From: Oleg Nesterov <oleg@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "Carlos López" <clopez@suse.de>,
linux-trace-kernel@vger.kernel.org,
linux-perf-users@vger.kernel.org,
"Masami Hiramatsu" <mhiramat@kernel.org>,
"Ingo Molnar" <mingo@redhat.com>,
"Arnaldo Carvalho de Melo" <acme@kernel.org>,
"Namhyung Kim" <namhyung@kernel.org>,
"Mark Rutland" <mark.rutland@arm.com>,
"Alexander Shishkin" <alexander.shishkin@linux.intel.com>,
"Jiri Olsa" <jolsa@kernel.org>, "Ian Rogers" <irogers@google.com>,
"Adrian Hunter" <adrian.hunter@intel.com>,
"James Clark" <james.clark@linaro.org>,
"open list:UPROBES" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] uprobes: replace deprecated kmap_atomic() with kmap_local_page()
Date: Thu, 5 Feb 2026 13:29:30 +0100 [thread overview]
Message-ID: <aYSNKqr2rmO7dHBm@redhat.com> (raw)
In-Reply-To: <20260205111208.GK232055@noisy.programming.kicks-ass.net>
On 02/05, Peter Zijlstra wrote:
>
> On Thu, Feb 05, 2026 at 11:57:25AM +0100, Carlos López wrote:
> > kmap_atomic() has been deprecated for a few years, and kmap_local_page()
> > should be used instead, so replace it. Since the uprobes code relied on
> > kmap_atomic() disabling page faults to access user pages, add the
> > required calls to keep the existing behavior.
>
> Are those pagefault_disable()s really needed here, or is this just
> cargo-culting?
No, I think there are not needed.
And the (already in tip) patches from Keke do not add pagefault_disable().
is_trap_at_addr() does pagefault_disable() because it is called with
mm->mmap_lock held.
Oleg.
next prev parent reply other threads:[~2026-02-05 12:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-05 10:57 [PATCH] uprobes: replace deprecated kmap_atomic() with kmap_local_page() Carlos López
2026-02-05 11:12 ` Peter Zijlstra
2026-02-05 11:19 ` Carlos López
2026-02-05 12:29 ` Oleg Nesterov [this message]
2026-02-05 11:25 ` Oleg Nesterov
2026-02-05 11:27 ` Carlos López
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