Upgrade to CloudABI v0.17.

Compared to the previous version, v0.16, there are a couple of minor
changes:

- CLOUDABI_AT_PID: Process identifiers for CloudABI processes.

  Initially, BSD process identifiers weren't exposed inside the runtime,
  due to them being pretty much useless inside of a cluster computing
  environment. When jobs are scheduled across systems, the BSD process
  number doesn't act as an identifier. Even on individual systems they
  may recycle relatively quickly.

  With this change, the kernel will now generate a UUIDv4 when executing
  a process. These UUIDs can be obtained within the process using
  program_getpid(). Right now, FreeBSD will not attempt to store this
  value. This should of course happen at some point in time, so that it
  may be printed by administration tools.

- Removal of some unused structure members for polling.

  With the polling framework being simplified/redesigned, it turns out
  some of the structure fields were not used by the C library. We can
  remove these to keep things nice and tidy.

Obtained from:	https://github.com/NuxiNL/cloudabi

1 files changed, 20 insertions, 4 deletions

diff --git a/sys/compat/cloudabi64/cloudabi64_module.c b/sys/compat/cloudabi64/cloudabi64_module.c
index da1ea1149a4b..9c71b87b08f4 100644
--- a/sys/compat/cloudabi64/cloudabi64_module.c
+++ b/sys/compat/cloudabi64/cloudabi64_module.c
@@ -63,10 +63,10 @@ cloudabi64_copyout_strings(struct image_params *imgp)
 int
 cloudabi64_fixup(register_t **stack_base, struct image_params *imgp)
 {
-	char canarybuf[64];
+	char canarybuf[64], pidbuf[16];
 	Elf64_Auxargs *args;
 	struct thread *td;
-	void *argdata, *canary;
+	void *argdata, *canary, *pid;
 	size_t argdatalen;
 	int error;
 
@@ -79,8 +79,9 @@ cloudabi64_fixup(register_t **stack_base, struct image_params *imgp)
 	td = curthread;
 	td->td_proc->p_osrel = __FreeBSD_version;
 
-	/* Store canary for stack smashing protection. */
 	argdata = *stack_base;
+
+	/* Store canary for stack smashing protection. */
 	arc4rand(canarybuf, sizeof(canarybuf), 0);
 	*stack_base -= howmany(sizeof(canarybuf), sizeof(register_t));
 	canary = *stack_base;
@@ -89,6 +90,20 @@ cloudabi64_fixup(register_t **stack_base, struct image_params *imgp)
 		return (error);
 
 	/*
+	 * Generate a random UUID that identifies the process. Right now
+	 * we don't store this UUID in the kernel. Ideally, it should be
+	 * exposed through ps(1).
+	 */
+	arc4rand(pidbuf, sizeof(pidbuf), 0);
+	pidbuf[6] = (pidbuf[6] & 0x0f) | 0x40;
+	pidbuf[8] = (pidbuf[8] & 0x3f) | 0x80;
+	*stack_base -= howmany(sizeof(pidbuf), sizeof(register_t));
+	pid = *stack_base;
+	error = copyout(pidbuf, pid, sizeof(pidbuf));
+	if (error != 0)
+		return (error);
+
+	/*
 	 * Compute length of program arguments. As the argument data is
 	 * binary safe, we had to add a trailing null byte in
 	 * exec_copyin_data_fds(). Undo this by reducing the length.
@@ -111,9 +126,10 @@ cloudabi64_fixup(register_t **stack_base, struct image_params *imgp)
 		VAL(CLOUDABI_AT_PAGESZ, args->pagesz),
 		PTR(CLOUDABI_AT_PHDR, args->phdr),
 		VAL(CLOUDABI_AT_PHNUM, args->phnum),
-		VAL(CLOUDABI_AT_TID, td->td_tid),
+		PTR(CLOUDABI_AT_PID, pid),
 		PTR(CLOUDABI_AT_SYSINFO_EHDR,
 		    imgp->proc->p_sysent->sv_shared_page_base),
+		VAL(CLOUDABI_AT_TID, td->td_tid),
 #undef VAL
 #undef PTR
 		{ .a_type = CLOUDABI_AT_NULL },