Warn if some location seems to lack a relocation

diff --git a/src/dwarflint.c b/src/dwarflint.c
index 335180c80f1d17f540eb335efe79b1b0d13715ac..17939c68bf4b5eb6ade609767fc73a744c327750 100644 (file)
--- a/src/dwarflint.c
+++ b/src/dwarflint.c
@@ -390,6 +390,7 @@ parse_opt (int key, char *arg __attribute__ ((unused)),
 #define PRI_CU "CU 0x%" PRIx64
 #define PRI_DIE "DIE 0x%" PRIx64
 #define PRI_NOT_ENOUGH ": not enough data for %s.\n"
+#define PRI_LACK_RELOCATION ": seems to lack a relocation.\n"
 
 struct sec
 {
@@ -2787,7 +2788,8 @@ read_die_chain (struct read_ctx *ctx,
          uint64_t offset = read_ctx_get_offset (ctx) + cu->offset;
          GElf_Rela rela_mem, *rela = NULL;
          Elf *elf = file->dwarf->elf;
-         //printf ("Datum @%#" PRIx64 ", form %s.\n", offset, dwarf_form_string (form));
+         bool type_is_rel = file->ehdr.e_type == ET_REL;
+
          switch (form)
            {
            case DW_FORM_strp:
@@ -2804,6 +2806,9 @@ read_die_chain (struct read_ctx *ctx,
                                             &where, skip_mismatched)))
                  relocate_one (reloc, rela, elf, file->ebl, dwarf_64 ? 8 : 4,
                                &addr, &where, sec_str, NULL);
+               else if (type_is_rel)
+                 wr_message (mc_impact_2 | mc_die_other | mc_reloc | mc_strings,
+                             &where, PRI_LACK_RELOCATION);
 
                if (strings == NULL)
                  wr_error (&where,
@@ -2848,7 +2853,11 @@ read_die_chain (struct read_ctx *ctx,
                                             &where, skip_mismatched)))
                  relocate_one (reloc, rela, elf, file->ebl, addr_64 ? 8 : 4,
                                &addr, &where, reloc_target (form, it), NULL);
-               /* XXX complain if no reloc.  */
+               else if ((type_is_rel
+                         || form == DW_FORM_ref_addr)
+                        && addr != 0)
+                 wr_message (mc_impact_2 | mc_die_rel | mc_reloc, &where,
+                             PRI_LACK_RELOCATION);
 
                if (form == DW_FORM_ref_addr)
                  record_ref (addr, &where, false);
@@ -2879,16 +2888,11 @@ read_die_chain (struct read_ctx *ctx,
            case DW_FORM_data1:
            case DW_FORM_ref1:
              {
-               uint8_t raw_value;
-               if (!read_ctx_read_ubyte (ctx, &raw_value))
+               /* Neither of these should be relocated.  */
+               uint8_t value;
+               if (!read_ctx_read_ubyte (ctx, &value))
                  goto cant_read;
 
-               uint64_t value = raw_value;
-               if ((rela = relocation_next (reloc, offset, &rela_mem,
-                                            &where, skip_mismatched)))
-                 relocate_one (reloc, rela, elf, file->ebl, 1,
-                               &value, &where, reloc_target (form, it), NULL);
-
                if (it->name == DW_AT_sibling)
                  sibling_addr = value;
                else if (form == DW_FORM_ref1)
@@ -2899,16 +2903,11 @@ read_die_chain (struct read_ctx *ctx,
            case DW_FORM_data2:
            case DW_FORM_ref2:
              {
-               uint16_t raw_value;
-               if (!read_ctx_read_2ubyte (ctx, &raw_value))
+               /* Neither of these should be relocated.  */
+               uint16_t value;
+               if (!read_ctx_read_2ubyte (ctx, &value))
                  goto cant_read;
 
-               uint64_t value = raw_value;
-               if ((rela = relocation_next (reloc, offset, &rela_mem,
-                                            &where, skip_mismatched)))
-                 relocate_one (reloc, rela, elf, file->ebl, 2,
-                               &value, &where, reloc_target (form, it), NULL);
-
                if (it->name == DW_AT_sibling)
                  sibling_addr = value;
                else if (form == DW_FORM_ref2)
@@ -2923,17 +2922,26 @@ read_die_chain (struct read_ctx *ctx,
                if (!read_ctx_read_4ubyte (ctx, &raw_value))
                  goto cant_read;
 
+               /* DW_FORM_ref4 shouldn't be relocated.  */
                uint64_t value = raw_value;
-               if ((rela = relocation_next (reloc, offset, &rela_mem,
-                                            &where, skip_mismatched)))
-                 relocate_one (reloc, rela, elf, file->ebl, 4,
-                               &value, &where, reloc_target (form, it), NULL);
+               if (form == DW_FORM_data4)
+                 {
+                   if ((rela = relocation_next (reloc, offset, &rela_mem,
+                                                &where, skip_mismatched)))
+                     relocate_one (reloc, rela, elf, file->ebl, 4,
+                                   &value, &where, reloc_target (form, it), NULL);
+                   else if (type_is_rel
+                            && (check_locptr || check_rangeptr))
+                     wr_message (mc_impact_2 | mc_die_other | mc_reloc
+                                 | (check_rangeptr ? mc_ranges : mc_loc),
+                                 &where, PRI_LACK_RELOCATION);
+                 }
 
                if (it->name == DW_AT_sibling)
                  sibling_addr = value;
                else if (check_locptr || check_rangeptr)
                  {
-                   if (check_rangeptr && (value % cu->address_size != 0))
+                   if (check_rangeptr && ((value % cu->address_size) != 0))
                      wr_message (mc_ranges | mc_impact_2, &where,
                                  ": rangeptr value %#" PRIx64
                                  " not aligned to CU address size.\n",
@@ -2954,10 +2962,20 @@ read_die_chain (struct read_ctx *ctx,
                uint64_t value;
                if (!read_ctx_read_8ubyte (ctx, &value))
                  goto cant_read;
-               if ((rela = relocation_next (reloc, offset, &rela_mem,
-                                            &where, skip_mismatched)))
-                 relocate_one (reloc, rela, elf, file->ebl, 8,
-                               &value, &where, reloc_target (form, it), NULL);
+
+               /* DW_FORM_ref8 shouldn't be relocated.  */
+               if (form == DW_FORM_data8)
+                 {
+                   if ((rela = relocation_next (reloc, offset, &rela_mem,
+                                                &where, skip_mismatched)))
+                     relocate_one (reloc, rela, elf, file->ebl, 8,
+                                   &value, &where, reloc_target (form, it), NULL);
+                   else if (type_is_rel
+                            && (check_locptr || check_rangeptr))
+                     wr_message (mc_impact_2 | mc_die_other | mc_reloc
+                                 | (check_rangeptr ? mc_ranges : mc_loc),
+                                 &where, PRI_LACK_RELOCATION);
+                 }
 
                if (it->name == DW_AT_sibling)
                  sibling_addr = value;
@@ -3052,13 +3070,13 @@ read_die_chain (struct read_ctx *ctx,
          else if (st == 0)
            wr_message (mc_impact_3 | mc_acc_suboptimal | mc_die_rel,
                        &where,
-                       ": Abbrev has_children, but the chain was empty.\n");
+                       ": abbrev has_children, but the chain was empty.\n");
        }
     }
 
   if (sibling_addr != 0)
     wr_error (&where,
-             ": This DIE should have had its sibling at 0x%"
+             ": this DIE should have had its sibling at 0x%"
              PRIx64 ", but the DIE chain ended.\n", sibling_addr);
 
   return got_die ? 1 : 0;
@@ -3096,6 +3114,9 @@ check_cu_structural (struct read_ctx *ctx,
                               &cu->where, skip_mismatched)))
     relocate_one (reloc, rela, file->dwarf->elf, file->ebl, dwarf_64 ? 8 : 4,
                  &abbrev_offset, &cu->where, sec_abbrev, NULL);
+  else if (file->ehdr.e_type == ET_REL)
+    wr_message (mc_impact_2 | mc_info | mc_reloc, &cu->where,
+               PRI_LACK_RELOCATION);
 
   /* Address size.  */
   if (!read_ctx_read_ubyte (ctx, &address_size))