Re: CONFIG_KPROBES=y build requires gawk

[Roland Dreier <rdreier@cisco.com>]

 > As Al Viro said, if we run awk with LC_ALL=C, then the characters will be
 > sorted as ASCII. So, your patch is OK if you can add LC_ALL=C just before
 > $(AWK). (I'm not so sure whether Makefile can accept it...)

OK, updated patch:

===

x86: Don't use POSIX character classes in gen-insn-attr-x86.awk

Not all awk implementations (including the default awk in Ubuntu 9.10)
support POSIX character classes.  Since x86-opcode-map.txt is plain
ASCII, we can just use explicit ranges for lower case, alphabetic, and
alphanumeric characters instead.  We set LC_ALL=C when invoking awk so
that ASCII ranges are never misinterpreted.

I verified that the Debian version of mawk, which doesn't have POSIX
character set suport, generates the byte-for-byte the same inat-tables.c
after this patch as gawk did on an unpatched kernel.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
---
 arch/x86/lib/Makefile                |    2 +-
 arch/x86/tools/gen-insn-attr-x86.awk |   10 ++++------
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 45b20e4..0c46d60 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -5,7 +5,7 @@
 inat_tables_script = $(srctree)/arch/x86/tools/gen-insn-attr-x86.awk
 inat_tables_maps = $(srctree)/arch/x86/lib/x86-opcode-map.txt
 quiet_cmd_inat_tables = GEN     $@
-      cmd_inat_tables = $(AWK) -f $(inat_tables_script) $(inat_tables_maps) > $@ || rm -f $@
+      cmd_inat_tables = LC_ALL=C $(AWK) -f $(inat_tables_script) $(inat_tables_maps) > $@ || rm -f $@
 
 $(obj)/inat-tables.c: $(inat_tables_script) $(inat_tables_maps)
 	$(call cmd,inat_tables)
diff --git a/arch/x86/tools/gen-insn-attr-x86.awk b/arch/x86/tools/gen-insn-attr-x86.awk
index 7a68506..eaf11f5 100644
--- a/arch/x86/tools/gen-insn-attr-x86.awk
+++ b/arch/x86/tools/gen-insn-attr-x86.awk
@@ -6,8 +6,6 @@
 
 # Awk implementation sanity check
 function check_awk_implement() {
-	if (!match("abc", "[[:lower:]]+"))
-		return "Your awk doesn't support charactor-class."
 	if (sprintf("%x", 0) != "0")
 		return "Your awk has a printf-format problem."
 	return ""
@@ -44,12 +42,12 @@ BEGIN {
 	delete gtable
 	delete atable
 
-	opnd_expr = "^[[:alpha:]/]"
+	opnd_expr = "^[A-Za-z/]"
 	ext_expr = "^\\("
 	sep_expr = "^\\|$"
-	group_expr = "^Grp[[:alnum:]]+"
+	group_expr = "^Grp[0-9A-Za-z]+"
 
-	imm_expr = "^[IJAO][[:lower:]]"
+	imm_expr = "^[IJAO][a-z]"
 	imm_flag["Ib"] = "INAT_MAKE_IMM(INAT_IMM_BYTE)"
 	imm_flag["Jb"] = "INAT_MAKE_IMM(INAT_IMM_BYTE)"
 	imm_flag["Iw"] = "INAT_MAKE_IMM(INAT_IMM_WORD)"
@@ -62,7 +60,7 @@ BEGIN {
 	imm_flag["Ob"] = "INAT_MOFFSET"
 	imm_flag["Ov"] = "INAT_MOFFSET"
 
-	modrm_expr = "^([CDEGMNPQRSUVW/][[:lower:]]+|NTA|T[012])"
+	modrm_expr = "^([CDEGMNPQRSUVW/][a-z]+|NTA|T[012])"
 	force64_expr = "\\([df]64\\)"
 	rex_expr = "^REX(\\.[XRWB]+)*"
 	fpu_expr = "^ESC" # TODO