Package: qemu Version: 0.7.0-2 Tags: patch upstream On PowerPC, the do_fork function zeroes out r7-r31 in the new CPU state structure after a clone, which it should not do, as the child's registers should match the parent; it also does not zero register r3, which holds the return value and should be zero in the child. As a result, programs which call clone() with the CLONE_VM flag set, or threaded programs using clone()-based threads, will segfault in the child process after the clone(). I've prepared and attached a patch which fixes this problem; I have already reported this problem to the upstream qemu-devel list and supplied the patch on that list. Credit goes to pbrook on OFTC #qemu for some extremely helpful debugging assistance and insight when tracking down the problem.
- Josh Triplett
diff -Naur qemu-0.7.0.orig/linux-user/syscall.c qemu-0.7.0/linux-user/syscall.c
--- qemu-0.7.0.orig/linux-user/syscall.c 2005-10-21 19:56:04.000000000 -0700
+++ qemu-0.7.0/linux-user/syscall.c 2005-10-21 20:02:20.000000000 -0700
@@ -1560,11 +1560,7 @@
if (!newsp)
newsp = env->gpr[1];
new_env->gpr[1] = newsp;
- {
- int i;
- for (i = 7; i < 32; i++)
- new_env->gpr[i] = 0;
- }
+ new_env->gpr[3] = 0;
#else
#error unsupported target CPU
#endif
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