On Wed, May 22, 2024 at 12:47 AM Michal Simek <michal.si...@amd.com> wrote: > > > > On 5/21/24 22:59, Tim Harvey wrote: > > If RANDOMIZE_BASE is enabled in the Linux kernel instructing it to > > randomize the virtual address at which the kernel image is loaded, it > > expects entropy to be provided by the bootloader by populating > > /chosen/kaslr-seed with a 64-bit value from source of entropy at boot. > > > > If we have DM_RNG enabled populate this value automatically when > > fdt_chosen is called. We skip this if ARMV8_SEC_FIRMWARE_SUPPORT > > is enabled as it's implementation uses a different source of entropy > > that is not yet implemented as DM_RNG. We also skip this if > > MEASURED_BOOT is enabled as in that case any modifications to the > > dt will cause measured boot to fail (although there are many other > > places the dt is altered). > > > > As this fdt node is added elsewhere create a library function and > > use it to deduplicate code. We will provide a parameter to specify the > > index of the rng device as well as a boolean to overwrite if present. > > > > For our automatic injection, we will use the first rng device and > > not overwrite if already present with a non-zero value (which may > > have been populated by an earlier boot stage). This way if a board > > specific ft_board_setup() function wants to customize this behavior > > it can call fdt_kaslrseed with a rng device index of its choosing and > > set overwrite true. > > > > Note that the kalsrseed command (CMD_KASLRSEED) is likely pointless now > > but left in place in case boot scripts exist that rely on this command > > existing and returning success. An informational message is printed to > > alert users of this command that it is likely no longer needed. > > > > Note that the Kernel's EFI STUB only relies on EFI_RNG_PROTOCOL for > > randomization and completely ignores the kaslr-seed for its own > > randomness needs (i.e the randomization of the physical placement of > > the kernel). It gets weeded out from the DTB that gets handed over via > > efi_install_fdt() as it would also mess up the measured boot DTB TPM > > measurements as well. > > > > Signed-off-by: Tim Harvey <thar...@gateworks.com> > > Cc: Michal Simek <michal.si...@amd.com> > > Cc: Andy Yan <andy....@rock-chips.com> > > Cc: Akash Gajjar <gajjar04ak...@gmail.com> > > Cc: Ilias Apalodimas <ilias.apalodi...@linaro.org> > > Cc: Simon Glass <s...@chromium.org> > > Cc: Patrick Delaunay <patrick.delau...@foss.st.com> > > Cc: Patrice Chotard <patrice.chot...@foss.st.com> > > Cc: Devarsh Thakkar <devar...@ti.com> > > Cc: Heinrich Schuchardt <xypron.g...@gmx.de> > > Cc: Hugo Villeneuve <hvillene...@dimonoff.com> > > Cc: Marek Vasut <ma...@denx.de> > > Cc: Tom Rini <tr...@konsulko.com> > > Cc: Chris Morgan <macromor...@hotmail.com> > > --- > > v3: > > - skip if CONFIG_MEASURED_BOOT > > - fix skip for CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT > > - pass in rng index and bool to specify overwrite > > - remove duplicate error strings printed outside of fdt_kaslrseed > > - added note to commit log about how EFI STUB weeds out kalsr-seed > > > > v2: > > - fix typo in commit msg > > - use stack for seed to avoid unecessary malloc/free > > - move to a library function and deduplicate code by using it > > elsewhere > > --- > > board/xilinx/common/board.c | 35 ------------------------- > > boot/fdt_support.c | 6 +++++ > > boot/pxe_utils.c | 35 ++----------------------- > > cmd/kaslrseed.c | 45 +++++--------------------------- > > include/kaslrseed.h | 19 ++++++++++++++ > > lib/Makefile | 1 + > > lib/kaslrseed.c | 51 +++++++++++++++++++++++++++++++++++++ > > 7 files changed, 85 insertions(+), 107 deletions(-) > > create mode 100644 include/kaslrseed.h > > create mode 100644 lib/kaslrseed.c > > > > diff --git a/board/xilinx/common/board.c b/board/xilinx/common/board.c > > index 30a81376ac41..f741e8957818 100644 > > --- a/board/xilinx/common/board.c > > +++ b/board/xilinx/common/board.c > > @@ -713,41 +713,6 @@ int ft_board_setup(void *blob, struct bd_info *bd) > > if (IS_ENABLED(CONFIG_FDT_FIXUP_PARTITIONS) && > > IS_ENABLED(CONFIG_NAND_ZYNQ)) > > fdt_fixup_mtdparts(blob, nodes, ARRAY_SIZE(nodes)); > > > > one more thing here. Please also removed unused variables. > > board/xilinx/common/board.c: In function 'ft_board_setup': > board/xilinx/common/board.c:707:25: warning: unused variable 'ret' > [-Wunused-variable] > 707 | int nodeoffset, ret; > | ^~~ > board/xilinx/common/board.c:707:13: warning: unused variable 'nodeoffset' > [-Wunused-variable] > 707 | int nodeoffset, ret; > | ^~~~~~~~~~ > AS arch/arm/cpu/armv8/cache.o > board/xilinx/common/board.c:706:12: warning: unused variable 'buf' > [-Wunused-variable] > 706 | u8 buf[MAX_RAND_SIZE]; > | ^~~ > board/xilinx/common/board.c:705:25: warning: unused variable 'dev' > [-Wunused-variable] > 705 | struct udevice *dev; > | ^~~ > board/xilinx/common/board.c:704:16: warning: unused variable 'n' > [-Wunused-variable] > 704 | size_t n = MAX_RAND_SIZE; > | ^ >
Hi Michal, Thanks... missed those. What defconfig are you building that gets to this codepath? I'll send a v4 after another day or so for others to respond. With these changes (and the previous response) do you have a rb or tested-by tag for me? Best Regards, Tim
