all: remove Linux 2.4 vs 2.6 detection

Linux 2.4 is dead.
(The libthread code hasn't worked for Linux 2.4 for a long time.)

2 files changed, 3 insertions, 44 deletions

diff --git a/src/libthread/README.Linux b/src/libthread/README.Linux
deleted file mode 100644
index 04c491a8..00000000
--- a/src/libthread/README.Linux
+++ /dev/null
@@ -1,40 +0,0 @@
-Thread support on Linux is confused by the recent thread local storage (TLS)
-support that has been put into the ELF tool chain.  The TLS libraries are 
-installed in /lib/tls on most Linux systems.
-
-We provide two different implementations of the os-dependent parts
-of libthread for Linux.  The first is intended for use on Linux 2.4 and earlier
-kernels, which do not support TLS.  It is in Linux.c and Linuxasm.c and
-does not use the pthread interface.  The second is intended for Linux 2.6
-and later kernels, which do support TLS.  It is in pthread.c and uses the
-standard pthread interface.  It expects to be linked against the TLS-aware
-thread library aka NPTL.
-
-If you use Linux.c and Linuxasm.c with TLS libraries, they do not
-set up the TLS properly so you will get incorrect programs.
-For example, there will only be one errno among all the procs
-in your program instead of one per proc.  The pthread NPTL
-implementation is needed to use the TLS libraries properly.
-
-If you use pthread.c without TLS libraries (i.e., with the old Linux
-pthread library known as LinuxThreads), then you will also get
-incorrect programs, although more obviously so.  The LinuxThreads
-library assumes it can look at the stack pointer to distinguish between
-threads, but libthread does its own stack management, breaking this
-assumption.  If you run a pthread-compiled program with the 
-LinuxThreads library, LinuxThreads itself will cause a segmentation
-fault in __pthread_getspecific() the first time it is called from a
-non-standard stack.
-
-So, it is important that you compile binaries that match your
-system's choice of TLS vs. not-TLS libraries.  The hard part is figuring
-out which your system has chosen.  Plan9port looks at the kernel
-version you are running and assumes that on kernels that support
-TLS (2.6+) you will be using TLS.
-
-Apparently Gentoo and maybe other distributions do not follow this rule.
-They use non-TLS libraries even on kernels that can support TLS.
-To accomodate them, you can add a line SYSVERSION=2.4 to $PLAN9/config
-to force the build to think you are running an old kernel.
-The INSTALL script sets up this file automatically on Linux systems.
-
diff --git a/src/libthread/sysofiles.sh b/src/libthread/sysofiles.sh
index 30a4c338..fd60f131 100644
--- a/src/libthread/sysofiles.sh
+++ b/src/libthread/sysofiles.sh
@@ -2,12 +2,11 @@
 
 test -f $PLAN9/config && . $PLAN9/config
 
-tag="$OBJTYPE-$SYSNAME-${SYSVERSION:-`uname -r`}-${CC9:-cc}"
-case "$tag" in
-*-NetBSD-*)
+case "$SYSNAME" in
+NetBSD)
 	echo ${SYSNAME}-${OBJTYPE}-asm.o $SYSNAME.o pthread.o stkmalloc.o
 	;;
-*-OpenBSD-*)
+OpenBSD)
 	echo ${SYSNAME}-${OBJTYPE}-asm.o ${SYSNAME}-${OBJTYPE}.o pthread.o stkmmap.o
 	;;
 *)