Messages in this thread |  | | From | hev <> | | Date | Mon, 27 Apr 2026 15:49:21 +0800 | | Subject | Re: [RFC PATCH 2/3] efi/loongarch: Randomize kernel preferred address for KASLR |
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Hi Lisa,
On Mon, Apr 27, 2026 at 1:08 PM Lisa Robinson <lisa@bytefly.space> wrote: > > Hi Rui > > > diff --git a/drivers/firmware/efi/libstub/loongarch.c b/drivers/firmware/efi/libstub/loongarch.c > > index 9825f5218137..80ba7d69e1b3 100644 > > --- a/drivers/firmware/efi/libstub/loongarch.c > > +++ b/drivers/firmware/efi/libstub/loongarch.c > > @@ -38,6 +38,21 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv) > > return EFI_SUCCESS; > > } > > > > +unsigned long efi_get_kimg_kaslr_address(void) > > +{ > > + unsigned int random_offset = 0; > > + > > +#ifdef CONFIG_RANDOMIZE_BASE > > + if (!efi_nokaslr) { > > + efi_get_random_bytes(sizeof(random_offset), (u8 *)&random_offset); > > + random_offset ^= (rdtime_l() << 16); > > random_offset &= ~(efi_get_kimg_min_align() - 1);
Thanks for pointing that out.
Aligning to 64K here seems preferable. Otherwise, it reduces the entropy.
Thanks, Rui
> > > + random_offset &= (CONFIG_RANDOMIZE_BASE_MAX_OFFSET - 1); > > + } > > +#endif > > + > > + return PHYSADDR(VMLINUX_LOAD_ADDRESS) + random_offset; > > +} > > + > > unsigned long __weak kernel_entry_address(unsigned long kernel_addr, > > efi_loaded_image_t *image) > > { > > -- > Lisa
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