Use separate sections for __dev/__cpu/__mem code/data

Introducing separate sections for __dev* (HOTPLUG),
__cpu* (HOTPLUG_CPU) and __mem* (MEMORY_HOTPLUG)
allows us to do a much more reliable Section mismatch
check in modpost. We are no longer dependent on the actual
configuration of for example HOTPLUG.

This has the effect that all users see much more
Section mismatch warnings than before because they
were almost all hidden when HOTPLUG was enabled.
The advantage of this is that when building a piece
of code then it is much more likely that the Section
mismatch errors are spotted and the warnings will be
felt less random of nature.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Greg KH <greg@kroah.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Adrian Bunk <bunk@kernel.org>

1 files changed, 39 insertions, 15 deletions

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 986513dcd70..730b321680c 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -670,27 +670,41 @@ int match(const char *sym, const char * const pat[])
 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 ALL_INIT_DATA_SECTIONS \
+        ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
+#define ALL_EXIT_DATA_SECTIONS \
+        ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
 
-#define INIT_TEXT_SECTIONS ".init.text$"
-#define EXIT_TEXT_SECTIONS ".exit.text$"
+#define ALL_INIT_TEXT_SECTIONS \
+        ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
+#define ALL_EXIT_TEXT_SECTIONS \
+        ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
 
-#define INIT_SECTIONS INIT_DATA_SECTIONS, INIT_TEXT_SECTIONS
-#define EXIT_SECTIONS EXIT_DATA_SECTIONS, EXIT_TEXT_SECTIONS
+#define ALL_INIT_SECTIONS ALL_INIT_DATA_SECTIONS, ALL_INIT_TEXT_SECTIONS
+#define ALL_EXIT_SECTIONS ALL_EXIT_DATA_SECTIONS, ALL_EXIT_TEXT_SECTIONS
 
 #define DATA_SECTIONS ".data$", ".data.rel$"
 #define TEXT_SECTIONS ".text$"
 
+#define INIT_SECTIONS      ".init.data$", ".init.text$"
+#define DEV_INIT_SECTIONS  ".devinit.data$", ".devinit.text$"
+#define CPU_INIT_SECTIONS  ".cpuinit.data$", ".cpuinit.text$"
+#define MEM_INIT_SECTIONS  ".meminit.data$", ".meminit.text$"
+
+#define EXIT_SECTIONS      ".exit.data$", ".exit.text$"
+#define DEV_EXIT_SECTIONS  ".devexit.data$", ".devexit.text$"
+#define CPU_EXIT_SECTIONS  ".cpuexit.data$", ".cpuexit.text$"
+#define MEM_EXIT_SECTIONS  ".memexit.data$", ".memexit.text$"
+
 /* init data sections */
-static const char *init_data_sections[] = { INIT_DATA_SECTIONS, NULL };
+static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
 
 /* all init sections */
-static const char *init_sections[] = { INIT_SECTIONS, NULL };
+static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
 
 /* All init and exit sections (code + data) */
 static const char *init_exit_sections[] =
-        {INIT_SECTIONS, EXIT_SECTIONS, NULL };
+        {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
 
 /* data section */
 static const char *data_sections[] = { DATA_SECTIONS, NULL };
@@ -734,22 +748,32 @@ const struct sectioncheck sectioncheck[] = {
  */
 {
         .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
-        .tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL }
+        .tosec   = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }
+},
+/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
+{
+        .fromsec = { DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL },
+        .tosec   = { INIT_SECTIONS, NULL }
+},
+/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
+{
+        .fromsec = { DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL },
+        .tosec   = { EXIT_SECTIONS, NULL }
 },
 /* Do not use exit code/data from init code */
 {
-        .fromsec = { INIT_SECTIONS, NULL },
-        .tosec   = { EXIT_SECTIONS, NULL },
+        .fromsec = { ALL_INIT_SECTIONS, NULL },
+        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 },
 /* Do not use init code/data from exit code */
 {
-        .fromsec = { EXIT_SECTIONS, NULL },
-        .tosec   = { INIT_SECTIONS, NULL }
+        .fromsec = { ALL_EXIT_SECTIONS, NULL },
+        .tosec   = { ALL_INIT_SECTIONS, NULL }
 },
 /* Do not export init/exit functions or data */
 {
         .fromsec = { "__ksymtab*", NULL },
-        .tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL }
+        .tosec   = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }
 }
 };