diff options
Diffstat (limited to 'libpthread/linuxthreads.old')
| -rw-r--r-- | libpthread/linuxthreads.old/internals.h | 24 | ||||
| -rw-r--r-- | libpthread/linuxthreads.old/pthread.c | 23 |
2 files changed, 30 insertions, 17 deletions
diff --git a/libpthread/linuxthreads.old/internals.h b/libpthread/linuxthreads.old/internals.h index 637fcea62..110dd9d56 100644 --- a/libpthread/linuxthreads.old/internals.h +++ b/libpthread/linuxthreads.old/internals.h @@ -252,17 +252,25 @@ extern pthread_descr __pthread_main_thread; Initially 0, meaning that the current thread is (by definition) the initial thread. */ -/* For non-MMU systems also remember to stack top of the initial thread. - * This is adapted when other stacks are malloc'ed since we don't know - * the bounds a-priori. -StS */ - extern char *__pthread_initial_thread_bos; #ifndef __ARCH_USE_MMU__ -extern char *__pthread_initial_thread_tos; +/* For non-MMU systems, we have no idea the bounds of the initial thread + * stack, so we have to track it on the fly relative to other stacks. Do + * so by scaling back our assumptions on the limits of the bos/tos relative + * to the known mid point. See also the comments in pthread_initialize(). */ +extern char *__pthread_initial_thread_tos, *__pthread_initial_thread_mid; #define NOMMU_INITIAL_THREAD_BOUNDS(tos,bos) \ - if ((tos)>=__pthread_initial_thread_bos \ - && (bos)<__pthread_initial_thread_tos) \ - __pthread_initial_thread_bos = (tos)+1 + do { \ + char *__tos = (tos); \ + char *__bos = (bos); \ + if (__tos >= __pthread_initial_thread_bos && \ + __bos < __pthread_initial_thread_tos) { \ + if (__bos < __pthread_initial_thread_mid) \ + __pthread_initial_thread_bos = __tos; \ + else \ + __pthread_initial_thread_tos = __bos; \ + } \ + } while (0) #else #define NOMMU_INITIAL_THREAD_BOUNDS(tos,bos) /* empty */ #endif /* __ARCH_USE_MMU__ */ diff --git a/libpthread/linuxthreads.old/pthread.c b/libpthread/linuxthreads.old/pthread.c index ad392e34e..a8830b1a4 100644 --- a/libpthread/linuxthreads.old/pthread.c +++ b/libpthread/linuxthreads.old/pthread.c @@ -168,12 +168,10 @@ pthread_descr __pthread_main_thread = &__pthread_initial_thread; char *__pthread_initial_thread_bos = NULL; -/* For non-MMU systems also remember to stack top of the initial thread. - * This is adapted when other stacks are malloc'ed since we don't know - * the bounds a-priori. -StS */ - #ifndef __ARCH_USE_MMU__ +/* See nommu notes in internals.h and pthread_initialize() below. */ char *__pthread_initial_thread_tos = NULL; +char *__pthread_initial_thread_mid = NULL; #endif /* __ARCH_USE_MMU__ */ /* File descriptor for sending requests to the thread manager. */ @@ -457,12 +455,19 @@ static void pthread_initialize(void) setrlimit(RLIMIT_STACK, &limit); } #else - /* For non-MMU assume __pthread_initial_thread_tos at upper page boundary, and - * __pthread_initial_thread_bos at address 0. These bounds are refined as we - * malloc other stack frames such that they don't overlap. -StS + /* For non-MMU, the initial thread stack can reside anywhere in memory. + * We don't have a way of knowing where the kernel started things -- top + * or bottom (well, that isn't exactly true, but the solution is fairly + * complex and error prone). All we can determine here is an address + * that lies within that stack. Save that address as a reference so that + * as other thread stacks are created, we can adjust the estimated bounds + * of the initial thread's stack appropriately. + * + * This checking is handled in NOMMU_INITIAL_THREAD_BOUNDS(), so see that + * for a few more details. */ - __pthread_initial_thread_tos = - (char *)(((long)CURRENT_STACK_FRAME + getpagesize()) & ~(getpagesize() - 1)); + __pthread_initial_thread_mid = CURRENT_STACK_FRAME; + __pthread_initial_thread_tos = (char *) -1; __pthread_initial_thread_bos = (char *) 1; /* set it non-zero so we know we have been here */ PDEBUG("initial thread stack bounds: bos=%p, tos=%p\n", __pthread_initial_thread_bos, __pthread_initial_thread_tos); |