DPDK patches and discussions
 help / color / mirror / Atom feed
From: "Mattias Rönnblom" <mattias.ronnblom@ericsson.com>
To: "xiangxia.m.yue@gmail.com" <xiangxia.m.yue@gmail.com>,
	"david.marchand@redhat.com" <david.marchand@redhat.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>, "stable@dpdk.org" <stable@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v2] eal: fix crash when the random init
Date: Thu, 16 Apr 2020 16:12:48 +0000	[thread overview]
Message-ID: <422efe07-2a23-f08c-b6cd-192f1c159913@ericsson.com> (raw)
In-Reply-To: <1586936615-35033-1-git-send-email-xiangxia.m.yue@gmail.com>

On 2020-04-15 09:43, xiangxia.m.yue@gmail.com wrote:
> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>
> When rte_rand_init is invoked, and the kernel running dpdk does't
> support *getentropy, at the same time, the cpu does't support rdseed,
> then rte_rand_init invoked rte_get_timer_cycles which invoked
> rte_get_hpet_cycles while *eal_hpet is not available.

You fail to mention that HPET must be enabled in the DPDK build (which 
it is not, by default), and enabled in the BIOS, for this bug to be 
triggered.


> To fix that, use rte_get_tsc_cycles instread of rte_get_timer_cycles.


"instead"


With those updates,

Acked-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>

> Fixes: faf8fd252785 ("eal: improve entropy for initial PRNG seed")
> Fixes: 3f002f069612 ("eal: replace libc-based random generation with LFSR")
>
> Cc: stable@dpdk.org
>
> Reported-by: Ravi Kerur <rkerur@gmail.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> ---
> v2:
> * use rte_get_tsc_cycles instread of rte_get_timer_cycles
>
> ---
>   lib/librte_eal/common/rte_random.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/librte_eal/common/rte_random.c b/lib/librte_eal/common/rte_random.c
> index 57ec8fb2b3dd..b7a089ac4fe0 100644
> --- a/lib/librte_eal/common/rte_random.c
> +++ b/lib/librte_eal/common/rte_random.c
> @@ -198,7 +198,7 @@ struct rte_rand_state *__rte_rand_get_state(void)
>   		return (uint64_t)rdseed_low | ((uint64_t)rdseed_high << 32);
>   #endif
>   	/* second fallback: seed using rdtsc */
> -	return rte_get_timer_cycles();
> +	return rte_get_tsc_cycles();
>   }
>   
>   RTE_INIT(rte_rand_init)



  reply	other threads:[~2020-04-16 16:12 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <586680073-11075-1-git-send-email-xiangxia.m.yue@gmail.com>
2020-04-15  7:43 ` xiangxia.m.yue
2020-04-16 16:12   ` Mattias Rönnblom [this message]
2020-04-15 17:41 ` [dpdk-dev] [PATCH v3] " xiangxia.m.yue
2020-04-21 16:17   ` David Marchand

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=422efe07-2a23-f08c-b6cd-192f1c159913@ericsson.com \
    --to=mattias.ronnblom@ericsson.com \
    --cc=david.marchand@redhat.com \
    --cc=dev@dpdk.org \
    --cc=stable@dpdk.org \
    --cc=xiangxia.m.yue@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).