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bh=0HCnFxTOtw1BYGCHOe07rJEdwebExkUdakGkvusvcp0=; b=nUoMvj4zn3a1estRRht7etxnYa4k1RpeBqT1zM0Y0KgZM6eSxMU5EkyotCOIYvqIa2DZku uL6CUEvzYZshvId4mT2PtytLBYbqRslBscyLR+zyV3uLmtetbm2+RJcdLqqej0e4OF8jsM EvvmMUfLBV0+qYUbVb7tpaxRgrk62/c= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1747324072; a=rsa-sha256; cv=none; b=Y0dArLY/is5xbIZ6sBEToo5Pr1075BPDKVxPXfj80AZMYMW5JERKmYxnDZVj7SmPsGRyWr W+Qh83OHFaSdvxQmNJ0d14GqEAFEW1oq02BxVCP9d0puD5keq8oGw2bTJiqWZ9aIani/fr NRotdATtY5vSHeE+PtG1vQFZecoVUuU= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 19007614BC; Thu, 15 May 2025 15:47:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABF87C4CEE7; Thu, 15 May 2025 15:47:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747324070; bh=wzc8O4szYX+d4pjGzQ2Eqb1YlzSsOZl/5hIYcHCkLAU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dVYHCIi79L3pvbQL4RxYqhKi4aTXb9VVMAiZ+bOIx5jL2SnMP10DC1fI2YzwreU96 OppBYixNs/jB0HjE/eh9yX4V8WAvktvmZ0uBR1hUHnNPNkUTkERP2qi5LpHENTOlDz ZQJH++rjOUs15rhauk5QP6EoB97c0c8Hl2Zv7N60khVeyDqdlpSDI6USqsbNkSQpSY x1+iCkBR+xeibyImJ+6COtr9amU3Zi8FKF06IE4X8SzBKRb+I8VhRY9sdg/AgcdBMi ovU2rG8sRl0Lq4/fKrg1dOgSMnZjeyuTA1d0kB7MBPwzHVapTllx+Hf6h8BnFF7i+D l4J7ufo9ooWNA== Date: Thu, 15 May 2025 08:47:47 -0700 From: Kees Cook To: Shung-Hsi Yu Cc: bpf@vger.kernel.org, linux-mm@kvack.org, Andrii Nakryiko , Ihor Solodrai , Andrew Morton , Michal Hocko , Vlastimil Babka , Uladzislau Rezki , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, regressions@lists.linux.dev, Greg Kroah-Hartman , Alexei Starovoitov , Daniel Borkmann , Pawan Gupta , Eduard Zingerman Subject: Re: [REGRESSION] bpf verifier slowdown due to vrealloc() change since 6.15-rc6 Message-ID: <202505150845.0F9E154@keescook> References: <20250515-bpf-verifier-slowdown-vwo2meju4cgp2su5ckj@6gi6ssxbnfqg> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250515-bpf-verifier-slowdown-vwo2meju4cgp2su5ckj@6gi6ssxbnfqg> X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 01E1CC0013 X-Stat-Signature: 4wzbnsteahqsop8cdaxisxutp4ie9jna X-Rspam-User: X-HE-Tag: 1747324071-488413 X-HE-Meta: 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 HeynoZMn 47wca8n318sGMbZrZaGPWtuEvlLf09cgxsuFKqClt2VNwGOMBR3h+LKyXHiEncTPEa+gHVLSvZqJcja4dFZAVSPEg0JMBqHcIZKRtMDNreX+j47NyhumCIT7tUB8Dsb70Ss9yKoQQJtcqKPCK+t0F8hM/CFsBE6YjtHaHtRVgIC95tq++esJilflb+QWwj6RjsZ6X/KTRsjLf3T+ZTNDeYjUQlXUckgGHbXcxtx/FbENE4AAs0myHvmnV7sq6n8lbwYCS5vvEtkzr3PUufEvv+klpmtktoL0pMj4KUYnOaDJiVuuF9XaOG03l16LZTUQXQDyjtuwynN9ssZtpHG2+Y9diNqbkqt9qFTjJlVJ4+LcJv+3pXwlyL4HKjLFxA+4Gv1LJAVd3RSn+tX4dwYvZaxuOOQ6vo4ZakzaV X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, May 15, 2025 at 09:12:25PM +0800, Shung-Hsi Yu wrote: > Bisect was done by Pawan and got to commit a0309faf1cb0 "mm: vmalloc: > support more granular vrealloc() sizing"[2]. To further zoom in the Can you try this patch? It's a clear bug fix, but if it doesn't improve things, I have another idea to rearrange the memset. >From e96a0e2519b1c5b50f45bd05bf60e6117d1132b2 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 15 May 2025 08:43:12 -0700 Subject: [PATCH] mm: vmalloc: Actually use the in-place vrealloc region The refactoring to not build a new vmalloc region only actually worked when shrinking. Actually return the resized area when it grows. Ugh. Fixes: a0309faf1cb0 ("mm: vmalloc: support more granular vrealloc() sizing") Signed-off-by: Kees Cook --- Cc: Andrew Morton Cc: Uladzislau Rezki Cc: --- mm/vmalloc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 2d7511654831..74bd00fd734d 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -4111,6 +4111,7 @@ void *vrealloc_noprof(const void *p, size_t size, gfp_t flags) if (want_init_on_alloc(flags)) memset((void *)p + old_size, 0, size - old_size); vm->requested_size = size; + return (void *)p; } /* TODO: Grow the vm_area, i.e. allocate and map additional pages. */ -- 2.34.1 -- Kees Cook