From: Alistair Popple <apopple@nvidia.com>
To: Gou Hao <gouhao@uniontech.com>
Cc: maddy@linux.ibm.com, mpe@ellerman.id.au, npiggin@gmail.com,
chleroy@kernel.org, maarten.lankhorst@linux.intel.com,
mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com,
simona@ffwll.ch, bharat@chelsio.com, jgg@ziepe.ca,
leon@kernel.org, akpm@linux-foundation.org, namcao@linutronix.de,
ynorov@nvidia.com, sshegde@linux.ibm.com, nilay@linux.ibm.com,
clg@kaod.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
linux-rdma@vger.kernel.org, linux-mm@kvack.org,
gouhaojake@163.com, kernel@uniontech.com
Subject: Re: [PATCH v2 5/6] lib/test_hmm: remove dead NULL checks after GFP_NOFAIL allocations
Date: Mon, 27 Jul 2026 11:41:27 +1000 [thread overview]
Message-ID: <ama3NaduNkQ16lEA@nvdebian.thelocal> (raw)
In-Reply-To: <20260724022851.466017-6-gouhao@uniontech.com>
On 2026-07-24 at 12:28 +1000, Gou Hao <gouhao@uniontech.com> wrote...
> kvcalloc with the __GFP_NOFAIL flag will never return NULL, so the
> subsequent NULL checks are unreachable dead code. Remove them.
Reviewed-by: Alistair Popple <apopple@nvidia.com>
> Signed-off-by: Gou Hao <gouhao@uniontech.com>
> ---
> lib/test_hmm.c | 6 ------
> 1 file changed, 6 deletions(-)
>
> diff --git a/lib/test_hmm.c b/lib/test_hmm.c
> index 9c59d1ceb5b57..d615e4e5fc447 100644
> --- a/lib/test_hmm.c
> +++ b/lib/test_hmm.c
> @@ -1209,16 +1209,10 @@ static int dmirror_migrate_to_device(struct dmirror *dmirror,
> if (!mmget_not_zero(mm))
> return -EINVAL;
>
> - ret = -ENOMEM;
> src_pfns = kvcalloc(PTRS_PER_PTE, sizeof(*src_pfns),
> GFP_KERNEL | __GFP_NOFAIL);
> - if (!src_pfns)
> - goto free_mem;
> -
> dst_pfns = kvcalloc(PTRS_PER_PTE, sizeof(*dst_pfns),
> GFP_KERNEL | __GFP_NOFAIL);
> - if (!dst_pfns)
> - goto free_mem;
>
> ret = 0;
> mmap_read_lock(mm);
> --
> 2.20.1
>
>
next prev parent reply other threads:[~2026-07-27 1:41 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-24 2:28 [PATCH v2 0/6] remove dead NULL checks after GFP_NOFAIL allocations and fix xive use-after-free Gou Hao
2026-07-24 2:28 ` [PATCH v2 1/6] powerpc/xive: remove dead NULL check after GFP_NOFAIL allocation Gou Hao
2026-07-24 4:55 ` Cédric Le Goater
2026-07-26 17:04 ` Cédric Le Goater
2026-07-27 3:11 ` Gou Hao
2026-07-27 6:16 ` Mukesh Kumar Chaurasiya
2026-07-24 2:28 ` [PATCH v2 2/6] powerpc/xive: add error return value to xive_smp_probe() Gou Hao
2026-07-24 4:55 ` Cédric Le Goater
2026-07-24 2:28 ` [PATCH v2 3/6] powerpc/xive: fix use-after-free of xive_ipis Gou Hao
2026-07-24 2:44 ` sashiko-bot
2026-07-24 4:58 ` Cédric Le Goater
2026-07-26 16:57 ` Cédric Le Goater
2026-07-24 2:28 ` [PATCH v2 4/6] drm: remove dead WARN_ON NULL check after GFP_NOFAIL allocation Gou Hao
2026-07-24 2:28 ` [PATCH v2 5/6] lib/test_hmm: remove dead NULL checks after GFP_NOFAIL allocations Gou Hao
2026-07-27 1:41 ` Alistair Popple [this message]
2026-07-24 2:28 ` [PATCH v2 6/6] RDMA/cxgb4: " Gou Hao
2026-07-24 2:53 ` sashiko-bot
2026-07-24 7:34 ` Potnuri Bharat Teja
2026-07-26 3:26 ` [PATCH v2 0/6] remove dead NULL checks after GFP_NOFAIL allocations and fix xive use-after-free Andrew Morton
2026-07-26 8:24 ` Leon Romanovsky
2026-07-26 8:23 ` (subset) " Leon Romanovsky
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