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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
> 
> 


  reply	other threads:[~2026-07-27  1:41 UTC|newest]

Thread overview: 18+ 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
2026-07-24  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  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  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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