Fix a potential illegal memory access in the Z80 assembler.

PR 25604
	* config/tc-z80.c (contains_register): Prevent an illegal memory
	access when checking an expression for a register name.
This commit is contained in:
Sergey Belyashov 2020-03-03 13:09:19 +00:00 committed by Nick Clifton
parent d8e4137b5e
commit 8326546ebb
2 changed files with 30 additions and 8 deletions

View File

@ -1,3 +1,9 @@
2020-03-03 Sergey Belyashov <sergey.belyashov@gmail.com>
PR 25604
* config/tc-z80.c (contains_register): Prevent an illegal memory
access when checking an expression for a register name.
2020-03-03 Alan Modra <amodra@gmail.com>
* config/obj-coff.h: Remove vestiges of coff-m68k and pe-mips

View File

@ -825,19 +825,35 @@ is_indir (const char *s)
}
/* Check whether a symbol involves a register. */
static int
static bfd_boolean
contains_register (symbolS *sym)
{
if (sym)
{
expressionS * ex = symbol_get_value_expression(sym);
expressionS * ex = symbol_get_value_expression (sym);
return (O_register == ex->X_op)
|| (ex->X_add_symbol && contains_register(ex->X_add_symbol))
|| (ex->X_op_symbol && contains_register(ex->X_op_symbol));
switch (ex->X_op)
{
case O_register:
return TRUE;
case O_add:
case O_subtract:
if (ex->X_op_symbol && contains_register (ex->X_op_symbol))
return TRUE;
/* Fall through. */
case O_uminus:
case O_symbol:
if (ex->X_add_symbol && contains_register (ex->X_add_symbol))
return TRUE;
break;
default:
break;
}
}
return 0;
return FALSE;
}
/* Parse general expression, not looking for indexed addressing. */
@ -1168,7 +1184,7 @@ emit_byte (expressionS * val, bfd_reloc_code_real_type r_type)
}
p = frag_more (1);
*p = val->X_add_number;
if ( contains_register (val->X_add_symbol) || contains_register (val->X_op_symbol) )
if (contains_register (val->X_add_symbol) || contains_register (val->X_op_symbol))
{
ill_op ();
}
@ -1188,7 +1204,7 @@ emit_byte (expressionS * val, bfd_reloc_code_real_type r_type)
}
else
{
/* For symbols only, constants are stored at begin of function */
/* For symbols only, constants are stored at begin of function. */
fix_new_exp (frag_now, p - frag_now->fr_literal, 1, val,
(r_type == BFD_RELOC_8_PCREL) ? TRUE : FALSE, r_type);
}