[dpdk-stable] patch 'eal: fix PRNG init with HPET enabled' has been queued to stable release 19.11.3

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 05/21/20. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Thanks.

Luca Boccassi

---
>From 952892aa67011669872daf1f07c864444220f7ae Mon Sep 17 00:00:00 2001
From: Tonghao Zhang <xiangxia.m.yue at gmail.com>
Date: Thu, 16 Apr 2020 01:41:06 +0800
Subject: [PATCH] eal: fix PRNG init with HPET enabled
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

[ upstream commit 9b41c276fd35fe3c0ed3fb0d9cf98a83a58b31b2 ]

When rte_rand_init is invoked, and the kernel running dpdk does not
support *getentropy, at the same time, the cpu does not support rdseed,
then rte_rand_init invoked rte_get_timer_cycles.

If HPET was enabled in the DPDK build (CONFIG_RTE_LIBEAL_USE_HPET=y) and
the system, rte_get_timer_cycles will invoke rte_get_hpet_cycles while
*eal_hpet is not available.

To fix that, use rte_get_tsc_cycles instead of rte_get_timer_cycles.

Fixes: 3f002f069612 ("eal: replace libc-based random generation with LFSR")

Signed-off-by: Tonghao Zhang <xiangxia.m.yue at gmail.com>
Acked-by: Mattias Rönnblom <mattias.ronnblom at ericsson.com>
---
 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 57ec8fb2b3..b7a089ac4f 100644
--- a/lib/librte_eal/common/rte_random.c
+++ b/lib/librte_eal/common/rte_random.c
@@ -198,7 +198,7 @@ __rte_random_initial_seed(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)
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-05-19 13:56:21.732295905 +0100
+++ 0072-eal-fix-PRNG-init-with-HPET-enabled.patch	2020-05-19 13:56:18.299503260 +0100
@@ -1,4 +1,4 @@
-From 9b41c276fd35fe3c0ed3fb0d9cf98a83a58b31b2 Mon Sep 17 00:00:00 2001
+From 952892aa67011669872daf1f07c864444220f7ae Mon Sep 17 00:00:00 2001
 From: Tonghao Zhang <xiangxia.m.yue at gmail.com>
 Date: Thu, 16 Apr 2020 01:41:06 +0800
 Subject: [PATCH] eal: fix PRNG init with HPET enabled
@@ -6,6 +6,8 @@
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 
+[ upstream commit 9b41c276fd35fe3c0ed3fb0d9cf98a83a58b31b2 ]
+
 When rte_rand_init is invoked, and the kernel running dpdk does not
 support *getentropy, at the same time, the cpu does not support rdseed,
 then rte_rand_init invoked rte_get_timer_cycles.
@@ -17,7 +19,6 @@
 To fix that, use rte_get_tsc_cycles instead of rte_get_timer_cycles.
 
 Fixes: 3f002f069612 ("eal: replace libc-based random generation with LFSR")
-Cc: stable at dpdk.org
 
 Signed-off-by: Tonghao Zhang <xiangxia.m.yue at gmail.com>
 Acked-by: Mattias Rönnblom <mattias.ronnblom at ericsson.com>