From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Guo, Jia" <jia.guo@intel.com>
Subject: Re: [PATCH V4 5/9] bus: add helper to handle sigbus
Date: Fri, 29 Jun 2018 19:23:13 +0800
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Cc: "jblunck@infradead.org" <jblunck@infradead.org>,
 "shreyansh.jain@nxp.com" <shreyansh.jain@nxp.com>,
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To: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
 "stephen@networkplumber.org" <stephen@networkplumber.org>,
 "Richardson, Bruce" <bruce.richardson@intel.com>,
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hi, konstantin


On 6/29/2018 6:51 PM, Ananyev, Konstantin wrote:
>> +int
>> +rte_bus_sigbus_handler(const void *failure_addr)
>> +{
>> +	struct rte_bus *bus;
>> +	int old_errno = rte_errno;
>> +	int ret = 0;
>> +
>> +	rte_errno = 0;
>> +
>> +	bus = rte_bus_find(NULL, bus_handle_sigbus, failure_addr);
>> +	if (bus == NULL) {
>> +		RTE_LOG(ERR, EAL, "No bus can handle the sigbus error!");
>> +		ret = -1;
>> +	} else if (rte_errno != 0) {
>> +		RTE_LOG(ERR, EAL, "Failed to handle the sigbus error!");
>> +		ret = -1;
>> +	}
>> +
>> +	/* if sigbus not be handled, return back old errno. */
>> +	if (ret)
>> +		rte_errno = old_errno;
> Hmm, not sure why we need to set/restore rte_errno here?

restore old_errno just use to let caller know that the generic sigbus 
still not handler by bus hotplug handler,  that involve find a bus 
handle but failed and can not find a hander,  and can corresponding use 
the previous sigbus handler to process it.
that is also unwser your question in other patch. do you think that make 
sense?

>> +
>> +	return ret;
>> +}