From 0ccade1ae2c00337d2b0bba2a175a060b93728a8 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 16 Feb 2023 09:40:08 +0100 Subject: [PATCH] x86/gas: replace inappropriate assertion when parsing registers PR gas/30117 Once a symbol had its expression evaluated, the "segment" of the symbol may be reg_section if a register is merely involved in the expression, not just when the expression references a "plain" register. Therefore the first of the assertions put in place by 4d1bb7955a8b was too strict. Convert it to an if() to deal with situations like this one found by fuzzing: x=s s=%eax+0 y=s or $6,x In non-debug builds this also avoids potentially silently generating bad code. --- gas/config/tc-i386.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c index e421a1718db..7cd50f5e267 100644 --- a/gas/config/tc-i386.c +++ b/gas/config/tc-i386.c @@ -13057,17 +13057,19 @@ parse_register (char *reg_string, char **end_op) { const expressionS *e = symbol_get_value_expression (symbolP); - know (e->X_op == O_register); - know (e->X_add_number >= 0 - && (valueT) e->X_add_number < i386_regtab_size); - r = i386_regtab + e->X_add_number; - if (!check_register (r)) + if (e->X_op == O_register) + { + know (e->X_add_number >= 0 + && (valueT) e->X_add_number < i386_regtab_size); + r = i386_regtab + e->X_add_number; + *end_op = input_line_pointer; + } + if (r && !check_register (r)) { as_bad (_("register '%s%s' cannot be used here"), register_prefix, r->reg_name); r = &bad_reg; } - *end_op = input_line_pointer; } *input_line_pointer = c; input_line_pointer = save; -- 2.30.2