On Mon, Feb 17, 2025 at 6:19 PM Roman Kagan <rka...@amazon.de> wrote: > > On Thu, Jan 02, 2025 at 04:32:17PM +0100, Roman Kagan wrote: > > When gcc is built for x86_64-linux-musl target, stack unwinding from > > within signal handler stops at the innermost signal frame. The reason > > for this behaviro is that the signal trampoline is not accompanied with > > appropiate CFI directives, and the fallback path in libgcc to recognize > > it by the code sequence is only enabled for glibc except 2.0. The > > latter is motivated by the lack of sys/ucontext.h in that glibc version. > > > > Given that all relevant libc-s ship sys/ucontext.h for over a decade, > > and that other arches aren't shy of unconditionally using it, follow > > suit and remove the preprocessor condition, too.
"Relevant libc"-s for x86 linux are LIBC_GLIBC, LIBC_UCLIBC, LIBC_BIONIC and LIBC_MUSL. As far as glibc is concerned, the latest glibc 2.0.x version was released in 1997 [1], so I guess we can remove the condition for version 2.0. Based on your claim, the other mentioned libcs also provide the required header for a long time. I have no objection to the patch, but I think that this patch is a bit late for gcc-15 and should be committed early in the gcc-16 development cycle. But let's hear release managers (CC'd). [1] https://sourceware.org/glibc/wiki/Glibc%20Timeline Thanks, Uros. > > > > Signed-off-by: Roman Kagan <rka...@amazon.de> > > --- > > libgcc/config/i386/linux-unwind.h | 7 ------- > > 1 file changed, 7 deletions(-) > > > > diff --git a/libgcc/config/i386/linux-unwind.h > > b/libgcc/config/i386/linux-unwind.h > > index fe316ee02cf2..8f37642bbf55 100644 > > --- a/libgcc/config/i386/linux-unwind.h > > +++ b/libgcc/config/i386/linux-unwind.h > > @@ -33,12 +33,6 @@ see the files COPYING3 and COPYING.RUNTIME respectively. > > If not, see > > > > #ifndef inhibit_libc > > > > -/* There's no sys/ucontext.h for glibc 2.0, so no > > - signal-turned-exceptions for them. There's also no configure-run for > > - the target, so we can't check on (e.g.) HAVE_SYS_UCONTEXT_H. Using the > > - target libc version macro should be enough. */ > > -#if defined __GLIBC__ && !(__GLIBC__ == 2 && __GLIBC_MINOR__ == 0) > > - > > #include <signal.h> > > #include <sys/ucontext.h> > > > > @@ -199,5 +193,4 @@ x86_frob_update_context (struct _Unwind_Context > > *context, > > } > > > > #endif /* ifdef __x86_64__ */ > > -#endif /* not glibc 2.0 */ > > #endif /* ifdef inhibit_libc */ > > Ping? > > Roman.
