Re: [PATCH 10/19] smbios: handle errors consistently

[Ani Sinha <anisinha@redhat.com>]

On Tue, 27 Feb 2024, Igor Mammedov wrote:

> 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.
>
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>

Other than the nit below,

Reviewed-by: Ani Sinha <anisinha@redhat.com>

> ---
>  include/hw/firmware/smbios.h |  4 ++--
>  hw/i386/fw_cfg.c             |  3 ++-
>  hw/smbios/smbios.c           | 32 ++++++++++++++++++++------------
>  hw/smbios/smbios_legacy.c    | 22 ++++++++++++++--------
>  4 files changed, 38 insertions(+), 23 deletions(-)
>
> diff --git a/include/hw/firmware/smbios.h b/include/hw/firmware/smbios.h
> index a6d8fd6591..d1194c9cc2 100644
> --- a/include/hw/firmware/smbios.h
> +++ b/include/hw/firmware/smbios.h
> @@ -310,7 +310,7 @@ 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);
> @@ -318,7 +318,7 @@ 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 fb1f05fcde..7c28b5f748 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"
> @@ -448,23 +447,25 @@ 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)
> @@ -1027,15 +1028,18 @@ 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)) {

nit: I would do a gfree(smbios_tables) here ..

> +        goto err_exit;
> +    }
> +    if (!smbios_validate_table(errp)) {
> +        goto err_exit;

and here. Then in 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);
> @@ -1044,6 +1048,10 @@ void smbios_get_tables(MachineState *ms,
>      } else {
>          abort();
>      }
> +
> +    return;
> +err_exit:

I would add a return here.

That way all paths explicitly return void.

> +    g_free(smbios_tables);

No return here?


>  }
>
>  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
>
>