Associate brk with vmap (instead of proc)

9298a90d · Silas Boyd-Wickizer · 297c42cd · 9298a90d · 9298a90d · 9298a90d
--- a/include/proc.hh
+++ b/include/proc.hh
@@ -43,7 +43,6 @@ enum procstate { EMBRYO, SLEEPING, RUNNABLE, RUNNING, ZOMBIE };
 // Per-process state
 struct proc : public rcu_freed {
  struct vmap *vmap;           // va -> vma
-  uptr brk;                    // Top of heap
  char *kstack;                // Bottom of kernel stack for this process
  volatile int pid;            // Process ID
  struct proc *parent;         // Parent process

--- a/include/vm.hh
+++ b/include/vm.hh
@@ -88,6 +88,8 @@ struct vmap {
  int copyout(uptr va, void *p, u64 len);
  NEW_DELETE_OPS(vmap)

+  uptr brk_;                    // Top of heap
+
 private:
  int pagefault_wcow(vma *m);
 };
--- a/kernel/exec.cc
+++ b/kernel/exec.cc
@@ -136,6 +136,7 @@ doheap(struct eargs *args)
    goto bad;
  if(args->vmap->insert(vmn, BRK, 1) < 0)
    goto bad;
+  args->vmap->brk_ = BRK + 8;  // XXX so that brk-1 points within heap vma..

  return;

@@ -202,7 +203,6 @@ exec(const char *path, char **argv)
  // Commit to the user image.
  oldvmap = myproc()->vmap;
  myproc()->vmap = vmp;
-  myproc()->brk = BRK + 8;  // XXX so that brk-1 points within heap vma..
  myproc()->tf->rip = elf.entry;  // main
  
  switchvm(myproc());

--- a/kernel/proc.cc
+++ b/kernel/proc.cc
@@ -36,7 +36,7 @@ struct kstack_tag kstack_tag[NCPU];
 enum { sched_debug = 0 };

 proc::proc(int npid) :
-  rcu_freed("proc"), vmap(0), brk(0), kstack(0),
+  rcu_freed("proc"), vmap(0), kstack(0),
  pid(npid), parent(0), tf(0), context(0), killed(0),
  ftable(0), cwd(0), tsc(0), curcycles(0), cpuid(0), epoch(0),
  on_runq(-1), cpu_pin(0), runq(0), oncv(0), cv_wakeup(0),
@@ -285,10 +285,10 @@ int
 growproc(int n)
 {
  struct vmap *m = myproc()->vmap;
-  auto curbrk = myproc()->brk;
+  auto curbrk = m->brk_;

  if(n < 0 && 0 - n <= curbrk){
-    myproc()->brk += n;
+    m->brk_ += n;
    return 0;
  }

@@ -312,7 +312,7 @@ growproc(int n)

    if (e->vma_start <= newstart) {
      if (e->vma_end >= newstart + newn) {
-        myproc()->brk += n;
+        m->brk_ += n;
        return 0;
      }

@@ -349,7 +349,7 @@ growproc(int n)
  span.replace(newstart, newn, repl);
 #endif

-  myproc()->brk += n;
+  m->brk_ += n;
  return 0;
 }

@@ -453,7 +453,6 @@ fork(int flags)
    np->vmap->ref++;
  }

-  np->brk = myproc()->brk;
  np->parent = myproc();
  *np->tf = *myproc()->tf;


--- a/kernel/sysproc.cc
+++ b/kernel/sysproc.cc
@@ -46,7 +46,7 @@ sys_sbrk(int n)
 {
  uptr addr;

-  addr = myproc()->brk;
+  addr = myproc()->vmap->brk_;
  if(growproc(n) < 0)
    return -1;
  return addr;

--- a/kernel/vm.cc
+++ b/kernel/vm.cc
@@ -145,7 +145,8 @@ vmap::vmap() :
 #if VM_RADIX
    rx(PGSHIFT),
 #endif
-    ref(1), pml4(setupkvm()), kshared((char*) ksalloc(slab_kshared))
+    ref(1), pml4(setupkvm()), kshared((char*) ksalloc(slab_kshared)),
+    brk_(0)
 {
  if (pml4 == 0) {
    cprintf("vmap_alloc: setupkvm out of memory\n");
@@ -289,6 +290,8 @@ vmap::copy(int share)
  if (share)
    tlbflush();  // Reload hardware page table

+  nm->brk_ = brk_;
+
  return nm;

 err: