[Qemu-commits] [qemu/qemu] a3ad58: hw/nvram/fw_cfg: Simplify fw_cfg_add_from_generato...

[Peter Maydell]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: a3ad58342a9d88d1baafc0aee39302f79faad480
      
https://github.com/qemu/qemu/commit/a3ad58342a9d88d1baafc0aee39302f79faad480
  Author: Philippe Mathieu-Daudé <philmd@redhat.com>
  Date:   2020-07-21 (Tue, 21 Jul 2020)

  Changed paths:
    M hw/nvram/fw_cfg.c
    M include/hw/nvram/fw_cfg.h

  Log Message:
  -----------
  hw/nvram/fw_cfg: Simplify fw_cfg_add_from_generator() error propagation

Document FWCfgDataGeneratorClass::get_data() return NULL
on error, and non-NULL on success. This allow us to simplify
fw_cfg_add_from_generator(). Since we don't need a local
variable to propagate the error, we can remove the ERRP_GUARD()
macro.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200721131911.27380-2-philmd@redhat.com>


  Commit: 077195187b47d83418e5fb521c89d7881fab3049
      
https://github.com/qemu/qemu/commit/077195187b47d83418e5fb521c89d7881fab3049
  Author: Philippe Mathieu-Daudé <philmd@redhat.com>
  Date:   2020-07-21 (Tue, 21 Jul 2020)

  Changed paths:
    M hw/nvram/fw_cfg.c
    M include/hw/nvram/fw_cfg.h
    M softmmu/vl.c

  Log Message:
  -----------
  hw/nvram/fw_cfg: Let fw_cfg_add_from_generator() return boolean value

Commits b6d7e9b66f..a43770df5d simplified the error propagation.
Similarly to commit 6fd5bef10b "qom: Make functions taking Error**
return bool, not void", let fw_cfg_add_from_generator() return a
boolean value, not void.
This allow to simplify parse_fw_cfg() and fixes the error handling
issue reported by Coverity (CID 1430396):

  In parse_fw_cfg():

    Variable assigned once to a constant guards dead code.

    Local variable local_err is assigned only once, to a constant
    value, making it effectively constant throughout its scope.
    If this is not the intent, examine the logic to see if there
    is a missing assignment that would make local_err not remain
    constant.

It's the call of fw_cfg_add_from_generator():

        Error *local_err = NULL;

        fw_cfg_add_from_generator(fw_cfg, name, gen_id, errp);
        if (local_err) {
            error_propagate(errp, local_err);
            return -1;
        }
        return 0;

If it fails, parse_fw_cfg() sets an error and returns 0, which is
wrong. Harmless, because the only caller passes &error_fatal.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Fixes: Coverity CID 1430396: 'Constant' variable guards dead code (DEADCODE)
Fixes: 6552d87c48 ("softmmu/vl: Let -fw_cfg option take a 'gen_id' argument")
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200721131911.27380-3-philmd@redhat.com>


  Commit: d0cc248164961a7ba9d43806feffd76f9f6d7f41
      
https://github.com/qemu/qemu/commit/d0cc248164961a7ba9d43806feffd76f9f6d7f41
  Author: Peter Maydell <peter.maydell@linaro.org>
  Date:   2020-07-22 (Wed, 22 Jul 2020)

  Changed paths:
    M hw/nvram/fw_cfg.c
    M include/hw/nvram/fw_cfg.h
    M softmmu/vl.c

  Log Message:
  -----------
  Merge remote-tracking branch 'remotes/philmd-gitlab/tags/fw_cfg-20200721' 
into staging

fw_cfg patches

Fixes the DEADCODE issue reported by Coverity (CID 1430396).

CI jobs result:
. https://gitlab.com/philmd/qemu/-/pipelines/169086301

# gpg: Signature made Tue 21 Jul 2020 18:52:46 BST
# gpg:                using RSA key FAABE75E12917221DCFD6BB2E3E32C2CDEADC0DE
# gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" 
[full]
# Primary key fingerprint: FAAB E75E 1291 7221 DCFD  6BB2 E3E3 2C2C DEAD C0DE

* remotes/philmd-gitlab/tags/fw_cfg-20200721:
  hw/nvram/fw_cfg: Let fw_cfg_add_from_generator() return boolean value
  hw/nvram/fw_cfg: Simplify fw_cfg_add_from_generator() error propagation

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>


Compare: https://github.com/qemu/qemu/compare/3cbc8970f55c...d0cc24816496