diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 32 | ||||
| -rw-r--r-- | lib/find_next_bit.c | 43 |
2 files changed, 75 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 14fb355e3ca..c4ecb2994ba 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 bda0d71a251..78ccd73a884 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 */ |