From 6a1db4ffb67ccb8c3861bb398bff5a033f2d7793 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Fri, 9 Jul 1999 14:34:22 +0000 Subject: Update. * elf/rtld.c: Split _dl_start in two pieces to prevent GOT usage before the relocation happened. Patch by Franz Sirl . --- ChangeLog | 4 ++++ elf/rtld.c | 31 ++++++++++++++++++++++++------- linuxthreads/ChangeLog | 8 ++++++++ linuxthreads/internals.h | 1 + linuxthreads/pthread.c | 2 ++ linuxthreads/spinlock.c | 16 +++++++++------- 6 files changed, 48 insertions(+), 14 deletions(-) diff --git a/ChangeLog b/ChangeLog index 37b8ff2..f4dce34 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,9 @@ 1999-07-09 Ulrich Drepper + * elf/rtld.c: Split _dl_start in two pieces to prevent GOT usage + before the relocation happened. + Patch by Franz Sirl . + * Versions.def (libnsl): Add GLIBC_2.2. * nis/Versions (libnsl) [GLIBC_2.2]: Add xdr_ypall. diff --git a/elf/rtld.c b/elf/rtld.c index 064cd20..4146c0e 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -129,6 +129,9 @@ static hp_timing_t relocate_time; static hp_timing_t load_time; extern unsigned long int _dl_num_relocations; /* in dl-lookup.c */ +static ElfW(Addr) _dl_start_final (void *arg, struct link_map *bootstrap_map_p, + hp_timing_t start_time); + #ifdef RTLD_START RTLD_START #else @@ -140,7 +143,6 @@ _dl_start (void *arg) { struct link_map bootstrap_map; hp_timing_t start_time; - ElfW(Addr) start_addr; /* This #define produces dynamic linking inline functions for bootstrap relocation instead of general-purpose relocation. */ @@ -175,7 +177,22 @@ _dl_start (void *arg) /* Now life is sane; we can call functions and access global data. Set up to use the operating system facilities, and find out from the operating system's program loader where to find the program - header table in core. */ + header table in core. Put the rest of _dl_start into a separate + function, that way the compiler cannot put accesses to the GOT + before ELF_DYNAMIC_RELOCATE. */ + return _dl_start_final (arg, &bootstrap_map, start_time); +} + + +static ElfW(Addr) +_dl_start_final (void *arg, struct link_map *bootstrap_map_p, + hp_timing_t start_time) +{ + /* The use of `alloca' here looks ridiculous but it helps. The goal + is to avoid the function from being inlined. There is no official + way to do this so we use this trick. gcc never inlines functions + which use `alloca'. */ + ElfW(Addr) *start_addr = alloca (sizeof (ElfW(Addr))); if (HP_TIMING_AVAIL) { @@ -188,10 +205,10 @@ _dl_start (void *arg) } /* Transfer data about ourselves to the permanent link_map structure. */ - _dl_rtld_map.l_addr = bootstrap_map.l_addr; - _dl_rtld_map.l_ld = bootstrap_map.l_ld; + _dl_rtld_map.l_addr = bootstrap_map_p->l_addr; + _dl_rtld_map.l_ld = bootstrap_map_p->l_ld; _dl_rtld_map.l_opencount = 1; - memcpy (_dl_rtld_map.l_info, bootstrap_map.l_info, + memcpy (_dl_rtld_map.l_info, bootstrap_map_p->l_info, sizeof _dl_rtld_map.l_info); _dl_setup_hash (&_dl_rtld_map); @@ -203,7 +220,7 @@ _dl_start (void *arg) file access. It will call `dl_main' (below) to do all the real work of the dynamic linker, and then unwind our frame and run the user entry point on the same stack we entered on. */ - start_addr = _dl_sysdep_start (arg, &dl_main); + *start_addr = _dl_sysdep_start (arg, &dl_main); if (HP_TIMING_AVAIL) { @@ -219,7 +236,7 @@ _dl_start (void *arg) if (_dl_debug_statistics) print_statistics (); - return start_addr; + return *start_addr; } /* Now life is peachy; we can do all normal operations. diff --git a/linuxthreads/ChangeLog b/linuxthreads/ChangeLog index ab97529..dfb0e3d 100644 --- a/linuxthreads/ChangeLog +++ b/linuxthreads/ChangeLog @@ -1,3 +1,11 @@ +1999-06-23 Robey Pointer + + * internals.h: Added p_nextlock entry to separate queueing for a + lock from queueing for a CV (sometimes a thread queues on a lock + to serialize removing itself from a CV queue). + * pthread.c: Added p_nextlock to initializers. + * spinlock.c: Changed to use p_nextlock instead of p_nextwaiting. + 1999-07-09 Ulrich Drepper * manager.c (pthread_handle_create): Free mmap region after stack diff --git a/linuxthreads/internals.h b/linuxthreads/internals.h index db84707..bcbfbcf 100644 --- a/linuxthreads/internals.h +++ b/linuxthreads/internals.h @@ -74,6 +74,7 @@ struct _pthread_descr_struct { pthread_descr p_nextlive, p_prevlive; /* Double chaining of active threads */ pthread_descr p_nextwaiting; /* Next element in the queue holding the thr */ + pthread_descr p_nextlock; /* can be on a queue and waiting on a lock */ pthread_t p_tid; /* Thread identifier */ int p_pid; /* PID of Unix process */ int p_priority; /* Thread priority (== 0 if not realtime) */ diff --git a/linuxthreads/pthread.c b/linuxthreads/pthread.c index b7cf573..c94e7e6 100644 --- a/linuxthreads/pthread.c +++ b/linuxthreads/pthread.c @@ -34,6 +34,7 @@ struct _pthread_descr_struct __pthread_initial_thread = { &__pthread_initial_thread, /* pthread_descr p_nextlive */ &__pthread_initial_thread, /* pthread_descr p_prevlive */ NULL, /* pthread_descr p_nextwaiting */ + NULL, /* pthread_descr p_nextlock */ PTHREAD_THREADS_MAX, /* pthread_t p_tid */ 0, /* int p_pid */ 0, /* int p_priority */ @@ -75,6 +76,7 @@ struct _pthread_descr_struct __pthread_manager_thread = { NULL, /* pthread_descr p_nextlive */ NULL, /* pthread_descr p_prevlive */ NULL, /* pthread_descr p_nextwaiting */ + NULL, /* pthread_descr p_nextlock */ 0, /* int p_tid */ 0, /* int p_pid */ 0, /* int p_priority */ diff --git a/linuxthreads/spinlock.c b/linuxthreads/spinlock.c index c8f8f71..ce6ff9e 100644 --- a/linuxthreads/spinlock.c +++ b/linuxthreads/spinlock.c @@ -27,7 +27,7 @@ 1: fastlock is taken, no thread is waiting on it ADDR: fastlock is taken, ADDR is address of thread descriptor for first waiting thread, other waiting threads are linked via - their p_nextwaiting field. + their p_nextlock field. The waiting list is not sorted by priority order. Actually, we always insert at top of list (sole insertion mode that can be performed without locking). @@ -50,8 +50,10 @@ void internal_function __pthread_lock(struct _pthread_fastlock * lock, self = thread_self(); newstatus = (long) self; } - if (self != NULL) - THREAD_SETMEM(self, p_nextwaiting, (pthread_descr) oldstatus); + if (self != NULL) { + ASSERT(self->p_nextlock == NULL); + THREAD_SETMEM(self, p_nextlock, (pthread_descr) oldstatus); + } } while(! compare_and_swap(&lock->__status, oldstatus, newstatus, &lock->__spinlock)); if (oldstatus != 0) suspend(self); @@ -83,7 +85,7 @@ again: maxptr = ptr; maxprio = thr->p_priority; } - ptr = &(thr->p_nextwaiting); + ptr = &(thr->p_nextlock); thr = *ptr; } /* Remove max prio thread from waiting list. */ @@ -92,16 +94,16 @@ again: to guard against concurrent lock operation */ thr = (pthread_descr) oldstatus; if (! compare_and_swap(&lock->__status, - oldstatus, (long)(thr->p_nextwaiting), + oldstatus, (long)(thr->p_nextlock), &lock->__spinlock)) goto again; } else { /* No risk of concurrent access, remove max prio thread normally */ thr = *maxptr; - *maxptr = thr->p_nextwaiting; + *maxptr = thr->p_nextlock; } /* Wake up the selected waiting thread */ - thr->p_nextwaiting = NULL; + thr->p_nextlock = NULL; restart(thr); } -- cgit v1.1