From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnout Vandecappelle Date: Fri, 28 May 2021 16:17:03 +0200 Subject: [Buildroot] [PATCH 1/1] package/capnproto: fix build on riscv32 In-Reply-To: References: <20210527210402.555334-1-fontaine.fabrice@gmail.com> <20210528065949.GA2170022@sunra> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net On 28/05/2021 09:11, Fabrice Fontaine wrote: > Hi Koen, > > Le ven. 28 mai 2021 ? 09:00, Koen Martens a ?crit : >> >> Hi, >> >> Thanks for diving into this. I've had emails about this for months, and briefly >> looked at it, but never found the time to properly figure it out. >> >> I see the patch below is also present upstream. Do you know whether this has >> already been released or when it will be? > I don't know when upstream will release a new version. > However, after digging through a lot of riscv32 build failures on > other packages, I'm not sure that this upstream patch is right > anymore. > Aliasing SYS_futex to SYS_futex_time64 has been rejected by vlc for example: > https://patches.videolan.org/patch/30581/ That patch looks OK to me: +/* 32bit architectures with 64bit time_t do not define __NR_futex syscall */ +#if !defined(SYS_futex) && defined(SYS_futex_time64) +#define SYS_futex SYS_futex_time64 +#endif The comment was "this patch won't work if the userspace ABI uses the 64-bit time_t on a 32-bit ISA that did start with 32-bit time_t" - but that's not true. On a 32-bit ISA that did start with 32-bit time_t, SYS_futex will be defined (or SYS_foo is not properly exported by libc and then SYS_futex_time64 isn't defined either). To be really safe, you should maybe also check that __TIMESIZE == 64 [1] - but that may break on musl or uClibc. Or even better of course would be to patch all code to use the __time64_t instead of time_t everywhere, independent of __TIMESIZE. But even then you'd need fallback to time_t for old libc/kernel. Regards, Arnout [1] https://www.gnu.org/software/libc/manual/html_node/64_002dbit-time-symbol-handling.html > So another option would be to just disable capnproto on riscv32. >> >> Given that this exact patch is also applied upstream, your patch below seems fine >> to me. >> >> Cheers, >> >> Koen >> >> On Thu, May 27, 2021 at 11:04:02PM +0200, Fabrice Fontaine wrote: >>> Fixes: >>> - http://autobuild.buildroot.org/results/1c1cd4775241ee57d878cad5c978413d4b4a8736 >>> >>> Signed-off-by: Fabrice Fontaine >>> --- >>> ...it-architectures-using-64-bit-time_t.patch | 37 +++++++++++++++++++ >>> 1 file changed, 37 insertions(+) >>> create mode 100644 package/capnproto/0001-mutex-Fix-build-on-32-bit-architectures-using-64-bit-time_t.patch >>> >>> diff --git a/package/capnproto/0001-mutex-Fix-build-on-32-bit-architectures-using-64-bit-time_t.patch b/package/capnproto/0001-mutex-Fix-build-on-32-bit-architectures-using-64-bit-time_t.patch >>> new file mode 100644 >>> index 0000000000..ce70ab8f29 >>> --- /dev/null >>> +++ b/package/capnproto/0001-mutex-Fix-build-on-32-bit-architectures-using-64-bit-time_t.patch >>> @@ -0,0 +1,37 @@ >>> +From e2a05a19e9dc51287e19cc9f11fd91449219e361 Mon Sep 17 00:00:00 2001 >>> +From: Khem Raj >>> +Date: Sun, 15 Nov 2020 12:10:28 -0800 >>> +Subject: [PATCH] mutex: Fix build on 32-bit architectures using 64-bit time_t >>> + >>> +mutex code uses SYS_futex, which it expects from system C library. >>> +in glibc (/usr/include/bits/syscall.h defines it in terms of of NR_futex) >>> +rv32 is using 64bit time_t from get go unlike other 32bit architectures >>> +in glibc, therefore it wont have NR_futex defined but just NR_futex_time64 >>> +this aliases it to NR_futex so that SYS_futex is then defined for rv32 >>> + >>> +Signed-off-by: Khem Raj >>> +[Retrieved from: >>> +https://github.com/capnproto/capnproto/commit/e2a05a19e9dc51287e19cc9f11fd91449219e361] >>> +Signed-off-by: Fabrice Fontaine >>> +--- >>> + c++/src/kj/mutex.c++ | 6 ++++++ >>> + 1 file changed, 6 insertions(+) >>> + >>> +diff --git a/c++/src/kj/mutex.c++ b/c++/src/kj/mutex.c++ >>> +index c81cead7b..e1594b117 100644 >>> +--- a/c++/src/kj/mutex.c++ >>> ++++ b/c++/src/kj/mutex.c++ >>> +@@ -39,7 +39,13 @@ >>> + >>> + #ifndef SYS_futex >>> + // Missing on Android/Bionic. >>> ++#ifdef __NR_futex >>> + #define SYS_futex __NR_futex >>> ++#elif defined(SYS_futex_time64) >>> ++#define SYS_futex SYS_futex_time64 >>> ++#else >>> ++#error "Need working SYS_futex" >>> ++#endif >>> + #endif >>> + >>> + #ifndef FUTEX_WAIT_PRIVATE >>> -- >>> 2.30.2 >>> > Best Regards, > > Fabrice > _______________________________________________ > buildroot mailing list > buildroot at busybox.net > http://lists.busybox.net/mailman/listinfo/buildroot >