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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-43bbfb7e280sm7560765e9.8.2025.03.02.04.19.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 02 Mar 2025 04:19:58 -0800 (PST) Date: Sun, 2 Mar 2025 12:19:57 +0000 From: David Laight To: Steven Rostedt Cc: Kent Overstreet , James Bottomley , Greg KH , Miguel Ojeda , Ventura Jack , "H. Peter Anvin" , Alice Ryhl , Linus Torvalds , Gary Guo , airlied@gmail.com, boqun.feng@gmail.com, hch@infradead.org, ksummit@lists.linux.dev, linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, Ralf Jung , Josh Poimboeuf Subject: Re: C aggregate passing (Rust kernel policy) Message-ID: <20250302121957.28f08504@pumpkin> In-Reply-To: <20250226124733.10b4b5fa@gandalf.local.home> References: <2rrp3fmznibxyg3ocvsfasfnpwfp2skhf4x7ihrnvm72lemykf@lwp2jkdbwqgm> <2025022611-work-sandal-2759@gregkh> <16127450a24e9df8112a347fe5f6df9c9cca2926.camel@HansenPartnership.com> <20250226110033.53508cbf@gandalf.local.home> <9c443013493f8f380f9c4d51b1eeeb9d29b208a3.camel@HansenPartnership.com> <20250226115726.27530000@gandalf.local.home> <20250226124733.10b4b5fa@gandalf.local.home> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 26 Feb 2025 12:47:33 -0500 Steven Rostedt wrote: > On Wed, 26 Feb 2025 12:41:30 -0500 > Kent Overstreet wrote: > > > It's been awhile since I've looked at one, I've been just automatically > > switching back to frame pointers for awhile, but - I never saw > > inaccurate backtraces, just failure to generate a backtrace - if memory > > serves. > > OK, maybe if the bug was bad enough, it couldn't get access to the ORC > tables for some reason. Not having a backtrace on crash is not as bad as > incorrect back traces, as the former is happening when the system is dieing > and live kernel patching doesn't help with that. I bet to differ. With no backtrace you have absolutely no idea what happened. A list of 'code addresses on the stack' (named as such) can be enough to determine the call sequence. Although to be really helpful you need a hexdump of the actual stack and the stack addresses of each 'code address'. David