Messages in this thread | | | From | Sami Tolvanen <> | Date | Wed, 30 Aug 2023 14:30:31 -0700 | Subject | Re: [PATCH v6 0/5] riscv: Introduce KASLR |
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Hi Alexandre,
On Sat, Jul 22, 2023 at 5:39 AM Alexandre Ghiti <alexghiti@rivosinc.com> wrote: > > The following KASLR implementation allows to randomize the kernel mapping: > > - virtually: we expect the bootloader to provide a seed in the device-tree > - physically: only implemented in the EFI stub, it relies on the firmware to > provide a seed using EFI_RNG_PROTOCOL. arm64 has a similar implementation > hence the patch 3 factorizes KASLR related functions for riscv to take > advantage. > > The new virtual kernel location is limited by the early page table that only > has one PUD and with the PMD alignment constraint, the kernel can only take > < 512 positions. > > base-commit-tag: v6.5-rc1
Thanks for continuing to work on this!
I reviewed the patches and the code looks correct to me. I also applied the series on top of v6.5 and after patching qemu to provide a kaslr-seed, I confirmed that the virtual offset appears to be random and is printed out when I panic the machine:
# echo PANIC > /sys/kernel/debug/provoke-crash/DIRECT [ 17.510012] lkdtm: Performing direct entry PANIC [ 17.510411] Kernel panic - not syncing: dumptest [...] [ 17.518693] Kernel Offset: 0x32c00000 from 0xffffffff80000000
For the series: Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
I didn't test the EFI bits, but the rest of the series: Tested-by: Sami Tolvanen <samitolvanen@google.com>
Conor, in another reply you mentioned you're planning on reviewing the patches as well. Did you have any feedback or concerns?
Sami
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