in the
.gnu_debugaltlink file.

2019-01-17  Tom de Vries  <tdevries@suse.de>

	PR libbacktrace/82857
	* dwarf.c (read_attribute): Handle DW_FORM_GNU_strp_alt
	using altlink.

From-SVN: r267996
---

diff --git a/libbacktrace/ChangeLog b/libbacktrace/ChangeLog
index fb8aebe95c1..458f16c9870 100644
--- a/libbacktrace/ChangeLog
+++ b/libbacktrace/ChangeLog
@@ -1,3 +1,9 @@
+2019-01-17  Tom de Vries  <tdevries@suse.de>
+
+	PR libbacktrace/82857
+	* dwarf.c (read_attribute): Handle DW_FORM_GNU_strp_alt
+	using altlink.
+
 2019-01-17  Tom de Vries  <tdevries@suse.de>
 
 	* dwarf.c (enum attr_val_encoding): Add ATTR_VAL_NONE.
diff --git a/libbacktrace/dwarf.c b/libbacktrace/dwarf.c
index 4cae5b4f4a3..45691b4ba69 100644
--- a/libbacktrace/dwarf.c
+++ b/libbacktrace/dwarf.c
@@ -843,14 +843,23 @@ read_attribute (enum dwarf_form form, struct dwarf_buf *buf,
       val->encoding = ATTR_VAL_REF_SECTION;
       return 1;
     case DW_FORM_GNU_strp_alt:
-      val->u.uint = read_offset (buf, is_dwarf64);
-      if (altlink == NULL)
-	{
-	  val->encoding = ATTR_VAL_NONE;
-	  return 1;
-	}
-      val->encoding = ATTR_VAL_REF_SECTION;
-      return 1;
+      {
+	uint64_t offset;
+	offset = read_offset (buf, is_dwarf64);
+	if (altlink == NULL)
+	  {
+	    val->encoding = ATTR_VAL_NONE;
+	    return 1;
+	  }
+	if (offset >= altlink->dwarf_str_size)
+	  {
+	    dwarf_buf_error (buf, "DW_FORM_GNU_strp_alt out of range");
+	    return 0;
+	  }
+	val->encoding = ATTR_VAL_STRING;
+	val->u.string = (const char *) altlink->dwarf_str + offset;
+	return 1;
+      }
     default:
       dwarf_buf_error (buf, "unrecognized DWARF form");
       return 0;