CVS commit: src

["Emmanuel Dreyfus" <manu%netbsd.org@localhost>]

Module Name:    src
Committed By:   manu
Date:           Wed Sep 12 02:00:55 UTC 2012

Modified Files:
        src/distrib/sets/lists/tests: mi
        src/lib/libc/arch/hppa/gen: swapcontext.S
        src/lib/libc/arch/mips/gen: _resumecontext.S swapcontext.S
        src/lib/libc/arch/powerpc64/gen: swapcontext.S
        src/lib/libc/arch/sparc/gen: swapcontext.S
        src/lib/libc/arch/sparc64/gen: swapcontext.S
        src/lib/libc/include: extern.h
        src/lib/libc/sys: Makefile.inc
        src/lib/libpthread: pthread_specific.c
        src/sys/arch/alpha/alpha: machdep.c
        src/sys/arch/alpha/include: mcontext.h
        src/sys/arch/sh3/include: mcontext.h
        src/sys/arch/sparc/include: mcontext.h
        src/sys/arch/sparc64/include: mcontext.h
        src/sys/sys: ucontext.h
        src/tests/lib/libc/sys: Makefile
        src/tests/lib/libpthread: Makefile
Added Files:
        src/tests/lib/libc/sys: t_swapcontext.c
        src/tests/lib/libpthread: t_swapcontext.c

Log Message:
setcontext() used to be incompatible with -lpthread since it affected
the TLS pointer, therefore wrecking the pthread environement.

Some ports had _UC_TLSBASE flag or equivalent (_UC_UNIQUE on alpha)
that controlled whether setcontext() would change the TLS pointer.
This change let libpthread override setcontext() with its own version
that unsets _UC_TLSBASE, enabling safe usage of setcontext() with
-lpthread.

We also have the following required changes here:
- rename alpha's _UC_UNIQUE into _UC_TLSBASE
- add _UC_TLSBASE definition in header file for all ports
  (powerpc, sh3, sparc and sparc64 lack the implementation for now)
- introduce a libc stub that can be overriden for setcontext()
- modify MD libcs swapcontext() implementations so that they use the
  setcontext() libc stub instead of doing a plain system call.

While we are there:
- document various MD _UC_* flags in header file
- add libc and libpthread tests for swapcontext() behavior
  (hopefully helpful to spot MD problems introduced with this change)

Future work:
- Deciding whether kernel support or _UC_TLSBASE should be added for
  powerpc, sh3, sparc and sparc64 is left to portmasters
  sparc64

Approved by core@


To generate a diff of this commit:
cvs rdiff -u -r1.490 -r1.491 src/distrib/sets/lists/tests/mi
cvs rdiff -u -r1.4 -r1.5 src/lib/libc/arch/hppa/gen/swapcontext.S
cvs rdiff -u -r1.6 -r1.7 src/lib/libc/arch/mips/gen/_resumecontext.S
cvs rdiff -u -r1.4 -r1.5 src/lib/libc/arch/mips/gen/swapcontext.S
cvs rdiff -u -r1.3 -r1.4 src/lib/libc/arch/powerpc64/gen/swapcontext.S
cvs rdiff -u -r1.3 -r1.4 src/lib/libc/arch/sparc/gen/swapcontext.S
cvs rdiff -u -r1.5 -r1.6 src/lib/libc/arch/sparc64/gen/swapcontext.S
cvs rdiff -u -r1.19 -r1.20 src/lib/libc/include/extern.h
cvs rdiff -u -r1.215 -r1.216 src/lib/libc/sys/Makefile.inc
cvs rdiff -u -r1.21 -r1.22 src/lib/libpthread/pthread_specific.c
cvs rdiff -u -r1.341 -r1.342 src/sys/arch/alpha/alpha/machdep.c
cvs rdiff -u -r1.7 -r1.8 src/sys/arch/alpha/include/mcontext.h
cvs rdiff -u -r1.9 -r1.10 src/sys/arch/sh3/include/mcontext.h
cvs rdiff -u -r1.12 -r1.13 src/sys/arch/sparc/include/mcontext.h
cvs rdiff -u -r1.8 -r1.9 src/sys/arch/sparc64/include/mcontext.h
cvs rdiff -u -r1.16 -r1.17 src/sys/sys/ucontext.h
cvs rdiff -u -r1.27 -r1.28 src/tests/lib/libc/sys/Makefile
cvs rdiff -u -r0 -r1.1 src/tests/lib/libc/sys/t_swapcontext.c
cvs rdiff -u -r1.7 -r1.8 src/tests/lib/libpthread/Makefile
cvs rdiff -u -r0 -r1.1 src/tests/lib/libpthread/t_swapcontext.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.