diff options
Diffstat (limited to 'linuxthreads/manager.c')
| -rw-r--r-- | linuxthreads/manager.c | 91 |
1 files changed, 62 insertions, 29 deletions
diff --git a/linuxthreads/manager.c b/linuxthreads/manager.c index b76203c505..1510551374 100644 --- a/linuxthreads/manager.c +++ b/linuxthreads/manager.c @@ -64,25 +64,29 @@ volatile pthread_descr __pthread_last_event; /* Stack segment numbers are also indices into the __pthread_handles array. */ /* Stack segment number 0 is reserved for the initial thread. */ +#if FLOATING_STACKS +# define thread_segment(seq) NULL +#else static inline pthread_descr thread_segment(int seg) { return (pthread_descr)(THREAD_STACK_START_ADDRESS - (seg - 1) * STACK_SIZE) - 1; } +#endif /* Flag set in signal handler to record child termination */ -static volatile int terminated_children = 0; +static volatile int terminated_children; /* Flag set when the initial thread is blocked on pthread_exit waiting for all other threads to terminate */ -static int main_thread_exiting = 0; +static int main_thread_exiting; /* Counter used to generate unique thread identifier. Thread identifier is pthread_threads_counter + segment. */ -static pthread_t pthread_threads_counter = 0; +static pthread_t pthread_threads_counter; #ifdef NEED_SEPARATE_REGISTER_STACK /* Signal masks for the manager. These have to be global only when clone2 @@ -338,6 +342,7 @@ static int pthread_allocate_stack(const pthread_attr_t *attr, void *map_addr; /* Allocate space for stack and thread descriptor at default address */ +#ifdef NEED_SEPARATE_REGISTER_STACK if (attr != NULL) { guardsize = page_roundup (attr->__guardsize, granularity); @@ -350,7 +355,7 @@ static int pthread_allocate_stack(const pthread_attr_t *attr, guardsize = granularity; stacksize = STACK_SIZE - granularity; } -#ifdef NEED_SEPARATE_REGISTER_STACK + new_thread = default_new_thread; new_thread_bottom = (char *) (new_thread + 1) - stacksize - guardsize; /* Includes guard area, unlike the normal case. Use the bottom @@ -361,6 +366,8 @@ static int pthread_allocate_stack(const pthread_attr_t *attr, in the same region. The cost is that we might be able to map slightly fewer stacks. */ + /* XXX Fix for floating stacks with variable sizes. */ + /* First the main stack: */ if (mmap((caddr_t)((char *)(new_thread + 1) - stacksize / 2), stacksize / 2, PROT_READ | PROT_WRITE | PROT_EXEC, @@ -382,37 +389,63 @@ static int pthread_allocate_stack(const pthread_attr_t *attr, guardaddr = new_thread_bottom + stacksize/2; /* We leave the guard area in the middle unmapped. */ #else /* !NEED_SEPARATE_REGISTER_STACK */ +# if FLOATING_STACKS + if (attr != NULL) + { + guardsize = page_roundup (attr->__guardsize, granularity); + stacksize = __pthread_max_stacksize - guardsize; + stacksize = MIN (stacksize, + page_roundup (attr->__stacksize, granularity)); + } + else + { + guardsize = granularity; + stacksize = __pthread_max_stacksize - guardsize; + } + + map_addr = mmap(NULL, stacksize + guardsize, + PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (map_addr == MAP_FAILED) + /* No more memory available. */ + return -1; + + guardaddr = map_addr; + if (guardsize > 0) + mprotect (guardaddr, guardsize, PROT_NONE); + + new_thread_bottom = (char *) map_addr + guardsize; + new_thread = ((pthread_descr) (new_thread_bottom + stacksize)) - 1; +# else + if (attr != NULL) + { + guardsize = page_roundup (attr->__guardsize, granularity); + stacksize = STACK_SIZE - guardsize; + stacksize = MIN (stacksize, + page_roundup (attr->__stacksize, granularity)); + } + else + { + guardsize = granularity; + stacksize = STACK_SIZE - granularity; + } + new_thread = default_new_thread; new_thread_bottom = (char *) (new_thread + 1) - stacksize; - map_addr = mmap((caddr_t)((char *)(new_thread + 1) - stacksize), - stacksize, PROT_READ | PROT_WRITE | PROT_EXEC, + map_addr = mmap((caddr_t)((char *)(new_thread + 1) - stacksize - guardsize), + stacksize + guardsize, + PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); if (map_addr == MAP_FAILED) /* Bad luck, this segment is already mapped. */ return -1; - /* We manage to get a stack. Now see whether we need a guard - and allocate it if necessary. Notice that the default - attributes (stack_size = STACK_SIZE - pagesize and guardsize - = pagesize) do not need a guard page, since the RLIMIT_STACK - soft limit prevents stacks from running into one another. */ - if (stacksize == STACK_SIZE - pagesize) - { - /* We don't need a guard page. */ - guardaddr = new_thread_bottom; - guardsize = 0; - } - else - { - /* Put a bad page at the bottom of the stack */ - guardaddr = (void *)new_thread_bottom - guardsize; - if (mmap ((caddr_t) guardaddr, guardsize, 0, MAP_FIXED, -1, 0) - == MAP_FAILED) - { - /* We don't make this an error. */ - guardaddr = new_thread_bottom; - guardsize = 0; - } - } + + /* We manage to get a stack. Protect the guard area pages if + necessary. */ + guardaddr = map_addr; + if (guardsize > 0) + mprotect (guardaddr, guardsize, PROT_NONE); +# endif #endif /* !NEED_SEPARATE_REGISTER_STACK */ } /* Clear the thread data structure. */ |