Perform some code cleanup

libc/calls/read.c

@@ -41,7 +41,6 @@
  * @param size in range [1..0x7ffff000] is reasonable
  * @return [1..size] bytes on success, 0 on EOF, or -1 w/ errno; with
  *     exception of size==0, in which case return zero means no error
- * @see write(), pread(), readv()
  * @asyncsignalsafe
  * @restartable
  * @vforksafe
@@ -49,7 +48,7 @@
 ssize_t read(int fd, void *buf, size_t size) {
   ssize_t rc;
   if (fd >= 0) {
-    if (IsAsan() && !__asan_is_valid(buf, size)) {
+    if ((!buf && size) || (IsAsan() && !__asan_is_valid(buf, size))) {
       rc = efault();
     } else if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
       rc = _weaken(__zipos_read)(
@@ -65,7 +64,7 @@ ssize_t read(int fd, void *buf, size_t size) {
       rc = sys_readv_nt(g_fds.p + fd, &(struct iovec){buf, size}, 1);
     }
   } else {
-    rc = einval();
+    rc = ebadf();
   }
   DATATRACE("read(%d, [%#.*hhs%s], %'zu) → %'zd% m", fd, MAX(0, MIN(40, rc)),
             buf, rc > 40 ? "..." : "", size, rc);

libc/calls/readv.c

@@ -46,8 +46,8 @@
  * @restartable
  */
 ssize_t readv(int fd, const struct iovec *iov, int iovlen) {
-  int i;
   ssize_t rc;
+
   if (fd >= 0 && iovlen >= 0) {
     if (IsAsan() && !__asan_is_valid_iov(iov, iovlen)) {
       rc = efault();
@@ -67,9 +67,12 @@ ssize_t readv(int fd, const struct iovec *iov, int iovlen) {
     } else {
       rc = sys_readv_nt(g_fds.p + fd, iov, iovlen);
     }
+  } else if (fd < 0) {
+    rc = ebadf();
   } else {
     rc = einval();
   }
+
 #if defined(SYSDEBUG) && _DATATRACE
   if (UNLIKELY(__strace > 0)) {
     if (rc == -1 && errno == EFAULT) {
@@ -81,5 +84,6 @@ ssize_t readv(int fd, const struct iovec *iov, int iovlen) {
     }
   }
 #endif
+
   return rc;
 }

libc/calls/setrlimit.c

@@ -18,11 +18,11 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
 #include "libc/calls/calls.h"
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/struct/rlimit.internal.h"
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
 #include "libc/intrin/describeflags.internal.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/sysv/consts/rlimit.h"
 #include "libc/sysv/errfuns.h"
 
@@ -43,6 +43,8 @@
  * - `RLIMIT_FSIZE` causes `SIGXFSZ` to sent to the process when the
  *   soft limit on file size is exceeded and the process is destroyed
  *   when the hard limit is exceeded. It works everywhere but Windows
+ *   and it also causes `EFBIG` to be returned by i/o functions after
+ *   the `SIGXFSZ` signal is delivered or ignored
  *
  * - `RLIMIT_NPROC` limits the number of simultaneous processes and it
  *   should work on all platforms except Windows. Please be advised it

libc/calls/tkill.c

@@ -17,10 +17,10 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/dce.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/nt/enum/threadaccess.h"
 #include "libc/nt/runtime.h"
 #include "libc/nt/thread.h"
@@ -48,6 +48,7 @@ static textwindows int sys_tkill_nt(int tid, int sig) {
  * @param tid is thread id
  * @param sig does nothing on xnu
  * @return 0 on success, or -1 w/ errno
+ * @asyncsignalsafe
  */
 int tkill(int tid, int sig) {
   int rc;

libc/calls/write.c

@@ -34,12 +34,27 @@
  * This function changes the current file position. For documentation
  * on file position behaviors and gotchas, see the lseek() function.
  *
- * @param fd is something open()'d earlier
+ * @param fd is open file descriptor
  * @param buf is copied from, cf. copy_file_range(), sendfile(), etc.
- * @param size in range [1..0x7ffff000] is reasonable
  * @return [1..size] bytes on success, or -1 w/ errno; noting zero is
  *     impossible unless size was passed as zero to do an error check
- * @see read(), pwrite(), writev(), SIGPIPE
+ * @raise EBADF if `fd` is negative or not an open file descriptor
+ * @raise EBADF if `fd` wasn't opened with `O_WRONLY` or `O_RDWR`
+ * @raise EPIPE if `fd` is a pipe whose other reader end was closed,
+ *     after the `SIGPIPE` signal was delivered, blocked, or ignored
+ * @raise EFBIG if `RLIMIT_FSIZE` soft limit was exceeded, after the
+ *     `SIGXFSZ` signal was either delivered, blocked, or ignored
+ * @raise EFAULT if `size` is nonzero and `buf` points to bad memory
+ * @raise EPERM if pledge() is in play without the stdio promise
+ * @raise ENOSPC if device containing `fd` is full
+ * @raise EIO if low-level i/o error happened
+ * @raise EINTR if signal was delivered instead
+ * @raise EAGAIN if `O_NONBLOCK` is in play and write needs to block
+ * @raise ENOBUFS if kernel lacked internal resources; which FreeBSD
+ *     and XNU say could happen with sockets, and OpenBSD documents it
+ *     as a general possibility; whereas other system don't specify it
+ * @raise ENXIO is specified only by POSIX and XNU when a request is
+ *     made of a nonexistent device or outside device capabilities
  * @asyncsignalsafe
  * @restartable
  * @vforksafe
@@ -47,7 +62,7 @@
 ssize_t write(int fd, const void *buf, size_t size) {
   ssize_t rc;
   if (fd >= 0) {
-    if (IsAsan() && !__asan_is_valid(buf, size)) {
+    if ((!buf && size) || (IsAsan() && !__asan_is_valid(buf, size))) {
       rc = efault();
     } else if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
       rc = _weaken(__zipos_write)(
@@ -63,7 +78,7 @@ ssize_t write(int fd, const void *buf, size_t size) {
       rc = sys_writev_nt(fd, &(struct iovec){buf, size}, 1);
     }
   } else {
-    rc = einval();
+    rc = ebadf();
   }
   DATATRACE("write(%d, %#.*hhs%s, %'zu) → %'zd% m", fd, MAX(0, MIN(40, rc)),
             buf, rc > 40 ? "..." : "", size, rc);

libc/calls/writev.c

@@ -50,7 +50,6 @@
  * @restartable
  */
 ssize_t writev(int fd, const struct iovec *iov, int iovlen) {
-  int i;
   ssize_t rc;
 
   if (fd >= 0 && iovlen >= 0) {
@@ -72,6 +71,8 @@ ssize_t writev(int fd, const struct iovec *iov, int iovlen) {
     } else {
       rc = sys_writev_nt(fd, iov, iovlen);
     }
+  } else if (fd < 0) {
+    rc = ebadf();
   } else {
     rc = einval();
   }

libc/runtime/clone.c

@@ -488,13 +488,11 @@ static int CloneLinux(int (*func)(void *arg, int tid), char *stk, size_t stksz,
 // COSMOPOLITAN
 
 /**
- * Creates thread without malloc being linked, e.g.
+ * Creates thread without malloc being linked.
  *
- *     int worker(void *arg) {
- *       return 0;
- *     }
+ * If you use clone() you're on you're own, e.g.
  *
- *     // NOTE: See _mktls() for _Thread_local support.
+ *     int worker(void *arg) { return 0; }
  *     struct CosmoTib tib = {.tib_self = &tib, .tib_tid = -1};
  *     char *stk = _mapstack();
  *     tid = clone(worker, stk, GetStackSize() - 16,

libc/thread/wait0.c

@@ -100,4 +100,7 @@ void _wait0(const atomic_int *ctid) {
       _wait0_poll(&ts);
     }
   }
+  if (IsOpenbsd()) {
+    sched_yield();  // TODO(jart): whhhy?
+  }
 }