diff options
| -rw-r--r-- | drivers/acpi/utilities/utalloc.c | 53 |
1 files changed, 28 insertions, 25 deletions
diff --git a/drivers/acpi/utilities/utalloc.c b/drivers/acpi/utilities/utalloc.c index 7dcb67e0b21..241c535c175 100644 --- a/drivers/acpi/utilities/utalloc.c +++ b/drivers/acpi/utilities/utalloc.c @@ -232,7 +232,7 @@ acpi_status acpi_ut_validate_buffer(struct acpi_buffer * buffer) * RETURN: Status * * DESCRIPTION: Validate that the buffer is of the required length or - * allocate a new buffer. Returned buffer is always zeroed. + * allocate a new buffer. Returned buffer is always zeroed. * ******************************************************************************/ @@ -240,7 +240,7 @@ acpi_status acpi_ut_initialize_buffer(struct acpi_buffer * buffer, acpi_size required_length) { - acpi_status status = AE_OK; + acpi_size input_buffer_length; /* Parameter validation */ @@ -248,55 +248,58 @@ acpi_ut_initialize_buffer(struct acpi_buffer * buffer, return (AE_BAD_PARAMETER); } - switch (buffer->length) { + /* + * Buffer->Length is used as both an input and output parameter. Get the + * input actual length and set the output required buffer length. + */ + input_buffer_length = buffer->length; + buffer->length = required_length; + + /* + * The input buffer length contains the actual buffer length, or the type + * of buffer to be allocated by this routine. + */ + switch (input_buffer_length) { case ACPI_NO_BUFFER: - /* Set the exception and returned the required length */ + /* Return the exception (and the required buffer length) */ - status = AE_BUFFER_OVERFLOW; - break; + return (AE_BUFFER_OVERFLOW); case ACPI_ALLOCATE_BUFFER: /* Allocate a new buffer */ buffer->pointer = acpi_os_allocate(required_length); - if (!buffer->pointer) { - return (AE_NO_MEMORY); - } - - /* Clear the buffer */ - - ACPI_MEMSET(buffer->pointer, 0, required_length); break; case ACPI_ALLOCATE_LOCAL_BUFFER: /* Allocate a new buffer with local interface to allow tracking */ - buffer->pointer = ACPI_ALLOCATE_ZEROED(required_length); - if (!buffer->pointer) { - return (AE_NO_MEMORY); - } + buffer->pointer = ACPI_ALLOCATE(required_length); break; default: /* Existing buffer: Validate the size of the buffer */ - if (buffer->length < required_length) { - status = AE_BUFFER_OVERFLOW; - break; + if (input_buffer_length < required_length) { + return (AE_BUFFER_OVERFLOW); } + break; + } - /* Clear the buffer */ + /* Validate allocation from above or input buffer pointer */ - ACPI_MEMSET(buffer->pointer, 0, required_length); - break; + if (!buffer->pointer) { + return (AE_NO_MEMORY); } - buffer->length = required_length; - return (status); + /* Have a valid buffer, clear it */ + + ACPI_MEMSET(buffer->pointer, 0, required_length); + return (AE_OK); } #ifdef NOT_USED_BY_LINUX |