*
* Userspace RCU library - x86 compatibility checks
*
- * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
#include <pthread.h>
#include <signal.h>
#include <assert.h>
-#include <urcu/uatomic_arch.h>
+#include <urcu/uatomic.h>
+
+/*
+ * Using attribute "weak" for __rcu_cas_avail and
+ * __urcu_x86_compat_mutex. Those are globally visible by the entire
+ * program, even though many shared objects may have their own version.
+ * The first version that gets loaded will be used by the entire
+ * program (executable and all shared objects).
+ */
/*
* It does not really matter if the constructor is called before using
- * the library, as long as the caller checks if __urcu_cas_avail < 0 and calls
+ * the library, as long as the caller checks if __rcu_cas_avail < 0 and calls
* compat_arch_init() explicitely if needed.
*/
-int __attribute__((constructor)) __urcu_cas_init(void);
-
-static pthread_mutex_t compat_mutex = PTHREAD_MUTEX_INITIALIZER;
+int __attribute__((constructor)) __rcu_cas_init(void);
/*
* -1: unknown
* 1: available
* 0: unavailable
*/
-int __urcu_cas_avail = -1;
+__attribute__((weak))
+int __rcu_cas_avail = -1;
+
+__attribute__((weak))
+pthread_mutex_t __urcu_x86_compat_mutex = PTHREAD_MUTEX_INITIALIZER;
/*
- * Imported from glibc 2.3.5. linuxthreads/sysdeps/i386/pt-machine.h.
+ * get_eflags/set_eflags/compare_and_swap_is_available imported from glibc
+ * 2.3.5. linuxthreads/sysdeps/i386/pt-machine.h.
*/
-int get_eflags (void)
+static int get_eflags (void)
{
int res;
__asm__ __volatile__ ("pushfl; popl %0" : "=r" (res) : );
return res;
}
-void set_eflags (int newflags)
+static void set_eflags (int newflags)
{
__asm__ __volatile__ ("pushl %0; popfl" : : "r" (newflags) : "cc");
}
-int compare_and_swap_is_available (void)
+static int compare_and_swap_is_available (void)
{
int oldflags = get_eflags ();
int changed;
return changed != 0;
}
-unsigned long _compat_uatomic_cmpxchg(void *addr, unsigned long old,
- unsigned long _new, int len)
+static void mutex_lock_signal_save(pthread_mutex_t *mutex, sigset_t *oldmask)
{
- sigset_t newmask, oldmask;
+ sigset_t newmask;
int ret;
/* Disable signals */
- ret = sigemptyset(&newmask);
+ ret = sigfillset(&newmask);
+ assert(!ret);
+ ret = pthread_sigmask(SIG_BLOCK, &newmask, oldmask);
+ assert(!ret);
+ ret = pthread_mutex_lock(&__urcu_x86_compat_mutex);
assert(!ret);
- ret = pthread_sigmask(SIG_SETMASK, &newmask, &oldmask);
+}
+
+static void mutex_lock_signal_restore(pthread_mutex_t *mutex, sigset_t *oldmask)
+{
+ int ret;
+
+ ret = pthread_mutex_unlock(&__urcu_x86_compat_mutex);
assert(!ret);
- ret = pthread_mutex_lock(&compat_mutex);
+ ret = pthread_sigmask(SIG_SETMASK, oldmask, NULL);
assert(!ret);
+}
+
+unsigned long _compat_uatomic_set(void *addr, unsigned long _new, int len)
+{
+ sigset_t mask;
+ unsigned long result;
+ mutex_lock_signal_save(&__urcu_x86_compat_mutex, &mask);
+ switch (len) {
+ case 1:
+ *(unsigned char *)addr = (unsigned char)_new;
+ result = *(unsigned char *)addr;
+ break;
+ case 2:
+ *(unsigned short *)addr = (unsigned short)_new;
+ result = *(unsigned short *)addr;
+ break;
+ case 4:
+ *(unsigned int *)addr = (unsigned int)_new;
+ result = *(unsigned int *)addr;
+ break;
+ default:
+ /*
+ * generate an illegal instruction. Cannot catch this with
+ * linker tricks when optimizations are disabled.
+ */
+ result = 0;
+ __asm__ __volatile__("ud2");
+ }
+ mutex_lock_signal_restore(&__urcu_x86_compat_mutex, &mask);
+ return result;
+}
+
+unsigned long _compat_uatomic_xchg(void *addr, unsigned long _new, int len)
+{
+ sigset_t mask;
+ unsigned long retval;
+
+ mutex_lock_signal_save(&__urcu_x86_compat_mutex, &mask);
+ switch (len) {
+ case 1:
+ retval = *(unsigned char *)addr;
+ *(unsigned char *)addr = (unsigned char)_new;
+ break;
+ case 2:
+ retval = *(unsigned short *)addr;
+ *(unsigned short *)addr = (unsigned short)_new;
+ break;
+ case 4:
+ retval = *(unsigned int *)addr;
+ *(unsigned int *)addr = (unsigned int)_new;
+ break;
+ default:
+ /*
+ * generate an illegal instruction. Cannot catch this with
+ * linker tricks when optimizations are disabled.
+ */
+ retval = 0; /* silence gcc warnings */
+ __asm__ __volatile__("ud2");
+ }
+ mutex_lock_signal_restore(&__urcu_x86_compat_mutex, &mask);
+ return retval;
+}
+
+unsigned long _compat_uatomic_cmpxchg(void *addr, unsigned long old,
+ unsigned long _new, int len)
+{
+ unsigned long retval;
+ sigset_t mask;
+
+ mutex_lock_signal_save(&__urcu_x86_compat_mutex, &mask);
switch (len) {
case 1:
{
unsigned char result = *(unsigned char *)addr;
- if (result == old)
+ if (result == (unsigned char)old)
*(unsigned char *)addr = (unsigned char)_new;
- return result;
+ retval = result;
+ break;
}
case 2:
{
unsigned short result = *(unsigned short *)addr;
- if (result == old)
+ if (result == (unsigned short)old)
*(unsigned short *)addr = (unsigned short)_new;
- return result;
+ retval = result;
+ break;
}
case 4:
{
unsigned int result = *(unsigned int *)addr;
- if (result == old)
+ if (result == (unsigned int)old)
*(unsigned int *)addr = (unsigned int)_new;
- return result;
+ retval = result;
+ break;
}
+ default:
+ /*
+ * generate an illegal instruction. Cannot catch this with
+ * linker tricks when optimizations are disabled.
+ */
+ retval = 0; /* silence gcc warnings */
+ __asm__ __volatile__("ud2");
}
- /* generate an illegal instruction. Cannot catch this with linker tricks
- * when optimizations are disabled. */
- __asm__ __volatile__("ud2");
- return 0;
+ mutex_lock_signal_restore(&__urcu_x86_compat_mutex, &mask);
+ return retval;
+}
- ret = pthread_mutex_unlock(&compat_mutex);
- assert(!ret);
- ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
- assert(!ret);
+void _compat_uatomic_or(void *addr, unsigned long v, int len)
+{
+ sigset_t mask;
+
+ mutex_lock_signal_save(&__urcu_x86_compat_mutex, &mask);
+ switch (len) {
+ case 1:
+ *(unsigned char *)addr |= (unsigned char)v;
+ break;
+ case 2:
+ *(unsigned short *)addr |= (unsigned short)v;
+ break;
+ case 4:
+ *(unsigned int *)addr |= (unsigned int)v;
+ break;
+ default:
+ /*
+ * generate an illegal instruction. Cannot catch this with
+ * linker tricks when optimizations are disabled.
+ */
+ __asm__ __volatile__("ud2");
+ }
+ mutex_lock_signal_restore(&__urcu_x86_compat_mutex, &mask);
+}
+
+void _compat_uatomic_and(void *addr, unsigned long v, int len)
+{
+ sigset_t mask;
+
+ mutex_lock_signal_save(&__urcu_x86_compat_mutex, &mask);
+ switch (len) {
+ case 1:
+ *(unsigned char *)addr &= (unsigned char)v;
+ break;
+ case 2:
+ *(unsigned short *)addr &= (unsigned short)v;
+ break;
+ case 4:
+ *(unsigned int *)addr &= (unsigned int)v;
+ break;
+ default:
+ /*
+ * generate an illegal instruction. Cannot catch this with
+ * linker tricks when optimizations are disabled.
+ */
+ __asm__ __volatile__("ud2");
+ }
+ mutex_lock_signal_restore(&__urcu_x86_compat_mutex, &mask);
+}
+
+unsigned long _compat_uatomic_add_return(void *addr, unsigned long v, int len)
+{
+ sigset_t mask;
+ unsigned long result;
+
+ mutex_lock_signal_save(&__urcu_x86_compat_mutex, &mask);
+ switch (len) {
+ case 1:
+ *(unsigned char *)addr += (unsigned char)v;
+ result = *(unsigned char *)addr;
+ break;
+ case 2:
+ *(unsigned short *)addr += (unsigned short)v;
+ result = *(unsigned short *)addr;
+ break;
+ case 4:
+ *(unsigned int *)addr += (unsigned int)v;
+ result = *(unsigned int *)addr;
+ break;
+ default:
+ /*
+ * generate an illegal instruction. Cannot catch this with
+ * linker tricks when optimizations are disabled.
+ */
+ result = 0; /* silence gcc warnings */
+ __asm__ __volatile__("ud2");
+ }
+ mutex_lock_signal_restore(&__urcu_x86_compat_mutex, &mask);
+ return result;
}
-int __urcu_cas_init(void)
+int __rcu_cas_init(void)
{
- if (__urcu_cas_avail < 0)
- __urcu_cas_avail = compare_and_swap_is_available();
- return __urcu_cas_avail;
+ if (__rcu_cas_avail < 0)
+ __rcu_cas_avail = compare_and_swap_is_available();
+ return __rcu_cas_avail;
}
projects / urcu.git / blobdiff