security/sdp/cache_cleanup.c

/*
 * Copyright (c) 2015 Samsung Electronics Co., Ltd.
 *
 * Sensitive Data Protection
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <sdp/common.h>
#include <sdp/cache_cleanup.h>

#if SDP_CACHE_CLEANUP_DEBUG
static void sdp_page_dump(unsigned char *buf, int len, const char* str)
{
    unsigned int i;
    char s[512];

    s[0] = 0;
    for(i=0;i<len && i<32;++i) {
        char tmp[8];
        sprintf(tmp, " %02x", buf[i]);
        strcat(s, tmp);
    }

    if (len > 32) {
        char tmp[8];
        sprintf(tmp, " ...");
        strcat(s, tmp);
    }

    printk("%s [%s len=%d]\n", s, str, len);
}
#else
static void sdp_page_dump(unsigned char *buf, int len, const char* str) {
    return;
}
#endif

void sdp_page_cleanup(struct page *page)
{
    if(page && page->mapping) {
        if(mapping_sensitive(page->mapping)) {
            void *d;

#if SDP_CACHE_CLEANUP_DEBUG
            printk("%s : deleting [%s] sensitive page.\n",
                    __func__, page->mapping->host->i_sb->s_type->name);
            //dump_stack();
#endif
            d = kmap_atomic(page);
            if(d) {
                sdp_page_dump((unsigned char *)d, PAGE_SIZE, "freeing");
                clear_page(d);
                sdp_page_dump((unsigned char *)d, PAGE_SIZE, "freed");
                kunmap_atomic(d);
            }
        }
    }
}