2 files changed, 75 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 14fb355e3caa..c4ecb2994ba3 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -79,6 +79,38 @@ config HEADERS_CHECK
           exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
           your build tree), to make sure they're suitable.
 
+config DEBUG_SECTION_MISMATCH
+        bool "Enable full Section mismatch analysis"
+        default n
+        help
+          The section mismatch analysis checks if there are illegal
+          references from one section to another section.
+          Linux will during link or during runtime drop some sections
+          and any use of code/data previously in these sections will
+          most likely result in an oops.
+          In the code functions and variables are annotated with
+          __init, __devinit etc. (see full list in include/linux/init.h)
+          which result in the code/data being placed in specific sections.
+          The section mismatch anaylsis are always done after a full
+          kernel build but enabling this options will in addition
+          do the following:
+          - Add the option -fno-inline-functions-called-once to gcc
+            When inlining a function annotated __init in a non-init
+            function we would loose the section information and thus
+            the analysis would not catch the illegal reference.
+            This options tell gcc to inline less but will also
+            result in a larger kernel.
+          - Run the section mismatch analysis for each module/built-in.o
+            When we run the section mismatch analysis on vmlinux.o we
+            looses valueable information about where the mismatch was
+            introduced.
+            Running the analysis for each module/built-in.o file
+            will tell where the mismatch happens much closer to the
+            source. The drawback is that we will report the same
+            mismatch at least twice.
+          - Enable verbose reporting from modpost to help solving
+            the section mismatches reported.
+
 config DEBUG_KERNEL
         bool "Kernel debugging"
         help
diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c
index bda0d71a2514..78ccd73a8841 100644
--- a/lib/find_next_bit.c
+++ b/lib/find_next_bit.c
@@ -178,4 +178,47 @@ found_middle_swap:
 
 EXPORT_SYMBOL(generic_find_next_zero_le_bit);
 
+unsigned long generic_find_next_le_bit(const unsigned long *addr, unsigned
+                long size, unsigned long offset)
+{
+        const unsigned long *p = addr + BITOP_WORD(offset);
+        unsigned long result = offset & ~(BITS_PER_LONG - 1);
+        unsigned long tmp;
+
+        if (offset >= size)
+                return size;
+        size -= result;
+        offset &= (BITS_PER_LONG - 1UL);
+        if (offset) {
+                tmp = ext2_swabp(p++);
+                tmp &= (~0UL << offset);
+                if (size < BITS_PER_LONG)
+                        goto found_first;
+                if (tmp)
+                        goto found_middle;
+                size -= BITS_PER_LONG;
+                result += BITS_PER_LONG;
+        }
+
+        while (size & ~(BITS_PER_LONG - 1)) {
+                tmp = *(p++);
+                if (tmp)
+                        goto found_middle_swap;
+                result += BITS_PER_LONG;
+                size -= BITS_PER_LONG;
+        }
+        if (!size)
+                return result;
+        tmp = ext2_swabp(p);
+found_first:
+        tmp &= (~0UL >> (BITS_PER_LONG - size));
+        if (tmp == 0UL)         /* Are any bits set? */
+                return result + size; /* Nope. */
+found_middle:
+        return result + __ffs(tmp);
+
+found_middle_swap:
+        return result + __ffs(ext2_swab(tmp));
+}
+EXPORT_SYMBOL(generic_find_next_le_bit);
 #endif /* __BIG_ENDIAN */