From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnout Vandecappelle Date: Fri, 28 May 2021 17:25:10 +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: <7eca6978-c70c-cb04-00f3-3ddad374e7f5@mind.be> 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 16:33, Fabrice Fontaine wrote: > Hi Arnout, > > Le ven. 28 mai 2021 ? 16:17, Arnout Vandecappelle a ?crit : >> >> >> >> 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. > Thanks for your feedback, I'll then send a v2 of my patch for vlc to > fix the build on riscv32 instead of disabling it. Well, no, only if upstream vlc is going to accept that approach. Regards, Arnout >> >> >> 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 >>> > Best Regards, > > Fabrice >