[PATCH][V2] fwts_acpica: don't add in RSDP or null table entries to XSDT or RSDT (LP: #1829167)

[Colin King]

From: Colin Ian King <colin.king at canonical.com>

BugLink: https://bugs.launchpad.net/fwts/+bug/1829167

Adding in the RSDP table to the XSDT and RSDT is illegal. It also
breaks ACPICA as this tries to checksum the RSDP and as it's a non-standard
table the length field is offset differently from most tables causing
the checksum to segfault.  Also don't in null tables, this does not make
sense.

Signed-off-by: Colin Ian King <colin.king at canonical.com>
---

V2: add in missing bug number

---
 src/acpica/fwts_acpica.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/acpica/fwts_acpica.c b/src/acpica/fwts_acpica.c
index 75f8fe3d..65dad3c5 100644
--- a/src/acpica/fwts_acpica.c
+++ b/src/acpica/fwts_acpica.c
@@ -1125,6 +1125,7 @@ int fwts_acpica_init(fwts_framework *fw)
 		return FWTS_ERROR;
 	if (table != NULL) {
 		uint64_t *entries;
+		int j;
 
 		fwts_acpica_XSDT = fwts_low_calloc(1, table->length);
 		if (fwts_acpica_XSDT == NULL) {
@@ -1135,18 +1136,19 @@ int fwts_acpica_init(fwts_framework *fw)
 
 		n = (table->length - sizeof(ACPI_TABLE_HEADER)) / sizeof(uint64_t);
 		entries = (uint64_t*)(table->data + sizeof(ACPI_TABLE_HEADER));
-		for (i = 0; i < n; i++) {
+		for (i = 0, j = 0; i < n; i++) {
 			fwts_acpi_table_info *tbl;
+
 			if (fwts_acpi_find_table_by_addr(fw, entries[i], &tbl) != FWTS_OK)
 				return FWTS_ERROR;
 			if (tbl) {
+				if (strncmp(tbl->name, "RSDP", 4) == 0)
+					continue;
 				if (strncmp(tbl->name, "FACP", 4) == 0) {
-					fwts_acpica_XSDT->TableOffsetEntry[i] = ACPI_PTR_TO_PHYSADDR(fwts_acpica_FADT);
+					fwts_acpica_XSDT->TableOffsetEntry[j++] = ACPI_PTR_TO_PHYSADDR(fwts_acpica_FADT);
 				} else {
-					fwts_acpica_XSDT->TableOffsetEntry[i] = ACPI_PTR_TO_PHYSADDR(tbl->data);
+					fwts_acpica_XSDT->TableOffsetEntry[j++] = ACPI_PTR_TO_PHYSADDR(tbl->data);
 				}
-			} else {
-				fwts_acpica_XSDT->TableOffsetEntry[i] = ACPI_PTR_TO_PHYSADDR(NULL);
 			}
 		}
 		fwts_acpica_XSDT->Header.Checksum = 0;
@@ -1160,6 +1162,7 @@ int fwts_acpica_init(fwts_framework *fw)
 		return FWTS_ERROR;
 	if (table) {
 		uint32_t *entries;
+		int j;
 
 		fwts_acpica_RSDT = fwts_low_calloc(1, table->length);
 		if (fwts_acpica_RSDT == NULL) {
@@ -1170,19 +1173,18 @@ int fwts_acpica_init(fwts_framework *fw)
 
 		n = (table->length - sizeof(ACPI_TABLE_HEADER)) / sizeof(uint32_t);
 		entries = (uint32_t*)(table->data + sizeof(ACPI_TABLE_HEADER));
-		for (i = 0; i < n; i++) {
+		for (i = 0, j = 0; i < n; i++) {
 			fwts_acpi_table_info *tbl;
 			if (fwts_acpi_find_table_by_addr(fw, entries[i], &tbl) != FWTS_OK)
 				return FWTS_ERROR;
 			if (tbl) {
+				if (strncmp(tbl->name, "RSDP", 4) == 0)
+					continue;
 				if (strncmp(tbl->name, "FACP", 4) == 0) {
-					fwts_acpica_RSDT->TableOffsetEntry[i] = ACPI_PTR_TO_PHYSADDR(fwts_acpica_FADT);
-				}
-				else {
-					fwts_acpica_RSDT->TableOffsetEntry[i] = ACPI_PTR_TO_PHYSADDR(tbl->data);
+					fwts_acpica_RSDT->TableOffsetEntry[j++] = ACPI_PTR_TO_PHYSADDR(fwts_acpica_FADT);
+				} else {
+					fwts_acpica_RSDT->TableOffsetEntry[j++] = ACPI_PTR_TO_PHYSADDR(tbl->data);
 				}
-			} else {
-				fwts_acpica_RSDT->TableOffsetEntry[i] = ACPI_PTR_TO_PHYSADDR(NULL);
 			}
 		}
 		fwts_acpica_RSDT->Header.Checksum = 0;
-- 
2.20.1