[IMPROVE] synchronize usage of sspt_file.htable.heads

Change-Id: I4fc0715b3a0ac9a06e59ffec112b0b412a640eca
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>

diff --git a/us_manager/sspt/sspt_debug.h b/us_manager/sspt/sspt_debug.h
index a6830ff..18e34b9 100644 (file)
--- a/us_manager/sspt/sspt_debug.h
+++ b/us_manager/sspt/sspt_debug.h
@@ -71,7 +71,7 @@ static inline void print_page_probes(const struct sspt_page *page)
        }
 }
 
-static inline void print_file_probes(const struct sspt_file *file)
+static inline void print_file_probes(struct sspt_file *file)
 {
        int i;
        unsigned long table_size;
@@ -93,12 +93,14 @@ static inline void print_file_probes(const struct sspt_file *file)
               "table_size=%lu, vm_start=%lx\n",
               file->dentry->d_iname, name, table_size, file->vm_start);
 
+       down_read(&file->htable.sem);
        for (i = 0; i < table_size; ++i) {
                head = &file->htable.heads[i];
                swap_hlist_for_each_entry_rcu(page, node, head, hlist) {
                        print_page_probes(page);
                }
        }
+       up_read(&file->htable.sem);
 }
 
 static inline void print_proc_probes(struct sspt_proc *proc)

diff --git a/us_manager/sspt/sspt_file.c b/us_manager/sspt/sspt_file.c
index c700f39..c55da68 100644 (file)
--- a/us_manager/sspt/sspt_file.c
+++ b/us_manager/sspt/sspt_file.c
@@ -48,17 +48,20 @@ static unsigned long htable_size(const struct sspt_file *file)
        return 1 << file->htable.bits;
 }
 
-static struct hlist_head *htable_head_by_key(const struct sspt_file *file,
-                                            unsigned long offset)
-{
-       return &file->htable.heads[hash_ptr((void *)offset, file->htable.bits)];
-}
-
 static struct hlist_head *htable_head_by_idx(const struct sspt_file *file,
                                             unsigned long idx)
 {
        return &file->htable.heads[idx];
 }
+
+static struct hlist_head *htable_head_by_key(const struct sspt_file *file,
+                                            unsigned long offset)
+{
+       unsigned long idx = hash_ptr((void *)offset, file->htable.bits);
+
+       return htable_head_by_idx(file, idx);
+}
+
 /**
  * @brief Create sspt_file struct
  *
@@ -93,6 +96,8 @@ struct sspt_file *sspt_file_create(struct dentry *dentry, int page_cnt)
                INIT_HLIST_HEAD(&heads[i]);
 
        obj->htable.heads = heads;
+       init_rwsem(&obj->htable.sem);
+
        return obj;
 
 err:
@@ -114,6 +119,7 @@ void sspt_file_free(struct sspt_file *file)
        struct hlist_node *n;
        DECLARE_NODE_PTR_FOR_HLIST(p);
 
+       down_write(&file->htable.sem);
        for (i = 0; i < table_size; ++i) {
                head = htable_head_by_idx(file, i);
                swap_hlist_for_each_entry_safe(page, p, n, head, hlist) {
@@ -121,6 +127,7 @@ void sspt_file_free(struct sspt_file *file)
                        sspt_page_free(page);
                }
        }
+       up_write(&file->htable.sem);
 
        kfree(file->htable.heads);
        kfree(file);
@@ -150,13 +157,16 @@ static struct sspt_page *sspt_find_page(struct sspt_file *file,
 static struct sspt_page *sspt_find_page_or_new(struct sspt_file *file,
                                               unsigned long offset)
 {
-       struct sspt_page *page = sspt_find_page(file, offset);
+       struct sspt_page *page;
 
+       down_write(&file->htable.sem);
+       page = sspt_find_page(file, offset);
        if (page == NULL) {
                page = sspt_page_create(offset);
                if (page)
                        sspt_add_page(file, page);
        }
+       up_write(&file->htable.sem);
 
        return page;
 }
@@ -172,6 +182,7 @@ struct sspt_page *sspt_find_page_mapped(struct sspt_file *file,
                                        unsigned long page)
 {
        unsigned long offset;
+       struct sspt_page *p;
 
        if (file->vm_start > page || file->vm_end < page) {
                /* TODO: or panic?! */
@@ -185,7 +196,11 @@ struct sspt_page *sspt_find_page_mapped(struct sspt_file *file,
 
        offset = page - file->vm_start;
 
-       return sspt_find_page(file, offset);
+       down_read(&file->htable.sem);
+       p = sspt_find_page(file, offset);
+       up_read(&file->htable.sem);
+
+       return p;
 }
 
 /**
@@ -226,11 +241,13 @@ void sspt_file_on_each_ip(struct sspt_file *file,
        struct hlist_head *head;
        DECLARE_NODE_PTR_FOR_HLIST(node);
 
+       down_read(&file->htable.sem);
        for (i = 0; i < table_size; ++i) {
                head = htable_head_by_idx(file, i);
                swap_hlist_for_each_entry(page, node, head, hlist)
                        sspt_page_on_each_ip(page, func, data);
        }
+       up_read(&file->htable.sem);
 }
 
 /**
@@ -243,22 +260,28 @@ void sspt_file_on_each_ip(struct sspt_file *file,
  */
 int sspt_file_check_install_pages(struct sspt_file *file)
 {
+       int ret = 0;
        int i, table_size;
        struct sspt_page *page;
        struct hlist_head *head;
-       struct hlist_node *tmp;
        DECLARE_NODE_PTR_FOR_HLIST(node);
 
        table_size = htable_size(file);
+
+       down_read(&file->htable.sem);
        for (i = 0; i < table_size; ++i) {
                head = htable_head_by_idx(file, i);
-               swap_hlist_for_each_entry_safe(page, node, tmp, head, hlist) {
-                       if (sspt_page_is_installed(page))
-                               return 1;
+               swap_hlist_for_each_entry(page, node, head, hlist) {
+                       if (sspt_page_is_installed(page)) {
+                               ret = 1;
+                               goto unlock;
+                       }
                }
        }
 
-       return 0;
+unlock:
+       up_read(&file->htable.sem);
+       return ret;
 }
 
 /**
@@ -276,9 +299,10 @@ void sspt_file_install(struct sspt_file *file)
        struct mm_struct *mm;
        DECLARE_NODE_PTR_FOR_HLIST(node);
 
+       down_read(&file->htable.sem);
        for (i = 0; i < table_size; ++i) {
                head = htable_head_by_idx(file, i);
-               swap_hlist_for_each_entry_rcu(page, node, head, hlist) {
+               swap_hlist_for_each_entry(page, node, head, hlist) {
                        page_addr = file->vm_start + page->offset;
                        if (page_addr < file->vm_start ||
                            page_addr >= file->vm_end)
@@ -289,6 +313,7 @@ void sspt_file_install(struct sspt_file *file)
                                sspt_register_page(page, file);
                }
        }
+       up_read(&file->htable.sem);
 }
 
 /**
@@ -307,20 +332,22 @@ int sspt_file_uninstall(struct sspt_file *file,
        int table_size = htable_size(file);
        struct sspt_page *page;
        struct hlist_head *head;
-       struct hlist_node *tmp;
        DECLARE_NODE_PTR_FOR_HLIST(node);
 
+       down_read(&file->htable.sem);
        for (i = 0; i < table_size; ++i) {
                head = htable_head_by_idx(file, i);
-               swap_hlist_for_each_entry_safe(page, node, tmp, head, hlist) {
+               swap_hlist_for_each_entry(page, node, head, hlist) {
                        err = sspt_unregister_page(page, flag, task);
                        if (err != 0) {
                                printk(KERN_INFO "ERROR sspt_file_uninstall: "
                                       "err=%d\n", err);
+                               up_read(&file->htable.sem);
                                return err;
                        }
                }
        }
+       up_read(&file->htable.sem);
 
        if (flag != US_DISARM) {
                file->loaded = 0;

diff --git a/us_manager/sspt/sspt_file.h b/us_manager/sspt/sspt_file.h
index 3bda6ce..38d34aa 100644 (file)
--- a/us_manager/sspt/sspt_file.h
+++ b/us_manager/sspt/sspt_file.h
@@ -26,6 +26,7 @@
 
 #include "sspt_ip.h"
 #include <linux/types.h>
+#include <linux/rwsem.h>
 
 enum US_FLAGS;
 struct vm_area_struct;
@@ -41,6 +42,7 @@ struct sspt_file {
 
        /* sspt_page */
        struct {
+               struct rw_semaphore sem;        /**< Semaphore for hash-table */
                unsigned long bits;             /**< Hash-table size */
                struct hlist_head *heads;       /**< Heads for pages */
        } htable;