[PATCH] makedumpfile: Add support to module data structures

[Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>]

When trying to refer a module data structure GET_DIE_NFIELDS
does not set the dwarf_info to the right module.

For instance:

struct ap_device {
	...
	struct list_head list;
	...
};

struct ap_device *dev;

As a result, it was able to resolve only dev->list and it was failing to
resolve dev->list.next.
The patch takes care of handling this by introducing GET_DIE_NFIELDS_ALL
which takes care of setting the dwarf_info to the appropriate module.

Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
---
 dwarf_info.c      |    8 -----
 erase_info.c      |   80 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 erase_info.h      |    3 +-
 extension_eppic.c |    2 +
 extension_eppic.h |    2 +
 5 files changed, 83 insertions(+), 12 deletions(-)

diff --git a/dwarf_info.c b/dwarf_info.c
index 6e21b8a..268e922 100644
--- a/dwarf_info.c
+++ b/dwarf_info.c
@@ -489,7 +489,6 @@ get_die_from_offset(Dwarf_Off offset, Dwarf_Die *die)
 		return FALSE;
 
 	if (!dwarf_offdie(dwarf_info.dwarfd, offset, die)) {
-		ERRMSG("Can't find the DIE.\n");
 		return FALSE;
 	}
 
@@ -1343,14 +1342,12 @@ get_die_nfields(unsigned long long die_off)
 	Dwarf_Die result, child, *die;
 
 	if (!get_die_from_offset((Dwarf_Off) die_off, &result)) {
-		ERRMSG("Can't find the DIE.\n");
 		return -1;
 	}
 
 	die = &result;
 	tag = dwarf_tag(die);
 	if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
-		ERRMSG("DIE is not of structure or union type.\n");
 		clean_dwfl_info();
 		return -1;
 	}
@@ -1388,14 +1385,12 @@ get_die_member(unsigned long long die_off, int index, long *offset,
 		return -1;
 
 	if (!get_die_from_offset((Dwarf_Off) die_off, &result)) {
-		ERRMSG("Can't find the DIE.\n");
 		return -1;
 	}
 
 	die = &result;
 	tag = dwarf_tag(die);
 	if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
-		ERRMSG("DIE is not of structure or union type.\n");
 		clean_dwfl_info();
 		return -1;
 	}
@@ -1471,7 +1466,6 @@ get_die_attr_type(unsigned long long die_off, int *type_flag,
 		return FALSE;
 
 	if (!get_die_from_offset((Dwarf_Off) die_off, &result)) {
-		ERRMSG("Can't find the DIE.\n");
 		return FALSE;
 	}
 
@@ -1509,7 +1503,6 @@ get_die_name(unsigned long long die_off)
 		return NULL;
 
 	if (!get_die_from_offset((Dwarf_Off) die_off, &result)) {
-		ERRMSG("Can't find the DIE.\n");
 		return NULL;
 	}
 
@@ -1554,7 +1547,6 @@ get_die_length(unsigned long long die_off, int flag)
 		return FALSE;
 
 	if (!get_die_from_offset((Dwarf_Off) die_off, &result)) {
-		ERRMSG("Can't find the DIE.\n");
 		return FALSE;
 	}
 
diff --git a/erase_info.c b/erase_info.c
index a789389..e0e0f71 100644
--- a/erase_info.c
+++ b/erase_info.c
@@ -34,7 +34,7 @@ struct call_back eppic_cb = {
 	&get_die_offset,
 	&get_die_length,
 	&get_die_member_all,
-	&get_die_nfields,
+	&get_die_nfields_all,
 	&get_symbol_addr_all,
 	&update_filter_info_raw
 };
@@ -2028,6 +2028,84 @@ get_domain_all(char *symname, int cmd, unsigned long long *die) {
 }
 
 /*
+ * Search for die in modules as well as vmlinux
+ */
+int
+get_die_nfields_all(unsigned long long die_off)
+{
+	short vmlinux_searched = 0;
+	long nfields = -1;
+	unsigned int i, current_mod;
+	struct module_info *modules;
+
+	/* Search in vmlinux if debuginfo is set to vmlinux */
+	if (!strcmp(get_dwarf_module_name(), "vmlinux")) {
+		nfields = get_die_nfields(die_off);
+		if (nfields > 0)
+			return nfields;
+
+		vmlinux_searched = 1;
+	}
+
+	/*
+	 * Proceed the search in modules. Try in the module
+	 * which resulted in a hit in the previous search
+	 */
+
+	modules = mod_st.modules;
+	current_mod = mod_st.current_mod;
+
+	if (strcmp(get_dwarf_module_name(), modules[current_mod].name)) {
+		if (!set_dwarf_debuginfo(modules[current_mod].name,
+				info->system_utsname.release, NULL, -1)) {
+			ERRMSG("Cannot set to current module %s\n",
+					modules[current_mod].name);
+			return -1;
+		}
+	}
+
+	nfields = get_die_nfields(die_off);
+	if (nfields > 0)
+		return nfields;
+
+	/* Search in all modules */
+	for (i = 0; i < mod_st.num_modules; i++) {
+
+		/* Already searched. Skip */
+		if (i == current_mod)
+			continue;
+
+		if (!set_dwarf_debuginfo(modules[i].name,
+				info->system_utsname.release, NULL, -1)) {
+			ERRMSG("Skipping Module section %s\n", modules[i].name);
+			continue;
+		}
+
+		nfields = get_die_nfields(die_off);
+
+		if (nfields < 0)
+			continue;
+
+		/*
+		 * Die found. Set the current_mod to this module index,
+		 * a minor optimization for fast lookup next time
+		 */
+		mod_st.current_mod = i;
+		return nfields;
+	}
+
+	/* Die not found in any module. Set debuginfo back to vmlinux */
+	set_dwarf_debuginfo("vmlinux", NULL, info->name_vmlinux,
+			info->fd_vmlinux);
+
+	if (!vmlinux_searched)
+		return get_die_nfields(die_off);
+	else
+		return -1;
+
+}
+
+/*
  * Search for die member in modules as well as vmlinux
  */
 int
diff --git a/erase_info.h b/erase_info.h
index a90fac0..4d4957e 100644
--- a/erase_info.h
+++ b/erase_info.h
@@ -35,6 +35,7 @@ unsigned long long get_symbol_addr_all(char *);
 long get_domain_all(char *, int, unsigned long long *);
 int get_die_member_all(unsigned long long die_off, int index, long *offset,
 		char **name, int *nbits, int *fbits, unsigned long long *m_die);
+int get_die_nfields_all(unsigned long long die_off);
 
 struct call_back {
 	long (*get_domain_all)(char *, int, unsigned long long *);
@@ -48,7 +49,7 @@ struct call_back {
 	int (*get_die_member_all)(unsigned long long die_off, int index,
 		long *offset, char **name, int *nbits, int *fbits,
 		unsigned long long *m_die);
-	int (*get_die_nfields)(unsigned long long die_off);
+	int (*get_die_nfields_all)(unsigned long long die_off);
 	unsigned long long (*get_symbol_addr_all)(char *symname);
 	int (*update_filter_info_raw)(unsigned long long, int, int);
 };
diff --git a/extension_eppic.c b/extension_eppic.c
index 7e045c9..bb36d5a 100644
--- a/extension_eppic.c
+++ b/extension_eppic.c
@@ -219,7 +219,7 @@ apimember(char *mname, ull idx, type_t *tm, member_t *m, ull *last_index)
 	ull m_die, die_off = idx;
 	char *name = NULL;
 
-	nfields = GET_DIE_NFIELDS(die_off);
+	nfields = GET_DIE_NFIELDS_ALL(die_off);
 	/*
 	 * GET_DIE_NFIELDS() returns < 0 if the die is not structure type
 	 * or union type
diff --git a/extension_eppic.h b/extension_eppic.h
index 42437f2..24189ba 100644
--- a/extension_eppic.h
+++ b/extension_eppic.h
@@ -88,7 +88,7 @@ struct call_back *cb;
 #define GET_DIE_OFFSET cb->get_die_offset
 #define GET_DIE_LENGTH cb->get_die_length
 #define GET_DIE_MEMBER_ALL cb->get_die_member_all
-#define GET_DIE_NFIELDS cb->get_die_nfields
+#define GET_DIE_NFIELDS_ALL cb->get_die_nfields_all
 #define GET_SYMBOL_ADDR_ALL cb->get_symbol_addr_all
 #define UPDATE_FILTER_INFO_RAW cb->update_filter_info_raw
 


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