From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Burakov, Anatoly" Subject: Re: [PATCH v2] mem: fix undefined behavior in NUMA code Date: Fri, 21 Sep 2018 09:57:02 +0100 Message-ID: <5e5d7251-8d51-e413-ae49-cbaae562fa19@intel.com> References: <2624b855f3454691212cdb244f04926631c391a2.1535544966.git.anatoly.burakov@intel.com> <7e4178219213303b982e505ae4cb4387d9d3814a.1537447684.git.anatoly.burakov@intel.com> <20180921064524eucas1p147ff66419605b9b141969e1a672196f9~WV1A0hUgX1031210312eucas1p1k@eucas1p1.samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: solal.pirelli@gmail.com, stable@dpdk.org To: Ilya Maximets , dev@dpdk.org Return-path: In-Reply-To: <20180921064524eucas1p147ff66419605b9b141969e1a672196f9~WV1A0hUgX1031210312eucas1p1k@eucas1p1.samsung.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 21-Sep-18 7:47 AM, Ilya Maximets wrote: > On 20.09.2018 15:50, Anatoly Burakov wrote: >> When NUMA-aware hugepages config option is set, we rely on >> libnuma to tell the kernel to allocate hugepages on a specific >> NUMA node. However, we allocate node mask before we check if >> NUMA is available in the first place, which, according to >> the manpage [1], causes undefined behaviour. >> >> Fix by only using nodemask when we have NUMA available. >> >> [1] https://linux.die.net/man/3/numa_alloc_onnode >> >> Bugzilla ID: 20 >> >> Fixes: 1b72605d2416 ("mem: balanced allocation of hugepages") >> Cc: i.maximets@samsung.com >> Cc: stable@dpdk.org >> >> Signed-off-by: Anatoly Burakov >> --- >> lib/librte_eal/linuxapp/eal/eal_memory.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c >> index dbf19499e..1a2a84a65 100644 >> --- a/lib/librte_eal/linuxapp/eal/eal_memory.c >> +++ b/lib/librte_eal/linuxapp/eal/eal_memory.c >> @@ -263,7 +263,7 @@ map_all_hugepages(struct hugepage_file *hugepg_tbl, struct hugepage_info *hpi, >> int node_id = -1; >> int essential_prev = 0; >> int oldpolicy; >> - struct bitmask *oldmask = numa_allocate_nodemask(); >> + struct bitmask *oldmask = NULL; >> bool have_numa = true; >> unsigned long maxnode = 0; >> >> @@ -275,6 +275,7 @@ map_all_hugepages(struct hugepage_file *hugepg_tbl, struct hugepage_info *hpi, >> >> if (have_numa) { >> RTE_LOG(DEBUG, EAL, "Trying to obtain current memory policy.\n"); >> + oldmask = numa_allocate_nodemask(); >> if (get_mempolicy(&oldpolicy, oldmask->maskp, >> oldmask->size + 1, 0, 0) < 0) { >> RTE_LOG(ERR, EAL, >> @@ -401,8 +402,8 @@ map_all_hugepages(struct hugepage_file *hugepg_tbl, struct hugepage_info *hpi, >> strerror(errno)); >> numa_set_localalloc(); >> } >> + numa_free_cpumask(oldmask); >> } >> - numa_free_cpumask(oldmask); > > There will be 'oldmask' leak in case no 'socket-mem' requested. Oh, right, you're correct! > >> #endif >> return i; >> } >> > -- Thanks, Anatoly