linux-kernel - Re: [PATCH v14 5/5] x86/sgx: Enable automatic SVN updates for SGX enclaves

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4baa3bd4-cbc3-49b3-b8e6-09a2079c8363@intel.com>
Date: Thu, 14 Aug 2025 09:50:58 -0700
From: Dave Hansen <dave.hansen@...el.com>
To: Elena Reshetova <elena.reshetova@...el.com>
Cc: jarkko@...nel.org, seanjc@...gle.com, kai.huang@...el.com,
 mingo@...nel.org, linux-sgx@...r.kernel.org, linux-kernel@...r.kernel.org,
 x86@...nel.org, asit.k.mallick@...el.com, vincent.r.scarlata@...el.com,
 chongc@...gle.com, erdemaktas@...gle.com, vannapurve@...gle.com,
 bondarn@...gle.com, scott.raynor@...el.com
Subject: Re: [PATCH v14 5/5] x86/sgx: Enable automatic SVN updates for SGX
 enclaves

On 8/14/25 00:34, Elena Reshetova wrote:
> +/* Mutex to ensure no concurrent EPC accesses during EUPDATESVN */
> +static DEFINE_MUTEX(sgx_svn_lock);
> +
>  int sgx_inc_usage_count(void)
>  {
> +	int ret;
> +
> +	guard(mutex)(&sgx_svn_lock);
> +
> +	if (!sgx_usage_count) {
> +		ret = sgx_update_svn();
> +		if (ret)
> +			return ret;
> +	}
> +
> +	sgx_usage_count++;
> +
>  	return 0;
>  }
>  
>  void sgx_dec_usage_count(void)
>  {
> -	return;
> +	sgx_usage_count--;
>  }

How is a plain int-- safe?

Where's the locking?