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h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hs/REWCj1nJJbdFLaDzl5x3SlkAUdGEOeK2cS1VirrpLk0LadSf0nMMFYkELitCEb 2cF/0fQYvMLiHmbRZwhac5JlGZi8yxE7lcFtAnbolD9wmjiSTUVPWoN8g0hFcOMXjP o5xr1kzh6WR2heWeC6UU0QJrGjqiD3QydgEZKLcM= Date: Sat, 25 Apr 2026 10:14:34 +0100 From: Catalin Marinas To: Dev Jain Cc: arnd@arndb.de, kees@kernel.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, akpm@linux-foundation.org, david@kernel.org, urezki@gmail.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, tglx@kernel.org, usama.anjum@arm.com, mathieu.desnoyers@efficios.com, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Ryan Roberts Subject: Re: [PATCH v3 1/3] vmalloc: add __GFP_SKIP_KASAN support Message-ID: References: <20260424130157.3163009-1-dev.jain@arm.com> <20260424130157.3163009-2-dev.jain@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260424130157.3163009-2-dev.jain@arm.com> X-Rspam-User: X-Rspamd-Queue-Id: 0D1DC140004 X-Rspamd-Server: rspam06 X-Stat-Signature: ife1y74oywh5sw14n1c4feq9wnoyxrrn X-HE-Tag: 1777108481-283319 X-HE-Meta: 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 ggkJcwJo wmUtfiLFBM2tF9Z5hsrAgEPujw9nJv8KiUd9z355FF07HYOkHgZI9nN+kvY05DlrnIyhN6XfvVU8IsedVomTT2pHRvHH611NMqNI+ZEBeOqnR8WkLeoKp3EBjDIqD5Pf5vL+QqZwh26f6oRAq8GN1JE/3dzZKgOJLQpCviNV4eLLWFoYk51+pKvUTNONjoGZgvbtuGnEoDx3X9rDbSmITYowz20dDi/hPGncxV1ybIgl9Ios= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Apr 24, 2026 at 06:31:55PM +0530, Dev Jain wrote: > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index b31b208f6ecb3..c94fcb2725b6b 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -3939,7 +3939,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, > __GFP_NOFAIL | __GFP_ZERO |\ > __GFP_NORETRY | __GFP_RETRY_MAYFAIL |\ > GFP_NOFS | GFP_NOIO | GFP_KERNEL_ACCOUNT |\ > - GFP_USER | __GFP_NOLOCKDEP) > + GFP_USER | __GFP_NOLOCKDEP | __GFP_SKIP_KASAN) > > static gfp_t vmalloc_fix_flags(gfp_t flags) > { > @@ -3980,6 +3980,9 @@ static gfp_t vmalloc_fix_flags(gfp_t flags) > * > * %__GFP_NOWARN can be used to suppress failure messages. > * > + * %__GFP_SKIP_KASAN can be used to skip unpoisoning of mapped pages > + * (when prot=%PAGE_KERNEL). I just realised, if we go with this flag for vmalloc(), there's also a comment in gfp_types.h implying that pages are unpoisoned by kasan_unpoison_vmalloc() instead. This is no longer the case with this patch. A VM_SKIP_KASAN flag may have been nicer but we already have THREADINFO_GFP and GFP_VMAP_STACK, so all those call sites would have to be moved to call the lower-level __vmalloc_node_range(). -- Catalin