fix TLS again;

still not quite but a lot better.

fix TLS again;
f8ab2079 · Russ Cox · 57ae1463 · f8ab2079 · f8ab2079
--- a/proc.c
+++ b/proc.c
@@ -70,12 +70,13 @@ ksegment(void)
  c = &cpus[cpunum()];
  c->gdt[SEG_KCODE] = SEG(STA_X|STA_R, 0, 0x100000 + 64*1024-1, 0);
  c->gdt[SEG_KDATA] = SEG(STA_W, 0, 0xffffffff, 0);
-  c->gdt[SEG_KCPU] = SEG(STA_W, (uint)(&c->tls+1), 0xffffffff, 0);
+  c->gdt[SEG_KCPU] = SEG(STA_W, &c->tlsstruct, 0xffffffff, 0);
  lgdt(c->gdt, sizeof(c->gdt));
  loadfsgs(SEG_KCPU << 3);
  
-  // Initialize cpu-local variables.
+  // Initialize cpu-local storage.
  c->tlsstruct = &c->tlsstruct;
+  asm volatile("");  // Do not let gcc reorder across this line.
  cpu = c;
  proc = 0;
 }

--- a/proc.h
+++ b/proc.h
@@ -58,7 +58,10 @@ struct cpu {
  volatile uint booted;        // Has the CPU started?
  int ncli;                    // Depth of pushcli nesting.
  int intena;                  // Were interrupts enabled before pushcli?
-  void *tls[2];
+  
+  // "Thread"-local storage variables
+  struct cpu *cpu;
+  struct proc *proc;
  void *tlsstruct;
 };