[Valgrind-developers] valgrind

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

CVS commit by fitzhardinge: 

Partial fix for bug 76869.  This fixes the problem with returning from
a signal handler when VDSOs are turned off in FC2.  Note that we don't
(yet) support VDSOs being on (use "echo 0 > /proc/sys/kernel/vdso").


  M +1 -0      coregrind/vg_include.h   1.191
  M +5 -1      coregrind/vg_signals.c   1.68
  M +5 -0      coregrind/vg_syscall.S   1.12
  M +1 -1      include/vg_kerneliface.h   1.17


--- valgrind/coregrind/vg_include.h  #1.190:1.191
@@ -1668,4 +1668,5 @@ extern Int VG_(do_syscall) ( UInt, ... )
 extern Int VG_(clone) ( Int (*fn)(void *), void *stack, Int flags, void *arg, 
                         Int *child_tid, Int *parent_tid);
+extern void VG_(sigreturn)(void);
 
 /* ---------------------------------------------------------------------

--- valgrind/coregrind/vg_syscall.S  #1.11:1.12
@@ -113,4 +113,9 @@
         pop     %ebx
         ret
+
+.globl VG_(sigreturn)
+VG_(sigreturn):
+        movl    $__NR_rt_sigreturn, %eax
+        int     $0x80
         
 ##--------------------------------------------------------------------##

--- valgrind/coregrind/vg_signals.c  #1.67:1.68
@@ -354,4 +354,7 @@ void calculate_SKSS_from_SCSS ( SKSS* ds
       skss_flags |= VKI_SA_SIGINFO;
 
+      /* use our own restorer */
+      skss_flags |= VKI_SA_RESTORER;
+
       /* Create SKSS entry for this signal. */
 
@@ -411,9 +414,10 @@ void VG_(handle_SCSS_change) ( Bool forc
       ksa.ksa_handler = vg_skss.skss_per_sig[sig].skss_handler;
       ksa.ksa_flags   = vg_skss.skss_per_sig[sig].skss_flags;
+      ksa.ksa_restorer = VG_(sigreturn);
+
       vg_assert(ksa.ksa_flags & VKI_SA_ONSTACK);
       VG_(ksigfillset)( &ksa.ksa_mask );
       VG_(ksigdelset)( &ksa.ksa_mask, VKI_SIGKILL );
       VG_(ksigdelset)( &ksa.ksa_mask, VKI_SIGSTOP );
-      ksa.ksa_restorer = NULL;
 
       if (VG_(clo_trace_signals)) 

--- valgrind/include/vg_kerneliface.h  #1.16:1.17
@@ -250,7 +250,7 @@ struct vki_ucontext {
 #define VKI_SA_NOMASK       VKI_SA_NODEFER
 #define VKI_SA_NOCLDWAIT    0x00000002
+#define VKI_SA_RESTORER     0x04000000
 #if 0
 #define VKI_SA_INTERRUPT    0x20000000 /* dummy -- ignored */
-#define VKI_SA_RESTORER     0x04000000
 #endif