Hi Dave,
Here comes a fix for the bt -f command.
The problem is that when the backchain is invalid on s390(x) we can get huge values for the stackframe size. This can lead to a termination of crash with a SIGSEGV. To fix this, we have to use in case of an invalid backchain the difference between the current backchain and the end of the stack as stackframe size.
---
diff -Naur crash-4.0-2.31/s390.c crash-4.0-2.31-s390-bt-f.fix/s390.c
--- crash-4.0-2.31/s390.c 2006-06-27 16:15:32.000000000 +0200
+++ crash-4.0-2.31-s390-bt-f.fix/s390.c 2006-07-03 16:37:34.000000000 +0200
@@ -714,7 +714,9 @@
frame_size = stack_base - old_backchain
+ KERNEL_STACK_SIZE;
} else {
- frame_size = backchain - old_backchain;
+ frame_size = MIN((backchain - old_backchain),
+ (stack_base - old_backchain +
+ KERNEL_STACK_SIZE));
}
for(j=0; j< frame_size; j+=4){
if(j % 16 == 0){
diff -Naur crash-4.0-2.31/s390x.c crash-4.0-2.31-s390-bt-f.fix/s390x.c
--- crash-4.0-2.31/s390x.c 2006-06-27 16:15:32.000000000 +0200
+++ crash-4.0-2.31-s390-bt-f.fix/s390x.c 2006-07-03 16:37:37.000000000 +0200
@@ -747,7 +747,9 @@
frame_size = stack_base - old_backchain
+ KERNEL_STACK_SIZE;
} else {
- frame_size = backchain - old_backchain;
+ frame_size = MIN((backchain - old_backchain),
+ (stack_base - old_backchain +
+ KERNEL_STACK_SIZE));
}
for(j=0; j< frame_size; j+=4){
if(j % 16 == 0){
