[PATCH v4 12/21] smbios: handle errors consistently

[Igor Mammedov <imammedo@redhat.com>]

Current code uses mix of error_report()+exit(1)
and error_setg() to handle errors.
Use newer error_setg() everywhere, beside consistency
it will allow to detect error condition without killing
QEMU and attempt switch-over to SMBIOS3.x tables/entrypoint
in follow up patch.

while at it, clear smbios_tables pointer after freeing.
that will avoid double free if smbios_get_tables() is called
multiple times.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Ani Sinha <anisinha@redhat.com>
---
 include/hw/firmware/smbios.h |  4 ++--
 hw/i386/fw_cfg.c             |  3 ++-
 hw/smbios/smbios.c           | 34 ++++++++++++++++++++++------------
 hw/smbios/smbios_legacy.c    | 22 ++++++++++++++--------
 4 files changed, 40 insertions(+), 23 deletions(-)

diff --git a/include/hw/firmware/smbios.h b/include/hw/firmware/smbios.h
index ccc51e72f5..d4b91d5a14 100644
--- a/include/hw/firmware/smbios.h
+++ b/include/hw/firmware/smbios.h
@@ -326,7 +326,7 @@ struct smbios_type_127 {
     struct smbios_structure_header header;
 } QEMU_PACKED;
 
-void smbios_validate_table(void);
+bool smbios_validate_table(Error **errp);
 void smbios_add_usr_blob_size(size_t size);
 void smbios_entry_add(QemuOpts *opts, Error **errp);
 void smbios_set_cpuid(uint32_t version, uint32_t features);
@@ -334,7 +334,7 @@ void smbios_set_defaults(const char *manufacturer, const char *product,
                          const char *version,
                          bool uuid_encoded, SmbiosEntryPointType ep_type);
 void smbios_set_default_processor_family(uint16_t processor_family);
-uint8_t *smbios_get_table_legacy(size_t *length);
+uint8_t *smbios_get_table_legacy(size_t *length, Error **errp);
 void smbios_get_tables(MachineState *ms,
                        const struct smbios_phys_mem_area *mem_array,
                        const unsigned int mem_array_size,
diff --git a/hw/i386/fw_cfg.c b/hw/i386/fw_cfg.c
index d1281066f4..e387bf50d0 100644
--- a/hw/i386/fw_cfg.c
+++ b/hw/i386/fw_cfg.c
@@ -71,7 +71,8 @@ void fw_cfg_build_smbios(PCMachineState *pcms, FWCfgState *fw_cfg)
     smbios_set_cpuid(cpu->env.cpuid_version, cpu->env.features[FEAT_1_EDX]);
 
     if (pcmc->smbios_legacy_mode) {
-        smbios_tables = smbios_get_table_legacy(&smbios_tables_len);
+        smbios_tables = smbios_get_table_legacy(&smbios_tables_len,
+                                                &error_fatal);
         fw_cfg_add_bytes(fw_cfg, FW_CFG_SMBIOS_ENTRIES,
                          smbios_tables, smbios_tables_len);
         return;
diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
index f9efe01233..512ecd46f3 100644
--- a/hw/smbios/smbios.c
+++ b/hw/smbios/smbios.c
@@ -19,7 +19,6 @@
 #include "qemu/units.h"
 #include "qapi/error.h"
 #include "qemu/config-file.h"
-#include "qemu/error-report.h"
 #include "qemu/module.h"
 #include "qemu/option.h"
 #include "sysemu/sysemu.h"
@@ -511,23 +510,25 @@ opts_init(smbios_register_config);
  */
 #define SMBIOS_21_MAX_TABLES_LEN 0xffff
 
-static void smbios_check_type4_count(uint32_t expected_t4_count)
+static bool smbios_check_type4_count(uint32_t expected_t4_count, Error **errp)
 {
     if (smbios_type4_count && smbios_type4_count != expected_t4_count) {
-        error_report("Expected %d SMBIOS Type 4 tables, got %d instead",
-                     expected_t4_count, smbios_type4_count);
-        exit(1);
+        error_setg(errp, "Expected %d SMBIOS Type 4 tables, got %d instead",
+                   expected_t4_count, smbios_type4_count);
+        return false;
     }
+    return true;
 }
 
-void smbios_validate_table(void)
+bool smbios_validate_table(Error **errp)
 {
     if (smbios_ep_type == SMBIOS_ENTRY_POINT_TYPE_32 &&
         smbios_tables_len > SMBIOS_21_MAX_TABLES_LEN) {
-        error_report("SMBIOS 2.1 table length %zu exceeds %d",
-                     smbios_tables_len, SMBIOS_21_MAX_TABLES_LEN);
-        exit(1);
+        error_setg(errp, "SMBIOS 2.1 table length %zu exceeds %d",
+                   smbios_tables_len, SMBIOS_21_MAX_TABLES_LEN);
+        return false;
     }
+    return true;
 }
 
 bool smbios_skip_table(uint8_t type, bool required_table)
@@ -1151,15 +1152,18 @@ void smbios_get_tables(MachineState *ms,
     smbios_build_type_41_table(errp);
     smbios_build_type_127_table();
 
-    smbios_check_type4_count(ms->smp.sockets);
-    smbios_validate_table();
+    if (!smbios_check_type4_count(ms->smp.sockets, errp)) {
+        goto err_exit;
+    }
+    if (!smbios_validate_table(errp)) {
+        goto err_exit;
+    }
     smbios_entry_point_setup();
 
     /* return tables blob and entry point (anchor), and their sizes */
     *tables = smbios_tables;
     *tables_len = smbios_tables_len;
     *anchor = (uint8_t *)&ep;
-
     /* calculate length based on anchor string */
     if (!strncmp((char *)&ep, "_SM_", 4)) {
         *anchor_len = sizeof(struct smbios_21_entry_point);
@@ -1168,6 +1172,12 @@ void smbios_get_tables(MachineState *ms,
     } else {
         abort();
     }
+
+    return;
+err_exit:
+    g_free(smbios_tables);
+    smbios_tables = NULL;
+    return;
 }
 
 static void save_opt(const char **dest, QemuOpts *opts, const char *name)
diff --git a/hw/smbios/smbios_legacy.c b/hw/smbios/smbios_legacy.c
index 21f143e738..a6544bf55a 100644
--- a/hw/smbios/smbios_legacy.c
+++ b/hw/smbios/smbios_legacy.c
@@ -19,7 +19,7 @@
 #include "qemu/bswap.h"
 #include "hw/firmware/smbios.h"
 #include "sysemu/sysemu.h"
-#include "qemu/error-report.h"
+#include "qapi/error.h"
 
 struct smbios_header {
     uint16_t length;
@@ -128,7 +128,7 @@ static void smbios_build_type_1_fields(void)
     }
 }
 
-uint8_t *smbios_get_table_legacy(size_t *length)
+uint8_t *smbios_get_table_legacy(size_t *length, Error **errp)
 {
     int i;
     size_t usr_offset;
@@ -136,15 +136,15 @@ uint8_t *smbios_get_table_legacy(size_t *length)
     /* complain if fields were given for types > 1 */
     if (find_next_bit(smbios_have_fields_bitmap,
                       SMBIOS_MAX_TYPE + 1, 2) < SMBIOS_MAX_TYPE + 1) {
-        error_report("can't process fields for smbios "
+        error_setg(errp, "can't process fields for smbios "
                      "types > 1 on machine versions < 2.1!");
-        exit(1);
+        goto err_exit;
     }
 
     if (test_bit(4, smbios_have_binfile_bitmap)) {
-        error_report("can't process table for smbios "
-                     "type 4 on machine versions < 2.1!");
-        exit(1);
+        error_setg(errp, "can't process table for smbios "
+                   "type 4 on machine versions < 2.1!");
+        goto err_exit;
     }
 
     g_free(smbios_entries);
@@ -173,7 +173,13 @@ uint8_t *smbios_get_table_legacy(size_t *length)
 
     smbios_build_type_0_fields();
     smbios_build_type_1_fields();
-    smbios_validate_table();
+    if (!smbios_validate_table(errp)) {
+        goto err_exit;
+    }
+
     *length = smbios_entries_len;
     return smbios_entries;
+err_exit:
+    g_free(smbios_entries);
+    return NULL;
 }
-- 
2.39.3