1 files changed, 211 insertions, 94 deletions

diff --git a/com32/tools/relocs.c b/com32/tools/relocs.c
index 24742060..86fc7c50 100644
--- a/com32/tools/relocs.c
+++ b/com32/tools/relocs.c
@@ -13,12 +13,16 @@
 #define USE_BSD
 #include <endian.h>
 #include <regex.h>
-#include <sys/types.h>
+#include <tools/le_byteshift.h>
+
+static void die(char *fmt, ...);
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 static Elf32_Ehdr ehdr;
 static unsigned long reloc_count, reloc_idx;
 static unsigned long *relocs;
+static unsigned long reloc16_count, reloc16_idx;
+static unsigned long *relocs16;
 
 struct section {
 	Elf32_Shdr     shdr;
@@ -29,60 +33,87 @@ struct section {
 };
 static struct section *secs;
 
-static void die(char *fmt, ...)
-{
-	va_list ap;
-	va_start(ap, fmt);
-	vfprintf(stderr, fmt, ap);
-	va_end(ap);
-	exit(1);
-}
+enum symtype {
+	S_ABS,
+	S_REL,
+	S_SEG,
+	S_LIN,
+	S_NSYMTYPES
+};
 
+static const char * const sym_regex_kernel[S_NSYMTYPES] = {
 /*
  * Following symbols have been audited.  Don't warn user about
  * absolute relocations present w.r.t these symbols.
  */
+	[S_ABS] =
+	"^(__.*_len|__.*_dwords)$",
 
-/* True absolute relocations */
+/*
+ * These symbols are known to be relative, even if the linker marks them
+ * as absolute (typically defined outside any section in the linker script.)
+ */
+	[S_REL] =
+	"^(__.*_start|__.*_end|_end|_[se](text|data))$",
+};
 
-static const char safe_abs_regex[] =
-"^(__.*_len|__.*_dwords)$";
-static regex_t safe_abs_regex_c;
 
-static int is_safe_abs_reloc(const char *sym_name)
-{
-	return !regexec(&safe_abs_regex_c, sym_name, 0, NULL, 0);
-}
+static const char * const sym_regex_realmode[S_NSYMTYPES] = {
+/*
+ * These are 16-bit segment symbols when compiling 16-bit code.
+ */
+	[S_SEG] =
+	"^real_mode_seg$",
 
-/* These are relative even though the linker marks them absolute */
+/*
+ * These are offsets belonging to segments, as opposed to linear addresses,
+ * when compiling 16-bit code.
+ */
+	[S_LIN] =
+	"^pa_",
+};
 
-static const char safe_rel_regex[] =
-"^(__.*_start|__.*_end|_end|_[se](text|data))$";
-static regex_t safe_rel_regex_c;
+static const char * const *sym_regex;
 
-static int is_safe_rel_reloc(const char *sym_name)
+static regex_t sym_regex_c[S_NSYMTYPES];
+static int is_reloc(enum symtype type, const char *sym_name)
 {
-	return !regexec(&safe_rel_regex_c, sym_name, 0, NULL, 0);
+	return sym_regex[type] &&
+		!regexec(&sym_regex_c[type], sym_name, 0, NULL, 0);
 }
 
-static void regex_init(void)
+static void regex_init(int use_real_mode)
 {
-	char errbuf[128];
-	int err;
+        char errbuf[128];
+        int err;
+	int i;
 
-	err = regcomp(&safe_abs_regex_c, safe_abs_regex,
-		      REG_EXTENDED|REG_NOSUB);
-	if (err) {
-		regerror(err, &safe_abs_regex_c, errbuf, sizeof errbuf);
-		die("%s", errbuf);
-	}
+	if (use_real_mode)
+		sym_regex = sym_regex_realmode;
+	else
+		sym_regex = sym_regex_kernel;
 
-	err = regcomp(&safe_rel_regex_c, safe_rel_regex,
-		      REG_EXTENDED|REG_NOSUB);
-	if (err) {
-		regerror(err, &safe_rel_regex_c, errbuf, sizeof errbuf);
-		die("%s", errbuf);
-	}
+	for (i = 0; i < S_NSYMTYPES; i++) {
+		if (!sym_regex[i])
+			continue;
+
+		err = regcomp(&sym_regex_c[i], sym_regex[i],
+			      REG_EXTENDED|REG_NOSUB);
+
+		if (err) {
+			regerror(err, &sym_regex_c[i], errbuf, sizeof errbuf);
+			die("%s", errbuf);
+		}
+        }
+}
+
+static void die(char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	exit(1);
 }
 
 static const char *sym_type(unsigned type)
@@ -153,13 +184,16 @@ static const char *rel_type(unsigned type)
 		REL_TYPE(R_386_RELATIVE),
 		REL_TYPE(R_386_GOTOFF),
 		REL_TYPE(R_386_GOTPC),
+		REL_TYPE(R_386_8),
+		REL_TYPE(R_386_PC8),
+		REL_TYPE(R_386_16),
+		REL_TYPE(R_386_PC16),
 #undef REL_TYPE
 	};
-	const char *name = NULL;
-	if (type < ARRAY_SIZE(type_name))
+	const char *name = "unknown type rel type name";
+	if (type < ARRAY_SIZE(type_name) && type_name[type]) {
 		name = type_name[type];
-	if (!name)
-		name = "unknown";
+	}
 	return name;
 }
 
@@ -189,7 +223,7 @@ static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
 		name = sym_strtab + sym->st_name;
 	}
 	else {
-		name = sec_name(secs[sym->st_shndx].shdr.sh_name);
+		name = sec_name(sym->st_shndx);
 	}
 	return name;
 }
@@ -428,7 +462,7 @@ static void print_absolute_symbols(void)
 	printf("\n");
 }
 
-static int print_absolute_relocs(FILE *f)
+static void print_absolute_relocs(void)
 {
 	int i, printed = 0;
 
@@ -472,17 +506,18 @@ static int print_absolute_relocs(FILE *f)
 			 * Before warning check if this absolute symbol
 			 * relocation is harmless.
 			 */
-			if (is_safe_abs_reloc(name) ||
-			    is_safe_rel_reloc(name))
+			if (is_reloc(S_ABS, name) || is_reloc(S_REL, name))
 				continue;
 
 			if (!printed) {
-				fprintf(f, "Unknown absolute relocations present\n");
-				fprintf(f, "Offset     Info     Type     Sym.Value Sym.Name\n");
+				printf("WARNING: Absolute relocations"
+					" present\n");
+				printf("Offset     Info     Type     Sym.Value "
+					"Sym.Name\n");
 				printed = 1;
 			}
 
-			fprintf(f, "%08x %08x %10s %08x  %s\n",
+			printf("%08x %08x %10s %08x  %s\n",
 				rel->r_offset,
 				rel->r_info,
 				rel_type(ELF32_R_TYPE(rel->r_info)),
@@ -492,12 +527,11 @@ static int print_absolute_relocs(FILE *f)
 	}
 
 	if (printed)
-		fputc('\n', f);
-
-	return printed;
+		printf("\n");
 }
 
-static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
+static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym),
+			int use_real_mode)
 {
 	int i;
 	/* Walk through the relocations */
@@ -522,31 +556,71 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
 			Elf32_Rel *rel;
 			Elf32_Sym *sym;
 			unsigned r_type;
+			const char *symname;
+			int shn_abs;
+
 			rel = &sec->reltab[j];
 			sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
 			r_type = ELF32_R_TYPE(rel->r_info);
-			/* Don't visit relocations to absolute symbols */
-			if (sym->st_shndx == SHN_ABS &&
-			    !is_safe_rel_reloc(sym_name(sym_strtab, sym)))
-				continue;
+
+			shn_abs = sym->st_shndx == SHN_ABS;
 
 			switch (r_type) {
 			case R_386_NONE:
 			case R_386_PC32:
+			case R_386_PC16:
+			case R_386_PC8:
 			case R_386_GOTPC:
 			case R_386_GOTOFF:
 			case R_386_GOT32:
 			case R_386_PLT32:
-				/* Relative relocations don't need to
-				   be adjusted */
+				/*
+				 * NONE can be ignored and and PC relative
+				 * relocations don't need to be adjusted.
+				 */
 				break;
+
+			case R_386_16:
+				symname = sym_name(sym_strtab, sym);
+				if (!use_real_mode)
+					goto bad;
+				if (shn_abs) {
+					if (is_reloc(S_ABS, symname))
+						break;
+					else if (!is_reloc(S_SEG, symname))
+						goto bad;
+				} else {
+					if (is_reloc(S_LIN, symname))
+						goto bad;
+					else
+						break;
+				}
+				visit(rel, sym);
+				break;
+
 			case R_386_32:
-				/* Visit relocations that need adjustment */
+				symname = sym_name(sym_strtab, sym);
+				if (shn_abs) {
+					if (is_reloc(S_ABS, symname))
+						break;
+					else if (!is_reloc(S_REL, symname))
+						goto bad;
+				} else {
+					if (use_real_mode &&
+					    !is_reloc(S_LIN, symname))
+						break;
+				}
 				visit(rel, sym);
 				break;
 			default:
 				die("Unsupported relocation type: %s (%d)\n",
 				    rel_type(r_type), r_type);
+				break;
+			bad:
+				symname = sym_name(sym_strtab, sym);
+				die("Invalid %s %s relocation: %s\n",
+				    shn_abs ? "absolute" : "relative",
+				    rel_type(r_type), symname);
 			}
 		}
 	}
@@ -554,8 +628,12 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
 
 static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
 {
-	(void)rel; (void)sym;
-	reloc_count += 1;
+	(void)sym;
+
+	if (ELF32_R_TYPE(rel->r_info) == R_386_16)
+		reloc16_count++;
+	else
+		reloc_count++;
 }
 
 static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
@@ -563,7 +641,10 @@ static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
 	(void)sym;
 
 	/* Remember the address that needs to be adjusted. */
-	relocs[reloc_idx++] = rel->r_offset;
+	if (ELF32_R_TYPE(rel->r_info) == R_386_16)
+		relocs16[reloc16_idx++] = rel->r_offset;
+	else
+		relocs[reloc_idx++] = rel->r_offset;
 }
 
 static int cmp_relocs(const void *va, const void *vb)
@@ -573,23 +654,41 @@ static int cmp_relocs(const void *va, const void *vb)
 	return (*a == *b)? 0 : (*a > *b)? 1 : -1;
 }
 
-static void emit_relocs(int as_text)
+static int write32(unsigned int v, FILE *f)
+{
+	unsigned char buf[4];
+
+	put_unaligned_le32(v, buf);
+	return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
+}
+
+static void emit_relocs(int as_text, int use_real_mode)
 {
 	int i;
 	/* Count how many relocations I have and allocate space for them. */
 	reloc_count = 0;
-	walk_relocs(count_reloc);
+	walk_relocs(count_reloc, use_real_mode);
 	relocs = malloc(reloc_count * sizeof(relocs[0]));
 	if (!relocs) {
 		die("malloc of %d entries for relocs failed\n",
 			reloc_count);
 	}
+
+	relocs16 = malloc(reloc16_count * sizeof(relocs[0]));
+	if (!relocs16) {
+		die("malloc of %d entries for relocs16 failed\n",
+			reloc16_count);
+	}
 	/* Collect up the relocations */
 	reloc_idx = 0;
-	walk_relocs(collect_reloc);
+	walk_relocs(collect_reloc, use_real_mode);
+
+	if (reloc16_count && !use_real_mode)
+		die("Segment relocations found but --realmode not specified\n");
 
 	/* Order the relocations for more efficient processing */
 	qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
+	qsort(relocs16, reloc16_count, sizeof(relocs16[0]), cmp_relocs);
 
 	/* Print the relocations */
 	if (as_text) {
@@ -598,61 +697,83 @@ static void emit_relocs(int as_text)
 		 */
 		printf(".section \".data.reloc\",\"a\"\n");
 		printf(".balign 4\n");
-		for (i = 0; i < reloc_count; i++) {
-			printf("\t .long 0x%08lx\n", relocs[i]);
+		if (use_real_mode) {
+			printf("\t.long %lu\n", reloc16_count);
+			for (i = 0; i < reloc16_count; i++)
+				printf("\t.long 0x%08lx\n", relocs16[i]);
+			printf("\t.long %lu\n", reloc_count);
+			for (i = 0; i < reloc_count; i++) {
+				printf("\t.long 0x%08lx\n", relocs[i]);
+			}
+		} else {
+			for (i = 0; i < reloc_count; i++) {
+				printf("\t.long 0x%08lx\n", relocs[i]);
+			}
+			/* Print a stop */
+			printf("\t.long 0x%08lx\n", (unsigned long)0);
 		}
+
 		printf("\n");
 	}
 	else {
-		unsigned char buf[4];
-		/* Now print each relocation */
-		for (i = 0; i < reloc_count; i++) {
-			buf[0] = (relocs[i] >>  0) & 0xff;
-			buf[1] = (relocs[i] >>  8) & 0xff;
-			buf[2] = (relocs[i] >> 16) & 0xff;
-			buf[3] = (relocs[i] >> 24) & 0xff;
-			fwrite(buf, 4, 1, stdout);
+		if (use_real_mode) {
+			write32(reloc16_count, stdout);
+			for (i = 0; i < reloc16_count; i++)
+				write32(relocs16[i], stdout);
+			write32(reloc_count, stdout);
+
+			/* Now print each relocation */
+			for (i = 0; i < reloc_count; i++)
+				write32(relocs[i], stdout);
+		} else {
+			/* Now print each relocation */
+			for (i = 0; i < reloc_count; i++) {
+				write32(relocs[i], stdout);
+			}
+
+			/* Print a stop */
+			write32(0, stdout);
 		}
-		/* Print a stop */
-		memset(buf, 0, sizeof buf);
-		fwrite(buf, 4, 1, stdout);
 	}
 }
 
 static void usage(void)
 {
-	die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n");
+	die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n");
 }
 
 int main(int argc, char **argv)
 {
 	int show_absolute_syms, show_absolute_relocs;
-	int as_text;
+	int as_text, use_real_mode;
 	const char *fname;
 	FILE *fp;
 	int i;
-	int err = 0;
 
 	show_absolute_syms = 0;
 	show_absolute_relocs = 0;
 	as_text = 0;
+	use_real_mode = 0;
 	fname = NULL;
 	for (i = 1; i < argc; i++) {
 		char *arg = argv[i];
 		if (*arg == '-') {
-			if (strcmp(argv[1], "--abs-syms") == 0) {
+			if (strcmp(arg, "--abs-syms") == 0) {
 				show_absolute_syms = 1;
 				continue;
 			}
-
-			if (strcmp(argv[1], "--abs-relocs") == 0) {
+			if (strcmp(arg, "--abs-relocs") == 0) {
 				show_absolute_relocs = 1;
 				continue;
 			}
-			else if (strcmp(argv[1], "--text") == 0) {
+			if (strcmp(arg, "--text") == 0) {
 				as_text = 1;
 				continue;
 			}
+			if (strcmp(arg, "--realmode") == 0) {
+				use_real_mode = 1;
+				continue;
+			}
 		}
 		else if (!fname) {
 			fname = arg;
@@ -663,10 +784,7 @@ int main(int argc, char **argv)
 	if (!fname) {
 		usage();
 	}
-
-
-	regex_init();
-
+	regex_init(use_real_mode);
 	fp = fopen(fname, "r");
 	if (!fp) {
 		die("Cannot open %s: %s\n",
@@ -682,10 +800,9 @@ int main(int argc, char **argv)
 		return 0;
 	}
 	if (show_absolute_relocs) {
-		print_absolute_relocs(stdout);
+		print_absolute_relocs();
 		return 0;
 	}
-	err = print_absolute_relocs(stderr);
-	emit_relocs(as_text);
-	return err;
+	emit_relocs(as_text, use_real_mode);
+	return 0;
 }