rcutorture: Fix kvm-again.sh re-run failure on ppc64

Discovered in the Open Source Lab of Oregon State University when running
torture.sh on a ppc64le VM.  Two bugs were exposed:

1. The kvm-transform.sh call hard-coded "bzImage" as the kernel image
   name.  On ppc64, the boot image is vmlinux, not bzImage, so the
   re-run failed to find the image.  Fix this by extracting the QEMU
   binary from the qemu-cmd file and passing it to identify_boot_image()
   to obtain the correct architecture-specific image name, the same way
   kvm.sh already does.

2. The rm -f invocation on re-run listed vmlinux among the files to
   delete.  On ppc64 vmlinux is the boot image, so deleting it broke
   the re-run on that architecture.  Drop vmlinux from the unconditional
   list, and instead conditionally delete it only when the boot image
   basename is not vmlinux.

In addition, identify qemu_binary before the copy step so that on
non-PowerPC systems (where vmlinux is not the boot image) the vmlinux
file can be removed immediately after the run directory is copied,
saving storage before any tests run.  This also eliminates the
per-iteration re-computation of qemu_binary and boot_image inside
the qemu-cmd transform loop.

Tested on a local x86_64 machine and on a PPC VM of the Open Source Lab
of Oregon State University.

Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

0 files changed, 0 insertions, 0 deletions