kbuild: refactor code in modpost to improve maintainability

There were a great deal of overlap between the two functions
that check which sections may reference .init.text and .exit.text.
Factor out common check to a separate function and
sort entries in the original functions.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 9c35f30..f22c8b4 100644 (file)
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -858,14 +858,6 @@ static void warn_sec_mismatch(const char *modname, const char *fromsec,
                             elf->strtab + before->st_name, refsymname))
                return;
 
-       /* fromsec whitelist - without a valid 'before'
-        * powerpc has a GOT table in .got2 section
-        * and also a .toc section */
-       if (strcmp(fromsec, ".got2") == 0)
-               return;
-       if (strcmp(fromsec, ".toc") == 0)
-               return;
-
        if (before && after) {
                warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
                     "(between '%s' and '%s')\n",
@@ -1087,6 +1079,61 @@ static void check_sec_ref(struct module *mod, const char *modname,
        }
 }
 
+/*
+ * 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",
+               ".opd",                 /* See comment [OPD] */
+               ".parainstructions",
+               ".pdr",
+               ".plt",                 /* seen on ARCH=um build on x86_64. Harmless */
+               ".smp_locks",
+               ".stab",
+               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;
+}
+
 /**
  * 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
@@ -1103,7 +1150,7 @@ static int init_section(const char *name)
        return 0;
 }
 
-/**
+/*
  * Identify sections from which references to a .init section is OK.
  *
  * Unfortunately references to read only data that referenced .init
@@ -1117,59 +1164,41 @@ static int init_section(const char *name)
  *
  * 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[] = {
-               ".init",
-               ".opd",   /* see comment [OPD] at exit_section_ref_ok() */
-               ".toc1",  /* used by ppc64 */
-               ".stab",
-               ".data.rel.ro", /* used by parisc64 */
-               ".parainstructions",
-               ".text.lock",
-               "__bug_table", /* used by powerpc for BUG() */
-               ".pci_fixup_header",
-               ".pci_fixup_final",
-               ".pdr",
-               "__param",
-               "__ex_table",
-               ".fixup",
-               ".smp_locks",
-               ".plt",  /* seen on ARCH=um build on x86_64. Harmless */
                "__ftr_fixup",          /* powerpc cpu feature fixup */
                "__fw_ftr_fixup",       /* powerpc firmware feature fixup */
-               ".cranges",     /* used by sh64 */
+               "__param",
+               ".data.rel.ro",         /* used by parisc64 */
+               ".init",
+               ".text.lock",
                NULL
        };
        /* Start of section names */
        const char *namelist2[] = {
                ".init.",
-               ".altinstructions",
-               ".eh_frame",
-               ".debug",
-               ".parainstructions",
+               ".pci_fixup",
                ".rodata",
-               ".note",                /* ignore ELF notes - may contain anything */
-               NULL
-       };
-       /* part of section name */
-       const char *namelist3 [] = {
-               ".unwind",  /* sample: IA_64.unwind.init.text */
                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;
-       for (s = namelist3; *s; s++)
-               if (strstr(name, *s) != NULL)
-                       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;
@@ -1194,59 +1223,26 @@ static int exit_section(const char *name)
 
 /*
  * Identify sections from which references to 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 exit_section_ref_ok(const char *name)
 {
        const char **s;
        /* Absolute section names */
        const char *namelist1[] = {
-               ".exit.text",
                ".exit.data",
+               ".exit.text",
+               ".exitcall.exit",
                ".init.text",
                ".rodata",
-               ".opd", /* See comment [OPD] */
-               ".toc1",  /* used by ppc64 */
-               ".altinstructions",
-               ".pdr",
-               "__bug_table", /* used by powerpc for BUG() */
-               ".exitcall.exit",
-               ".eh_frame",
-               ".parainstructions",
-               ".stab",
-               "__ex_table",
-               ".fixup",
-               ".smp_locks",
-               ".plt",  /* seen on ARCH=um build on x86_64. Harmless */
-               ".cranges",     /* used by sh64 */
-               NULL
-       };
-       /* Start of section names */
-       const char *namelist2[] = {
-               ".debug",
-               ".note",                /* ignore ELF notes - may contain anything */
-               NULL
-       };
-       /* part of section name */
-       const char *namelist3 [] = {
-               ".unwind",  /* Sample: IA_64.unwind.exit.text */
                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;
-       for (s = namelist3; *s; s++)
-               if (strstr(name, *s) != NULL)
-                       return 1;
        return 0;
 }