@@ -1427,6 +1427,8 @@ build_header(BIOSLinker *linker, GArray *table_data,
AcpiTableHeader *h, const char *sig, int len, uint8_t rev,
const char *oem_id, const char *oem_table_id)
{
+ unsigned tbl_offset = (char *)h - table_data->data;
+ unsigned checksum_offset = (char *)&h->checksum - table_data->data;
memcpy(&h->signature, sig, 4);
h->length = cpu_to_le32(len);
h->revision = rev;
@@ -1447,10 +1449,9 @@ build_header(BIOSLinker *linker, GArray *table_data,
h->oem_revision = cpu_to_le32(1);
memcpy(h->asl_compiler_id, ACPI_BUILD_APPNAME4, 4);
h->asl_compiler_revision = cpu_to_le32(1);
- h->checksum = 0;
/* Checksum to be filled in by Guest linker */
bios_linker_loader_add_checksum(linker, ACPI_BUILD_TABLE_FILE,
- h, len, &h->checksum);
+ tbl_offset, len, checksum_offset);
}
void *acpi_data_push(GArray *table_data, unsigned size)
@@ -189,8 +189,8 @@ void bios_linker_loader_alloc(BIOSLinker *linker,
}
/*
- * bios_linker_loader_add_checksum: ask guest to add checksum of file data
- * into (same) file at the specified pointer.
+ * bios_linker_loader_add_checksum: ask guest to add checksum of ACPI
+ * table in the specified file at the specified offset.
*
* Checksum calculation simply sums -X for each byte X in the range
* using 8-bit math (i.e. ACPI checksum).
@@ -198,35 +198,25 @@ void bios_linker_loader_alloc(BIOSLinker *linker,
* @linker: linker object instance
* @file: file that includes the checksum to be calculated
* and the data to be checksummed
- * @start, @size: range of data to checksum
- * @checksum: location of the checksum to be patched within file blob
- *
- * Notes:
- * - checksum byte initial value must have been pushed into blob
- * associated with @file and reside at address @checksum.
- * - @size bytes must have been pushed into blob associated wtih @file
- * and reside at address @start.
- * - Guest calculates checksum of specified range of data, result is added to
- * initial value at @checksum into copy of @file in Guest memory.
- * - Range might include the checksum itself.
- * - To avoid confusion, caller must always put 0x0 at @checksum.
- * - @file must be loaded into Guest memory using bios_linker_loader_alloc
+ * @start_offset, @size: range of data in the file to checksum,
+ * relative to the start of file blob
+ * @checksum_offset: location of the checksum to be patched within file blob,
+ * relative to the start of file blob
*/
void bios_linker_loader_add_checksum(BIOSLinker *linker, const char *file_name,
- void *start, unsigned size,
- uint8_t *checksum)
+ unsigned start_offset, unsigned size,
+ unsigned checksum_offset)
{
BiosLinkerLoaderEntry entry;
const BiosLinkerFileEntry *file = bios_linker_find_file(linker, file_name);
- ptrdiff_t checksum_offset = (gchar *)checksum - file->blob->data;
- ptrdiff_t start_offset = (gchar *)start - file->blob->data;
- assert(checksum_offset >= 0);
- assert(start_offset >= 0);
- assert(checksum_offset + 1 <= file->blob->len);
+ assert(file);
+ assert(start_offset < file->blob->len);
assert(start_offset + size <= file->blob->len);
- assert(*checksum == 0x0);
+ assert(checksum_offset >= start_offset);
+ assert(checksum_offset + 1 <= start_offset + size);
+ *(file->blob->data + checksum_offset) = 0;
memset(&entry, 0, sizeof entry);
strncpy(entry.cksum.file, file_name, sizeof entry.cksum.file - 1);
entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM);
@@ -357,11 +357,10 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)
ACPI_BUILD_RSDP_FILE, rsdt_pa_offset, rsdt_pa_size,
ACPI_BUILD_TABLE_FILE, rsdt_tbl_offset);
- rsdp->checksum = 0;
/* Checksum to be filled by Guest linker */
bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
- rsdp, sizeof *rsdp,
- &rsdp->checksum);
+ (char *)rsdp - rsdp_table->data, sizeof *rsdp,
+ (char *)&rsdp->checksum - rsdp_table->data);
return rsdp_table;
}
@@ -2527,11 +2527,10 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)
ACPI_BUILD_RSDP_FILE, rsdt_pa_offset, rsdt_pa_size,
ACPI_BUILD_TABLE_FILE, rsdt_tbl_offset);
- rsdp->checksum = 0;
/* Checksum to be filled by Guest linker */
bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
- rsdp, sizeof *rsdp,
- &rsdp->checksum);
+ (char *)rsdp - rsdp_table->data, sizeof *rsdp,
+ (char *)&rsdp->checksum - rsdp_table->data);
return rsdp_table;
}
@@ -17,8 +17,8 @@ void bios_linker_loader_alloc(BIOSLinker *linker,
bool alloc_fseg);
void bios_linker_loader_add_checksum(BIOSLinker *linker, const char *file,
- void *start, unsigned size,
- uint8_t *checksum);
+ unsigned start_offset, unsigned size,
+ unsigned checksum_offset);
void bios_linker_loader_add_pointer(BIOSLinker *linker,
const char *dest_file,
It should help to make clear that bios_linker works in terms of offsets within a file. Also it should prevent mistakes where user passes as arguments pointers to unrelated to file blobs. While at it, considering that it's a ACPI checksum and it's initial value must be 0, move checksum field zeroing into bios_linker_loader_add_checksum() instead of doing it at every call site manually before bios_linker_loader_add_checksum() is called. In addition add extra boundary checks. Signed-off-by: Igor Mammedov <imammedo@redhat.com> --- hw/acpi/aml-build.c | 5 +++-- hw/acpi/bios-linker-loader.c | 36 +++++++++++++----------------------- hw/arm/virt-acpi-build.c | 5 ++--- hw/i386/acpi-build.c | 5 ++--- include/hw/acpi/bios-linker-loader.h | 4 ++-- 5 files changed, 22 insertions(+), 33 deletions(-)