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Remove 80386 bandaids from code repocopied from i386. rtld_start.S still

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todo.
This commit is contained in:
Peter Wemm 2003-04-30 21:09:06 +00:00
parent 8e80f8a438
commit 7c1622ff28
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=114332
1 changed files with 4 additions and 78 deletions
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82
libexec/rtld-elf/amd64/lockdflt.c
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@ -48,7 +48,6 @@
* instruction and catching the SIGILL which results on the 80386.
*/
#include <setjmp.h>
#include <signal.h>
#include <stdlib.h>
#include <time.h>
@ -131,36 +130,6 @@ lock_destroy(void *lock)
free(l->base);
}
/*
* 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);
}
/*
* Better reader/writer locks for the 80486 and later CPUs.
*/
@ -206,42 +175,6 @@ wlock_release(void *lock)
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;
}
void
lockdflt_init(LockInfo *li)
{
@ -249,17 +182,10 @@ lockdflt_init(LockInfo *li)
li->context_destroy = NULL;
li->lock_create = lock_create;
li->lock_destroy = lock_destroy;
if (cpu_supports_cmpxchg()) {
/* Use fast locks that require an 80486 or later. */
li->rlock_acquire = rlock_acquire;
li->wlock_acquire = wlock_acquire;
li->rlock_release = rlock_release;
li->wlock_release = wlock_release;
} else {
/* It's a cruddy old 80386. */
li->rlock_acquire = li->wlock_acquire = lock80386_acquire;
li->rlock_release = li->wlock_release = lock80386_release;
}
li->rlock_acquire = rlock_acquire;
li->wlock_acquire = wlock_acquire;
li->rlock_release = rlock_release;
li->wlock_release = wlock_release;
/*
* Construct a mask to block all signals except traps which might
* conceivably be generated within the dynamic linker itself.