From 23637568ad0c9b5ab0ad27d2f2f26d1e9282c527 Mon Sep 17 00:00:00 2001
From: Jonathan Nieder <jrnieder@gmail.com>
Date: Sun, 13 Dec 2009 16:04:38 -0600
Subject: [PATCH] x86: Fix kprobes build with non-gawk awk
The instruction attribute table generator fails when run by mawk
or original-awk:
$ mawk -f arch/x86/tools/gen-insn-attr-x86.awk \
arch/x86/lib/x86-opcode-map.txt > /dev/null
Semantic error at 240: Second IMM error
$ echo $?
1
Line 240 contains "c8: ENTER Iw,Ib", which indicates that this
instruction has two immediate operands, the second of which is
one byte. The script loops through the immediate operands using
a for loop.
Unfortunately, there is no guarantee in awk that a for (variable
in array) loop will return the indices in increasing order.
Internally, both original-awk and mawk iterate over a hash table
for this purpose, and both implementations happen to produce the
index 2 before 1. The supposed second immediate operand is more
than one byte wide, producing the error.
So loop over the indices in increasing order instead. As a
side-effect, with mawk this means the silly two-entry hash table
never has to be built.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091213220437.GA27718@progeny.tock>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/tools/gen-insn-attr-x86.awk | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/tools/gen-insn-attr-x86.awk b/arch/x86/tools/gen-insn-attr-x86.awk
index e34e92a28eb66..7a6850683c34d 100644
--- a/arch/x86/tools/gen-insn-attr-x86.awk
+++ b/arch/x86/tools/gen-insn-attr-x86.awk
@@ -226,12 +226,12 @@ function add_flags(old,new) {
}
# convert operands to flags.
-function convert_operands(opnd, i,imm,mod)
+function convert_operands(count,opnd, i,j,imm,mod)
{
imm = null
mod = null
- for (i in opnd) {
- i = opnd[i]
+ for (j = 1; j <= count; j++) {
+ i = opnd[j]
if (match(i, imm_expr) == 1) {
if (!imm_flag[i])
semantic_error("Unknown imm opnd: " i)
@@ -282,8 +282,8 @@ function convert_operands(opnd, i,imm,mod)
# parse one opcode
if (match($i, opnd_expr)) {
opnd = $i
- split($(i++), opnds, ",")
- flags = convert_operands(opnds)
+ count = split($(i++), opnds, ",")
+ flags = convert_operands(count, opnds)
}
if (match($i, ext_expr))
ext = $(i++)
--
2.30.2