diff options
Diffstat (limited to '')
| -rw-r--r-- | libc-top-half/musl/include/pthread.h | 2 | ||||
| -rw-r--r-- | libc-top-half/musl/include/unistd.h | 2 | ||||
| -rw-r--r-- | libc-top-half/musl/src/env/__init_tls.c | 51 | ||||
| -rw-r--r-- | libc-top-half/musl/src/include/pthread.h | 2 | ||||
| -rw-r--r-- | libc-top-half/musl/src/internal/pthread_impl.h | 5 | ||||
| -rw-r--r-- | libc-top-half/musl/src/thread/__wait.c | 2 | ||||
| -rw-r--r-- | libc-top-half/musl/src/thread/pthread_attr_get.c | 4 | ||||
| -rw-r--r-- | libc-top-half/musl/src/thread/pthread_barrier_destroy.c | 2 | ||||
| -rw-r--r-- | libc-top-half/musl/src/thread/pthread_barrier_wait.c | 8 | ||||
| -rw-r--r-- | libc-top-half/musl/src/thread/pthread_create.c | 52 | ||||
| -rw-r--r-- | libc-top-half/musl/src/thread/wasm32/wasi_thread_start.s | 31 |
11 files changed, 144 insertions, 17 deletions
diff --git a/libc-top-half/musl/include/pthread.h b/libc-top-half/musl/include/pthread.h index 01fe5f2..b14fe82 100644 --- a/libc-top-half/musl/include/pthread.h +++ b/libc-top-half/musl/include/pthread.h @@ -85,7 +85,9 @@ extern "C" { int pthread_create(pthread_t *__restrict, const pthread_attr_t *__restrict, void *(*)(void *), void *__restrict); int pthread_detach(pthread_t); +#ifdef __wasilibc_unmodified_upstream _Noreturn void pthread_exit(void *); +#endif int pthread_join(pthread_t, void **); #ifdef __GNUC__ diff --git a/libc-top-half/musl/include/unistd.h b/libc-top-half/musl/include/unistd.h index b5cb5c6..0be83e3 100644 --- a/libc-top-half/musl/include/unistd.h +++ b/libc-top-half/musl/include/unistd.h @@ -336,7 +336,9 @@ pid_t gettid(void); #endif #define _POSIX_VDISABLE 0 +#if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT) #define _POSIX_THREADS _POSIX_VERSION +#endif #define _POSIX_THREAD_PROCESS_SHARED _POSIX_VERSION #define _POSIX_THREAD_SAFE_FUNCTIONS _POSIX_VERSION #define _POSIX_THREAD_ATTR_STACKADDR _POSIX_VERSION diff --git a/libc-top-half/musl/src/env/__init_tls.c b/libc-top-half/musl/src/env/__init_tls.c index ee785bc..ece8d24 100644 --- a/libc-top-half/musl/src/env/__init_tls.c +++ b/libc-top-half/musl/src/env/__init_tls.c @@ -16,6 +16,43 @@ volatile int __thread_list_lock; #ifndef __wasilibc_unmodified_upstream + +/* These symbols are generated by wasm-ld. __stack_high/__stack_low + * symbols are only available in LLVM v16 and higher, therefore they're + * defined as weak symbols and if not available, __heap_base/__data_end + * is used instead. + * + * TODO: remove usage of __heap_base/__data_end for stack size calculation + * once we drop support for LLVM v15 and older. + */ +extern unsigned char __heap_base; +extern unsigned char __data_end; +extern unsigned char __global_base; +extern weak unsigned char __stack_high; +extern weak unsigned char __stack_low; + +static inline void setup_default_stack_size() +{ + ptrdiff_t stack_size; + + if (&__stack_high) + stack_size = &__stack_high - &__stack_low; + else { + unsigned char *sp; + __asm__( + ".globaltype __stack_pointer, i32\n" + "global.get __stack_pointer\n" + "local.set %0\n" + : "=r"(sp)); + stack_size = sp > &__global_base ? &__heap_base - &__data_end : (ptrdiff_t)&__global_base; + } + + if (stack_size > __default_stacksize) + __default_stacksize = + stack_size < DEFAULT_STACK_MAX ? + stack_size : DEFAULT_STACK_MAX; +} + void __wasi_init_tp() { __init_tp((void *)__get_tp()); } @@ -31,6 +68,20 @@ int __init_tp(void *p) if (!r) libc.can_do_threads = 1; td->detach_state = DT_JOINABLE; td->tid = __syscall(SYS_set_tid_address, &__thread_list_lock); +#else + setup_default_stack_size(); + td->detach_state = DT_JOINABLE; + /* + * Initialize the TID to a value which doesn't conflict with + * host-allocated TIDs, so that TID-based locks can work. + * + * Note: + * - Host-allocated TIDs range from 1 to 0x1fffffff. (inclusive) + * - __tl_lock and __lockfile uses TID 0 as "unlocked". + * - __lockfile relies on the fact the most significant two bits + * of TIDs are 0. + */ + td->tid = 0x3fffffff; #endif td->locale = &libc.global_locale; td->robust_list.head = &td->robust_list.head; diff --git a/libc-top-half/musl/src/include/pthread.h b/libc-top-half/musl/src/include/pthread.h index 7167d3e..0aba813 100644 --- a/libc-top-half/musl/src/include/pthread.h +++ b/libc-top-half/musl/src/include/pthread.h @@ -7,7 +7,9 @@ hidden int __pthread_once(pthread_once_t *, void (*)(void)); hidden void __pthread_testcancel(void); hidden int __pthread_setcancelstate(int, int *); hidden int __pthread_create(pthread_t *restrict, const pthread_attr_t *restrict, void *(*)(void *), void *restrict); +#ifdef __wasilibc_unmodified_upstream hidden _Noreturn void __pthread_exit(void *); +#endif hidden int __pthread_join(pthread_t, void **); hidden int __pthread_mutex_lock(pthread_mutex_t *); hidden int __pthread_mutex_trylock(pthread_mutex_t *); diff --git a/libc-top-half/musl/src/internal/pthread_impl.h b/libc-top-half/musl/src/internal/pthread_impl.h index a6d188b..1e7b974 100644 --- a/libc-top-half/musl/src/internal/pthread_impl.h +++ b/libc-top-half/musl/src/internal/pthread_impl.h @@ -216,7 +216,12 @@ extern hidden unsigned __default_stacksize; extern hidden unsigned __default_guardsize; #define DEFAULT_STACK_SIZE 131072 +#ifdef __wasilibc_unmodified_upstream #define DEFAULT_GUARD_SIZE 8192 +#else +/* guard doesn't make much sense without mprotect. */ +#define DEFAULT_GUARD_SIZE 0 +#endif #define DEFAULT_STACK_MAX (8<<20) #define DEFAULT_GUARD_MAX (1<<20) diff --git a/libc-top-half/musl/src/thread/__wait.c b/libc-top-half/musl/src/thread/__wait.c index c0e4aac..7ffa987 100644 --- a/libc-top-half/musl/src/thread/__wait.c +++ b/libc-top-half/musl/src/thread/__wait.c @@ -48,7 +48,7 @@ void __wait(volatile int *addr, volatile int *waiters, int val, int priv) __syscall(SYS_futex, addr, FUTEX_WAIT|priv, val, 0) != -ENOSYS || __syscall(SYS_futex, addr, FUTEX_WAIT, val, 0); #else - __wasilibc_futex_wait(addr, FUTEX_WAIT, val, 0); + __wasilibc_futex_wait(addr, FUTEX_WAIT, val, -1); #endif } if (waiters) a_dec(waiters); diff --git a/libc-top-half/musl/src/thread/pthread_attr_get.c b/libc-top-half/musl/src/thread/pthread_attr_get.c index f12ff44..0ac251c 100644 --- a/libc-top-half/musl/src/thread/pthread_attr_get.c +++ b/libc-top-half/musl/src/thread/pthread_attr_get.c @@ -17,6 +17,7 @@ int pthread_attr_getinheritsched(const pthread_attr_t *restrict a, int *restrict return 0; } +#ifdef __wasilibc_unmodified_upstream /* WASI has no CPU scheduling support. */ int pthread_attr_getschedparam(const pthread_attr_t *restrict a, struct sched_param *restrict param) { param->sched_priority = a->_a_prio; @@ -28,6 +29,7 @@ int pthread_attr_getschedpolicy(const pthread_attr_t *restrict a, int *restrict *policy = a->_a_policy; return 0; } +#endif int pthread_attr_getscope(const pthread_attr_t *restrict a, int *restrict scope) { @@ -56,11 +58,13 @@ int pthread_barrierattr_getpshared(const pthread_barrierattr_t *restrict a, int return 0; } +#ifdef __wasilibc_unmodified_upstream /* Forward declaration of WASI's `__clockid` type. */ int pthread_condattr_getclock(const pthread_condattr_t *restrict a, clockid_t *restrict clk) { *clk = a->__attr & 0x7fffffff; return 0; } +#endif int pthread_condattr_getpshared(const pthread_condattr_t *restrict a, int *restrict pshared) { diff --git a/libc-top-half/musl/src/thread/pthread_barrier_destroy.c b/libc-top-half/musl/src/thread/pthread_barrier_destroy.c index 4ce0b2e..a347a2c 100644 --- a/libc-top-half/musl/src/thread/pthread_barrier_destroy.c +++ b/libc-top-half/musl/src/thread/pthread_barrier_destroy.c @@ -9,7 +9,9 @@ int pthread_barrier_destroy(pthread_barrier_t *b) while ((v = b->_b_lock) & INT_MAX) __wait(&b->_b_lock, 0, v, 0); } +#ifdef __wasilibc_unmodified_upstream /* WASI does not understand processes or locking between them. */ __vm_wait(); +#endif } return 0; } diff --git a/libc-top-half/musl/src/thread/pthread_barrier_wait.c b/libc-top-half/musl/src/thread/pthread_barrier_wait.c index cc2a8bb..0891b71 100644 --- a/libc-top-half/musl/src/thread/pthread_barrier_wait.c +++ b/libc-top-half/musl/src/thread/pthread_barrier_wait.c @@ -23,7 +23,9 @@ static int pshared_barrier_wait(pthread_barrier_t *b) __wait(&b->_b_count, &b->_b_waiters2, v, 0); } +#ifdef __wasilibc_unmodified_upstream /* WASI does not understand processes or locking between them. */ __vm_lock(); +#endif /* Ensure all threads have a vm lock before proceeding */ if (a_fetch_add(&b->_b_count, -1)==1-limit) { @@ -44,7 +46,9 @@ static int pshared_barrier_wait(pthread_barrier_t *b) if (v==INT_MIN+1 || (v==1 && w)) __wake(&b->_b_lock, 1, 0); +#ifdef __wasilibc_unmodified_upstream /* WASI does not understand processes or locking between them. */ __vm_unlock(); +#endif return ret; } @@ -84,8 +88,12 @@ int pthread_barrier_wait(pthread_barrier_t *b) a_spin(); a_inc(&inst->finished); while (inst->finished == 1) +#ifdef __wasilibc_unmodified_upstream __syscall(SYS_futex,&inst->finished,FUTEX_WAIT|FUTEX_PRIVATE,1,0) != -ENOSYS || __syscall(SYS_futex,&inst->finished,FUTEX_WAIT,1,0); +#else + __futexwait(&inst->finished, 1, 0); +#endif return PTHREAD_BARRIER_SERIAL_THREAD; } diff --git a/libc-top-half/musl/src/thread/pthread_create.c b/libc-top-half/musl/src/thread/pthread_create.c index 1aa7be7..676e2cc 100644 --- a/libc-top-half/musl/src/thread/pthread_create.c +++ b/libc-top-half/musl/src/thread/pthread_create.c @@ -60,7 +60,11 @@ void __tl_sync(pthread_t td) if (tl_lock_waiters) __wake(&__thread_list_lock, 1, 0); } +#ifdef __wasilibc_unmodified_upstream _Noreturn void __pthread_exit(void *result) +#else +static void __pthread_exit(void *result) +#endif { pthread_t self = __pthread_self(); sigset_t set; @@ -191,7 +195,7 @@ _Noreturn void __pthread_exit(void *result) __tl_unlock(); free(self->map_base); // Can't use `exit()` here, because it is too high level - for (;;) __wasi_proc_exit(0); + return; } #endif @@ -212,7 +216,6 @@ _Noreturn void __pthread_exit(void *result) // do it manually here __tl_unlock(); // Can't use `exit()` here, because it is too high level - for (;;) __wasi_proc_exit(0); #endif } @@ -235,9 +238,14 @@ struct start_args { volatile int control; unsigned long sig_mask[_NSIG/8/sizeof(long)]; #else + /* + * Note: the offset of the "stack" and "tls_base" members + * in this structure is hardcoded in wasi_thread_start. + */ + void *stack; + void *tls_base; void *(*start_func)(void *); void *start_arg; - void *tls_base; #endif }; @@ -271,32 +279,41 @@ static int start_c11(void *p) return 0; } #else -__attribute__((export_name("wasi_thread_start"))) -_Noreturn void wasi_thread_start(int tid, void *p) + +/* + * We want to ensure wasi_thread_start is linked whenever + * pthread_create is used. The following reference is to ensure that. + * Otherwise, the linker doesn't notice the dependency because + * wasi_thread_start is used indirectly via a wasm export. + */ +void wasi_thread_start(int tid, void *p); +hidden void *__dummy_reference = wasi_thread_start; + +hidden void __wasi_thread_start_C(int tid, void *p) { struct start_args *args = p; - __asm__(".globaltype __tls_base, i32\n" - "local.get %0\n" - "global.set __tls_base\n" - :: "r"(args->tls_base)); pthread_t self = __pthread_self(); // Set the thread ID (TID) on the pthread structure. The TID is stored // atomically since it is also stored by the parent thread; this way, // whichever thread (parent or child) reaches this point first can proceed // without waiting. atomic_store((atomic_int *) &(self->tid), tid); - // Set the stack pointer. - __asm__(".globaltype __stack_pointer, i32\n" - "local.get %0\n" - "global.set __stack_pointer\n" - :: "r"(self->stack)); // Execute the user's start function. - int (*start)(void*) = (int(*)(void*)) args->start_func; - __pthread_exit((void *)(uintptr_t)start(args->start_arg)); + __pthread_exit(args->start_func(args->start_arg)); } #endif +#ifdef __wasilibc_unmodified_upstream #define ROUND(x) (((x)+PAGE_SIZE-1)&-PAGE_SIZE) +#else +/* + * As we allocate stack with malloc() instead of mmap/mprotect, + * there is no point to round it up to PAGE_SIZE. + * Instead, round up to a sane alignment. + * Note: PAGE_SIZE is rather big on WASM. (65536) + */ +#define ROUND(x) (((x)+16-1)&-16) +#endif /* pthread_key_create.c overrides this */ static volatile size_t dummy = 0; @@ -484,6 +501,7 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att /* Correct the stack size */ new->stack_size = stack - stack_limit; + args->stack = new->stack; /* just for convenience of asm trampoline */ args->start_func = entry; args->start_arg = arg; args->tls_base = (void*)new_tls_base; @@ -561,5 +579,7 @@ fail: return EAGAIN; } +#ifdef __wasilibc_unmodified_upstream weak_alias(__pthread_exit, pthread_exit); +#endif weak_alias(__pthread_create, pthread_create); diff --git a/libc-top-half/musl/src/thread/wasm32/wasi_thread_start.s b/libc-top-half/musl/src/thread/wasm32/wasi_thread_start.s new file mode 100644 index 0000000..0fe9854 --- /dev/null +++ b/libc-top-half/musl/src/thread/wasm32/wasi_thread_start.s @@ -0,0 +1,31 @@ + .text + + .export_name wasi_thread_start, wasi_thread_start + + .globaltype __stack_pointer, i32 + .globaltype __tls_base, i32 + .functype __wasi_thread_start_C (i32, i32) -> () + + .hidden wasi_thread_start + .globl wasi_thread_start + .type wasi_thread_start,@function + +wasi_thread_start: + .functype wasi_thread_start (i32, i32) -> () + + # Set up the minimum C environment. + # Note: offsetof(start_arg, stack) == 0 + local.get 1 # start_arg + i32.load 0 # stack + global.set __stack_pointer + + local.get 1 # start_arg + i32.load 4 # tls_base + global.set __tls_base + + # Make the C function do the rest of work. + local.get 0 # tid + local.get 1 # start_arg + call __wasi_thread_start_C + + end_function |