mm: fix vmemmap pages free bug by pagetrace

PD#153090: mm: fix vmemmap pages free bug by pagetrace

A page in vmemap will be freed when pagetrace is enabled.
This caused page information wrong and may cause unexpected
panic issue.

Change-Id: I486c62af592a98c22bd1ab071b3a224c3298986d
Signed-off-by: tao zeng <tao.zeng@amlogic.com>

diff --git a/drivers/amlogic/memory_ext/page_trace.c b/drivers/amlogic/memory_ext/page_trace.c
index 4fa3e3c..0d411c6 100644 (file)
--- a/drivers/amlogic/memory_ext/page_trace.c
+++ b/drivers/amlogic/memory_ext/page_trace.c
@@ -167,8 +167,8 @@ static void push_ip(struct page_trace *base, struct page_trace *ip)
 
        /* debug check */
        check_trace_valid(base);
-       end = ((unsigned long)trace_buffer + ptrace_size);
-       WARN_ON(((unsigned long)base) >= end);
+       end = (((unsigned long)trace_buffer) + ptrace_size);
+       WARN_ON((unsigned long)(base + trace_step - 1) >= end);
 
        base[0] = *ip;
 }
@@ -482,10 +482,12 @@ void set_page_trace(struct page *page, int order, gfp_t gfp_flags)
                        trace.migrate_type = gfpflags_to_migratetype(gfp_flags);
                trace.order = order;
                base = find_page_base(page);
+       #if DEBUG_PAGE_TRACE
                pr_debug("%s, base:%p, page:%lx, _ip:%x, o:%d, f:%x, ip:%lx\n",
                         __func__, base, page_to_pfn(page),
                         (*((unsigned int *)&trace)), order,
                         gfp_flags, ip);
+       #endif
                push_ip(base, &trace);
        }
 }
@@ -494,12 +496,20 @@ EXPORT_SYMBOL(set_page_trace);
 void reset_page_trace(struct page *page, int order)
 {
        struct page_trace *base;
-       int i;
+       int i, cnt;
+#if DEBUG_PAGE_TRACE
+       unsigned long end;
+#endif
 
        if (page && trace_buffer) {
                base = find_page_base(page);
+               cnt = 1 << order;
+       #if DEBUG_PAGE_TRACE
                check_trace_valid(base);
-               for (i = 0; i < (1 << order); i++) {
+               end = ((unsigned long)trace_buffer + ptrace_size);
+               WARN_ON((unsigned long)(base + cnt * trace_step - 1) >= end);
+       #endif
+               for (i = 0; i < cnt; i++) {
                        base->order = IP_INVALID;
                        base += (trace_step);
                }
@@ -522,23 +532,25 @@ static void __init page_trace_pre_work(struct page *start_page,
        struct page *page, *last_page;
 
        size = PAGE_ALIGN(size);
+       size >>= PAGE_SHIFT;
 
        page = start_page;
-       last_page = page + (size >> PAGE_SHIFT);
-       for (i = 0; i < size >> PAGE_SHIFT;) {
+       last_page = page + size;
+       for (i = 0; i < size;) {
                order = page_private(page);
                pr_debug("page:%p, order:%d\n", page, order);
                list_del(&page->lru);   /* del from buddy */;
                set_page_private(page, 0);
-               for (j = 0; j < (1 << order); j++) {
-                       set_init_page_trace(page, 0, GFP_KERNEL);
+               for (j = 0; j < ((1 << order) - 1); j++) {
+                       if (i < size)
+                               set_init_page_trace(page, 0, GFP_KERNEL);
                        page++;
                        i++;
                }
        }
 
        /* free tailed pages */
-       while (page > last_page) {
+       while (page >= last_page) {
                __free_pages(page, 0);
                page--;
                tailed++;