From: Andreas Gruenbacher <agruen@suse.de>

Subject: genksyms: add --override flag

Patch-mainline: Not yet, <jeffm: asked msuchanek to submit, Oct 4, 2017>

References: none

Add --override flag to genksyms to allow overriding types with old

definitions using the 'override' keyword. This is similar to -p --preserve,

but it doesn't abort the build if a symtype cannot be preserved

[mmarek: added KBUILD_OVERRIDE env var to set this globally for the entire

 build]

---

 scripts/Makefile.build      |  1 +

 scripts/genksyms/genksyms.c | 21 +++++++++++++++------

 2 files changed, 16 insertions(+), 6 deletions(-)

--- a/scripts/Makefile.build

+++ b/scripts/Makefile.build

@@ -129,6 +129,7 @@ $(obj)/%.i: $(src)/%.c FORCE

 genksyms = scripts/genksyms/genksyms		\

 	$(if $(1), -T $(2))			\

 	$(if $(KBUILD_PRESERVE), -p)		\

+	$(if $(KBUILD_OVERRIDE),-o)		\

 	-r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)

 # These mirror gensymtypes_S and co below, keep them in synch.

--- a/scripts/genksyms/genksyms.c

+++ b/scripts/genksyms/genksyms.c

@@ -33,7 +33,7 @@ char *cur_filename;

 int in_source_file;

 static int flag_debug, flag_dump_defs, flag_reference, flag_dump_types,

-	   flag_preserve, flag_warnings;

+	   flag_override, flag_preserve, flag_warnings;

 static int errors;

 static int nsyms;

@@ -243,7 +243,7 @@ static struct symbol *__add_symbol(const char *name, enum symbol_type type,

 				sym->is_declared = 1;

 				return sym;

 			} else if (!sym->is_declared) {

-				if (sym->is_override && flag_preserve) {

+				if (sym->is_override && flag_override) {

 					print_location();

 					fprintf(stderr, "ignoring ");

 					print_type_name(type, name);

@@ -656,11 +656,13 @@ void export_symbol(const char *name)

 			struct symbol *n = sym->expansion_trail;

 			if (sym->status != STATUS_UNCHANGED) {

+				int fail = sym->is_override && flag_preserve;

+

 				if (!has_changed) {

 					print_location();

 					fprintf(stderr, "%s: %s: modversion "

 						"changed because of changes "

-						"in ", flag_preserve ? "error" :

+						"in ", fail ? "error" :

 						       "warning", name);

 				} else

 					fprintf(stderr, ", ");

@@ -668,7 +670,7 @@ void export_symbol(const char *name)

 				if (sym->status == STATUS_DEFINED)

 					fprintf(stderr, " (became defined)");

 				has_changed = 1;

-				if (flag_preserve)

+				if (fail)

 					errors++;

 			}

 			sym->expansion_trail = 0;

@@ -724,6 +726,7 @@ static void genksyms_usage(void)

 	      "  -D, --dump            Dump expanded symbol defs (for debugging only)\n"

 	      "  -r, --reference file  Read reference symbols from a file\n"

 	      "  -T, --dump-types file Dump expanded types into file\n"

+	      "  -o, --override        Allow to override reference modversions\n"

 	      "  -p, --preserve        Preserve reference modversions or fail\n"

 	      "  -w, --warnings        Enable warnings\n"

 	      "  -q, --quiet           Disable warnings (default)\n"

@@ -735,6 +738,7 @@ static void genksyms_usage(void)

 	      "  -D                    Dump expanded symbol defs (for debugging only)\n"

 	      "  -r file               Read reference symbols from a file\n"

 	      "  -T file               Dump expanded types into file\n"

+	      "  -o                    Allow to override reference modversions\n"

 	      "  -p                    Preserve reference modversions or fail\n"

 	      "  -w                    Enable warnings\n"

 	      "  -q                    Disable warnings (default)\n"

@@ -758,15 +762,16 @@ int main(int argc, char **argv)

 		{"reference", 1, 0, 'r'},

 		{"dump-types", 1, 0, 'T'},

 		{"preserve", 0, 0, 'p'},

+		{"override", 0, 0, 'o'},

 		{"version", 0, 0, 'V'},

 		{"help", 0, 0, 'h'},

 		{0, 0, 0, 0}

 	};

-	while ((o = getopt_long(argc, argv, "s:dwqVDr:T:ph",

+	while ((o = getopt_long(argc, argv, "s:dwqVDr:T:oph",

 				&long_opts[0], NULL)) != EOF)

 #else				/* __GNU_LIBRARY__ */

-	while ((o = getopt(argc, argv, "s:dwqVDr:T:ph")) != EOF)

+	while ((o = getopt(argc, argv, "s:dwqVDr:T:oph")) != EOF)

 #endif				/* __GNU_LIBRARY__ */

 		switch (o) {

 		case 'd':

@@ -800,7 +805,11 @@ int main(int argc, char **argv)

 				return 1;

 			}

 			break;

+		case 'o':

+			flag_override = 1;

+			break;

 		case 'p':

+			flag_override = 1;

 			flag_preserve = 1;

 			break;

 		case 'h':