From dd481ccffd926ea70b107a98a9f4eb00822070c4 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 20 Feb 2014 17:50:31 +0000 Subject: Fix __ASSUME_ACCEPT4 issues (bug 16609). In , Aurelien noted issues with the definition of __ASSUME_ACCEPT4, which I discussed in more detail in ; these are now bug 16609. As previously noted, __ASSUME_ACCEPT4 is used in two ways: * In OS-independent code, to mean "accept4 can be assumed to work rather than fail with ENOSYS". It doesn't matter whether it's implemented with socketcall or a separate syscall. * In Linux-specific code, to mean "the socketcall multiplex syscall can be assumed to handle the accept4 operation. When used in Linux-specific code, it *never* refers to anything relating to the accept4 syscall, only to the socketcall multiplexer. This patch splits the macro into separate __ASSUME_ACCEPT4_SOCKETCALL, __ASSUME_ACCEPT4_SYSCALL and __ASSUME_ACCEPT4 to clarify the different cases involved. A macro __ASSUME_SOCKETCALL is added for convenience in writing logic relating to all socketcall architectures. In addition, to address the issue of architectures where socketcall support for accept4 was added before a separate syscall was added (and so the separate syscall should not be used unless known to be present or fallback to socketcall is available), a fourth macro __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL is added to indicate that the syscall became available at the same time as socketcall support. This is then used in the relevant places in a conditional determining whether to undefine __NR_accept4 (the simple approach to avoiding the syscall's presence causing problems; I didn't try to implement runtime fallback from the syscall to socketcall). Architecture-specific note: alpha defined __ASSUME_ACCEPT4 for 2.6.33 and later, but actually the syscall was added for alpha in 3.2, so this patch uses the correct condition for __ASSUME_ACCEPT4_SYSCALL there. Tested x86_64, including that disassembly of the installed shared libraries is unchanged by this patch. [BZ #16609] * sysdeps/unix/sysv/linux/kernel-features.h [__i386__ || __powerpc__ || __s390__ || __sh__ || __sparc__] (__ASSUME_SOCKETCALL): Define. [__LINUX_KERNEL_VERSION && __ASSUME_SOCKETCALL] (__ASSUME_ACCEPT4_SOCKETCALL): Likewise. [(__LINUX_KERNEL_VERSION >= 0x02061c && (__x86_64__ || __sparc__)) || (__LINUX_KERNEL_VERSION >= 0x020625 && (__powerpc__ || __sh__))] (__ASSUME_ACCEPT4_SYSCALL): Likewise. [__sparc__] (__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL): Likewise. [__ASSUME_ACCEPT4_SOCKETCALL || __ASSUME_ACCEPT4_SYSCALL] (__ASSUME_ACCEPT4): Define instead of using previous [__LINUX_KERNEL_VERSION >= 0x02061c && (__i386__ || __x86_64__ || __powerpc__ || __sparc__ || __s390__)] condition. * sysdeps/unix/sysv/linux/aarch64/kernel-features.h (__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL. * sysdeps/unix/sysv/linux/accept4.c [__ASSUME_SOCKETCALL && !__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL && !__ASSUME_ACCEPT4_SYSCALL] (__NR_accept4): Undefine. [!__ASSUME_ACCEPT4]: Change condition to [!__ASSUME_ACCEPT4_SOCKETCALL]. * sysdeps/unix/sysv/linux/alpha/kernel-features.h (__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL. Correct condition to [__LINUX_KERNEL_VERSION >= 0x030200]. * sysdeps/unix/sysv/linux/arm/kernel-features.h [__LINUX_KERNEL_VERSION >= 0x020624] (__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL. * sysdeps/unix/sysv/linux/i386/accept4.S [__ASSUME_ACCEPT4]: Change conditions to [__ASSUME_ACCEPT4_SOCKETCALL]. * sysdeps/unix/sysv/linux/ia64/kernel-features.h [__LINUX_KERNEL_VERSION >= 0x030300] (__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL. * sysdeps/unix/sysv/linux/internal_accept4.S [__ASSUME_SOCKETCALL && !__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL && !__ASSUME_ACCEPT4_SYSCALL] (__NR_accept4): Undefine. [__ASSUME_ACCEPT4]: Change condition to [__ASSUME_ACCEPT4_SOCKETCALL]. * sysdeps/unix/sysv/linux/m68k/kernel-features.h (__ASSUME_SOCKETCALL): Define. [__LINUX_KERNEL_VERSION >= 0x02061c] (__ASSUME_ACCEPT4): Remove. * sysdeps/unix/sysv/linux/microblaze/kernel-features.h (__ASSUME_SOCKETCALL): Define. (__ASSUME_ACCEPT4): Remove. [__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_ACCEPT4_SYSCALL): Define. * sysdeps/unix/sysv/linux/mips/kernel-features.h [__LINUX_KERNEL_VERSION >= 0x02061f] (__ASSUME_ACCEPT4_SYSCALL): Likewise. * sysdeps/unix/sysv/linux/tile/kernel-features.h (__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL. * sysdeps/unix/sysv/linux/hppa/kernel-features.h [__LINUX_KERNEL_VERSION >= 0x020622] (__ASSUME_ACCEPT4_SYSCALL): Define. --- sysdeps/unix/sysv/linux/kernel-features.h | 44 ++++++++++++++++++++++++++++--- 1 file changed, 40 insertions(+), 4 deletions(-) (limited to 'sysdeps/unix/sysv/linux/kernel-features.h') diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h index 784f4dd491..b6d7714073 100644 --- a/sysdeps/unix/sysv/linux/kernel-features.h +++ b/sysdeps/unix/sysv/linux/kernel-features.h @@ -40,6 +40,18 @@ /* The sendfile syscall was introduced in 2.2.0. */ #define __ASSUME_SENDFILE 1 +/* Some architectures use the socketcall multiplexer for some or all + socket-related operations, via a socket.S file in glibc, instead of + separate syscalls. __ASSUME_SOCKETCALL is defined for such + architectures. */ +#if defined __i386__ \ + || defined __powerpc__ \ + || defined __s390__ \ + || defined __sh__ \ + || defined __sparc__ +# define __ASSUME_SOCKETCALL 1 +#endif + /* Linux 2.3.39 introduced IPC64. Except for powerpc. Linux 2.4.0 on PPC introduced a correct IPC64. But PowerPC64 does not support a separate 64-bit syscall, already 64-bit. */ @@ -164,10 +176,34 @@ # define __ASSUME_DUP3 1 #endif -/* Support for the accept4 syscall was added in 2.6.28. */ -#if __LINUX_KERNEL_VERSION >= 0x02061c \ - && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \ - || defined __sparc__ || defined __s390__) +/* Support for accept4 functionality was added in 2.6.28, but for some + architectures using a separate syscall rather than socketcall that + syscall was only added later, and some architectures first had + socketcall support then a separate syscall. Define + __ASSUME_ACCEPT4_SOCKETCALL if glibc uses socketcall on this + architecture and accept4 is available through socketcall, + __ASSUME_ACCEPT4_SYSCALL if it is available through a separate + syscall, __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL if it became + available through a separate syscall at the same time as through + socketcall, and __ASSUME_ACCEPT4 if the accept4 function is known + to work. */ +#if __LINUX_KERNEL_VERSION >= 0x02061c && defined __ASSUME_SOCKETCALL +# define __ASSUME_ACCEPT4_SOCKETCALL 1 +#endif + +/* The accept4 syscall was added for x86_64 and SPARC in 2.6.28, and + for PowerPC and SH in 2.6.37. */ +#if (__LINUX_KERNEL_VERSION >= 0x02061c \ + && (defined __x86_64__ || defined __sparc__)) \ + || (__LINUX_KERNEL_VERSION >= 0x020625 \ + && (defined __powerpc__ || defined __sh__)) +# define __ASSUME_ACCEPT4_SYSCALL 1 +#endif +#ifdef __sparc__ +# define __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL 1 +#endif + +#if defined __ASSUME_ACCEPT4_SOCKETCALL || defined __ASSUME_ACCEPT4_SYSCALL # define __ASSUME_ACCEPT4 1 #endif -- cgit v1.2.3-70-g09d2