2008-02-27 Martin Hunt <hunt@redhat.com>

	* sym.h (_stp_module): Add text_size, lock, and unwind data
	pointer.
	* sym.c (_stp_find_module_by_addr): New function.
	(_stp_kallsyms_lookup): Call _stp_find_module_by_addr().
	(_stp_get_unwind_info): New.

	* runtime.h: Move debug macros to debug.h. Include it.
	* debug.h: New file.
	* map.c: Update debug calls.
	* map-gen.c: Update debug calls.
	* pmap-gen.c: Update debug calls.

	* mempool.c: New file.

	* symbols.c: Use rwlocks. Use new dbug macros. Handle
	unwind info if present.

	* transport.c: Include mempool.c. Update dbug and kbug calls
	to new macros.
	* transport_msgs.h (_stp_command_name): Add
	struct containing message names for debugging.

	* control.c, procfs.c: Use new dbug macros. Use
	new mempool functions.

1 files changed, 117 insertions, 68 deletions

diff --git a/runtime/transport/symbols.c b/runtime/transport/symbols.c
index e740dde8..8c453a55 100644
--- a/runtime/transport/symbols.c
+++ b/runtime/transport/symbols.c
@@ -16,16 +16,6 @@
 #define _SYMBOLS_C_
 #include "../sym.h"
 
-DEFINE_SPINLOCK(_stp_module_lock);
-#define STP_TRYLOCK_MODULES  ({						\
-		int numtrylock = 0;					\
-		while (!spin_trylock_irqsave (&_stp_module_lock, flags) && (++numtrylock < MAXTRYLOCK)) \
-			ndelay (TRYLOCKDELAY);				\
-		(numtrylock >= MAXTRYLOCK);				\
-			})
-#define STP_LOCK_MODULES  spin_lock_irqsave(&_stp_module_lock, flags)
-#define STP_UNLOCK_MODULES spin_unlock_irqrestore(&_stp_module_lock, flags)
-
 static char *_stp_symbol_data = NULL;
 static int _stp_symbol_state = 0;
 static char *_stp_module_data = NULL;
@@ -63,7 +53,7 @@ static unsigned _stp_get_sym_sizes(struct module *m, unsigned *dsize)
 }
 
 /* allocate space for a module and symbols */
-static struct _stp_module * _stp_alloc_module(unsigned num, unsigned datasize)
+static struct _stp_module * _stp_alloc_module(unsigned num, unsigned datasize, unsigned unwindsize)
 {
 	struct _stp_module *mod = (struct _stp_module *)_stp_kzalloc(sizeof(struct _stp_module));
 	if (mod == NULL)
@@ -85,6 +75,14 @@ static struct _stp_module * _stp_alloc_module(unsigned num, unsigned datasize)
 		mod->allocated |= 2;
 	}
 
+	mod->unwind_data = _stp_kmalloc(unwindsize);
+	if (mod->unwind_data == NULL) {
+		mod->unwind_data = _stp_vmalloc(unwindsize);
+		if (mod->unwind_data == NULL)
+			goto bad;
+		mod->allocated |= 4;
+	}
+	
 	mod->num_symbols = num;
 	return mod;
 
@@ -97,19 +95,40 @@ bad:
 				_stp_kfree(mod->symbols);
 			mod->symbols = NULL;
 		}
+		if (mod->symbol_data) {
+			if (mod->allocated & 2)
+				_stp_vfree(mod->symbol_data);
+			else
+				_stp_kfree(mod->symbol_data);
+			mod->symbol_data = NULL;
+		}
+		_stp_kfree(mod); 
+		if (mod->symbols) {
+			if (mod->allocated & 1)
+				_stp_vfree(mod->symbols);
+			else
+				_stp_kfree(mod->symbols);
+			mod->symbols = NULL;
+		}
 		_stp_kfree(mod); 
 	}
 	return NULL;
 }
 
-static struct _stp_module * _stp_alloc_module_from_module (struct module *m)
+static struct _stp_module * _stp_alloc_module_from_module (struct module *m, uint32_t unwind_len)
 {
 	unsigned datasize, num = _stp_get_sym_sizes(m, &datasize);
-	return _stp_alloc_module(num, datasize);
+	return _stp_alloc_module(num, datasize, unwind_len);
 }
 
 static void _stp_free_module(struct _stp_module *mod)
 {
+	/* The module write lock is held. Any prior readers of this */
+	/* module's data will have read locks and need to finish before */
+	/* the memory is freed. */
+	write_lock(&mod->lock);
+	write_unlock(&mod->lock); /* there will be no more readers */
+
 	/* free symbol memory */
 	if (mod->symbols) {
 		if (mod->allocated & 1)
@@ -126,21 +145,30 @@ static void _stp_free_module(struct _stp_module *mod)
 		mod->symbol_data = NULL;
 
 	}
+	if (mod->unwind_data) {
+		if (mod->allocated & 4)
+			_stp_vfree(mod->unwind_data);
+		else
+			_stp_kfree(mod->unwind_data);
+		mod->unwind_data = NULL;
+
+	}
 	if (mod->sections) {
 		_stp_kfree(mod->sections);
 		mod->sections = NULL;
 	}
+
 	/* free module memory */
 	_stp_kfree(mod);
 }
 
 /* Delete a module and free its memory. */
-/* The lock should already be held before calling this. */
+/* The module lock should already be held before calling this. */
 static void _stp_del_module(struct _stp_module *mod)
 {
 	int i, num;
 
-	// kbug("deleting %s\n", mod->name);
+	// kbug(DEBUG_SYMBOLS, "deleting %s\n", mod->name);
 
 	/* signal relocation code to clear its cache */
 	_stp_module_relocate((char *)-1, NULL, 0);
@@ -185,7 +213,7 @@ static unsigned long _stp_kallsyms_lookup_name(const char *name);
 static int _stp_do_symbols(const char __user *buf, int count)
 {
 	struct _stp_symbol *s;
-	unsigned datasize, num;	
+	unsigned datasize, num, unwindsize;	
 	int i;
 
 	switch (_stp_symbol_state) {
@@ -198,23 +226,26 @@ static int _stp_do_symbols(const char __user *buf, int count)
 			return -EFAULT;
 		if (get_user(datasize, (unsigned __user *)(buf+4)))
 			return -EFAULT;
-		//kbug("num=%d datasize=%d\n", num, datasize);
+		if (get_user(unwindsize, (unsigned __user *)(buf+8)))
+			return -EFAULT;
+		dbug(DEBUG_UNWIND, "num=%d datasize=%d unwindsize=%d\n", num, datasize, unwindsize);
 
-		_stp_modules[0] = _stp_alloc_module(num, datasize);
+		_stp_modules[0] = _stp_alloc_module(num, datasize, unwindsize);
 		if (_stp_modules[0] == NULL) {
 			errk("cannot allocate memory\n");
 			return -EFAULT;
 		}
+		rwlock_init(&_stp_modules[0]->lock);
 		_stp_symbol_state = 1;
 		break;
 	case 1:
-		//kbug("got stap_symbols, count=%d\n", count);
+		dbug(DEBUG_SYMBOLS, "got stap_symbols, count=%d\n", count);
 		if (copy_from_user ((char *)_stp_modules[0]->symbols, buf, count))
 			return -EFAULT;
 		_stp_symbol_state = 2;
 		break;
 	case 2:
-		//kbug("got symbol data, count=%d buf=%p\n", count, buf);
+		dbug(DEBUG_SYMBOLS, "got symbol data, count=%d buf=%p\n", count, buf);
 		if (copy_from_user (_stp_modules[0]->symbol_data, buf, count))
 			return -EFAULT;
 		_stp_num_modules = 1;
@@ -227,8 +258,19 @@ static int _stp_do_symbols(const char __user *buf, int count)
                 /* NB: this mapping is used by kernel/_stext pseudo-relocations. */
 		_stp_modules[0]->text = _stp_kallsyms_lookup_name("_stext");
 		_stp_modules[0]->data = _stp_kallsyms_lookup_name("_etext");
+		_stp_modules[0]->text_size = _stp_modules[0]->data - _stp_modules[0]->text;		
 		_stp_modules_by_addr[0] = _stp_modules[0];
-		//kbug("done with symbol data\n");
+		dbug(DEBUG_SYMBOLS, "Got kernel symbols. text=%p len=%u\n", 
+		     (int64_t)_stp_modules[0]->text, _stp_modules[0]->text_size);
+		break;
+	case 3:
+		dbug(DEBUG_UNWIND, "got unwind data, count=%d\n", count);
+		_stp_symbol_state = 4;
+		if (copy_from_user (_stp_modules[0]->unwind_data, buf, count)) {
+			_dbug("cfu failed\n");
+			return -EFAULT;
+		}
+		_stp_modules[0]->unwind_data_len = count;
 		break;
 	default:
 		errk("unexpected symbol data of size %d.\n", count);
@@ -266,10 +308,8 @@ static void u32_swap(void *a, void *b, int size)
 
 static void generic_swap(void *a, void *b, int size)
 {
-	char t;
-
 	do {
-		t = *(char *)a;
+		char t = *(char *)a;
 		*(char *)a++ = *(char *)b;
 		*(char *)b++ = t;
 	} while (--size > 0);
@@ -328,7 +368,7 @@ void _stp_sort(void *base, size_t num, size_t size,
 }
 
 /* Create a new _stp_module and load the symbols */
-static struct _stp_module *_stp_load_module_symbols (struct _stp_module *imod)
+static struct _stp_module *_stp_load_module_symbols (struct _stp_module *imod, uint32_t unwind_len)
 {
 	unsigned i, num=0;
 	struct module *m = (struct module *)imod->module;
@@ -336,12 +376,12 @@ static struct _stp_module *_stp_load_module_symbols (struct _stp_module *imod)
 	char *dataptr;
 
 	if (m == NULL) {
-		kbug("imod->module is NULL\n");
+		kbug(DEBUG_SYMBOLS, "imod->module is NULL\n");
 		return NULL;
 	}
 	if (try_module_get(m)) {
 
-		mod = _stp_alloc_module_from_module(m);
+		mod = _stp_alloc_module_from_module(m, unwind_len);
 		if (mod == NULL) {
 			module_put(m);
 			errk("failed to allocate memory for module.\n");
@@ -354,6 +394,8 @@ static struct _stp_module *_stp_load_module_symbols (struct _stp_module *imod)
 		mod->data = imod->data;
 		mod->num_sections = imod->num_sections;
 		mod->sections = imod->sections;
+		mod->text_size = m->core_text_size;
+		rwlock_init(&mod->lock);
 
 		/* now copy all the symbols we are interested in */
 		dataptr = mod->symbol_data;
@@ -375,24 +417,32 @@ static struct _stp_module *_stp_load_module_symbols (struct _stp_module *imod)
 	return mod;
 }
 
-/* Do we already have this module? */
-static int _stp_module_exists(struct _stp_module *mod)
+/* Remove any old module info from our database */
+static void _stp_module_exists_delete (struct _stp_module *mod)
 {
-	int i, res;
-	unsigned long flags;
-	// kbug("exists? %s\n", mod->name);
-	STP_LOCK_MODULES;
-	for (i = 1; i < _stp_num_modules; i++) {
-		res = strcmp(_stp_modules[i]->name, mod->name);
-		if (res > 0)
+	int i, num;
+
+	/* remove any old modules with the same name */
+	for (num = 1; num < _stp_num_modules; num++) {
+		if (strcmp(_stp_modules[num]->name, mod->name) == 0) {
+			dbug(DEBUG_SYMBOLS, "found existing module with name %s. Deleting.\n", mod->name);
+			_stp_del_module(_stp_modules[num]);
 			break;
-		if (res == 0 && _stp_modules[i]->module == mod->module) {
-			STP_UNLOCK_MODULES;
-			return 1;
 		}
 	}
-	STP_UNLOCK_MODULES;
-	return 0;
+
+	/* remove modules with overlapping addresses */
+	for (num = 1; num < _stp_num_modules; num++) {
+		if (mod->text + mod->text_size < _stp_modules_by_addr[num]->text)
+			continue;
+		if (mod->text < _stp_modules_by_addr[num]->text 
+		    + _stp_modules_by_addr[num]->text_size) {
+			dbug(DEBUG_SYMBOLS, "New module %s overlaps with old module %s. Deleting old.\n", 
+			     mod->name, _stp_modules_by_addr[num]->name);
+			_stp_del_module(_stp_modules_by_addr[num]);
+		}
+	}
+
 }
 
 static int _stp_ins_module(struct _stp_module *mod)
@@ -400,9 +450,11 @@ static int _stp_ins_module(struct _stp_module *mod)
 	int i, num, res, ret = 0;
 	unsigned long flags;
 
-	// kbug("insert %s\n", mod->name);
+	// kbug(DEBUG_SYMBOLS, "insert %s\n", mod->name);
 
-	STP_LOCK_MODULES;
+	STP_WLOCK_MODULES;
+
+	_stp_module_exists_delete(mod);
 
 	/* check for overflow */
 	if (_stp_num_modules == STP_MAX_MODULES) {
@@ -412,32 +464,25 @@ static int _stp_ins_module(struct _stp_module *mod)
 	}
 	
 	/* insert alphabetically in _stp_modules[] */
-	for (num = 1; num < _stp_num_modules; num++) {
-		res = strcmp(_stp_modules[num]->name, mod->name);
-		if (res < 0)
-			continue;
-		if (res > 0)
+	for (num = 1; num < _stp_num_modules; num++)
+		if (strcmp(_stp_modules[num]->name, mod->name) > 0)
 			break;
-		_stp_del_module(_stp_modules[num]);
-		break;
-	}
 	for (i = _stp_num_modules; i > num; i--)
 		_stp_modules[i] = _stp_modules[i-1];
 	_stp_modules[num] = mod;
 
 	/* insert by text address in _stp_modules_by_addr[] */
-	for (num = 1; num < _stp_num_modules; num++) {
-		if (_stp_modules_by_addr[num]->text > mod->text)
+	for (num = 1; num < _stp_num_modules; num++)
+		if (mod->text < _stp_modules_by_addr[num]->text)
 			break;
-	}
 	for (i = _stp_num_modules; i > num; i--)
 		_stp_modules_by_addr[i] = _stp_modules_by_addr[i-1];
 	_stp_modules_by_addr[num] = mod;
-
+	
 	_stp_num_modules++;
 
 done:
-	STP_UNLOCK_MODULES;
+	STP_WUNLOCK_MODULES;
 	return ret;
 }
 
@@ -456,13 +501,13 @@ static int _stp_do_module(const char __user *buf, int count)
 	if (copy_from_user ((char *)&tmpmod, buf, sizeof(tmpmod)))
 		return -EFAULT;
 
-	section_len = count - sizeof(tmpmod);
+	section_len = count - sizeof(tmpmod) - tmpmod.unwind_len;
 	if (section_len <= 0) {
 		errk("section_len = %d\n", section_len);
 		return -EFAULT;
 	}
-	kbug("Got module %s, count=%d section_len=%d\n", 
-	     tmpmod.name, count, section_len);
+	dbug(DEBUG_SYMBOLS, "Got module %s, count=%d section_len=%d unwind_len=%d\n", 
+	     tmpmod.name, count, section_len, tmpmod.unwind_len);
 
 	strcpy(mod.name, tmpmod.name);
 	mod.module = tmpmod.module;
@@ -470,9 +515,6 @@ static int _stp_do_module(const char __user *buf, int count)
 	mod.data = tmpmod.data;
 	mod.num_sections = tmpmod.num_sections;
 	
-	if (_stp_module_exists(&mod))
-		return count;
-
 	/* copy in section data */
 	mod.sections = _stp_kmalloc(section_len);
 	if (mod.sections == NULL) {
@@ -489,18 +531,27 @@ static int _stp_do_module(const char __user *buf, int count)
 				 + (long)((long)mod.sections + mod.num_sections * sizeof(struct _stp_symbol)));
 	}
 
-	#ifdef DEBUG_SYMBOLS
+	#if 0
 	for (i = 0; i < mod.num_sections; i++)
-		printk("section %d (stored at %p): %s %lx\n", i, &mod.sections[i], mod.sections[i].symbol, mod.sections[i].addr);
+		_dbug("section %d (stored at %p): %s %lx\n", i, &mod.sections[i], mod.sections[i].symbol, mod.sections[i].addr);
 	#endif
 
 	/* load symbols from tmpmod.module to mod */
-	m = _stp_load_module_symbols(&mod);	
+	m = _stp_load_module_symbols(&mod, tmpmod.unwind_len); 
 	if (m == NULL) {
 		_stp_kfree(mod.sections);
 		return 0;
 	}
 
+	dbug(DEBUG_SYMBOLS, "module %s loaded.  Text=%p text_size=%u\n", m->name, (int64_t)m->text, m->text_size);
+	/* finally copy unwind info */
+	if (copy_from_user (m->unwind_data, buf+sizeof(tmpmod)+section_len, tmpmod.unwind_len)) {
+		_stp_free_module(m);
+		_stp_kfree(mod.sections);
+		return -EFAULT;
+	}
+	m->unwind_data_len = tmpmod.unwind_len;
+
 	if (_stp_ins_module(m) < 0) {
 		_stp_free_module(m);
 		return -ENOMEM;
@@ -513,20 +564,18 @@ static int _stp_ctl_send (int type, void *data, int len);
 
 static int _stp_module_load_notify(struct notifier_block * self, unsigned long val, void * data)
 {
-#ifdef CONFIG_MODULES
 	struct module *mod = (struct module *)data;
 	struct _stp_module rmod;
 
 	switch (val) {
 	case MODULE_STATE_COMING:
-		dbug("module %s loaded\n", mod->name);
+		dbug(DEBUG_SYMBOLS, "module %s load notify\n", mod->name);
 		strlcpy(rmod.name, mod->name, STP_MODULE_NAME_LEN);
 		_stp_ctl_send(STP_MODULE, &rmod, sizeof(struct _stp_module));
 		break;
 	default:
 		errk("module loaded? val=%ld\n", val);
 	}
-#endif
 	return 0;
 }