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From: Ingo Molnar <mingo@kernel.org>
To: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Sandipan Das <sandipan.das@amd.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org, Uros Bizjak <ubizjak@gmail.com>
Subject: Re: [PATCH] perf/x86/amd/uncore: fix error codes in amd_uncore_init()
Date: Fri, 13 Oct 2023 11:06:37 +0200	[thread overview]
Message-ID: <ZSkInflBriOL9V3M@gmail.com> (raw)
In-Reply-To: <0c973a20-e10c-4989-b7d9-86cb0f522718@kadam.mountain>


* Dan Carpenter <dan.carpenter@linaro.org> wrote:

> On Fri, Oct 13, 2023 at 09:30:46AM +0200, Ingo Molnar wrote:
>
> > Ugh, why on Earth didn't GCC warn about this? The bad pattern is pretty 
> > simple & obvious once pointed out ... compilers should have no trouble 
> > realizing that 'ret' is returned uninitialized in some of these control 
> > paths. Yet not a peep from the compiler ...
> 
> We disabled that warning years ago (5?) because GCC had too many false 
> positives.

GCC had some pretty bogus notions about 'possible' uninitialized use that 
encouraged some bad code patterns, but in this case there's readily 
provable uninitialized use, that a compiler should warn about.

Is it possible to disable just the unreliable, probabilistic part of GCC's 
uninitialized variables warnings?

Thanks,

	Ingo

  reply	other threads:[~2023-10-13  9:06 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-13  7:18 [PATCH] perf/x86/amd/uncore: fix error codes in amd_uncore_init() Dan Carpenter
2023-10-13  7:30 ` Ingo Molnar
2023-10-13  8:12   ` Dan Carpenter
2023-10-13  9:06     ` Ingo Molnar [this message]
2023-10-13  9:09       ` Uros Bizjak
2023-10-14  9:03         ` Ingo Molnar
2023-10-16 10:39           ` Dan Carpenter
2023-10-16 11:18             ` Ingo Molnar
2023-10-13  7:44 ` Sandipan Das
2023-10-13  9:03   ` Ingo Molnar
2023-10-13  9:07     ` Sandipan Das

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