acpi: make bios_linker_loader_add_pointer() API offset based

cleanup bios_linker_loader_add_pointer() API by switching
arguments to taking offsets relative to corresponding files
instead of doing pointer arithmetic on behalf of user which
were confusing.

Also make offset inside of source file explicit in API
so that user won't have to manually set it in
destination file blob and while at it add additional
boundary checks.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 23 insertions, 22 deletions

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 1e8364a3d4..b3ce5be77c 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -306,26 +306,23 @@ static void fadt_setup(AcpiFadtDescriptorRev1 *fadt, AcpiPmInfo *pm)
 /* FADT */
 static void
 build_fadt(GArray *table_data, BIOSLinker *linker, AcpiPmInfo *pm,
-           unsigned facs, unsigned dsdt,
+           unsigned facs_tbl_offset, unsigned dsdt_tbl_offset,
            const char *oem_id, const char *oem_table_id)
 {
     AcpiFadtDescriptorRev1 *fadt = acpi_data_push(table_data, sizeof(*fadt));
+    unsigned fw_ctrl_offset = (char *)&fadt->firmware_ctrl - table_data->data;
+    unsigned dsdt_entry_offset = (char *)&fadt->dsdt - table_data->data;
 
-    fadt->firmware_ctrl = cpu_to_le32(facs);
     /* FACS address to be filled by Guest linker */
-    bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
-                                   ACPI_BUILD_TABLE_FILE,
-                                   &fadt->firmware_ctrl,
-                                   sizeof fadt->firmware_ctrl);
+    bios_linker_loader_add_pointer(linker,
+        ACPI_BUILD_TABLE_FILE, fw_ctrl_offset, sizeof(fadt->firmware_ctrl),
+        ACPI_BUILD_TABLE_FILE, facs_tbl_offset);
 
-    fadt->dsdt = cpu_to_le32(dsdt);
     /* DSDT address to be filled by Guest linker */
-    bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
-                                   ACPI_BUILD_TABLE_FILE,
-                                   &fadt->dsdt,
-                                   sizeof fadt->dsdt);
-
     fadt_setup(fadt, pm);
+    bios_linker_loader_add_pointer(linker,
+        ACPI_BUILD_TABLE_FILE, dsdt_entry_offset, sizeof(fadt->dsdt),
+        ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);
 
     build_header(linker, table_data,
                  (void *)fadt, "FACP", sizeof(*fadt), 1, oem_id, oem_table_id);
@@ -2258,6 +2255,9 @@ static void
 build_tpm_tcpa(GArray *table_data, BIOSLinker *linker, GArray *tcpalog)
 {
     Acpi20Tcpa *tcpa = acpi_data_push(table_data, sizeof *tcpa);
+    unsigned log_addr_size = sizeof(tcpa->log_area_start_address);
+    unsigned log_addr_offset =
+        (char *)&tcpa->log_area_start_address - table_data->data;
 
     tcpa->platform_class = cpu_to_le16(TPM_TCPA_ACPI_CLASS_CLIENT);
     tcpa->log_area_minimum_length = cpu_to_le32(TPM_LOG_AREA_MINIMUM_SIZE);
@@ -2267,10 +2267,9 @@ build_tpm_tcpa(GArray *table_data, BIOSLinker *linker, GArray *tcpalog)
                              false /* high memory */);
 
     /* log area start address to be filled by Guest linker */
-    bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
-                                   ACPI_BUILD_TPMLOG_FILE,
-                                   &tcpa->log_area_start_address,
-                                   sizeof(tcpa->log_area_start_address));
+    bios_linker_loader_add_pointer(linker,
+        ACPI_BUILD_TABLE_FILE, log_addr_offset, log_addr_size,
+        ACPI_BUILD_TPMLOG_FILE, 0);
 
     build_header(linker, table_data,
                  (void *)tcpa, "TCPA", sizeof(*tcpa), 2, NULL, NULL);
@@ -2442,21 +2441,23 @@ build_dmar_q35(GArray *table_data, BIOSLinker *linker)
 }
 
 static GArray *
-build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt)
+build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)
 {
     AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);
+    unsigned rsdt_pa_size = sizeof(rsdp->rsdt_physical_address);
+    unsigned rsdt_pa_offset =
+        (char *)&rsdp->rsdt_physical_address - rsdp_table->data;
 
     bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, rsdp_table, 16,
                              true /* fseg memory */);
 
     memcpy(&rsdp->signature, "RSD PTR ", 8);
     memcpy(rsdp->oem_id, ACPI_BUILD_APPNAME6, 6);
-    rsdp->rsdt_physical_address = cpu_to_le32(rsdt);
     /* Address to be filled by Guest linker */
-    bios_linker_loader_add_pointer(linker, ACPI_BUILD_RSDP_FILE,
-                                   ACPI_BUILD_TABLE_FILE,
-                                   &rsdp->rsdt_physical_address,
-                                   sizeof rsdp->rsdt_physical_address);
+    bios_linker_loader_add_pointer(linker,
+        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,