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From: Dave Hansen <dave.hansen@intel.com>
To: Elena Reshetova <elena.reshetova@intel.com>
Cc: jarkko@kernel.org, seanjc@google.com, kai.huang@intel.com,
	mingo@kernel.org, linux-sgx@vger.kernel.org,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	asit.k.mallick@intel.com, vincent.r.scarlata@intel.com,
	chongc@google.com, erdemaktas@google.com, vannapurve@google.com,
	bondarn@google.com, scott.raynor@intel.com
Subject: Re: [PATCH v14 5/5] x86/sgx: Enable automatic SVN updates for SGX enclaves
Date: Thu, 14 Aug 2025 09:50:58 -0700	[thread overview]
Message-ID: <4baa3bd4-cbc3-49b3-b8e6-09a2079c8363@intel.com> (raw)
In-Reply-To: <20250814073640.1507050-6-elena.reshetova@intel.com>

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?

  parent reply	other threads:[~2025-08-14 16:51 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-08-14  7:34 [PATCH v14 0/5] Enable automatic SVN updates for SGX enclaves Elena Reshetova
2025-08-14  7:34 ` [PATCH v14 1/5] x86/sgx: Introduce functions to count the sgx_(vepc_)open() Elena Reshetova
2025-08-14  7:34 ` [PATCH v14 2/5] x86/cpufeatures: Add X86_FEATURE_SGX_EUPDATESVN feature flag Elena Reshetova
2025-08-14  7:34 ` [PATCH v14 3/5] x86/sgx: Define error codes for use by ENCLS[EUPDATESVN] Elena Reshetova
2025-08-14  7:34 ` [PATCH v14 4/5] x86/sgx: Implement ENCLS[EUPDATESVN] Elena Reshetova
2025-08-14  9:35   ` Huang, Kai
2025-08-14 11:48     ` Reshetova, Elena
2025-08-14 22:31       ` Huang, Kai
2025-08-15 12:05         ` Reshetova, Elena
2025-08-14  7:34 ` [PATCH v14 5/5] x86/sgx: Enable automatic SVN updates for SGX enclaves Elena Reshetova
2025-08-14  9:36   ` Huang, Kai
2025-08-14 16:50   ` Dave Hansen [this message]
2025-08-14 21:40     ` Huang, Kai
2025-08-15  6:59       ` Reshetova, Elena
2025-08-18  5:03         ` Huang, Kai
2025-08-18  5:41           ` Reshetova, Elena

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