Re: [Qemu-devel] [FIX PATCH] target/ppc: Proper cleanup when ppc_cpu_realizefn fails

[David Gibson <david@gibson.dropbear.id.au>]

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On Thu, Jun 15, 2017 at 11:14:24AM +0530, Bharata B Rao wrote:
> If ppc_cpu_realizefn() fails after cpu_exec_realizefn() has been
> called, we will have to undo whatever cpu_exec_realizefn() did
> by explicitly calling cpu_exec_unrealizeffn() which is currently
> missing. Failure to do this proper cleanup will result in CPU
> which was never fully realized to linger on the cpus list causing
> SIGSEGV later (for eg when running "info cpus").
> 
> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>

Applied to ppc-for-2.10.

> ---
>  target/ppc/translate_init.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
> index e837cd2..53aff5a 100644
> --- a/target/ppc/translate_init.c
> +++ b/target/ppc/translate_init.c
> @@ -9825,14 +9825,14 @@ static void ppc_cpu_realizefn(DeviceState *dev, Error **errp)
>          error_append_hint(errp, "Adjust the number of cpus to %d "
>                            "or try to raise the number of threads per core\n",
>                            cpu->cpu_dt_id * smp_threads / max_smt);
> -        return;
> +        goto unrealize;
>      }
>  #endif
>  
>      if (tcg_enabled()) {
>          if (ppc_fixup_cpu(cpu) != 0) {
>              error_setg(errp, "Unable to emulate selected CPU with TCG");
> -            return;
> +            goto unrealize;
>          }
>      }
>  
> @@ -9841,14 +9841,14 @@ static void ppc_cpu_realizefn(DeviceState *dev, Error **errp)
>          error_setg(errp, "CPU does not possess a BookE or 4xx MMU. "
>                     "Please use qemu-system-ppc or qemu-system-ppc64 instead "
>                     "or choose another CPU model.");
> -        return;
> +        goto unrealize;
>      }
>  #endif
>  
>      create_ppc_opcodes(cpu, &local_err);
>      if (local_err != NULL) {
>          error_propagate(errp, local_err);
> -        return;
> +        goto unrealize;
>      }
>      init_ppc_proc(cpu);
>  
> @@ -10033,6 +10033,10 @@ static void ppc_cpu_realizefn(DeviceState *dev, Error **errp)
>          fflush(stdout);
>      }
>  #endif
> +    return;
> +
> +unrealize:
> +    cpu_exec_unrealizefn(cs);
>  }
>  
>  static void ppc_cpu_unrealizefn(DeviceState *dev, Error **errp)

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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