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authorjhb <jhb@FreeBSD.org>2004-11-16 20:45:51 +0000
committerjhb <jhb@FreeBSD.org>2004-11-16 20:45:51 +0000
commit59f4aaaef08d97e11805b862c9c1a8647150006c (patch)
tree42ef5a8187c807b144c5243e9e9b4dedf71a87ba /libexec
parentcc03c9de7d057c1fb843aa928c6c607a3c775700 (diff)
downloadFreeBSD-src-59f4aaaef08d97e11805b862c9c1a8647150006c.zip
FreeBSD-src-59f4aaaef08d97e11805b862c9c1a8647150006c.tar.gz
Remove 80386 support from the ELF run time linker.
Diffstat (limited to 'libexec')
-rw-r--r--libexec/rtld-elf/i386/lockdflt.c144
-rw-r--r--libexec/rtld-elf/rtld_lock.c19
2 files changed, 0 insertions, 163 deletions
diff --git a/libexec/rtld-elf/i386/lockdflt.c b/libexec/rtld-elf/i386/lockdflt.c
deleted file mode 100644
index 42dc7fe..0000000
--- a/libexec/rtld-elf/i386/lockdflt.c
+++ /dev/null
@@ -1,144 +0,0 @@
-/*-
- * Copyright 1999, 2000 John D. Polstra.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * $FreeBSD$
- */
-
-/*
- * Thread locking implementation for the dynamic linker.
- *
- * On 80486 and later CPUs we use the "simple, non-scalable
- * reader-preference lock" from:
- *
- * J. M. Mellor-Crummey and M. L. Scott. "Scalable Reader-Writer
- * Synchronization for Shared-Memory Multiprocessors." 3rd ACM Symp. on
- * Principles and Practice of Parallel Programming, April 1991.
- *
- * In this algorithm the lock is a single word. Its low-order bit is
- * set when a writer holds the lock. The remaining high-order bits
- * contain a count of readers desiring the lock. The algorithm requires
- * atomic "compare_and_store" and "add" operations.
- *
- * The "compare_and_store" operation requires the "cmpxchg" instruction
- * on the x86. Unfortunately, the 80386 CPU does not support that
- * instruction -- only the 80486 and later models support it. So on the
- * 80386 we must use simple test-and-set exclusive locks instead. We
- * determine which kind of lock to use by trying to execute a "cmpxchg"
- * instruction and catching the SIGILL which results on the 80386.
- */
-
-#include <setjmp.h>
-#include <signal.h>
-
-static inline int
-cmpxchgl(int old, int new, volatile int *m)
-{
- int result;
-
- __asm __volatile ("lock; cmpxchgl %2, %0"
- : "+m"(*m), "=a"(result)
- : "r"(new), "1"(old)
- : "cc");
-
- return result;
-}
-
-static inline int
-xchgl(int v, volatile int *m)
-{
- int result;
-
- __asm __volatile ("xchgl %0, %1"
- : "=r"(result), "+m"(*m)
- : "0"(v));
-
- return result;
-}
-
-/*
- * Crude exclusive locks for the 80386, which does not support the
- * cmpxchg instruction.
- */
-static void
-lock80386_acquire(void *lock)
-{
- Lock *l = (Lock *)lock;
- sigset_t tmp_oldsigmask;
-
- for ( ; ; ) {
- sigprocmask(SIG_BLOCK, &fullsigmask, &tmp_oldsigmask);
- if (xchgl(1, &l->lock) == 0)
- break;
- sigprocmask(SIG_SETMASK, &tmp_oldsigmask, NULL);
- while (l->lock != 0)
- ; /* Spin */
- }
- oldsigmask = tmp_oldsigmask;
-}
-
-static void
-lock80386_release(void *lock)
-{
- Lock *l = (Lock *)lock;
-
- l->lock = 0;
- sigprocmask(SIG_SETMASK, &oldsigmask, NULL);
-}
-
-/*
- * Code to determine at runtime whether the CPU supports the cmpxchg
- * instruction. This instruction allows us to use locks that are more
- * efficient, but it didn't exist on the 80386.
- */
-static jmp_buf sigill_env;
-
-static void
-sigill(int sig)
-{
- longjmp(sigill_env, 1);
-}
-
-static int
-cpu_supports_cmpxchg(void)
-{
- struct sigaction act, oact;
- int result;
- volatile int lock;
-
- memset(&act, 0, sizeof act);
- act.sa_handler = sigill;
- sigemptyset(&act.sa_mask);
- act.sa_flags = 0;
-
- sigaction(SIGILL, &act, &oact);
- if (setjmp(sigill_env) == 0) {
- lock = 0;
- cmpxchgl(0, 1, &lock);
- result = 1;
- } else
- result = 0;
- sigaction(SIGILL, &oact, NULL);
- return result;
-}
-
diff --git a/libexec/rtld-elf/rtld_lock.c b/libexec/rtld-elf/rtld_lock.c
index 77b16f6..7bffc94 100644
--- a/libexec/rtld-elf/rtld_lock.c
+++ b/libexec/rtld-elf/rtld_lock.c
@@ -137,16 +137,6 @@ def_lock_release(void *lock)
}
}
-#if __i386__
-/*
- * Import a crude exclusive lock implementation for i386 processors.
- * This file will be removed once i386 support is deprecated in favor
- * of i486+.
- */
-#include "i386/lockdflt.c"
-
-#endif
-
static int
def_thread_set_flag(int mask)
{
@@ -250,15 +240,6 @@ lockdflt_init()
rtld_locks[i].handle = NULL;
}
-#if __i386__
- if (!cpu_supports_cmpxchg()) {
- /* It's a cruddy old 80386. */
- deflockinfo.rlock_acquire = lock80386_acquire;
- deflockinfo.wlock_acquire = lock80386_acquire;
- deflockinfo.lock_release = lock80386_release;
- }
-#endif
-
memcpy(&lockinfo, &deflockinfo, sizeof(lockinfo));
_rtld_thread_init(NULL);
/*
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