2 files changed, 82 insertions, 44 deletions

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 342bca62c496..eeac3e313b2b 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -69,6 +69,15 @@ static inline int is_kernel(unsigned long addr)
         return in_gate_area_no_task(addr);
 }
 
+static int is_ksym_addr(unsigned long addr)
+{
+        if (all_var)
+                return is_kernel(addr);
+
+        return is_kernel_text(addr) || is_kernel_inittext(addr) ||
+                is_kernel_extratext(addr);
+}
+
 /* expand a compressed symbol data into the resulting uncompressed string,
    given the offset to where the symbol is in the compressed stream */
 static unsigned int kallsyms_expand_symbol(unsigned int off, char *result)
@@ -155,6 +164,73 @@ unsigned long kallsyms_lookup_name(const char *name)
         return module_kallsyms_lookup_name(name);
 }
 
+static unsigned long get_symbol_pos(unsigned long addr,
+                                    unsigned long *symbolsize,
+                                    unsigned long *offset)
+{
+        unsigned long symbol_start = 0, symbol_end = 0;
+        unsigned long i, low, high, mid;
+
+        /* This kernel should never had been booted. */
+        BUG_ON(!kallsyms_addresses);
+
+        /* do a binary search on the sorted kallsyms_addresses array */
+        low = 0;
+        high = kallsyms_num_syms;
+
+        while (high - low > 1) {
+                mid = (low + high) / 2;
+                if (kallsyms_addresses[mid] <= addr)
+                        low = mid;
+                else
+                        high = mid;
+        }
+
+        /*
+         * search for the first aliased symbol. Aliased
+         * symbols are symbols with the same address
+         */
+        while (low && kallsyms_addresses[low-1] == kallsyms_addresses[low])
+                --low;
+
+        symbol_start = kallsyms_addresses[low];
+
+        /* Search for next non-aliased symbol */
+        for (i = low + 1; i < kallsyms_num_syms; i++) {
+                if (kallsyms_addresses[i] > symbol_start) {
+                        symbol_end = kallsyms_addresses[i];
+                        break;
+                }
+        }
+
+        /* if we found no next symbol, we use the end of the section */
+        if (!symbol_end) {
+                if (is_kernel_inittext(addr))
+                        symbol_end = (unsigned long)_einittext;
+                else if (all_var)
+                        symbol_end = (unsigned long)_end;
+                else
+                        symbol_end = (unsigned long)_etext;
+        }
+
+        *symbolsize = symbol_end - symbol_start;
+        *offset = addr - symbol_start;
+
+        return low;
+}
+
+/*
+ * Lookup an address but don't bother to find any names.
+ */
+int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize,
+                                unsigned long *offset)
+{
+        if (is_ksym_addr(addr))
+                return !!get_symbol_pos(addr, symbolsize, offset);
+
+        return !!module_address_lookup(addr, symbolsize, offset, NULL);
+}
+
 /*
  * Lookup an address
  * - modname is set to NULL if it's in the kernel
@@ -167,57 +243,18 @@ const char *kallsyms_lookup(unsigned long addr,
                             unsigned long *offset,
                             char **modname, char *namebuf)
 {
-        unsigned long i, low, high, mid;
         const char *msym;
 
-        /* This kernel should never had been booted. */
-        BUG_ON(!kallsyms_addresses);
-
         namebuf[KSYM_NAME_LEN] = 0;
         namebuf[0] = 0;
 
-        if ((all_var && is_kernel(addr)) ||
-            (!all_var && (is_kernel_text(addr) || is_kernel_inittext(addr) ||
-                                is_kernel_extratext(addr)))) {
-                unsigned long symbol_end = 0;
-
-                /* do a binary search on the sorted kallsyms_addresses array */
-                low = 0;
-                high = kallsyms_num_syms;
-
-                while (high-low > 1) {
-                        mid = (low + high) / 2;
-                        if (kallsyms_addresses[mid] <= addr) low = mid;
-                        else high = mid;
-                }
-
-                /* search for the first aliased symbol. Aliased symbols are
-                   symbols with the same address */
-                while (low && kallsyms_addresses[low - 1] == kallsyms_addresses[low])
-                        --low;
+        if (is_ksym_addr(addr)) {
+                unsigned long pos;
 
+                pos = get_symbol_pos(addr, symbolsize, offset);
                 /* Grab name */
-                kallsyms_expand_symbol(get_symbol_offset(low), namebuf);
-
-                /* Search for next non-aliased symbol */
-                for (i = low + 1; i < kallsyms_num_syms; i++) {
-                        if (kallsyms_addresses[i] > kallsyms_addresses[low]) {
-                                symbol_end = kallsyms_addresses[i];
-                                break;
-                        }
-                }
-
-                /* if we found no next symbol, we use the end of the section */
-                if (!symbol_end) {
-                        if (is_kernel_inittext(addr))
-                                symbol_end = (unsigned long)_einittext;
-                        else
-                                symbol_end = all_var ? (unsigned long)_end : (unsigned long)_etext;
-                }
-
-                *symbolsize = symbol_end - kallsyms_addresses[low];
+                kallsyms_expand_symbol(get_symbol_offset(pos), namebuf);
                 *modname = NULL;
-                *offset = addr - kallsyms_addresses[low];
                 return namebuf;
         }
 
diff --git a/kernel/module.c b/kernel/module.c
index 7c77a0a9275c..7f60e782de1e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2040,7 +2040,8 @@ const char *module_address_lookup(unsigned long addr,
         list_for_each_entry(mod, &modules, list) {
                 if (within(addr, mod->module_init, mod->init_size)
                     || within(addr, mod->module_core, mod->core_size)) {
-                        *modname = mod->name;
+                        if (modname)
+                                *modname = mod->name;
                         return get_ksymbol(mod, addr, size, offset);
                 }
         }