[v2] rerandomize RNG seeds on reboot and handle record&replay

[PATCH v2 3/8] riscv: re-randomize rng-seed on reboot

Jason A. Donenfeld posted 8 patches 3 years, 4 months ago

Diff against v3 v4
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Maintainers: "Cédric Le Goater" <clg@kaod.org>, Peter Maydell <peter.maydell@linaro.org>, Andrew Jeffery <andrew@aj.id.au>, Joel Stanley <joel@jms.id.au>, Richard Henderson <richard.henderson@linaro.org>, Helge Deller <deller@gmx.de>, Sergio Lopez <slp@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Eduardo Habkost <eduardo@habkost.net>, Paul Burton <paulburton@kernel.org>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, Stafford Horne <shorne@gmail.com>, BALATON Zoltan <balaton@eik.bme.hu>, Daniel Henrique Barboza <danielhb413@gmail.com>, David Gibson <david@gibson.dropbear.id.au>, Greg Kurz <groug@kaod.org>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, David Hildenbrand <david@redhat.com>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Eric Farman <farman@linux.ibm.com>, Cornelia Huck <cohuck@redhat.com>, Thomas Huth <thuth@redhat.com>, Yanan Wang <wangyanan55@huawei.com>, Juan Quintela <quintela@redhat.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>

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[PATCH v2 3/8] riscv: re-randomize rng-seed on reboot

Posted by Jason A. Donenfeld 3 years, 4 months ago

When the system reboots, the rng-seed that the FDT has should be
re-randomized, so that the new boot gets a new seed. Since the FDT is in
the ROM region at this point, we add a hook right after the ROM has been
added, so that we have a pointer to that copy of the FDT.

Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Alistair Francis <alistair.francis@wdc.com>
Cc: Bin Meng <bin.meng@windriver.com>
Cc: qemu-riscv@nongnu.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 hw/riscv/boot.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
index 1ae7596873..aaecf21543 100644
--- a/hw/riscv/boot.c
+++ b/hw/riscv/boot.c
@@ -30,6 +30,7 @@
 #include "sysemu/device_tree.h"
 #include "sysemu/qtest.h"
 #include "sysemu/kvm.h"
+#include "sysemu/reset.h"
 
 #include <libfdt.h>
 
@@ -241,6 +242,8 @@ uint64_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
 
     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
                           &address_space_memory);
+    qemu_register_reset(qemu_fdt_randomize_seeds,
+                        rom_ptr_for_as(&address_space_memory, fdt_addr, fdtsize));
 
     return fdt_addr;
 }
-- 
2.37.3

Re: [PATCH v2 3/8] riscv: re-randomize rng-seed on reboot

Posted by Alistair Francis 3 years, 4 months ago

On Wed, Oct 12, 2022 at 6:55 AM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
>
> When the system reboots, the rng-seed that the FDT has should be
> re-randomized, so that the new boot gets a new seed. Since the FDT is in
> the ROM region at this point, we add a hook right after the ROM has been
> added, so that we have a pointer to that copy of the FDT.
>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>
> Cc: Alistair Francis <alistair.francis@wdc.com>
> Cc: Bin Meng <bin.meng@windriver.com>
> Cc: qemu-riscv@nongnu.org
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  hw/riscv/boot.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
> index 1ae7596873..aaecf21543 100644
> --- a/hw/riscv/boot.c
> +++ b/hw/riscv/boot.c
> @@ -30,6 +30,7 @@
>  #include "sysemu/device_tree.h"
>  #include "sysemu/qtest.h"
>  #include "sysemu/kvm.h"
> +#include "sysemu/reset.h"
>
>  #include <libfdt.h>
>
> @@ -241,6 +242,8 @@ uint64_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
>
>      rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
>                            &address_space_memory);
> +    qemu_register_reset(qemu_fdt_randomize_seeds,
> +                        rom_ptr_for_as(&address_space_memory, fdt_addr, fdtsize));
>
>      return fdt_addr;
>  }
> --
> 2.37.3
>
>