| Message ID | 20190527043336.112854-2-hsinyi@chromium.org |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | None | expand |
| Context | Check | Description |
|---|---|---|
| robh/checkpatch | warning | "total: 0 errors, 1 warnings, 48 lines checked" |
Quoting Hsin-Yi Wang (2019-05-26 21:33:35) > Introducing a chosen node, rng-seed, which is an entropy that can be > passed to kernel called very early to increase initial device > randomness. Bootloader should provide this entropy and the value is > read from /chosen/rng-seed in DT. > > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> > --- Reviewed-by: Stephen Boyd <swboyd@chromium.org>
On Tue, May 28, 2019 at 11:53 PM Stephen Boyd <swboyd@chromium.org> wrote: > > Quoting Hsin-Yi Wang (2019-05-26 21:33:35) > > Introducing a chosen node, rng-seed, which is an entropy that can be > > passed to kernel called very early to increase initial device > > randomness. Bootloader should provide this entropy and the value is > > read from /chosen/rng-seed in DT. > > > > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> > > --- > > Reviewed-by: Stephen Boyd <swboyd@chromium.org> > Hi Rob, Is this series accepted? Or is there any other related concern? If it's fine, I also have sent a patch for updating schemas/chosen.yaml document. Thanks
On Mon, Jun 10, 2019 at 06:59:11PM +0800, Hsin-Yi Wang wrote: > On Tue, May 28, 2019 at 11:53 PM Stephen Boyd <swboyd@chromium.org> wrote: > > > > Quoting Hsin-Yi Wang (2019-05-26 21:33:35) > > > Introducing a chosen node, rng-seed, which is an entropy that can be > > > passed to kernel called very early to increase initial device > > > randomness. Bootloader should provide this entropy and the value is > > > read from /chosen/rng-seed in DT. > > > > > > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> > > > --- > > > > Reviewed-by: Stephen Boyd <swboyd@chromium.org> > > > > Hi Rob, > > Is this series accepted? Or is there any other related concern? > > If it's fine, I also have sent a patch for updating > schemas/chosen.yaml document. The kernel change is fine, but please put the documentation change into the schema doc (in github.com/devicetree-org/dt-schema) and don't modify chosen.txt. Rob
diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt index 45e79172a646..678e81bc4383 100644 --- a/Documentation/devicetree/bindings/chosen.txt +++ b/Documentation/devicetree/bindings/chosen.txt @@ -28,6 +28,20 @@ mode) when EFI_RNG_PROTOCOL is supported, it will be overwritten by the Linux EFI stub (which will populate the property itself, using EFI_RNG_PROTOCOL). +rng-seed +----------- + +This property serves as an entropy to add device randomness. It is parsed +as a byte array, e.g. + +/ { + chosen { + rng-seed = <0x31 0x95 0x1b 0x3c 0xc9 0xfa 0xb3 ...>; + }; +}; + +This random value should be provided by bootloader. + stdout-path ----------- diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index de893c9616a1..9d63330582bb 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -24,6 +24,7 @@ #include <linux/debugfs.h> #include <linux/serial_core.h> #include <linux/sysfs.h> +#include <linux/random.h> #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ #include <asm/page.h> @@ -1079,6 +1080,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, { int l; const char *p; + const void *rng_seed; pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); @@ -1113,6 +1115,14 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, pr_debug("Command line is: %s\n", (char*)data); + rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); + if (rng_seed && l > 0) { + add_device_randomness(rng_seed, l); + + /* try to clear seed so it won't be found. */ + fdt_nop_property(initial_boot_params, node, "rng-seed"); + } + /* break now */ return 1; }
Introducing a chosen node, rng-seed, which is an entropy that can be passed to kernel called very early to increase initial device randomness. Bootloader should provide this entropy and the value is read from /chosen/rng-seed in DT. Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> --- change log v4->v5: * use fdt_nop_property() since property might not be wiped entirely if following entries are smaller than property length. --- Documentation/devicetree/bindings/chosen.txt | 14 ++++++++++++++ drivers/of/fdt.c | 10 ++++++++++ 2 files changed, 24 insertions(+)