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Fri, 30 Aug 2024 10:33:10 -0400 X-MC-Unique: 7oYBhr9PPP66Lp4ib6DiPA-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4EFCA1955D58; Fri, 30 Aug 2024 14:33:06 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.225.148]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 6EFD819560AE; Fri, 30 Aug 2024 14:33:00 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 30 Aug 2024 16:32:58 +0200 (CEST) Date: Fri, 30 Aug 2024 16:31:51 +0200 From: Oleg Nesterov To: Jiri Olsa Cc: Andrii Nakryiko , Andrii Nakryiko , linux-trace-kernel@vger.kernel.org, peterz@infradead.org, rostedt@goodmis.org, mhiramat@kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, paulmck@kernel.org, willy@infradead.org, surenb@google.com, akpm@linux-foundation.org, linux-mm@kvack.org Subject: Re: [PATCH v4 4/8] uprobes: travers uprobe's consumer list locklessly under SRCU protection Message-ID: <20240830143151.GC20163@redhat.com> References: <20240829183741.3331213-1-andrii@kernel.org> <20240829183741.3331213-5-andrii@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-Stat-Signature: dib1345gsf1kznhcyusqm4tbtmmc48uq X-Rspamd-Queue-Id: 965D4A0015 X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1725028397-403098 X-HE-Meta: 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 jjYqnno3 e5VK02gCYxl3ixiDMtFWfPwOH0CWkZ5fswJGOCqUzUGKmaV9fqZzyNKbqj2YjsPMeEBJ2Eu2kLNq7LzbbsG0/W27opurDuek+h7WIJV92vtvGgpUBgXjD5dU8l5pp3ldInDnL1NlXrivTMX499C9YnFyM4WxU5E/bvxpvv7oaPQ+RQiwagXEBZtgfYrdKTK9hlcgCQCouNf6CU3kADU1SSgRHyIkw0aJUdNOv1aWt+Pbido+xaWYeN3KH85ZF6yZ15yqsRxm4fQgAh3tR51G87OzgDjIlq2yS4hoz7dHBgtVH5cp7JbqF8jyzNHHLqocdk4yDDAJnyi/fe00ImcJ2acQDqeNKhjirAhTpPuKWbOA1VRSx6FnLoLqopjtT1N+XsQ6d X-Bogosity: Ham, tests=bogofilter, spamicity=0.000184, 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 08/30, Jiri Olsa wrote: > > with this change the probe will not get removed in the attached test, > it'll get 2 hits, without this change just 1 hit I don't understand the code in tools/...bpf../ at all, can't comment, > but I'm not sure it's a big problem, because seems like that's not the > intended way the removal should be used anyway, as explained by Oleg [1] It seems that I confused you again ;) No, I think you found a problem. UPROBE_HANDLER_REMOVE can be lost if uc->filter == NULL of if it returns true. See another reply I sent a minute ago. I think the fix is simple, plus we need to cleanup this logic anyway, I'll try to send some code on Monday. Oleg.