asharing: Annotate sharing in sys_map, sys_unmap, pagefault, and sys_openat

a64fdf99 · Austin Clements · 9275cbb6 · a64fdf99 · a64fdf99 · a64fdf99
--- a/kernel/fs.cc
+++ b/kernel/fs.cc
@@ -22,6 +22,7 @@
 #include "buf.hh"
 #include "file.hh"
 #include "cpu.hh"
+#include "kmtrace.hh"

 #define min(a, b) ((a) < (b) ? (a) : (b))
 static void itrunc(struct inode*);
@@ -757,6 +758,16 @@ namex(inode *cwd, const char *path, int nameiparent, char *name)
    ip = idup(cwd);

  while((r = skipelem(&path, name)) == 1){
+    // XXX Doing this here requires some annoying reasoning about all
+    // of the callers of namei/nameiparent.  Also, since the abstract
+    // scope is implicit, it might be wrong (or non-existent) and
+    // documenting the abstract object sets of each scope becomes
+    // difficult and probably unmaintainable.  We have to compute this
+    // information here because it's the only place that's canonical.
+    // Maybe this should return the set of inodes traversed and let
+    // the caller declare the variables?  Would it help for the caller
+    // to pass in an abstract scope?
+    mtreadavar("inode:%x.%x", ip->dev, ip->inum);
    next = 0;
    if(next == 0){
      if(ip->type == 0)
@@ -785,6 +796,7 @@ namex(inode *cwd, const char *path, int nameiparent, char *name)
    gc_end_epoch();
    return 0;
  }
+  mtreadavar("inode:%x.%x", ip->dev, ip->inum);
  gc_end_epoch();
  return ip;
 }

--- a/kernel/sysfile.cc
+++ b/kernel/sysfile.cc
@@ -11,6 +11,7 @@
 #include "fcntl.h"
 #include "cpu.hh"
 #include "net.hh"
+#include "kmtrace.hh"

 static bool
 getfile(int fd, sref<file> *f)
@@ -280,6 +281,12 @@ sys_openat(int dirfd, const char *path, int omode)

  if(argcheckstr(path) < 0)
    return -1;
+
+  // Reads the dirfd FD, dirfd's inode, the inodes of all files in
+  // path; writes the returned FD
+  mt_ascope ascope("%s(%d,%s,%d)", __func__, dirfd, path, omode);
+  mtreadavar("inode:%x.%x", cwd->dev, cwd->inum);
+
  if(omode & O_CREATE){
    if((ip = create(cwd, path, T_FILE, 0, 0)) == 0)
      return -1;
@@ -309,6 +316,7 @@ sys_openat(int dirfd, const char *path, int omode)
    return -1;
  }
  iunlock(ip);
+  mtwriteavar("fd:%x.%x", myproc()->pid, fd);

  f->type = file::FD_INODE;
  f->ip = ip;

--- a/kernel/sysproc.cc
+++ b/kernel/sysproc.cc
@@ -9,6 +9,7 @@
 #include "cpu.hh"
 #include "vm.hh"
 #include "sperf.hh"
+#include "kmtrace.hh"

 long
 sys_fork(int flags)
@@ -87,6 +88,12 @@ sys_map(uptr addr, u64 len)
 {
  ANON_REGION(__func__, &perfgroup);

+#if MTRACE
+  mt_ascope ascope("%s(%p,%lx)", __func__, addr, len);
+  for (uptr i = PGROUNDDOWN(addr); i < PGROUNDUP(addr + len); i += PGSIZE)
+    mtwriteavar("page:%016x", i);
+#endif
+
  vmnode *vmn = new vmnode(PGROUNDUP(len) / PGSIZE);
  if (vmn == 0)
    return -1;
@@ -104,6 +111,12 @@ sys_unmap(uptr addr, u64 len)
 {
  ANON_REGION(__func__, &perfgroup);

+#if MTRACE
+  mt_ascope ascope("%s(%p,%lx)", __func__, addr, len);
+  for (uptr i = PGROUNDDOWN(addr); i < PGROUNDUP(addr + len); i += PGSIZE)
+    mtwriteavar("page:%016x", i);
+#endif
+
  uptr align_addr = PGROUNDDOWN(addr);
  uptr align_len = PGROUNDUP(addr + len) - align_addr;
  if (myproc()->vmap->remove(align_addr, align_len) < 0)

--- a/kernel/vm.cc
+++ b/kernel/vm.cc
@@ -14,6 +14,7 @@
 #include "crange.hh"
 #include "cpputil.hh"
 #include "sperf.hh"
+#include "kmtrace.hh"

 enum { vm_debug = 0 };

@@ -555,6 +556,11 @@ vmap::pagefault(uptr va, u32 err)
 int
 pagefault(struct vmap *vmap, uptr va, u32 err)
 {
+#if MTRACE
+  mt_ascope ascope("%s(%p)", __func__, va);
+  mtwriteavar("page:%016x", PGROUNDDOWN(va));
+#endif
+
  return vmap->pagefault(va, err);
 }