diff options
Diffstat (limited to 'drivers/acpi/executer/exmisc.c')
| -rw-r--r-- | drivers/acpi/executer/exmisc.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/acpi/executer/exmisc.c b/drivers/acpi/executer/exmisc.c index 794d9b8de956..bd98aab017cf 100644 --- a/drivers/acpi/executer/exmisc.c +++ b/drivers/acpi/executer/exmisc.c @@ -445,10 +445,24 @@ acpi_ex_do_math_op(u16 opcode, acpi_integer integer0, acpi_integer integer1) case AML_SHIFT_LEFT_OP: /* shift_left (Operand, shift_count, Result) */ + /* + * We need to check if the shiftcount is larger than the integer bit + * width since the behavior of this is not well-defined in the C language. + */ + if (integer1 >= acpi_gbl_integer_bit_width) { + return (0); + } return (integer0 << integer1); case AML_SHIFT_RIGHT_OP: /* shift_right (Operand, shift_count, Result) */ + /* + * We need to check if the shiftcount is larger than the integer bit + * width since the behavior of this is not well-defined in the C language. + */ + if (integer1 >= acpi_gbl_integer_bit_width) { + return (0); + } return (integer0 >> integer1); case AML_SUBTRACT_OP: /* Subtract (Integer0, Integer1, Result) */ |