[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20250124164752.hmwq6mctc6nf7uni@jpoimboe>
Date: Fri, 24 Jan 2025 08:47:52 -0800
From: Josh Poimboeuf <jpoimboe@...nel.org>
To: Jens Remus <jremus@...ux.ibm.com>
Cc: x86@...nel.org, Peter Zijlstra <peterz@...radead.org>,
Steven Rostedt <rostedt@...dmis.org>,
Ingo Molnar <mingo@...nel.org>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
linux-kernel@...r.kernel.org, Indu Bhagat <indu.bhagat@...cle.com>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>, Namhyung Kim <namhyung@...nel.org>,
Ian Rogers <irogers@...gle.com>,
Adrian Hunter <adrian.hunter@...el.com>,
linux-perf-users@...r.kernel.org, Mark Brown <broonie@...nel.org>,
linux-toolchains@...r.kernel.org, Jordan Rome <jordalgo@...a.com>,
Sam James <sam@...too.org>, linux-trace-kernel@...r.kernel.org,
Andrii Nakryiko <andrii.nakryiko@...il.com>,
Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
Florian Weimer <fweimer@...hat.com>,
Andy Lutomirski <luto@...nel.org>,
Masami Hiramatsu <mhiramat@...nel.org>,
Weinan Liu <wnliu@...gle.com>, Heiko Carstens <hca@...ux.ibm.com>,
Vasily Gorbik <gor@...ux.ibm.com>
Subject: Re: [PATCH v4 05/39] x86/asm: Avoid emitting DWARF CFI for non-VDSO
On Fri, Jan 24, 2025 at 05:08:57PM +0100, Jens Remus wrote:
> On 22.01.2025 03:30, Josh Poimboeuf wrote:
> > -#ifndef BUILD_VDSO
> > - /*
> > - * Emit CFI data in .debug_frame sections, not .eh_frame sections.
> > - * The latter we currently just discard since we don't do DWARF
> > - * unwinding at runtime. So only the offline DWARF information is
> > - * useful to anyone. Note we should not use this directive if we
> > - * ever decide to enable DWARF unwinding at runtime.
> > - */
> > - .cfi_sections .debug_frame
> > -#else
> > - /*
> > - * For the vDSO, emit both runtime unwind information and debug
> > - * symbols for the .dbg file.
> > - */
> > - .cfi_sections .eh_frame, .debug_frame
> > -#endif
> > +#else /* !BUILD_VDSO */
> > +
>
> Did you remove ".cfi_sections .debug_frame" on purpose from the
> !BUILD_VDSO path compared to V3?
Yes, since non-VDSO assembly files won't be emitting any .cfi, there's
no .debug_frame to output anyway.
> Presumably to not only not emit DWARF CFI from assembler, but any
> source?
This only impacts assembly files, notice the __ASSEMBLY__ check at the
top of the file.
--
Josh
Powered by blists - more mailing lists