[PATCH] sparse: Increase pre_buffer[] and check overflow

[PATCH] sparse: Increase pre_buffer[] and check overflow

[Atsushi Nemoto]

I got this error when running sparse on mips kernel with gcc 4.3:

builtin:272:1: warning: Newline in string or character constant

The linus-mips kernel uses '$(CC) -dM -E' to generates arguments for
sparse.  With gcc 4.3, it generates lot of '-D' options and causes
pre_buffer overflow.

This patch increase pre_buffer[] size and add extra checking for
overflow instead of silently truncating.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
---
diff --git a/lib.c b/lib.c
index 0abcc9a..b8b2d57 100644
--- a/lib.c
+++ b/lib.c
@@ -186,7 +186,7 @@ void die(const char *fmt, ...)
 }
 
 static unsigned int pre_buffer_size;
-static char pre_buffer[8192];
+static char pre_buffer[16384];
 
 int Waddress_space = 1;
 int Wbitwise = 0;
@@ -238,6 +238,8 @@ void add_pre_buffer(const char *fmt, ...)
 		fmt, args);
 	pre_buffer_size = size;
 	va_end(args);
+	if (pre_buffer_size >= sizeof(pre_buffer) - 1)
+		die("pre_buffer overflow");
 }
 
 static char **handle_switch_D(char *arg, char **next)

Re: [PATCH] sparse: Increase pre_buffer[] and check overflow

[Atsushi Nemoto]

On Wed, 09 Jul 2008 00:28:05 +0900 (JST), Atsushi Nemoto <anemo@mba.ocn.ne.jp> wrote:
> The linus-mips kernel uses '$(CC) -dM -E' to generates arguments for
> sparse.  With gcc 4.3, it generates lot of '-D' options and causes
> pre_buffer overflow.

Here is an example of sparse commandline:

sparse -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise
-D__DBL_MIN_EXP__='(-1021)' -D__HQ_FBIT__='15' -D__SFRACT_IBIT__='0'
-D__FLT_MIN__='1.17549435e-38F' -D__UFRACT_MAX__='0XFFFFP-16UR'
-D__DEC64_DEN__='0.000000000000001E-383DD' -D__DQ_FBIT__='63'
-D__ULFRACT_FBIT__='32' -D__SACCUM_EPSILON__='0x1P-7HK'
-D__CHAR_BIT__='8' -D__USQ_IBIT__='0' -D__ACCUM_FBIT__='15'
-DR3000='1' -D__USFRACT_FBIT__='8'
-D__ULLFRACT_MAX__='0XFFFFFFFFFFFFFFFFP-64ULLR'
-D__WCHAR_MAX__='2147483647' -D__LACCUM_IBIT__='32'
-D__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4='1'
-D__DBL_DENORM_MIN__='4.9406564584124654e-324'
-D__FLT_EVAL_METHOD__='0' -D__unix__='1'
-D__LLACCUM_MAX__='0X7FFFFFFFFFFFFFFFP-31LLK' -D__FRACT_FBIT__='15'
-D_MIPS_ISA='_MIPS_ISA_MIPS32' -D__UACCUM_FBIT__='16'
-D__LANGUAGE_C='1' -D__DBL_MIN_10_EXP__='(-307)'
-D__FINITE_MATH_ONLY__='0' -D_MIPS_TUNE='"mips32r2"'
-D__LFRACT_IBIT__='0' -D__LFRACT_MAX__='0X7FFFFFFFP-31LR'
-D__DEC64_MAX_EXP__='384' -D_ABIO32='1' -D__SA_FBIT__='15'
-D__SHRT_MAX__='32767' -D__LDBL_MAX__='1.7976931348623157e+308L'
-D__FRACT_MAX__='0X7FFFP-15R' -D__UFRACT_FBIT__='16'
-D__UFRACT_MIN__='0.0UR' -D__LANGUAGE_C__='1' -D__UINTMAX_TYPE__='long
long unsigned int' -D__LLFRACT_EPSILON__='0x1P-63LLR' -D__linux='1'
-D__DEC32_EPSILON__='1E-6DF' -D__OPTIMIZE__='1' -D__unix='1'
-D__ULFRACT_MAX__='0XFFFFFFFFP-32ULR' -D__TA_IBIT__='64'
-D__LDBL_MAX_EXP__='1024' -D__MIPSEL__='1' -D__linux__='1'
-D__ULLFRACT_MIN__='0.0ULLR' -D__SCHAR_MAX__='127' -D__DBL_DIG__='15'
-D__LLACCUM_MIN__='(-0X1P31LLK-0X1P31LLK)' -D__SQ_FBIT__='31'
-D__SIZEOF_POINTER__='4' -D__USACCUM_IBIT__='8'
-D__USER_LABEL_PREFIX__='' -D__STDC_HOSTED__='0'
-D__LDBL_HAS_INFINITY__='1' -D__LFRACT_MIN__='(-0.5LR-0.5LR)'
-D__mips_fpr='32' -D__HA_IBIT__='8' -D__TQ_IBIT__='0'
-D__FLT_EPSILON__='1.19209290e-7F' -D__mips__='1'
-D__USFRACT_IBIT__='0' -D__LDBL_MIN__='2.2250738585072014e-308L'
-D__FRACT_MIN__='(-0.5R-0.5R)' -D__DEC32_MAX__='9.999999E96DF'
-D__DA_IBIT__='32' -DMIPSEL='1' -D__UQQ_FBIT__='8'
-D__SIZEOF_LONG__='4' -D__UACCUM_MAX__='0XFFFFFFFFP-16UK'
-D__DECIMAL_DIG__='17' -D__LFRACT_EPSILON__='0x1P-31LR'
-D__ULFRACT_MIN__='0.0ULR' -D__gnu_linux__='1'
-D__LDBL_HAS_QUIET_NAN__='1' -D__ULACCUM_IBIT__='32'
-D__UACCUM_EPSILON__='0x1P-16UK'
-D__ULLACCUM_MAX__='0XFFFFFFFFFFFFFFFFP-32ULLK' -D__HQ_IBIT__='0'
-D__FLT_HAS_DENORM__='1' -D__SIZEOF_LONG_DOUBLE__='8' -D_R3000='1'
-D__DQ_IBIT__='0' -D__DBL_MAX__='1.7976931348623157e+308'
-D__ULFRACT_IBIT__='0' -D__DBL_HAS_INFINITY__='1'
-D__ACCUM_IBIT__='16' -D__DEC32_MIN_EXP__='(-95)'
-D__LACCUM_MAX__='0X7FFFFFFFFFFFFFFFP-31LK' -D__LDBL_HAS_DENORM__='1'
-D__DEC128_MAX__='9.999999999999999999999999999999999E6144DL'
-D__DEC32_MIN__='1E-95DF' -D__ACCUM_MAX__='0X7FFFFFFFP-15K'
-D__DBL_MAX_EXP__='1024' -D__USACCUM_EPSILON__='0x1P-8UHK'
-D__R3000__='1' -D__DEC128_EPSILON__='1E-33DL'
-D__SFRACT_MAX__='0X7FP-7HR' -D__FRACT_IBIT__='0'
-D__UACCUM_MIN__='0.0UK' -Dmips='1' -D__UACCUM_IBIT__='16'
-D__LONG_LONG_MAX__='9223372036854775807LL' -D__SIZEOF_SIZE_T__='4'
-D__ULACCUM_MAX__='0XFFFFFFFFFFFFFFFFP-32ULK' -D__SIZEOF_WINT_T__='4'
-D__SA_IBIT__='16' -D__ULLACCUM_MIN__='0.0ULLK'
-D__GXX_ABI_VERSION='1002' -D__UTA_FBIT__='64'
-D__FLT_MIN_EXP__='(-125)' -D__USFRACT_MAX__='0XFFP-8UHR'
-D__UFRACT_IBIT__='0' -D_MIPSEL='1'
-D__DBL_MIN__='2.2250738585072014e-308' -D_MIPS_ARCH='"mips32r2"'
-D__LACCUM_MIN__='(-0X1P31LK-0X1P31LK)' -D__ULLACCUM_FBIT__='32'
-D__ULLFRACT_EPSILON__='0x1P-64ULLR' -D__DEC128_MIN__='1E-6143DL'
-D__REGISTER_PREFIX__='' -D__DBL_HAS_DENORM__='1'
-D__ACCUM_MIN__='(-0X1P15K-0X1P15K)' -D__SQ_IBIT__='0'
-D__UHA_FBIT__='8' -D__SFRACT_MIN__='(-0.5HR-0.5HR)' -D__R3000='1'
-D__UTQ_FBIT__='128' -D__FLT_MANT_DIG__='24' -D__VERSION__='"4.3.1"'
-D__ULLFRACT_FBIT__='64' -D__FRACT_EPSILON__='0x1P-15R'
-D__ULACCUM_MIN__='0.0ULK' -D__UDA_FBIT__='32'
-D__LLACCUM_EPSILON__='0x1P-31LLK' -D_MIPS_TUNE_MIPS32R2='1'
-D__USFRACT_MIN__='0.0UHR' -D__UQQ_IBIT__='0'
-D__DEC64_EPSILON__='1E-15DD' -D__DEC128_MIN_EXP__='(-6143)'
-D__UHQ_FBIT__='16' -D__LLACCUM_FBIT__='31' -Dunix='1'
-D__SIZE_TYPE__='unsigned int' -D__UDQ_FBIT__='64'
-D__DEC32_DEN__='0.000001E-95DF' -D__ELF__='1' -D__mips_isa_rev='2'
-D__ULFRACT_EPSILON__='0x1P-32ULR' -D__LLFRACT_FBIT__='63'
-D__FLT_RADIX__='2' -D__LDBL_EPSILON__='2.2204460492503131e-16L'
-D__SACCUM_MAX__='0X7FFFP-7HK' -D__SIZEOF_PTRDIFF_T__='4'
-D__LACCUM_EPSILON__='0x1P-31LK' -D_MIPS_SZPTR='32'
-D__USACCUM_MAX__='0XFFFFP-8UHK' -D__SFRACT_EPSILON__='0x1P-7HR'
-D__FLT_HAS_QUIET_NAN__='1' -D__FLT_MAX_10_EXP__='38'
-D__LONG_MAX__='2147483647L' -D__FLT_HAS_INFINITY__='1'
-D__USA_FBIT__='16' -D__DEC64_MAX__='9.999999999999999E384DD'
-D__DEC64_MANT_DIG__='16' -D__SACCUM_FBIT__='7' -D_mips='1'
-D__SIZEOF_INT__='4' -D__DEC32_MAX_EXP__='96' -D__QQ_FBIT__='7'
-Dlinux='1'
-D__DEC128_DEN__='0.000000000000000000000000000000001E-6143DL'
-D__UTA_IBIT__='64' -D_MIPS_SZINT='32' -D__LDBL_MANT_DIG__='53'
-D__SFRACT_FBIT__='7' -D__SACCUM_MIN__='(-0X1P7HK-0X1P7HK)'
-D__DBL_HAS_QUIET_NAN__='1' -D__MIPSEL='1' -D__WCHAR_TYPE__='int'
-D__SIZEOF_FLOAT__='4' -D__USQ_FBIT__='32'
-D__DEC64_MIN_EXP__='(-383)' -D__ULLACCUM_IBIT__='32'
-D__FLT_DIG__='6' -D__INT_MAX__='2147483647' -D__LACCUM_FBIT__='31'
-D__USACCUM_MIN__='0.0UHK' -D__UHA_IBIT__='8' -D__FLT_MAX_EXP__='128'
-D__UTQ_IBIT__='0' -D_MIPS_SIM='_ABIO32' -D__DBL_MANT_DIG__='53'
-D__DEC64_MIN__='1E-383DD' -D__WINT_TYPE__='unsigned int'
-D__SIZEOF_SHORT__='2' -D__ULLFRACT_IBIT__='0'
-D__LDBL_MIN_EXP__='(-1021)' -D_MIPS_FPSET='16' -D__UDA_IBIT__='32'
-D__LFRACT_FBIT__='31' -D__LDBL_MAX_10_EXP__='308'
-D__DBL_EPSILON__='2.2204460492503131e-16' -D__SIZEOF_WCHAR_T__='4'
-D__LLFRACT_MAX__='0X7FFFFFFFFFFFFFFFP-63LLR' -D__TQ_FBIT__='127'
-D__ULLACCUM_EPSILON__='0x1P-32ULLK' -D__UHQ_IBIT__='0'
-D__LLACCUM_IBIT__='32' -D__DEC_EVAL_METHOD__='2' -D__TA_FBIT__='63'
-D_MIPS_ARCH_MIPS32R2='1' -D__mips_soft_float='1' -D__UDQ_IBIT__='0'
-D__ACCUM_EPSILON__='0x1P-15K'
-D__INTMAX_MAX__='9223372036854775807LL'
-D__FLT_DENORM_MIN__='1.40129846e-45F' -D__LLFRACT_IBIT__='0'
-DVMLINUX_LOAD_ADDRESS='0xffffffff80100000'
-D__FLT_MAX__='3.40282347e+38F' -DLANGUAGE_C='1'
-D__USACCUM_FBIT__='8' -D__SIZEOF_DOUBLE__='8'
-D__FLT_MIN_10_EXP__='(-37)' -D__UFRACT_EPSILON__='0x1P-16UR'
-D__INTMAX_TYPE__='long long int' -D_LANGUAGE_C='1'
-D__DEC128_MAX_EXP__='6144' -D__DEC32_MANT_DIG__='7' -D__HA_FBIT__='7'
-D__DBL_MAX_10_EXP__='308'
-D__LDBL_DENORM_MIN__='4.9406564584124654e-324L' -D__STDC__='1'
-D__PTRDIFF_TYPE__='int' -D__LLFRACT_MIN__='(-0.5LLR-0.5LLR)'
-D__mips='32' -D__DA_FBIT__='31' -D_MIPS_SZLONG='32'
-D__USA_IBIT__='16' -D__DEC128_MANT_DIG__='34'
-D__LDBL_MIN_10_EXP__='(-307)' -D__SIZEOF_LONG_LONG__='8'
-D__ULACCUM_EPSILON__='0x1P-32ULK' -D__SACCUM_IBIT__='8'
-D__LDBL_DIG__='15' -D__GNUC_GNU_INLINE__='1'
-D__USFRACT_EPSILON__='0x1P-8UHR' -D__ULACCUM_FBIT__='32'
-D__QQ_IBIT__='0' -nostdinc -isystem
/usr/lib/gcc/mipsel-linux/4.3.1/include -Wp,-MD,init/.main.o.d
-nostdinc -isystem /usr/lib/gcc/mipsel-linux/4.3.1/include
-D__KERNEL__ -Iinclude -Iinclude2 -I/home/git/linux-mips/include
-include include/linux/autoconf.h -I/home/git/linux-mips/init -Iinit
-Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing
-fno-common -Werror-implicit-function-declaration -O2
-fno-stack-protector -mabi=32 -G 0 -mno-abicalls -fno-pic -pipe
-msoft-float -ffreestanding -march=mips32r2 -Wa,-mips32r2 -Wa,--trap
-I/home/git/linux-mips/include/asm-mips/mach-mips
-Iinclude/asm-mips/mach-mips
-I/home/git/linux-mips/include/asm-mips/mach-generic
-Iinclude/asm-mips/mach-generic
-D"VMLINUX_LOAD_ADDRESS=0xffffffff80100000" -fomit-frame-pointer
-Wdeclaration-after-statement -Wno-pointer-sign -D"KBUILD_STR(s)=#s"
-D"KBUILD_BASENAME=KBUILD_STR(main)"
-D"KBUILD_MODNAME=KBUILD_STR(main)" /home/git/linux-mips/init/main.c ;


Many of them are not required for kernel build.  So another workaround
might be filtering some patterns out on kernel side.  Something like
this:

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index ad36c94..4ffa809 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -641,6 +641,9 @@ LDFLAGS			+= -m $(ld-emul)
 ifdef CONFIG_MIPS
 CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -xc /dev/null | \
 	egrep -vw '__GNUC_(|MINOR_|PATCHLEVEL_)_' | \
+	egrep -vw '__(FLT|DBL|LDBL)_[A-Z_0-9]+__' | \
+	egrep -vw '__[A-Z]*(ACCUM|FRACT)_[A-Z_0-9]+__' | \
+	egrep -vw '__DEC[0-9]+_[A-Z_0-9]+__' | \
 	sed -e 's/^\#define /-D/' -e "s/ /='/" -e "s/$$/'/")
 ifdef CONFIG_64BIT
 CHECKFLAGS		+= -m64

Re: [PATCH] sparse: Increase pre_buffer[] and check overflow

[Al Viro]

On Wed, Jul 09, 2008 at 12:59:53AM +0900, Atsushi Nemoto wrote:
explicit (and __STDC__ is redundant): -D__linux__ -Dlinux -D__STDC__
-Dunix -D__unix__ -Wbitwise

Not used anywhere in the tree:
-D__DBL_MIN_EXP__='(-1021)' -D__HQ_FBIT__='15' -D__SFRACT_IBIT__='0'
-D__FLT_MIN__='1.17549435e-38F' -D__UFRACT_MAX__='0XFFFFP-16UR'
-D__DEC64_DEN__='0.000000000000001E-383DD' -D__DQ_FBIT__='63'
-D__ULFRACT_FBIT__='32' -D__SACCUM_EPSILON__='0x1P-7HK'
-D__CHAR_BIT__='8' -D__USQ_IBIT__='0' -D__ACCUM_FBIT__='15'

Maybe, let me check...  Nope, not used.
> -DR3000='1'

Not used anywhere:
> -D__USFRACT_FBIT__='8'
> -D__ULLFRACT_MAX__='0XFFFFFFFFFFFFFFFFP-64ULLR'
> -D__WCHAR_MAX__='2147483647' -D__LACCUM_IBIT__='32'
> -D__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4='1'
> -D__DBL_DENORM_MIN__='4.9406564584124654e-324'
> -D__FLT_EVAL_METHOD__='0'

Explicitly passed: -D__unix__='1'

Not used:
> -D__LLACCUM_MAX__='0X7FFFFFFFFFFFFFFFP-31LLK' -D__FRACT_FBIT__='15'

Used:
-D_MIPS_ISA='_MIPS_ISA_MIPS32'

Not used:
> -D__UACCUM_FBIT__='16'
> -D__LANGUAGE_C='1' -D__DBL_MIN_10_EXP__='(-307)'
> -D__FINITE_MATH_ONLY__='0' -D_MIPS_TUNE='"mips32r2"'
> -D__LFRACT_IBIT__='0' -D__LFRACT_MAX__='0X7FFFFFFFP-31LR'
> -D__DEC64_MAX_EXP__='384' -D_ABIO32='1' -D__SA_FBIT__='15'
> -D__SHRT_MAX__='32767' -D__LDBL_MAX__='1.7976931348623157e+308L'
> -D__FRACT_MAX__='0X7FFFP-15R' -D__UFRACT_FBIT__='16'
> -D__UFRACT_MIN__='0.0UR' -D__LANGUAGE_C__='1'

Not used, might be worth defining in sparse:
-D__UINTMAX_TYPE__='long
> long unsigned int'

Not used:
 -D__LLFRACT_EPSILON__='0x1P-63LLR'

Explicitly passed:
 -D__linux='1'

Not used:
> -D__DEC32_EPSILON__='1E-6DF'

Passed by sparse:
-D__OPTIMIZE__='1'

Explicitly passed: -D__unix='1'

Not used:
> -D__ULFRACT_MAX__='0XFFFFFFFFP-32ULR' -D__TA_IBIT__='64'
> -D__LDBL_MAX_EXP__='1024'

Used: -D__MIPSEL__='1'

Explicitly passed: -D__linux__='1'

[...]

And AFAICS, the ratio gets even worse further into the list...

Re: [PATCH] sparse: Increase pre_buffer[] and check overflow

[Morten Welinder]

> Not used anywhere in the tree:
> -D__DBL_MIN_EXP__='(-1021)' -D__HQ_FBIT__='15' -D__SFRACT_IBIT__='0'
> -D__FLT_MIN__='1.17549435e-38F' -D__UFRACT_MAX__='0XFFFFP-16UR'
> -D__DEC64_DEN__='0.000000000000001E-383DD' -D__DQ_FBIT__='63'
> -D__ULFRACT_FBIT__='32' -D__SACCUM_EPSILON__='0x1P-7HK'
> -D__CHAR_BIT__='8' -D__USQ_IBIT__='0' -D__ACCUM_FBIT__='15'

Wrong tree, :-)  Check your equivalent of
/usr/lib64/gcc/x86_64-suse-linux/4.1.0/include/float.h

The kernel probably doesn't care much, but sparse as a general tool
ought to care.

Morten

Re: [PATCH] sparse: Increase pre_buffer[] and check overflow

[Sam Ravnborg]

On Wed, Jul 09, 2008 at 12:28:05AM +0900, Atsushi Nemoto wrote:
> I got this error when running sparse on mips kernel with gcc 4.3:
> 
> builtin:272:1: warning: Newline in string or character constant
> 
> The linus-mips kernel uses '$(CC) -dM -E' to generates arguments for
> sparse.  With gcc 4.3, it generates lot of '-D' options and causes
> pre_buffer overflow.

Why does mips have this need when all other archs does not?
We should fix sparse so it is dynamically allocated - but
that is not an excuse for mips to use odd stuff like this.

So please someone from mips land explain why this is needed.

	Sam

Re: [PATCH] sparse: Increase pre_buffer[] and check overflow

[Atsushi Nemoto]

On Tue, 8 Jul 2008 22:45:47 +0200, Sam Ravnborg <sam@ravnborg.org> wrote:
> > The linus-mips kernel uses '$(CC) -dM -E' to generates arguments for
> > sparse.  With gcc 4.3, it generates lot of '-D' options and causes
> > pre_buffer overflow.
> 
> Why does mips have this need when all other archs does not?
> We should fix sparse so it is dynamically allocated - but
> that is not an excuse for mips to use odd stuff like this.
> 
> So please someone from mips land explain why this is needed.

This was introduced by commit 59b3e8e9aac69d2d02853acac7e2affdfbabca50.
("[MIPS] Makefile crapectomy.")

Before the commit, CHECKFLAGS was adjusted like this:

CHECKFLAGS-y				+= -D__linux__ -D__mips__ \
					   -D_MIPS_SZINT=32 \
					   -D_ABIO32=1 \
					   -D_ABIN32=2 \
					   -D_ABI64=3
CHECKFLAGS-$(CONFIG_32BIT)		+= -D_MIPS_SIM=_ABIO32 \
					   -D_MIPS_SZLONG=32 \
					   -D_MIPS_SZPTR=32 \
					   -D__PTRDIFF_TYPE__=int
CHECKFLAGS-$(CONFIG_64BIT)		+= -m64 -D_MIPS_SIM=_ABI64 \
					   -D_MIPS_SZLONG=64 \
					   -D_MIPS_SZPTR=64 \
					   -D__PTRDIFF_TYPE__="long int"
CHECKFLAGS-$(CONFIG_CPU_BIG_ENDIAN)	+= -D__MIPSEB__
CHECKFLAGS-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -D__MIPSEL__
CHECKFLAGS				= $(CHECKFLAGS-y)
CHECKFLAGS-$(CONFIG_CPU_R3000)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS1
CHECKFLAGS-$(CONFIG_CPU_TX39XX)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS1
CHECKFLAGS-$(CONFIG_CPU_R6000)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS2
CHECKFLAGS-$(CONFIG_CPU_R4300)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS3
CHECKFLAGS-$(CONFIG_CPU_VR41XX)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS3
CHECKFLAGS-$(CONFIG_CPU_R4X00)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS3
CHECKFLAGS-$(CONFIG_CPU_TX49XX)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS3
CHECKFLAGS-$(CONFIG_CPU_MIPS32_R1)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS32
CHECKFLAGS-$(CONFIG_CPU_MIPS32_R2)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS32
CHECKFLAGS-$(CONFIG_CPU_MIPS64_R1)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS64
CHECKFLAGS-$(CONFIG_CPU_MIPS64_R2)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS64
CHECKFLAGS-$(CONFIG_CPU_R5000)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS4
CHECKFLAGS-$(CONFIG_CPU_R5432)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS4
CHECKFLAGS-$(CONFIG_CPU_NEVADA)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS4
CHECKFLAGS-$(CONFIG_CPU_RM7000)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS4
CHECKFLAGS-$(CONFIG_CPU_RM9000)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS4
CHECKFLAGS-$(CONFIG_CPU_SB1)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS64
CHECKFLAGS-$(CONFIG_CPU_R8000)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS4
CHECKFLAGS-$(CONFIG_CPU_R10000)	+= -D_MIPS_ISA=_MIPS_ISA_MIPS4

And now:

CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -xc /dev/null | \
	egrep -vw '__GNUC_(|MINOR_|PATCHLEVEL_)_' | \
	sed -e 's/^\#define /-D/' -e "s/ /='/" -e "s/$$/'/")
ifdef CONFIG_64BIT
CHECKFLAGS		+= -m64
endif

It looks fairly simple, unless you run make C=1 V=1 ...

---
Atsushi Nemoto

Re: [PATCH] sparse: Increase pre_buffer[] and check overflow

[Sam Ravnborg]

On Thu, Jul 10, 2008 at 01:18:18AM +0900, Atsushi Nemoto wrote:
> On Tue, 8 Jul 2008 22:45:47 +0200, Sam Ravnborg <sam@ravnborg.org> wrote:
> > > The linus-mips kernel uses '$(CC) -dM -E' to generates arguments for
> > > sparse.  With gcc 4.3, it generates lot of '-D' options and causes
> > > pre_buffer overflow.
> > 
> > Why does mips have this need when all other archs does not?
> > We should fix sparse so it is dynamically allocated - but
> > that is not an excuse for mips to use odd stuff like this.
> > 
> > So please someone from mips land explain why this is needed.
> 
> This was introduced by commit 59b3e8e9aac69d2d02853acac7e2affdfbabca50.
> ("[MIPS] Makefile crapectomy.")
> 
> Before the commit, CHECKFLAGS was adjusted like this:
> 
> CHECKFLAGS-y				+= -D__linux__ -D__mips__ \
> 					   -D_MIPS_SZINT=32 \
> 					   -D_ABIO32=1 \
...

So the expalnation seems that gcc for mips define much more
than the usual gcc does.
My gcc define 76 symbols for i386.

And we use this stuff in the kernel.

OK - thanks for the details.

	Sam

Re: [PATCH] sparse: Increase pre_buffer[] and check overflow

[Al Viro]

On Wed, Jul 09, 2008 at 06:32:12PM +0200, Sam Ravnborg wrote:
> So the expalnation seems that gcc for mips define much more
> than the usual gcc does.
> My gcc define 76 symbols for i386.
> 
> And we use this stuff in the kernel.

How much of it do we really use?  Let's see - on i386 gcc-4.1.2 I see
79 symbols.  64 simply never occur in the tree.  At all.  Out of remaining
15, we have

__GNUC__, __GNUC_MAJOR__, __GNUC_PATCHLEVEL__ - provided by sparse.
__STDC__: few users, provided by sparse.
__SIZE_TYPE__: one odd user, defined by sparse anyway
__PTRDIFF_TYPE__: one odd user, defined by sparse anyway

__linux__ - few users, explicitly added in top-level Makefile
linux - 3 users.  Defined in top-level Makefile.
unix - no real users (some instances, of course, but none outside of comments,
#include pathnames and string constants).  Defined in top-level Makefile,
anyway.

__USER_LABEL_PREFIX__, __REGISTER_PREFIX__ - arch/m68knommu/lib/*.S; not
a sparse fodder anyway *and* defaults are given in files themselves.

__ELF__: arch/alpha/boot/tools/objstrip.c (userland helper, actually, *and*
misplaced there; it's used as a proxy for type of kernel image)

__i386__: a bunch
__i386: one user, redundant (__i386__ *and* i386 in the same #if)
i386: 3 users besides the aforementioned one.

So...  Only 3 symbols out of the entire bunch are arch-dependent *and* not
provided by sparse itself.  Absolute majority of the rest is never ever
used in the tree.

I very much doubt that mips situation is seriously different...

Re: [PATCH] sparse: Increase pre_buffer[] and check overflow

[Atsushi Nemoto]

On Thu, 10 Jul 2008 18:39:45 +0100, Al Viro <viro@ZenIV.linux.org.uk> wrote:
> So...  Only 3 symbols out of the entire bunch are arch-dependent *and* not
> provided by sparse itself.  Absolute majority of the rest is never ever
> used in the tree.
> 
> I very much doubt that mips situation is seriously different...

Then, how about this?  Ralf, is this filter reasonable?


Subject: [PATCH] mips: reduce symbols passed to CHECKFLAGS

Without this patch, gcc 4.3 will produces so many symbols and causes
pre_buffer[] overflow in sparse.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
---
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index d319cd6..6c4eb9f 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -619,7 +619,7 @@ LDFLAGS			+= -m $(ld-emul)
 
 ifdef CONFIG_MIPS
 CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -xc /dev/null | \
-	egrep -vw '__GNUC_(|MINOR_|PATCHLEVEL_)_' | \
+	egrep '(MIPS|mips|_ABI|_TYPE__)' | \
 	sed -e 's/^\#define /-D/' -e "s/ /='/" -e "s/$$/'/")
 ifdef CONFIG_64BIT
 CHECKFLAGS		+= -m64