8322 nl: misleading-indentation

[unleashed/tickless.git] / usr / src / lib / libc / port / threads / tls.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include "lint.h"
#include "thr_uberdata.h"

#define MIN_MOD_SLOTS   8

/*
 * Used to inform libc_init() that we are on the primary link map,
 * and to cause certain functions (like malloc() and sbrk()) to fail
 * (with ENOTSUP) when they are called on an alternate link map.
 */
int primary_link_map = 0;

#if defined(_LP64)
#define ALIGN   16
#else
#define ALIGN   8
#endif

/*
 * Grow the TLS module information array as necessary to include the
 * specified module-id.  tls_modinfo->tls_size must be a power of two.
 * Return a pointer to the (possibly reallocated) module information array.
 */
static TLS_modinfo *
tls_modinfo_alloc(tls_metadata_t *tlsm, ulong_t moduleid)
{
        tls_t *tls_modinfo = &tlsm->tls_modinfo;
        TLS_modinfo *modinfo;
        size_t mod_slots;

        if ((modinfo = tls_modinfo->tls_data) == NULL ||
            tls_modinfo->tls_size <= moduleid) {
                if ((mod_slots = tls_modinfo->tls_size) == 0)
                        mod_slots = MIN_MOD_SLOTS;
                while (mod_slots <= moduleid)
                        mod_slots *= 2;
                modinfo = lmalloc(mod_slots * sizeof (TLS_modinfo));
                if (tls_modinfo->tls_data != NULL) {
                        (void) memcpy(modinfo, tls_modinfo->tls_data,
                            tls_modinfo->tls_size * sizeof (TLS_modinfo));
                        lfree(tls_modinfo->tls_data,
                            tls_modinfo->tls_size * sizeof (TLS_modinfo));
                }
                tls_modinfo->tls_data = modinfo;
                tls_modinfo->tls_size = mod_slots;
        }
        return (modinfo);
}

/*
 * This is called from the dynamic linker, before libc_init() is called,
 * to setup all of the TLS blocks that are available at process startup
 * and hence must be included as part of the static TLS block.
 * No locks are needed because we are single-threaded at this point.
 * We must be careful not to call any function that could possibly
 * invoke the dynamic linker.  That is, we must only call functions
 * that are wholly private to libc.
 */
void
__tls_static_mods(TLS_modinfo **tlslist, unsigned long statictlssize)
{
        ulwp_t *oldself = __curthread();
        tls_metadata_t *tlsm;
        TLS_modinfo **tlspp;
        TLS_modinfo *tlsp;
        TLS_modinfo *modinfo;
        caddr_t data;
        caddr_t data_end;
        int max_modid;

        primary_link_map = 1;           /* inform libc_init */
        if (statictlssize == 0)
                return;

        /*
         * Retrieve whatever dynamic TLS metadata was generated by code
         * running on alternate link maps prior to now (we must be running
         * on the primary link map now since __tls_static_mods() is only
         * called on the primary link map).
         */
        tlsm = &__uberdata.tls_metadata;
        if (oldself != NULL) {
                (void) memcpy(tlsm,
                    &oldself->ul_uberdata->tls_metadata, sizeof (*tlsm));
                ASSERT(tlsm->static_tls.tls_data == NULL);
        }

        /*
         * We call lmalloc() to allocate the template even though libc_init()
         * has not yet been called.  lmalloc() must and does deal with this.
         */
        ASSERT((statictlssize & (ALIGN - 1)) == 0);
        tlsm->static_tls.tls_data = data = lmalloc(statictlssize);
        data_end = data + statictlssize;
        tlsm->static_tls.tls_size = statictlssize;
        /*
         * Initialize the static TLS template.
         * We make no assumptions about the order in memory of the TLS
         * modules we are processing, only that they fit within the
         * total size we are given and that they are self-consistent.
         * We do not assume any order for the moduleid's; we only assume
         * that they are reasonably small integers.
         */
        for (max_modid = 0, tlspp = tlslist; (tlsp = *tlspp) != NULL; tlspp++) {
                ASSERT(tlsp->tm_flags & TM_FLG_STATICTLS);
                ASSERT(tlsp->tm_stattlsoffset > 0);
                ASSERT(tlsp->tm_stattlsoffset <= statictlssize);
                ASSERT((tlsp->tm_stattlsoffset & (ALIGN - 1)) == 0);
                ASSERT(tlsp->tm_filesz <= tlsp->tm_memsz);
                ASSERT(tlsp->tm_memsz <= tlsp->tm_stattlsoffset);
                if (tlsp->tm_filesz)
                        (void) memcpy(data_end-tlsp->tm_stattlsoffset,
                            tlsp->tm_tlsblock, tlsp->tm_filesz);
                if (max_modid < tlsp->tm_modid)
                        max_modid = tlsp->tm_modid;
        }
        /*
         * Record the static TLS_modinfo information.
         */
        modinfo = tls_modinfo_alloc(tlsm, max_modid);
        for (tlspp = tlslist; (tlsp = *tlspp) != NULL; tlspp++)
                (void) memcpy(&modinfo[tlsp->tm_modid],
                    tlsp, sizeof (*tlsp));

        /*
         * Copy the new tls_metadata back to the old, if any,
         * since it will be copied up again in libc_init().
         */
        if (oldself != NULL)
                (void) memcpy(&oldself->ul_uberdata->tls_metadata,
                    tlsm, sizeof (*tlsm));
}

/*
 * This is called from the dynamic linker for each module not included
 * in the static TLS mod list, after the module has been loaded but
 * before any of the module's init code has been executed.
 */
void
__tls_mod_add(TLS_modinfo *tlsp)
{
        tls_metadata_t *tlsm = &curthread->ul_uberdata->tls_metadata;
        ulong_t moduleid = tlsp->tm_modid;
        TLS_modinfo *modinfo;

        lmutex_lock(&tlsm->tls_lock);
        ASSERT(!(tlsp->tm_flags & TM_FLG_STATICTLS));
        ASSERT(tlsp->tm_filesz <= tlsp->tm_memsz);
        modinfo = tls_modinfo_alloc(tlsm, moduleid);
        (void) memcpy(&modinfo[moduleid], tlsp, sizeof (*tlsp));
        lmutex_unlock(&tlsm->tls_lock);
}

/*
 * Called for each module as it is unloaded from memory by dlclose().
 */
void
__tls_mod_remove(TLS_modinfo *tlsp)
{
        tls_metadata_t *tlsm = &curthread->ul_uberdata->tls_metadata;
        ulong_t moduleid = tlsp->tm_modid;
        TLS_modinfo *modinfo;

        lmutex_lock(&tlsm->tls_lock);
        ASSERT(tlsm->tls_modinfo.tls_data != NULL &&
            moduleid < tlsm->tls_modinfo.tls_size);
        modinfo = tlsm->tls_modinfo.tls_data;
        (void) memset(&modinfo[moduleid], 0, sizeof (TLS_modinfo));
        lmutex_unlock(&tlsm->tls_lock);
}

extern  int     _preexec_exit_handlers();
extern  void    libc_init();

const Lc_interface tls_rtldinfo[] = {
        {CI_VERSION,    (int(*)())CI_V_CURRENT},
        {CI_ATEXIT,     (int(*)())_preexec_exit_handlers},
        {CI_TLS_MODADD, (int(*)())__tls_mod_add},
        {CI_TLS_MODREM, (int(*)())__tls_mod_remove},
        {CI_TLS_STATMOD, (int(*)())__tls_static_mods},
        {CI_THRINIT,    (int(*)())libc_init},
        {CI_NULL,       (int(*)())NULL}
};

/*
 * Return the address of a TLS variable for the current thread.
 * Run the constructors for newly-allocated dynamic TLS.
 */
void *
slow_tls_get_addr(TLS_index *tls_index)
{
        ulwp_t *self = curthread;
        tls_metadata_t *tlsm = &self->ul_uberdata->tls_metadata;
        TLS_modinfo *tlsp;
        ulong_t moduleid;
        tls_t *tlsent;
        caddr_t base;
        void (**initarray)(void);
        ulong_t arraycnt = 0;

        /*
         * Defer signals until we have finished calling
         * all of the constructors.
         */
        sigoff(self);
        lmutex_lock(&tlsm->tls_lock);
        if ((moduleid = tls_index->ti_moduleid) < self->ul_ntlsent)
                tlsent = self->ul_tlsent;
        else {
                ASSERT(moduleid < tlsm->tls_modinfo.tls_size);
                tlsent = lmalloc(tlsm->tls_modinfo.tls_size * sizeof (tls_t));
                if (self->ul_tlsent != NULL) {
                        (void) memcpy(tlsent, self->ul_tlsent,
                            self->ul_ntlsent * sizeof (tls_t));
                        lfree(self->ul_tlsent,
                            self->ul_ntlsent * sizeof (tls_t));
                }
                self->ul_tlsent = tlsent;
                self->ul_ntlsent = tlsm->tls_modinfo.tls_size;
        }
        tlsent += moduleid;
        if ((base = tlsent->tls_data) == NULL) {
                tlsp = (TLS_modinfo *)tlsm->tls_modinfo.tls_data + moduleid;
                if (tlsp->tm_memsz == 0) {      /* dlclose()d module? */
                        base = NULL;
                } else if (tlsp->tm_flags & TM_FLG_STATICTLS) {
                        /* static TLS is already allocated/initialized */
                        base = (caddr_t)self - tlsp->tm_stattlsoffset;
                        tlsent->tls_data = base;
                        tlsent->tls_size = 0;   /* don't lfree() this space */
                } else {
                        /* allocate/initialize the dynamic TLS */
                        base = lmalloc(tlsp->tm_memsz);
                        if (tlsp->tm_filesz != 0)
                                (void) memcpy(base, tlsp->tm_tlsblock,
                                    tlsp->tm_filesz);
                        tlsent->tls_data = base;
                        tlsent->tls_size = tlsp->tm_memsz;
                        /* remember the constructors */
                        arraycnt = tlsp->tm_tlsinitarraycnt;
                        initarray = tlsp->tm_tlsinitarray;
                }
        }
        lmutex_unlock(&tlsm->tls_lock);

        /*
         * Call constructors, if any, in ascending order.
         * We have to do this after dropping tls_lock because
         * we have no idea what the constructors will do.
         * At least we have signals deferred until they are done.
         */
        if (arraycnt) {
                do {
                        (**initarray++)();
                } while (--arraycnt != 0);
        }

        if (base == NULL)       /* kludge to get x86/x64 to boot */
                base = (caddr_t)self - 512;

        sigon(self);
        return (base + tls_index->ti_tlsoffset);
}

#ifdef  TLS_GET_ADDR_IS_WRITTEN_IN_ASSEMBLER
/*
 * For speed, we do not make reference to any static data in this function.
 * If necessary to do so, we do a tail call to slow_tls_get_addr().
 */
void *
__tls_get_addr(TLS_index *tls_index)
{
        ulwp_t *self = curthread;
        tls_t *tlsent = self->ul_tlsent;
        ulong_t moduleid;
        caddr_t base;

        if ((moduleid = tls_index->ti_moduleid) < self->ul_ntlsent &&
            (base = tlsent[moduleid].tls_data) != NULL)
                return (base + tls_index->ti_tlsoffset);

        return (slow_tls_get_addr(tls_index));
}
#endif  /* TLS_GET_ADDR_IS_WRITTEN_IN_ASSEMBLER */

/*
 * This is called by _thrp_setup() to initialize the thread's static TLS.
 * Constructors for initially allocated static TLS are called here.
 */
void
tls_setup()
{
        ulwp_t *self = curthread;
        tls_metadata_t *tlsm = &self->ul_uberdata->tls_metadata;
        TLS_modinfo *tlsp;
        long moduleid;
        ulong_t nmods;

        if (tlsm->static_tls.tls_size == 0)     /* no static TLS */
                return;

        /* static TLS initialization */
        (void) memcpy((caddr_t)self - tlsm->static_tls.tls_size,
            tlsm->static_tls.tls_data, tlsm->static_tls.tls_size);

        /* call TLS constructors for the static TLS just initialized */
        lmutex_lock(&tlsm->tls_lock);
        nmods = tlsm->tls_modinfo.tls_size;
        for (moduleid = 0; moduleid < nmods; moduleid++) {
                /*
                 * Resume where we left off in the module array.
                 * tls_modinfo.tls_data may have changed since we
                 * dropped and reacquired tls_lock, but TLS modules
                 * retain their positions in the new array.
                 */
                tlsp = (TLS_modinfo *)tlsm->tls_modinfo.tls_data + moduleid;
                /*
                 * Call constructors for this module if there are any
                 * to be called and if it is part of the static TLS.
                 */
                if (tlsp->tm_tlsinitarraycnt != 0 &&
                    (tlsp->tm_flags & TM_FLG_STATICTLS)) {
                        ulong_t arraycnt = tlsp->tm_tlsinitarraycnt;
                        void (**initarray)(void) = tlsp->tm_tlsinitarray;

                        /*
                         * Call the constructors in ascending order.
                         * We must drop tls_lock while doing this because
                         * we have no idea what the constructors will do.
                         */
                        lmutex_unlock(&tlsm->tls_lock);
                        do {
                                (**initarray++)();
                        } while (--arraycnt != 0);
                        lmutex_lock(&tlsm->tls_lock);
                }
        }
        lmutex_unlock(&tlsm->tls_lock);
}

/*
 * This is called by _thrp_exit() to deallocate the thread's TLS.
 * Destructors for all allocated TLS are called here.
 */
void
tls_exit()
{
        ulwp_t *self = curthread;
        tls_metadata_t *tlsm = &self->ul_uberdata->tls_metadata;
        tls_t *tlsent;
        TLS_modinfo *tlsp;
        long moduleid;
        ulong_t nmods;

        if (tlsm->static_tls.tls_size == 0 && self->ul_ntlsent == 0)
                return;         /* no TLS */

        /*
         * Call TLS destructors for all TLS allocated for this thread.
         */
        lmutex_lock(&tlsm->tls_lock);
        nmods = tlsm->tls_modinfo.tls_size;
        for (moduleid = nmods - 1; moduleid >= 0; --moduleid) {
                /*
                 * Resume where we left off in the module array.
                 * tls_modinfo.tls_data may have changed since we
                 * dropped and reacquired tls_lock, but TLS modules
                 * retain their positions in the new array.
                 */
                tlsp = (TLS_modinfo *)tlsm->tls_modinfo.tls_data + moduleid;
                /*
                 * Call destructors for this module if there are any
                 * to be called and if it is part of the static TLS or
                 * if the dynamic TLS for the module has been allocated.
                 */
                if (tlsp->tm_tlsfiniarraycnt != 0 &&
                    ((tlsp->tm_flags & TM_FLG_STATICTLS) ||
                    (moduleid < self->ul_ntlsent &&
                    (tlsent = self->ul_tlsent) != NULL &&
                    tlsent[moduleid].tls_data != NULL))) {
                        ulong_t arraycnt = tlsp->tm_tlsfiniarraycnt;
                        void (**finiarray)(void) = tlsp->tm_tlsfiniarray;

                        /*
                         * Call the destructors in descending order.
                         * We must drop tls_lock while doing this because
                         * we have no idea what the destructors will do.
                         */
                        lmutex_unlock(&tlsm->tls_lock);
                        finiarray += arraycnt;
                        do {
                                (**--finiarray)();
                        } while (--arraycnt != 0);
                        lmutex_lock(&tlsm->tls_lock);
                }
        }
        lmutex_unlock(&tlsm->tls_lock);

        tls_free(self);
}

/*
 * We only free the dynamically allocated TLS; the statically
 * allocated TLS is reused when the ulwp_t is reallocated.
 */
void
tls_free(ulwp_t *ulwp)
{
        ulong_t moduleid;
        tls_t *tlsent;
        size_t ntlsent;
        void *base;
        size_t size;

        if ((tlsent = ulwp->ul_tlsent) == NULL ||
            (ntlsent = ulwp->ul_ntlsent) == 0)
                return;

        for (moduleid = 0; moduleid < ntlsent; moduleid++, tlsent++) {
                if ((base = tlsent->tls_data) != NULL &&
                    (size = tlsent->tls_size) != 0)
                        lfree(base, size);
                tlsent->tls_data = NULL;        /* paranoia */
                tlsent->tls_size = 0;
        }
        lfree(ulwp->ul_tlsent, ntlsent * sizeof (tls_t));
        ulwp->ul_tlsent = NULL;
        ulwp->ul_ntlsent = 0;
}