From 129adfeb539ca3844b1e1d755bfe5e193eb4bb5d Mon Sep 17 00:00:00 2001
From: David van Moolenbroek <david@minix3.org>
Date: Mon, 10 Aug 2015 18:06:10 +0200
Subject: [PATCH] Annotations and tweaks for live update

This change is necessary for instrumentation-aided state transfer.

Change-Id: I24be938009f02e302a15083f9a7a11824975e42b
---
 minix/fs/pfs/pfs.c           | 4 +++-
 minix/fs/procfs/service.c    | 5 +++--
 minix/lib/libminixfs/cache.c | 6 ++++--
 minix/lib/libvtreefs/inode.h | 9 ++++++++-
 minix/servers/pm/mproc.h     | 4 +++-
 minix/servers/rs/exec.c      | 4 +++-
 minix/servers/rs/glo.h       | 2 --
 minix/servers/rs/main.c      | 3 ---
 minix/servers/vfs/exec.c     | 4 +++-
 minix/servers/vfs/glo.h      | 2 --
 minix/servers/vfs/main.c     | 3 ---
 minix/servers/vm/glo.h       | 7 ++++++-
 minix/servers/vm/main.c      | 4 ++--
 sys/lib/libsa/subr_prf.c     | 3 +++
 14 files changed, 38 insertions(+), 22 deletions(-)

diff --git a/minix/fs/pfs/pfs.c b/minix/fs/pfs/pfs.c
index 1ff8977cd..0a5b0ca08 100644
--- a/minix/fs/pfs/pfs.c
+++ b/minix/fs/pfs/pfs.c
@@ -198,8 +198,10 @@ pfs_putnode(ino_t ino_nr, unsigned int count)
 		return EINVAL;
 
 	/* For pipes, free the inode data buffer. */
-	if (rip->i_data != NULL)
+	if (rip->i_data != NULL) {
 		free(rip->i_data);
+		rip->i_data = NULL;
+	}
 
 	/* Return the inode to the free list. */
 	rip->i_free = TRUE;
diff --git a/minix/fs/procfs/service.c b/minix/fs/procfs/service.c
index a76bf3108..bd695e1dd 100644
--- a/minix/fs/procfs/service.c
+++ b/minix/fs/procfs/service.c
@@ -19,10 +19,11 @@ struct policies {
 	enum policy supported;
 };
 
-static struct {
+typedef struct {
 	struct rproc proc[NR_SYS_PROCS];
 	struct rprocpub pub[NR_SYS_PROCS];
-} rproc;
+} ixfer_rproc_t;
+static ixfer_rproc_t rproc;
 
 static struct policies policies[NR_SYS_PROCS];
 
diff --git a/minix/lib/libminixfs/cache.c b/minix/lib/libminixfs/cache.c
index ffb7aadc5..b54b800af 100644
--- a/minix/lib/libminixfs/cache.c
+++ b/minix/lib/libminixfs/cache.c
@@ -66,6 +66,8 @@ static fsblkcnt_t fs_btotal = 0, fs_bused = 0;
 
 static int quiet = 0;
 
+typedef struct buf *noxfer_buf_ptr_t; /* annotation for temporary buf ptrs */
+
 void lmfs_setquiet(int q) { quiet = q; }
 
 static int fs_bufs_heuristic(int minbufs, fsblkcnt_t btotal,
@@ -988,7 +990,7 @@ void lmfs_readahead(dev_t dev, block64_t base_block, unsigned int nblocks,
  * However, the caller must also not rely on all or even any of the blocks to
  * be present in the cache afterwards--failures are (deliberately!) ignored.
  */
-  static struct buf *bufq[LMFS_MAX_PREFETCH]; /* static because of size only */
+  static noxfer_buf_ptr_t bufq[LMFS_MAX_PREFETCH]; /* static for size only */
   struct buf *bp;
   unsigned int count;
   int r;
@@ -1131,7 +1133,7 @@ void lmfs_flushdev(dev_t dev)
 /* Flush all dirty blocks for one device. */
 
   register struct buf *bp;
-  static struct buf **dirty;
+  static noxfer_buf_ptr_t *dirty;
   static unsigned int dirtylistsize = 0;
   unsigned int ndirty;
 
diff --git a/minix/lib/libvtreefs/inode.h b/minix/lib/libvtreefs/inode.h
index 3340cca32..d8c84cd66 100644
--- a/minix/lib/libvtreefs/inode.h
+++ b/minix/lib/libvtreefs/inode.h
@@ -1,6 +1,13 @@
 #ifndef _VTREEFS_INODE_H
 #define _VTREEFS_INODE_H
 
+/*
+ * Callback data can be a pointer or a (cast) integer value.  For now, we
+ * instruct the state transfer framework that it should translate only
+ * recognized pointers.
+ */
+typedef cbdata_t cixfer_cbdata_t;
+
 /*
  * The inodes that are active, form a fully connected tree.  Each node except
  * the root node has a parent and a tail queue of children, where each child
@@ -27,7 +34,7 @@ struct inode {
 	unsigned int i_count;		/* reference count */
 	index_t i_index;		/* index number in parent / NO_INDEX */
 	int i_indexed;			/* number of indexed entries */
-	cbdata_t i_cbdata;		/* callback data */
+	cixfer_cbdata_t i_cbdata;	/* callback data */
 	unsigned short i_flags;		/* I_DELETED or 0 */
 
 	/* Tree structure */
diff --git a/minix/servers/pm/mproc.h b/minix/servers/pm/mproc.h
index b99a54cfb..aadc3466f 100644
--- a/minix/servers/pm/mproc.h
+++ b/minix/servers/pm/mproc.h
@@ -13,6 +13,8 @@
 /* Needs to be included here, for 'ps' etc */
 #include "const.h"
 
+typedef struct sigaction ixfer_sigaction;
+
 EXTERN struct mproc {
   char mp_exitstatus;		/* storage for status when process exits */
   char mp_sigstatus;		/* storage for signal # for killed procs */
@@ -45,7 +47,7 @@ EXTERN struct mproc {
   sigset_t mp_sigpending;	/* pending signals to be handled */
   sigset_t mp_ksigpending;	/* bitmap for pending signals from the kernel */
   sigset_t mp_sigtrace;		/* signals to hand to tracer first */
-  struct sigaction mp_sigact[_NSIG]; /* as in sigaction(2) */
+  ixfer_sigaction mp_sigact[_NSIG]; /* as in sigaction(2) */
 #ifdef __ACK__
   char mp_padding[60];		/* align structure with new libc */
 #endif
diff --git a/minix/servers/rs/exec.c b/minix/servers/rs/exec.c
index 1e2c75d91..feb3df4dc 100644
--- a/minix/servers/rs/exec.c
+++ b/minix/servers/rs/exec.c
@@ -19,6 +19,8 @@ static struct exec_loaders {
 	{ NULL }
 };
 
+extern struct minix_kerninfo *_minix_kerninfo;
+
 int srv_execve(int proc_e, char *exec, size_t exec_len, char **argv,
 	char **envp)
 {
@@ -73,7 +75,7 @@ static int do_exec(int proc_e, char *exec, size_t exec_len, char *progname,
 
 	memset(&execi, 0, sizeof(execi));
 
-	execi.stack_high = kinfo.user_sp;
+	execi.stack_high = _minix_kerninfo->kinfo->user_sp;
 	execi.stack_size = DEFAULT_STACK_LIMIT;
 	execi.proc_e = proc_e;
 	execi.hdr = exec;
diff --git a/minix/servers/rs/glo.h b/minix/servers/rs/glo.h
index 938e55f97..da65c1efa 100644
--- a/minix/servers/rs/glo.h
+++ b/minix/servers/rs/glo.h
@@ -54,7 +54,5 @@ EXTERN unsigned system_hz;
 
 EXTERN struct machine machine;		/* machine info */
 
-EXTERN struct kinfo kinfo;     /* kernel information */
-
 #endif /* RS_GLO_H */
 
diff --git a/minix/servers/rs/main.c b/minix/servers/rs/main.c
index 28e491b8d..5805b9fc2 100644
--- a/minix/servers/rs/main.c
+++ b/minix/servers/rs/main.c
@@ -53,9 +53,6 @@ int main(void)
   if (OK != (s=sys_getmachine(&machine)))
 	  panic("couldn't get machine info: %d", s);
 
-  if (OK != (s=sys_getkinfo(&kinfo)))
-	  panic("couldn't get kernel kinfo: %d", s);
-
   /* Main loop - get work and do it, forever. */         
   while (TRUE) {              
       /* Perform sensitive background operations when RS is idle. */
diff --git a/minix/servers/vfs/exec.c b/minix/servers/vfs/exec.c
index 1eef3821d..90e19c057 100644
--- a/minix/servers/vfs/exec.c
+++ b/minix/servers/vfs/exec.c
@@ -82,6 +82,8 @@ static const struct exec_loaders exec_loaders[] = {
 #define lock_exec() lock_proc(fproc_addr(VM_PROC_NR))
 #define unlock_exec() unlock_proc(fproc_addr(VM_PROC_NR))
 
+extern struct minix_kerninfo *_minix_kerninfo;
+
 /*===========================================================================*
  *				get_read_vp				     *
  *===========================================================================*/
@@ -213,7 +215,7 @@ int pm_exec(vir_bytes path, size_t path_len, vir_bytes frame, size_t frame_len,
 
   /* passed from exec() libc code */
   execi.userflags = 0;
-  execi.args.stack_high = kinfo.user_sp;
+  execi.args.stack_high = _minix_kerninfo->kinfo->user_sp;
   execi.args.stack_size = DEFAULT_STACK_LIMIT;
 
   fp->text_size = 0;
diff --git a/minix/servers/vfs/glo.h b/minix/servers/vfs/glo.h
index 3fbdb05ea..6be3b66e9 100644
--- a/minix/servers/vfs/glo.h
+++ b/minix/servers/vfs/glo.h
@@ -43,6 +43,4 @@ EXTERN int err_code;		/* temporary storage for error number */
 /* Data initialized elsewhere. */
 extern int (* const call_vec[])(void);
 
-EXTERN struct kinfo kinfo;     /* kernel information */
-
 #endif
diff --git a/minix/servers/vfs/main.c b/minix/servers/vfs/main.c
index c8036c830..68db53b6e 100644
--- a/minix/servers/vfs/main.c
+++ b/minix/servers/vfs/main.c
@@ -65,9 +65,6 @@ int main(void)
 
   printf("Started VFS: %d worker thread(s)\n", NR_WTHREADS);
 
-  if (OK != (sys_getkinfo(&kinfo)))
-	panic("couldn't get kernel kinfo");
-
   /* This is the main loop that gets work, processes it, and sends replies. */
   while (TRUE) {
 	yield_all();	/* let other threads run */
diff --git a/minix/servers/vm/glo.h b/minix/servers/vm/glo.h
index d808aa213..e5fa4541b 100644
--- a/minix/servers/vm/glo.h
+++ b/minix/servers/vm/glo.h
@@ -1,3 +1,5 @@
+#ifndef _VM_GLO_H
+#define _VM_GLO_H
 
 #include <minix/sys_config.h>
 #include <minix/type.h>
@@ -19,7 +21,8 @@ EXTERN struct vmproc vmproc[VMP_NR];
 
 long enable_filemap;
 
-EXTERN kinfo_t kernel_boot_info;
+typedef kinfo_t ixfer_kinfo_t;
+EXTERN ixfer_kinfo_t kernel_boot_info;
 
 #if SANITYCHECKS
 EXTERN int nocheck;
@@ -41,3 +44,5 @@ EXTERN  mem_type_t mem_type_anon,       /* anonymous memory */
 /* total number of memory pages */
 EXTERN int total_pages;
 EXTERN int num_vm_instances;
+
+#endif /* !_VM_GLO_H */
diff --git a/minix/servers/vm/main.c b/minix/servers/vm/main.c
index b25a1320f..b6b305698 100644
--- a/minix/servers/vm/main.c
+++ b/minix/servers/vm/main.c
@@ -262,7 +262,7 @@ static int sef_cb_init_fresh(int type, sef_init_info_t *info)
 
 static struct vmproc *init_proc(endpoint_t ep_nr)
 {
-	static struct boot_image *ip;
+	struct boot_image *ip;
 
 	for (ip = &kernel_boot_info.boot_procs[0];
 		ip < &kernel_boot_info.boot_procs[NR_BOOT_PROCS]; ip++) {
@@ -429,7 +429,7 @@ void init_vm(void)
 {
 	int s, i;
 	static struct memory mem_chunks[NR_MEMS];
-	static struct boot_image *ip;
+	struct boot_image *ip;
 	extern void __minix_init(void);
 	multiboot_module_t *mod;
 	vir_bytes kern_dyn, kern_static;
diff --git a/sys/lib/libsa/subr_prf.c b/sys/lib/libsa/subr_prf.c
index d6fc0defc..b43b61146 100644
--- a/sys/lib/libsa/subr_prf.c
+++ b/sys/lib/libsa/subr_prf.c
@@ -174,6 +174,9 @@ vsnprintf(char *buf, size_t size, const char *fmt, va_list ap)
 	if (sbuf){ /* handle case where sbuf == NULL */
 		*sbuf = '\0';
 	}
+#if defined(_MINIX_MAGIC)
+	sbuf = ebuf = NULL; /* leave no dangling pointers */
+#endif
 	return scount;
 #else /* __minix is not defined */
 	*sbuf = '\0';