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) | |||
| 445 | 445 | ||
| 446 | case AML_SHIFT_LEFT_OP: /* shift_left (Operand, shift_count, Result) */ | 446 | case AML_SHIFT_LEFT_OP: /* shift_left (Operand, shift_count, Result) */ |
| 447 | 447 | ||
| 448 | /* | ||
| 449 | * We need to check if the shiftcount is larger than the integer bit | ||
| 450 | * width since the behavior of this is not well-defined in the C language. | ||
| 451 | */ | ||
| 452 | if (integer1 >= acpi_gbl_integer_bit_width) { | ||
| 453 | return (0); | ||
| 454 | } | ||
| 448 | return (integer0 << integer1); | 455 | return (integer0 << integer1); |
| 449 | 456 | ||
| 450 | case AML_SHIFT_RIGHT_OP: /* shift_right (Operand, shift_count, Result) */ | 457 | case AML_SHIFT_RIGHT_OP: /* shift_right (Operand, shift_count, Result) */ |
| 451 | 458 | ||
| 459 | /* | ||
| 460 | * We need to check if the shiftcount is larger than the integer bit | ||
| 461 | * width since the behavior of this is not well-defined in the C language. | ||
| 462 | */ | ||
| 463 | if (integer1 >= acpi_gbl_integer_bit_width) { | ||
| 464 | return (0); | ||
| 465 | } | ||
| 452 | return (integer0 >> integer1); | 466 | return (integer0 >> integer1); |
| 453 | 467 | ||
| 454 | case AML_SUBTRACT_OP: /* Subtract (Integer0, Integer1, Result) */ | 468 | case AML_SUBTRACT_OP: /* Subtract (Integer0, Integer1, Result) */ |