[Valgrind-developers] valgrind

[Jeremy F. <je...@go...>]

CVS commit by fitzhardinge: 

Only set the thread's status to WaitSys if we're actually waiting for
a proxyLWP to complete a syscall.

Update sigaltstack test to use mmap to allocate the stack.


  M +7 -5      coregrind/vg_syscalls.c   1.54
  M +5 -3      memcheck/tests/sigaltstack.c   1.3


--- valgrind/coregrind/vg_syscalls.c  #1.53:1.54
@@ -4392,8 +4392,6 @@ Bool VG_(pre_syscall) ( ThreadId tid )
    */
 
-   /* post_syscall expects us to be "waiting" even if we don't
-      block */
    tst->syscallno = syscallno;
-   tst->status = VgTs_WaitSys;
+   vg_assert(tst->status == VgTs_Runnable);
 
    if (syscallno < MAX_SPECIAL_SYS && special_sys[syscallno].before != NULL) {
@@ -4455,4 +4453,9 @@ Bool VG_(pre_syscall) ( ThreadId tid )
    VGP_POPCC(VgpCoreSysWrap);
 
+   /* If we're waiting on the syscall because it's in the hands of the
+      ProxyLWP, then set the thread state to WaitSys. */
+   if (!syscall_done)
+      tst->status = VgTs_WaitSys;
+
    return syscall_done;
 }
@@ -4478,5 +4481,4 @@ void VG_(post_syscall) ( ThreadId tid )
 
    vg_assert(syscallno != -1);                  /* must be a current syscall */
-   vg_assert(tst->status == VgTs_WaitSys);      /* should be blocked waiting */
 
    if (syscallno < MAX_SPECIAL_SYS && special_sys[syscallno].before != NULL) {

--- valgrind/memcheck/tests/sigaltstack.c  #1.2:1.3
@@ -4,4 +4,5 @@
 #include <malloc.h>
 #include <signal.h>
+#include <sys/mman.h>
 
 void sig_handler(int sig){
@@ -15,7 +15,9 @@ int main(int argv, char** argc) {
   stack_t sigstk;
   struct sigaction act;
-  sigstk.ss_sp = (char *)malloc(SIGSTKSZ);
+  static const int size = SIGSTKSZ;
+  char *stk = (char *)mmap(0, size, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+  sigstk.ss_sp = stk;
 
-  sigstk.ss_size = SIGSTKSZ;
+  sigstk.ss_size = size;
   sigstk.ss_flags = 0;
   fprintf(stderr, "calling sigaltstack, stack base is %p\n", sigstk.ss_sp);