1 files changed, 128 insertions, 177 deletions

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index e463013..6c206b9 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -605,6 +605,61 @@ static int strrcmp(const char *s, const char *sub)
 	return memcmp(s + slen - sublen, sub, sublen);
 }
 
+/* if sym is empty or point to a string
+ * like ".[0-9]+" then return 1.
+ * This is the optional prefix added by ld to some sections
+ */
+static int number_prefix(const char *sym)
+{
+	if (*sym++ == '\0')
+		return 1;
+	if (*sym != '.')
+		return 0;
+	do {
+		char c = *sym++;
+		if (c < '0' || c > '9')
+			return 0;
+	} while (*sym);
+	return 1;
+}
+
+/* The pattern is an array of simple patterns.
+ * "foo" will match an exact string equal to "foo"
+ * "foo*" will match a string that begins with "foo"
+ * "foo$" will match a string equal to "foo" or "foo.1"
+ *   where the '1' can be any number including several digits.
+ *   The $ syntax is for sections where ld append a dot number
+ *   to make section name unique.
+ */
+int match(const char *sym, const char * const pat[])
+{
+	const char *p;
+	while (*pat) {
+		p = *pat++;
+		const char *endp = p + strlen(p) - 1;
+
+		/* "foo*" */
+		if (*endp == '*') {
+			if (strncmp(sym, p, strlen(p) - 1) == 0)
+				return 1;
+		}
+		/* "foo$" */
+		else if (*endp == '$') {
+			if (strncmp(sym, p, strlen(p) - 1) == 0) {
+				if (number_prefix(sym + strlen(p) - 1))
+					return 1;
+			}
+		}
+		/* no wildcards */
+		else {
+			if (strcmp(p, sym) == 0)
+				return 1;
+		}
+	}
+	/* no match */
+	return 0;
+}
+
 /*
  * Functions used only during module init is marked __init and is stored in
  * a .init.text section. Likewise data is marked __initdata and stored in
@@ -653,6 +708,68 @@ static int data_section(const char *name)
 		return 0;
 }
 
+/* sections that we do not want to do full section mismatch check on */
+static const char *section_white_list[] =
+	{ ".debug*", ".stab*", ".note*", ".got*", ".toc*", NULL };
+
+#define INIT_DATA_SECTIONS ".init.data$"
+#define EXIT_DATA_SECTIONS ".exit.data$"
+
+#define INIT_TEXT_SECTIONS ".init.text$"
+#define EXIT_TEXT_SECTIONS ".exit.text$"
+
+#define INIT_SECTIONS INIT_DATA_SECTIONS, INIT_TEXT_SECTIONS
+#define EXIT_SECTIONS EXIT_DATA_SECTIONS, EXIT_TEXT_SECTIONS
+
+#define DATA_SECTIONS ".data$"
+#define TEXT_SECTIONS ".text$"
+
+struct sectioncheck {
+	const char *fromsec[20];
+	const char *tosec[20];
+};
+
+const struct sectioncheck sectioncheck[] = {
+/* Do not reference init/exit code/data from
+ * normal code and data
+ */
+{
+	.fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
+	.tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL }
+},
+/* Do not use exit code/data from init code */
+{
+	.fromsec = { INIT_SECTIONS, NULL },
+	.tosec   = { EXIT_SECTIONS, NULL },
+},
+/* Do not use init code/data from exit code */
+{
+	.fromsec = { EXIT_SECTIONS, NULL },
+	.tosec   = { INIT_SECTIONS, NULL }
+},
+/* Do not export init/exit functions or data */
+{
+	.fromsec = { "__ksymtab*", NULL },
+	.tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL }
+}
+};
+
+static int section_mismatch(const char *fromsec, const char *tosec)
+{
+	int i;
+	int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
+	const struct sectioncheck *check = &sectioncheck[0];
+
+	for (i = 0; i < elems; i++) {
+		if (match(fromsec, check->fromsec) &&
+		    match(tosec, check->tosec))
+			return 1;
+		check++;
+	}
+	return 0;
+}
+
+
 /**
  * Whitelist to allow certain references to pass with no warning.
  *
@@ -695,18 +812,11 @@ static int data_section(const char *name)
  *   This pattern is identified by
  *   refsymname = __init_begin, _sinittext, _einittext
  *
- * Pattern 5:
- *   Xtensa uses literal sections for constants that are accessed PC-relative.
- *   Literal sections may safely reference their text sections.
- *   (Note that the name for the literal section omits any trailing '.text')
- *   tosec = <section>[.text]
- *   fromsec = <section>.literal
  **/
 static int secref_whitelist(const char *modname, const char *tosec,
 			    const char *fromsec, const char *atsym,
 			    const char *refsymname)
 {
-	int len;
 	const char **s;
 	const char *pat2sym[] = {
 		"driver",
@@ -757,15 +867,6 @@ static int secref_whitelist(const char *modname, const char *tosec,
 		if (strcmp(refsymname, *s) == 0)
 			return 1;
 
-	/* Check for pattern 5 */
-	if (strrcmp(tosec, ".text") == 0)
-		len = strlen(tosec) - strlen(".text");
-	else
-		len = strlen(tosec);
-	if ((strncmp(tosec, fromsec, len) == 0) && (strlen(fromsec) > len) &&
-	    (strcmp(fromsec + len, ".literal") == 0))
-		return 1;
-
 	return 0;
 }
 
@@ -1011,8 +1112,7 @@ static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
 }
 
 static void section_rela(const char *modname, struct elf_info *elf,
-                         Elf_Shdr *sechdr, int section(const char *),
-                         int section_ref_ok(const char *))
+                         Elf_Shdr *sechdr)
 {
 	Elf_Sym  *sym;
 	Elf_Rela *rela;
@@ -1031,7 +1131,7 @@ static void section_rela(const char *modname, struct elf_info *elf,
 	fromsec = secstrings + sechdr->sh_name;
 	fromsec += strlen(".rela");
 	/* if from section (name) is know good then skip it */
-	if (section_ref_ok(fromsec))
+	if (match(fromsec, section_white_list))
 		return;
 
 	for (rela = start; rela < stop; rela++) {
@@ -1059,14 +1159,13 @@ static void section_rela(const char *modname, struct elf_info *elf,
 
 		tosec = secstrings +
 			elf->sechdrs[sym->st_shndx].sh_name;
-		if (section(tosec))
+		if (section_mismatch(fromsec, tosec))
 			warn_sec_mismatch(modname, fromsec, elf, sym, r);
 	}
 }
 
 static void section_rel(const char *modname, struct elf_info *elf,
-                        Elf_Shdr *sechdr, int section(const char *),
-                        int section_ref_ok(const char *))
+                        Elf_Shdr *sechdr)
 {
 	Elf_Sym *sym;
 	Elf_Rel *rel;
@@ -1085,7 +1184,7 @@ static void section_rel(const char *modname, struct elf_info *elf,
 	fromsec = secstrings + sechdr->sh_name;
 	fromsec += strlen(".rel");
 	/* if from section (name) is know good then skip it */
-	if (section_ref_ok(fromsec))
+	if (match(fromsec, section_white_list))
 		return;
 
 	for (rel = start; rel < stop; rel++) {
@@ -1127,7 +1226,7 @@ static void section_rel(const char *modname, struct elf_info *elf,
 
 		tosec = secstrings +
 			elf->sechdrs[sym->st_shndx].sh_name;
-		if (section(tosec))
+		if (section_mismatch(fromsec, tosec))
 			warn_sec_mismatch(modname, fromsec, elf, sym, r);
 	}
 }
@@ -1145,9 +1244,7 @@ static void section_rel(const char *modname, struct elf_info *elf,
  * be discarded and warns about it.
  **/
 static void check_sec_ref(struct module *mod, const char *modname,
-			  struct elf_info *elf,
-			  int section(const char *),
-			  int section_ref_ok(const char *))
+                          struct elf_info *elf)
 {
 	int i;
 	Elf_Ehdr *hdr = elf->hdr;
@@ -1157,156 +1254,12 @@ static void check_sec_ref(struct module *mod, const char *modname,
 	for (i = 0; i < hdr->e_shnum; i++) {
 		/* We want to process only relocation sections and not .init */
 		if (sechdrs[i].sh_type == SHT_RELA)
-			section_rela(modname, elf, &elf->sechdrs[i],
-			             section, section_ref_ok);
+			section_rela(modname, elf, &elf->sechdrs[i]);
 		else if (sechdrs[i].sh_type == SHT_REL)
-			section_rel(modname, elf, &elf->sechdrs[i],
-			            section, section_ref_ok);
+			section_rel(modname, elf, &elf->sechdrs[i]);
 	}
 }
 
-/*
- * Identify sections from which references to either a
- * .init or a .exit section is OK.
- *
- * [OPD] Keith Ownes <kaos@sgi.com> commented:
- * For our future {in}sanity, add a comment that this is the ppc .opd
- * section, not the ia64 .opd section.
- * ia64 .opd should not point to discarded sections.
- * [.rodata] like for .init.text we ignore .rodata references -same reason
- */
-static int initexit_section_ref_ok(const char *name)
-{
-	const char **s;
-	/* Absolute section names */
-	const char *namelist1[] = {
-		"__bug_table",	/* used by powerpc for BUG() */
-		"__ex_table",
-		".altinstructions",
-		".cranges",	/* used by sh64 */
-		".fixup",
-		".machvec",	/* ia64 + powerpc uses these */
-		".machine.desc",
-		".opd",		/* See comment [OPD] */
-		"__dbe_table",
-		".parainstructions",
-		".pdr",
-		".plt",		/* seen on ARCH=um build on x86_64. Harmless */
-		".smp_locks",
-		".stab",
-		".m68k_fixup",
-		".xt.prop",	/* xtensa informational section */
-		".xt.lit",	/* xtensa informational section */
-		NULL
-	};
-	/* Start of section names */
-	const char *namelist2[] = {
-		".debug",
-		".eh_frame",
-		".note",	/* ignore ELF notes - may contain anything */
-		".got",		/* powerpc - global offset table */
-		".toc",		/* powerpc - table of contents */
-		NULL
-	};
-	/* part of section name */
-	const char *namelist3 [] = {
-		".unwind",  /* Sample: IA_64.unwind.exit.text */
-		NULL
-	};
-
-	for (s = namelist1; *s; s++)
-		if (strcmp(*s, name) == 0)
-			return 1;
-	for (s = namelist2; *s; s++)
-		if (strncmp(*s, name, strlen(*s)) == 0)
-			return 1;
-	for (s = namelist3; *s; s++)
-		if (strstr(name, *s) != NULL)
-			return 1;
-	return 0;
-}
-
-
-/*
- * Identify sections from which references to a .init section is OK.
- *
- * Unfortunately references to read only data that referenced .init
- * sections had to be excluded. Almost all of these are false
- * positives, they are created by gcc. The downside of excluding rodata
- * is that there really are some user references from rodata to
- * init code, e.g. drivers/video/vgacon.c:
- *
- * const struct consw vga_con = {
- *        con_startup:            vgacon_startup,
- *
- * where vgacon_startup is __init.  If you want to wade through the false
- * positives, take out the check for rodata.
- */
-static int init_section_ref_ok(const char *name)
-{
-	const char **s;
-	/* Absolute section names */
-	const char *namelist1[] = {
-		"__dbe_table",		/* MIPS generate these */
-		"__ftr_fixup",		/* powerpc cpu feature fixup */
-		"__fw_ftr_fixup",	/* powerpc firmware feature fixup */
-		"__param",
-		".data.rel.ro",		/* used by parisc64 */
-		".init",
-		".text.lock",
-		NULL
-	};
-	/* Start of section names */
-	const char *namelist2[] = {
-		".init.",
-		".pci_fixup",
-		".rodata",
-		NULL
-	};
-
-	if (initexit_section_ref_ok(name))
-		return 1;
-
-	for (s = namelist1; *s; s++)
-		if (strcmp(*s, name) == 0)
-			return 1;
-	for (s = namelist2; *s; s++)
-		if (strncmp(*s, name, strlen(*s)) == 0)
-			return 1;
-
-	/* If section name ends with ".init" we allow references
-	 * as is the case with .initcallN.init, .early_param.init,
-	 * .taglist.init etc
-	 */
-	if (strrcmp(name, ".init") == 0)
-		return 1;
-	return 0;
-}
-
-/*
- * Identify sections from which references to a .exit section is OK.
- */
-static int exit_section_ref_ok(const char *name)
-{
-	const char **s;
-	/* Absolute section names */
-	const char *namelist1[] = {
-		".exit.data",
-		".exit.text",
-		".exitcall.exit",
-		".rodata",
-		NULL
-	};
-
-	if (initexit_section_ref_ok(name))
-		return 1;
-
-	for (s = namelist1; *s; s++)
-		if (strcmp(*s, name) == 0)
-			return 1;
-	return 0;
-}
-
 static void read_symbols(char *modname)
 {
 	const char *symname;
@@ -1347,10 +1300,8 @@ static void read_symbols(char *modname)
 		handle_moddevtable(mod, &info, sym, symname);
 	}
 	if (!is_vmlinux(modname) ||
-	     (is_vmlinux(modname) && vmlinux_section_warnings)) {
-		check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
-		check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
-	}
+	     (is_vmlinux(modname) && vmlinux_section_warnings))
+		check_sec_ref(mod, modname, &info);
 
 	version = get_modinfo(info.modinfo, info.modinfo_len, "version");
 	if (version)