[Crash-utility] [PATCH 2/4] module's percpu basic procedure.

[Toshikazu Nakayama]

- Initialize new member at module_init()
- Make static SEC_FOUND to .data..percpu and .data.percpu sections
  at store_section_data()
  These can not read from /dev/mem or core file.
  (not include in kallsyms nor module_core.)
- Install syms into st->mod_load_namespace at store_load_module_symbols()
  module's percpu section include bfd of module object.
  The syment.value is sum of bfd value and module.percpu.

Signed-off-by: Toshikazu Nakayama <nakayama.ts at ncos.nec.co.jp>
---
 kernel.c  |    1 +
 symbols.c |   12 +++++++++++-
 2 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/kernel.c b/kernel.c
index 9ba0dc4..3439c5a 100755
--- a/kernel.c
+++ b/kernel.c
@@ -2694,6 +2694,7 @@ module_init(void)
 		MEMBER_OFFSET_INIT(module_init_size, "module", "init_size");
 		MEMBER_OFFSET_INIT(module_init_text_size, "module", 
 			"init_text_size");
+		MEMBER_OFFSET_INIT(module_percpu, "module", "percpu");
 
 		/*
 		 *  Make sure to pick the kernel "modules" list_head symbol,
diff --git a/symbols.c b/symbols.c
index ec9c893..0a1d170 100755
--- a/symbols.c
+++ b/symbols.c
@@ -1349,6 +1349,7 @@ store_module_symbols_v2(ulong total, int mods_installed)
 		lm->mod_ext_symcnt = mcnt;
 		lm->mod_init_module_ptr = ULONG(modbuf + 
 			OFFSET(module_module_init));
+		lm->mod_percpu = ULONG(modbuf + OFFSET(module_percpu));
 		if (THIS_KERNEL_VERSION >= LINUX(2,6,27)) {
 			lm->mod_etext_guess = lm->mod_base +
 				UINT(modbuf + OFFSET(module_core_text_size));
@@ -8346,6 +8347,10 @@ store_section_data(struct load_module *lm, bfd *bfd, asection *section)
 	lm->mod_section_data[i].section = section;
 	lm->mod_section_data[i].priority = prio;
 	lm->mod_section_data[i].flags = section->flags & ~SEC_FOUND;
+	/* percpu section isn't included in kallsyms nor module_core area. */
+	if (lm->mod_percpu &&
+	    (STREQ(name,".data.percpu") || STREQ(name, ".data..percpu")))
+		lm->mod_section_data[i].flags |= SEC_FOUND;
 	lm->mod_section_data[i].size = bfd_section_size(bfd, section);
 	lm->mod_section_data[i].offset = 0;
 	if (strlen(name) < MAX_MOD_SEC_NAME)
@@ -9314,7 +9319,12 @@ store_load_module_symbols(bfd *bfd, int dynamic, void *minisyms,
 				else if ((spx = kallsyms_module_symbol(lm, &syminfo))) {
 					syminfo.value = spx->value;
 					found = TRUE;
-                                } else {
+				} else if (lm->mod_percpu &&
+					(STREQ(secname, ".data.percpu") ||
+					STREQ(secname, ".data..percpu"))) {
+					syminfo.value += lm->mod_percpu;
+					found = TRUE;
+				} else {
                                         syminfo.value += lm->mod_section_data[i].offset + lm->mod_base;
                                         found = TRUE;
                                 }
-- 
1.7.3.2.161.g3089c