Problems solved on for libtcc, pie, riscv64, arm64

I found some problems with a testcase from mailing list.

On x86_64 an overflow on reloc R_X86_64_32 occurred that was
not reported when using -run -ltcc.
The problem could be solved by compiling tcc with -fPIE, -pie
or --disable-static.

Makefile, configure, libtcc.c, x86_64-link.c:
- add --config-pie to configure help. Ignore -pie in libtcc.c
  and check reloc overflow in x86_64-link.c

arm64-gen.c:
- Fix reading from constant like '*(int *)0x7fffb7f1280c'

elf.h, riscv64-link.c:
- fix for -run -ltcc. Ignore reloc R_RISCV_SET_ULEB128 and
  R_RISCV_SUB_ULEB128 that are used in .debug_loclists section.

Author: hermantb

Makefile

@@ -24,6 +24,11 @@ CFLAGS += $(CPPFLAGS)
 VPATH = $(TOPSRC)
 -LTCC = $(TOP)/$(LIBTCC)
 
+ifeq ($(CONFIG_pie),yes)
+CFLAGS += -fPIE
+LDFLAGS += -pie
+endif
+
 ifdef CONFIG_WIN32
  CFG = -win
  ifneq ($(CONFIG_static),yes)

arm64-gen.c

@@ -503,17 +503,19 @@ ST_FUNC void load(int r, SValue *sv)
     }
 
     if (svr == (VT_CONST | VT_LVAL)) {
+	uint64_t i = sv->c.i;
+
 	if (sv->sym)
             arm64_sym(30, sv->sym, // use x30 for address
-	              arm64_check_offset(0, arm64_type_size(svtt), sv->c.i));
+	              arm64_check_offset(0, arm64_type_size(svtt), i));
 	else
-	    arm64_movimm (30, sv->c.i);
+	    arm64_movimm (30, i), i = 0;
         if (IS_FREG(r))
             arm64_ldrv(arm64_type_size(svtt), fltr(r), 30,
-		       arm64_check_offset(1, arm64_type_size(svtt), sv->c.i));
+		       arm64_check_offset(1, arm64_type_size(svtt), i));
         else
             arm64_ldrx(!(svtt&VT_UNSIGNED), arm64_type_size(svtt), intr(r), 30,
-		       arm64_check_offset(1, arm64_type_size(svtt), sv->c.i));
+		       arm64_check_offset(1, arm64_type_size(svtt), i));
         return;
     }
 
@@ -621,17 +623,19 @@ ST_FUNC void store(int r, SValue *sv)
     }
 
     if (svr == (VT_CONST | VT_LVAL)) {
+	uint64_t i = sv->c.i;
+
 	if (sv->sym)
             arm64_sym(30, sv->sym, // use x30 for address
-		      arm64_check_offset(0, arm64_type_size(svtt), sv->c.i));
+		      arm64_check_offset(0, arm64_type_size(svtt), i));
 	else
-	    arm64_movimm (30, sv->c.i);
+	    arm64_movimm (30, i), i = 0;
         if (IS_FREG(r))
             arm64_strv(arm64_type_size(svtt), fltr(r), 30,
-		       arm64_check_offset(1, arm64_type_size(svtt), sv->c.i));
+		       arm64_check_offset(1, arm64_type_size(svtt), i));
         else
             arm64_strx(arm64_type_size(svtt), intr(r), 30,
-		       arm64_check_offset(1, arm64_type_size(svtt), sv->c.i));
+		       arm64_check_offset(1, arm64_type_size(svtt), i));
         return;
     }
 

configure

@@ -230,6 +230,7 @@ Advanced options (experts only):
   --config-new_dtags=yes   use new ELF DTAGs (DT_RUNPATH instead of DT_RPATH)
   --config-codesign=no     do not use codesign on apple to sign executables
   --config-dwarf=x         use dwarf debug info instead of stabs (x=2..5)
+  --config-pie             compile with pie
 
 Cross build options (experimental):
   --cpu=CPU                target CPU [$cpu]

elf.h

@@ -3313,8 +3313,12 @@ typedef Elf32_Addr Elf32_Conflict;
 #define R_RISCV_SET16		55
 #define R_RISCV_SET32		56
 #define R_RISCV_32_PCREL	57
+#define R_RISCV_IRELATIVE	58
+#define R_RISCV_PLT32		59
+#define R_RISCV_SET_ULEB128	60
+#define R_RISCV_SUB_ULEB128	61
 
-#define R_RISCV_NUM		58
+#define R_RISCV_NUM		62
 
 
 #endif	/* elf.h */

libtcc.c

@@ -1674,6 +1674,7 @@ static const TCCOption tcc_options[] = {
     { "C", 0, 0 },
     { "-param", 0, TCC_OPTION_HAS_ARG },
     { "pedantic", 0, 0 },
+    { "pie", 0, 0 },
     { "pipe", 0, 0 },
     { "s", 0, 0 },
     { "traditional", 0, 0 },

riscv64-link.c

@@ -51,6 +51,8 @@ ST_FUNC int code_reloc (int reloc_type)
     case R_RISCV_SUB64:
     case R_RISCV_32:
     case R_RISCV_64:
+    case R_RISCV_SET_ULEB128:
+    case R_RISCV_SUB_ULEB128:
         return 0;
 
     case R_RISCV_CALL_PLT:
@@ -77,6 +79,8 @@ ST_FUNC int gotplt_entry_type (int reloc_type)
     case R_RISCV_ADD16:
     case R_RISCV_SUB8:
     case R_RISCV_SUB16:
+    case R_RISCV_SET_ULEB128:
+    case R_RISCV_SUB_ULEB128:
         return NO_GOTPLT_ENTRY;
 
     case R_RISCV_BRANCH:
@@ -367,6 +371,10 @@ ST_FUNC void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr,
         }
 	add32le(ptr, val - addr);
         return;
+    case R_RISCV_SET_ULEB128:
+    case R_RISCV_SUB_ULEB128:
+	/* ignore. used in section .debug_loclists */
+        return;
     case R_RISCV_COPY:
         /* XXX */
         return;

x86_64-link.c

@@ -221,6 +221,10 @@ ST_FUNC void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr,
                 qrel->r_addend = (int)read32le(ptr) + val;
                 qrel++;
             }
+            if ((type == R_X86_64_32 && (unsigned long long)val > 4294967295ULL) ||
+                (type == R_X86_64_32S &&
+	         ((long long)val < -2147483648LL || (long long)val > 2147483647LL)))
+                tcc_error_noabort("internal error: relocation %d failed", type);
             add32le(ptr, val);
             break;
 
@@ -251,7 +255,7 @@ ST_FUNC void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr,
               /* ignore overflow with undefined weak symbols */
               if (((ElfW(Sym)*)symtab_section->data)[sym_index].st_shndx != SHN_UNDEF)
 #endif
-                tcc_error_noabort("internal error: relocation failed");
+                tcc_error_noabort("internal error: relocation %d failed", type);
             }
             add32le(ptr, diff);
         }