dwarflint: Validate DW_AT_{low,high}_pc for consistent relocation

diff --git a/src/dwarflint.c b/src/dwarflint.c
index 5e3efc2e9684499a3743d00c59b97b7f31ab5d3b..9e197db778d0ec3da1b93b691f9f80f615ab24fb 100644 (file)
--- a/src/dwarflint.c
+++ b/src/dwarflint.c
@@ -2955,6 +2955,11 @@ read_die_chain (struct read_ctx *ctx,
 
       addr_record_add (&cu->die_addrs, cu->offset + die_off);
 
+      uint64_t low_pc = (uint64_t)-1, high_pc = (uint64_t)-1;
+      bool low_pc_relocated = false, high_pc_relocated = false;
+      GElf_Sym low_pc_symbol_mem, *low_pc_symbol = &low_pc_symbol_mem;
+      GElf_Sym high_pc_symbol_mem, *high_pc_symbol = &high_pc_symbol_mem;
+
       /* Attribute values.  */
       for (struct abbrev_attrib *it = abbrev->attribs;
           it->name != 0; ++it)
@@ -3176,10 +3181,32 @@ read_die_chain (struct read_ctx *ctx,
                if (!read_ctx_read_offset (ctx, addr_64, &addr))
                  goto cant_read;
 
+               uint64_t *addrp = NULL;
+               bool *relocatedp = NULL;
+               GElf_Sym **symbolp = NULL;
+
+               switch (it->name)
+                 {
+                 case DW_AT_low_pc:
+                   relocatedp = &low_pc_relocated;
+                   symbolp = &low_pc_symbol;
+                   addrp = &low_pc;
+                   break;
+
+                 case DW_AT_high_pc:
+                   relocatedp = &high_pc_relocated;
+                   symbolp = &high_pc_symbol;
+                   addrp = &high_pc;
+                 };
+
                if ((rel = relocation_next (reloc, ctx_offset,
                                            &where, skip_mismatched)))
-                 relocate_one (reloc, rel, addr_64 ? 8 : 4, &addr, &where,
-                               reloc_target (form, it), NULL);
+                 {
+                   relocate_one (reloc, rel, addr_64 ? 8 : 4, &addr, &where,
+                                 reloc_target (form, it), symbolp);
+                   *relocatedp = true;
+                   *addrp = addr;
+                 }
                else if (type_is_rel && addr != 0)
                  /* In non-rel files, neither addr, nor ref_addr
                     /need/ a relocation.  We at least check that
@@ -3190,9 +3217,10 @@ read_die_chain (struct read_ctx *ctx,
 
                if (form == DW_FORM_ref_addr)
                  record_ref (addr, &where, false);
-               else if ((abbrev->tag == DW_TAG_compile_unit
-                         || abbrev->tag == DW_TAG_partial_unit)
-                        && it->name == DW_AT_low_pc)
+
+               if (it->name == DW_AT_low_pc
+                   && (abbrev->tag == DW_TAG_compile_unit
+                       || abbrev->tag == DW_TAG_partial_unit))
                  cu->base = addr;
 
                break;
@@ -3366,9 +3394,22 @@ read_die_chain (struct read_ctx *ctx,
 
            default:
              wr_error (&where,
-                       ": internal error: unhandled form 0x%x\n", form);
+                       ": internal error: unhandled form 0x%x.\n", form);
            }
        }
+      where.ref = NULL;
+
+      if (high_pc != (uint64_t)-1 && low_pc != (uint64_t)-1)
+       {
+         if (high_pc_relocated != low_pc_relocated)
+           wr_message (mc_die_other | mc_impact_2 | mc_reloc, &where,
+                       ": only one of DW_AT_low_pc and DW_AT_high_pc is relocated.\n");
+         else
+           check_range_relocations (mc_die_other, &where,
+                                    file,
+                                    low_pc_symbol, high_pc_symbol,
+                                    "DW_AT_low_pc and DW_AT_high_pc");
+       }
 
       where.ref = &abbrev->where;