From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.3 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 18755 invoked from network); 6 Aug 2020 02:19:07 -0000 Received: from mother.openwall.net (195.42.179.200) by inbox.vuxu.org with ESMTPUTF8; 6 Aug 2020 02:19:07 -0000 Received: (qmail 7398 invoked by uid 550); 6 Aug 2020 02:19:01 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 7359 invoked from network); 6 Aug 2020 02:19:00 -0000 Date: Wed, 5 Aug 2020 22:18:47 -0400 From: Rich Felker To: musl@lists.openwall.com Message-ID: <20200806021844.GK6949@brightrain.aerifal.cx> References: <20200803133338.GB6949@brightrain.aerifal.cx> <20200803141513.GD6949@brightrain.aerifal.cx> <20200804181845.GI6949@brightrain.aerifal.cx> <20200804185642.GG2076@voyager> <20200804191506.GJ6949@brightrain.aerifal.cx> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="EVF5PPMfhYS0aIcm" Content-Disposition: inline In-Reply-To: <20200804191506.GJ6949@brightrain.aerifal.cx> User-Agent: Mutt/1.5.21 (2010-09-15) Subject: [musl] [PATCH] use new socket syscalls, fallback to socketcall --EVF5PPMfhYS0aIcm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Aug 04, 2020 at 03:15:06PM -0400, Rich Felker wrote: > On Tue, Aug 04, 2020 at 08:56:42PM +0200, Markus Wichmann wrote: > > On Tue, Aug 04, 2020 at 02:18:45PM -0400, Rich Felker wrote: > > > Of these, only ppc, ppc64, sh, and possibly s390 (we only support > > > 64-bit "s390x" and I'm not sure if it ever lacked the broken-down > > > syscalls) are relevant. The rest are either unsupported by musl > > > (including pre-EABI arm) or already using SYS_socketcall. > > > > According to musl source, all currently supported architectures have > > __NR_socket (I didn't check the other calls; I just assumed that > > __NR_socket was a stand-in for all the other ones). > > > > Therefore the required change can be performed by changing the > > __socketcall macro (and __socketcall_cp of course). Something like this, > > maybe? (If using GCC statement expressions is alright): > > > > #ifdef __NR_socketcall > > #define __socketcall(nm, a, b, c, d, e, f) \ > > ({int r = __syscall(__NR_ ## nm, a, b, c, d, e, f); \ > > if (r == -ENOSYS) \ > > r = __syscall(__NR_socketcall, __SC_ ## nm, \ > > (long[6]){(long)a, (long) b, (long)c, (long)d, (long)e, (long) f}); > > r;}) > > #else > > #define __socketcall(nm, a, b, c, d, e, f) __syscall(__NR_ ## nm, a, b, c, d, e, f) > > #endif > > This would work, but we don't use statement-expressions in musl. I > think an alternative with an inline function would be trivial, though: > > static inline long __socketcall(int sys, int sock, long a, long b, long c, long d, long e, long f) > { > long r = __syscall(sys, a, b, c, d, e, f); > if (r != -ENOSYS) return r; > return __syscall(SYS_socketcall, sock, ((long[6]){a, b, c, d, e, f})); > } > #define __socketcall(nm, a, b, c, d, e, f) __socketcall(SYS_##nm, __SC_##nm, \ > (long)(a), (long)(b), (long)(c), (long)(d), (long)(e), (long)(f)) > > However it may (will?) end up including SYS_socketcall fallback code > even on archs that never need it if SYS_socketcall is defined. > Probably arch/*/syscall_arch.h should #undef SYS_socketcall if it's > never needed. I'm not sure if there are any such archs. > > I kinda just thought of getting rid of the __socketcall abstraction, > but indeed it looks like a lot of ugly boilerplate to duplicate across > ~15 functions, so I think keeping it in src/internal/syscall.h makes > the most sense. OK, that roughly works. Special care is needed for SYS_accept since it doesn't exist on i386, m68k, or s390x and needs to be emulated with SYS_accept4. microblaze and mips (plain o32) seem to be the only archs that define SYS_socketcall but don't ever need to use it. Attached is a patch that seems to work implementing the above idea with fixups. It's not heavily tested yet. Rich --EVF5PPMfhYS0aIcm Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="socketcall_fallback.diff" diff --git a/arch/i386/syscall_arch.h b/arch/i386/syscall_arch.h index 69642e57..f92b7aa9 100644 --- a/arch/i386/syscall_arch.h +++ b/arch/i386/syscall_arch.h @@ -87,5 +87,3 @@ static inline long __syscall6(long n, long a1, long a2, long a3, long a4, long a #define VDSO_CGT32_VER "LINUX_2.6" #define VDSO_CGT_SYM "__vdso_clock_gettime64" #define VDSO_CGT_VER "LINUX_2.6" - -#define SYSCALL_USE_SOCKETCALL diff --git a/arch/m68k/syscall_arch.h b/arch/m68k/syscall_arch.h index af79c306..6a9d0ae8 100644 --- a/arch/m68k/syscall_arch.h +++ b/arch/m68k/syscall_arch.h @@ -87,5 +87,4 @@ static inline long __syscall6(long n, long a, long b, long c, long d, long e, lo return d0; } -#define SYSCALL_USE_SOCKETCALL #define SYSCALL_IPC_BROKEN_MODE diff --git a/arch/microblaze/syscall_arch.h b/arch/microblaze/syscall_arch.h index 169013f8..61d8248e 100644 --- a/arch/microblaze/syscall_arch.h +++ b/arch/microblaze/syscall_arch.h @@ -95,3 +95,5 @@ static inline long __syscall6(long n, long a, long b, long c, long d, long e, lo } #define SYSCALL_IPC_BROKEN_MODE + +#undef SYS_socketcall diff --git a/arch/mips/syscall_arch.h b/arch/mips/syscall_arch.h index 380a94b3..5b7c38de 100644 --- a/arch/mips/syscall_arch.h +++ b/arch/mips/syscall_arch.h @@ -149,3 +149,5 @@ static inline long __syscall7(long n, long a, long b, long c, long d, long e, lo #define SO_SNDTIMEO_OLD 0x1005 #define SO_RCVTIMEO_OLD 0x1006 + +#undef SYS_socketcall diff --git a/arch/s390x/syscall_arch.h b/arch/s390x/syscall_arch.h index afb99852..83cc9a27 100644 --- a/arch/s390x/syscall_arch.h +++ b/arch/s390x/syscall_arch.h @@ -72,5 +72,3 @@ static inline long __syscall6(long n, long a, long b, long c, long d, long e, lo register long r7 __asm__("r7") = f; __asm_syscall("+r"(r2), "r"(r1), "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7)); } - -#define SYSCALL_USE_SOCKETCALL diff --git a/src/internal/syscall.h b/src/internal/syscall.h index 975a0031..bd073c1a 100644 --- a/src/internal/syscall.h +++ b/src/internal/syscall.h @@ -2,6 +2,7 @@ #define _INTERNAL_SYSCALL_H #include +#include #include #include "syscall_arch.h" @@ -57,15 +58,23 @@ hidden long __syscall_ret(unsigned long), #define __syscall_cp(...) __SYSCALL_DISP(__syscall_cp,__VA_ARGS__) #define syscall_cp(...) __syscall_ret(__syscall_cp(__VA_ARGS__)) -#ifndef SYSCALL_USE_SOCKETCALL -#define __socketcall(nm,a,b,c,d,e,f) __syscall(SYS_##nm, a, b, c, d, e, f) -#define __socketcall_cp(nm,a,b,c,d,e,f) __syscall_cp(SYS_##nm, a, b, c, d, e, f) +static inline long __alt_socketcall(int sys, int sock, int cp, long a, long b, long c, long d, long e, long f) +{ + long r; + if (cp) r = __syscall_cp(sys, a, b, c, d, e, f); + else r = __syscall(sys, a, b, c, d, e, f); + if (r != -ENOSYS) return r; +#ifndef SYS_socketcall + return r; #else -#define __socketcall(nm,a,b,c,d,e,f) __syscall(SYS_socketcall, __SC_##nm, \ - ((long [6]){ (long)a, (long)b, (long)c, (long)d, (long)e, (long)f })) -#define __socketcall_cp(nm,a,b,c,d,e,f) __syscall_cp(SYS_socketcall, __SC_##nm, \ - ((long [6]){ (long)a, (long)b, (long)c, (long)d, (long)e, (long)f })) + if (cp) return __syscall_cp(SYS_socketcall, sock, ((long[6]){a, b, c, d, e, f})); + else return __syscall(SYS_socketcall, sock, ((long[6]){a, b, c, d, e, f})); #endif +} +#define __socketcall(nm, a, b, c, d, e, f) __alt_socketcall(SYS_##nm, __SC_##nm, 0, \ + (long)(a), (long)(b), (long)(c), (long)(d), (long)(e), (long)(f)) +#define __socketcall_cp(nm, a, b, c, d, e, f) __alt_socketcall(SYS_##nm, __SC_##nm, 1, \ + (long)(a), (long)(b), (long)(c), (long)(d), (long)(e), (long)(f)) /* fixup legacy 16-bit junk */ @@ -338,6 +347,10 @@ hidden long __syscall_ret(unsigned long), #define __SC_recvmmsg 19 #define __SC_sendmmsg 20 +#ifndef SYS_accept +#define SYS_accept SYS_accept4 +#endif + #ifndef SO_RCVTIMEO_OLD #define SO_RCVTIMEO_OLD 20 #endif --EVF5PPMfhYS0aIcm--