android-mainline/ANDROID-Revert-Merge-tag-modules-for-v5.4-of-git-git.kernel.org-pub-scm-linux-kernel-git-jeyu-linux.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Raghavendra Rao Ananta <rananta@codeaurora.org>
Date: Fri, 18 Oct 2019 11:20:57 -0700
Subject: ANDROID: Revert "Merge tag 'modules-for-v5.4' of
 git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux"

This reverts commit e0703556644a531e50b5dc61b9f6ea83af5f6604, reversing
changes made to 8808cf8cbc4da1ceef9307fba7e499563908c211.

Introducing symbol-namespaces into the kernel has caused issues with
respect to the ABI checker. Hence, revert the changes until a valid
fix is available. The revert was done based off of 5.4-rc1.

Change-Id: I529ced269661f457ce667a76eb383843002f0a7d
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>
---
 include/linux/export.h | 14 +++++++----
 scripts/mod/modpost.c  | 55 +++++++++++++++---------------------------
 2 files changed, 28 insertions(+), 41 deletions(-)

diff --git a/include/linux/export.h b/include/linux/export.h
index 941d075f03d6..621158ecd2e2 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -18,6 +18,8 @@ extern struct module __this_module;
 #define THIS_MODULE ((struct module *)0)
 #endif
 
+#define NS_SEPARATOR "."
+
 #ifdef CONFIG_MODVERSIONS
 /* Mark the CRC weak since genksyms apparently decides not to
  * generate a checksums for some symbols */
@@ -46,11 +48,11 @@ extern struct module __this_module;
  * absolute relocations that require runtime processing on relocatable
  * kernels.
  */
-#define __KSYMTAB_ENTRY_NS(sym, sec)					\
+#define __KSYMTAB_ENTRY_NS(sym, sec, ns)				\
 	__ADDRESSABLE(sym)						\
 	asm("	.section \"___ksymtab" sec "+" #sym "\", \"a\"	\n"	\
 	    "	.balign	4					\n"	\
-	    "__ksymtab_" #sym ":				\n"	\
+	    "__ksymtab_" #ns NS_SEPARATOR #sym ":		\n"	\
 	    "	.long	" #sym "- .				\n"	\
 	    "	.long	__kstrtab_" #sym "- .			\n"	\
 	    "	.long	__kstrtabns_" #sym "- .			\n"	\
@@ -72,14 +74,16 @@ struct kernel_symbol {
 	int namespace_offset;
 };
 #else
-#define __KSYMTAB_ENTRY_NS(sym, sec)					\
-	static const struct kernel_symbol __ksymtab_##sym		\
+#define __KSYMTAB_ENTRY_NS(sym, sec, ns)				\
+	static const struct kernel_symbol __ksymtab_##sym##__##ns	\
+	asm("__ksymtab_" #ns NS_SEPARATOR #sym)				\
 	__attribute__((section("___ksymtab" sec "+" #sym), used))	\
 	__aligned(sizeof(void *))					\
 	= { (unsigned long)&sym, __kstrtab_##sym, __kstrtabns_##sym }
 
 #define __KSYMTAB_ENTRY(sym, sec)					\
 	static const struct kernel_symbol __ksymtab_##sym		\
+	asm("__ksymtab_" #sym)						\
 	__attribute__((section("___ksymtab" sec "+" #sym), used))	\
 	__aligned(sizeof(void *))					\
 	= { (unsigned long)&sym, __kstrtab_##sym, NULL }
@@ -111,7 +115,7 @@ struct kernel_symbol {
 	static const char __kstrtabns_##sym[]				\
 	__attribute__((section("__ksymtab_strings"), used, aligned(1)))	\
 	= #ns;								\
-	__KSYMTAB_ENTRY_NS(sym, sec)
+	__KSYMTAB_ENTRY_NS(sym, sec, ns)
 
 #define ___EXPORT_SYMBOL(sym, sec)					\
 	___export_symbol_common(sym, sec);				\
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index d2a30a7b3f07..a5dca74cc3ca 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -348,38 +348,26 @@ static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
 		return export_unknown;
 }
 
-static const char *namespace_from_kstrtabns(struct elf_info *info,
-					    Elf_Sym *kstrtabns)
+static char *sym_extract_namespace(const char **symname)
 {
-	char *value = info->ksymtab_strings + kstrtabns->st_value;
-	return value[0] ? value : NULL;
-}
-
-static void sym_update_namespace(const char *symname, const char *namespace)
-{
-	struct symbol *s = find_symbol(symname);
+	char *namespace = NULL;
+	char *ns_separator;
 
-	/*
-	 * That symbol should have been created earlier and thus this is
-	 * actually an assertion.
-	 */
-	if (!s) {
-		merror("Could not update namespace(%s) for symbol %s\n",
-		       namespace, symname);
-		return;
+	ns_separator = strchr(*symname, '.');
+	if (ns_separator) {
+		namespace = NOFAIL(strndup(*symname, ns_separator - *symname));
+		*symname = ns_separator + 1;
 	}
 
-	free(s->namespace);
-	s->namespace =
-		namespace && namespace[0] ? NOFAIL(strdup(namespace)) : NULL;
+	return namespace;
 }
 
 /**
  * Add an exported symbol - it may have already been added without a
  * CRC, in this case just update the CRC
  **/
-static struct symbol *sym_add_exported(const char *name, struct module *mod,
-				       enum export export)
+static struct symbol *sym_add_exported(const char *name, const char *namespace,
+				       struct module *mod, enum export export)
 {
 	struct symbol *s = find_symbol(name);
 
@@ -395,6 +383,8 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod,
 			s->module = mod;
 		}
 	}
+	free(s->namespace);
+	s->namespace = namespace ? strdup(namespace) : NULL;
 	s->preloaded = 0;
 	s->vmlinux   = is_vmlinux(mod->name);
 	s->kernel    = 0;
@@ -686,6 +676,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
 	enum export export;
 	bool is_crc = false;
 	const char *name;
+	char *namespace;
 
 	if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
 	    strstarts(symname, "__ksymtab"))
@@ -758,7 +749,9 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
 		/* All exported symbols */
 		if (strstarts(symname, "__ksymtab_")) {
 			name = symname + strlen("__ksymtab_");
-			sym_add_exported(name, mod, export);
+			namespace = sym_extract_namespace(&name);
+			sym_add_exported(name, namespace, mod, export);
+			free(namespace);
 		}
 		if (strcmp(symname, "init_module") == 0)
 			mod->has_init = 1;
@@ -2054,16 +2047,6 @@ static void read_symbols(const char *modname)
 		handle_moddevtable(mod, &info, sym, symname);
 	}
 
-	/* Apply symbol namespaces from __kstrtabns_<symbol> entries. */
-	for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
-		symname = remove_dot(info.strtab + sym->st_name);
-
-		if (strstarts(symname, "__kstrtabns_"))
-			sym_update_namespace(symname + strlen("__kstrtabns_"),
-					     namespace_from_kstrtabns(&info,
-								      sym));
-	}
-
 	// check for static EXPORT_SYMBOL_* functions && global vars
 	for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
 		unsigned char bind = ELF_ST_BIND(sym->st_info);
@@ -2217,7 +2200,7 @@ static int check_exports(struct module *mod)
 		else
 			basename = mod->name;
 
-		if (exp->namespace) {
+		if (exp->namespace && exp->namespace[0]) {
 			add_namespace(&mod->required_namespaces,
 				      exp->namespace);
 
@@ -2475,12 +2458,12 @@ static void read_dump(const char *fname, unsigned int kernel)
 			mod = new_module(modname);
 			mod->skip = 1;
 		}
-		s = sym_add_exported(symname, mod, export_no(export));
+		s = sym_add_exported(symname, namespace, mod,
+				     export_no(export));
 		s->kernel    = kernel;
 		s->preloaded = 1;
 		s->is_static = 0;
 		sym_update_crc(symname, mod, crc, export_no(export));
-		sym_update_namespace(symname, namespace);
 	}
 	release_file(file, size);
 	return;