diff options
Diffstat (limited to 'usr/src/uts/common/disp/thread.c')
| -rw-r--r-- | usr/src/uts/common/disp/thread.c | 80 |
1 files changed, 79 insertions, 1 deletions
diff --git a/usr/src/uts/common/disp/thread.c b/usr/src/uts/common/disp/thread.c index f2685af534..854b33798d 100644 --- a/usr/src/uts/common/disp/thread.c +++ b/usr/src/uts/common/disp/thread.c @@ -21,7 +21,7 @@ /* * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2013, Joyent, Inc. All rights reserved. + * Copyright (c) 2018 Joyent, Inc. */ #include <sys/types.h> @@ -74,6 +74,7 @@ #include <sys/waitq.h> #include <sys/cpucaps.h> #include <sys/kiconv.h> +#include <sys/ctype.h> struct kmem_cache *thread_cache; /* cache of free threads */ struct kmem_cache *lwp_cache; /* cache of free lwps */ @@ -791,6 +792,11 @@ thread_free(kthread_t *t) nthread--; mutex_exit(&pidlock); + if (t->t_name != NULL) { + kmem_free(t->t_name, THREAD_NAME_MAX); + t->t_name = NULL; + } + /* * Free thread, lwp and stack. This needs to be done carefully, since * if T_TALLOCSTK is set, the thread is part of the stack. @@ -2127,3 +2133,75 @@ stkinfo_percent(caddr_t t_stk, caddr_t t_stkbase, caddr_t sp) } return (percent); } + +/* + * NOTE: This will silently truncate a name > THREAD_NAME_MAX - 1 characters + * long. It is expected that callers (acting on behalf of userland clients) + * will perform any required checks to return the correct error semantics. + * It is also expected callers on behalf of userland clients have done + * any necessary permission checks. + */ +int +thread_setname(kthread_t *t, const char *name) +{ + char *buf = NULL; + + /* + * We optimistically assume that a thread's name will only be set + * once and so allocate memory in preparation of setting t_name. + * If it turns out a name has already been set, we just discard (free) + * the buffer we just allocated and reuse the current buffer + * (as all should be THREAD_NAME_MAX large). + * + * Such an arrangement means over the lifetime of a kthread_t, t_name + * is either NULL or has one value (the address of the buffer holding + * the current thread name). The assumption is that most kthread_t + * instances will not have a name assigned, so dynamically allocating + * the memory should minimize the footprint of this feature, but by + * having the buffer persist for the life of the thread, it simplifies + * usage in highly constrained situations (e.g. dtrace). + */ + if (name != NULL && name[0] != '\0') { + for (size_t i = 0; name[i] != '\0'; i++) { + if (!isprint(name[i])) + return (EINVAL); + } + + buf = kmem_zalloc(THREAD_NAME_MAX, KM_SLEEP); + (void) strlcpy(buf, name, THREAD_NAME_MAX); + } + + mutex_enter(&ttoproc(t)->p_lock); + if (t->t_name == NULL) { + t->t_name = buf; + } else { + if (buf != NULL) { + (void) strlcpy(t->t_name, name, THREAD_NAME_MAX); + kmem_free(buf, THREAD_NAME_MAX); + } else { + bzero(t->t_name, THREAD_NAME_MAX); + } + } + mutex_exit(&ttoproc(t)->p_lock); + return (0); +} + +int +thread_vsetname(kthread_t *t, const char *fmt, ...) +{ + char name[THREAD_NAME_MAX]; + va_list va; + int rc; + + va_start(va, fmt); + rc = vsnprintf(name, sizeof (name), fmt, va); + va_end(va); + + if (rc < 0) + return (EINVAL); + + if (rc >= sizeof (name)) + return (ENAMETOOLONG); + + return (thread_setname(t, name)); +} |