From 23637568ad0c9b5ab0ad27d2f2f26d1e9282c527 Mon Sep 17 00:00:00 2001 From: Jonathan Nieder 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 $? 1 Line 240 contains "c8: ENTER Iw,Ib", which indicates that this instruction has two immediate operands, the second of which is one byte. The script loops through the immediate operands using a for loop. Unfortunately, there is no guarantee in awk that a for (variable in array) loop will return the indices in increasing order. Internally, both original-awk and mawk iterate over a hash table for this purpose, and both implementations happen to produce the index 2 before 1. The supposed second immediate operand is more than one byte wide, producing the error. So loop over the indices in increasing order instead. As a side-effect, with mawk this means the silly two-entry hash table never has to be built. Signed-off-by: Jonathan Nieder Acked-by Masami Hiramatsu Cc: Jim Keniston Cc: Frederic Weisbecker LKML-Reference: <20091213220437.GA27718@progeny.tock> Signed-off-by: Ingo Molnar --- arch/x86/tools/gen-insn-attr-x86.awk | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/x86/tools/gen-insn-attr-x86.awk b/arch/x86/tools/gen-insn-attr-x86.awk index e34e92a28eb6..7a6850683c34 100644 --- a/arch/x86/tools/gen-insn-attr-x86.awk +++ b/arch/x86/tools/gen-insn-attr-x86.awk @@ -226,12 +226,12 @@ function add_flags(old,new) { } # convert operands to flags. -function convert_operands(opnd, i,imm,mod) +function convert_operands(count,opnd, i,j,imm,mod) { imm = null mod = null - for (i in opnd) { - i = opnd[i] + for (j = 1; j <= count; j++) { + i = opnd[j] if (match(i, imm_expr) == 1) { if (!imm_flag[i]) semantic_error("Unknown imm opnd: " i) @@ -282,8 +282,8 @@ function convert_operands(opnd, i,imm,mod) # parse one opcode if (match($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++) -- 2.20.1