Module Name: src
Committed By: riastradh
Date: Thu May 14 19:21:06 UTC 2020
Modified Files:
src/sys/arch/evbarm/fdt: fdt_machdep.c
Log Message:
Teach arm fdt kernel to use /chosen/netbsd,efirng data.
Feed it in as a separate random source, with zero entropy since this
is a best-effort fallback for devices we really don't know anything
about.
To generate a diff of this commit:
cvs rdiff -u -r1.68 -r1.69 src/sys/arch/evbarm/fdt/fdt_machdep.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/evbarm/fdt/fdt_machdep.c
diff -u src/sys/arch/evbarm/fdt/fdt_machdep.c:1.68 src/sys/arch/evbarm/fdt/fdt_machdep.c:1.69
--- src/sys/arch/evbarm/fdt/fdt_machdep.c:1.68 Sun Mar 8 08:26:54 2020
+++ src/sys/arch/evbarm/fdt/fdt_machdep.c Thu May 14 19:21:06 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: fdt_machdep.c,v 1.68 2020/03/08 08:26:54 skrll Exp $ */
+/* $NetBSD: fdt_machdep.c,v 1.69 2020/05/14 19:21:06 riastradh Exp $ */
/*-
* Copyright (c) 2015-2017 Jared McNeill <[email protected]>
@@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fdt_machdep.c,v 1.68 2020/03/08 08:26:54 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fdt_machdep.c,v 1.69 2020/05/14 19:21:06 riastradh Exp $");
#include "opt_machdep.h"
#include "opt_bootconfig.h"
@@ -65,6 +65,7 @@ __KERNEL_RCSID(0, "$NetBSD: fdt_machdep.
#include <sys/md5.h>
#include <sys/pserialize.h>
#include <sys/rnd.h>
+#include <sys/rndsource.h>
#include <net/if.h>
#include <net/if_dl.h>
@@ -119,7 +120,8 @@ u_long uboot_args[4] __attribute__((__se
const uint8_t *fdt_addr_r __attribute__((__section__(".data")));
static uint64_t initrd_start, initrd_end;
-static uint64_t rndseed_start, rndseed_end;
+static uint64_t rndseed_start, rndseed_end; /* our on-disk seed */
+static uint64_t efirng_start, efirng_end; /* firmware's EFI RNG output */
#include <libfdt.h>
#include <dev/fdt/fdtvar.h>
@@ -313,6 +315,10 @@ fdt_build_bootconfig(uint64_t mem_start,
if (rndseed_size > 0)
fdt_memory_remove_range(rndseed_start, rndseed_size);
+ const uint64_t efirng_size = efirng_end - efirng_start;
+ if (efirng_size > 0)
+ fdt_memory_remove_range(efirng_start, efirng_size);
+
const int framebuffer = OF_finddevice("/chosen/framebuffer");
if (framebuffer >= 0) {
for (index = 0;
@@ -451,6 +457,70 @@ fdt_setup_rndseed(void)
rnd_seed(rndseed, rndseed_size);
}
+static void
+fdt_probe_efirng(uint64_t *pstart, uint64_t *pend)
+{
+ int chosen, len;
+ const void *start_data, *end_data;
+
+ *pstart = *pend = 0;
+ chosen = OF_finddevice("/chosen");
+ if (chosen < 0)
+ return;
+
+ start_data = fdtbus_get_prop(chosen, "netbsd,efirng-start", &len);
+ end_data = fdtbus_get_prop(chosen, "netbsd,efirng-end", NULL);
+ if (start_data == NULL || end_data == NULL)
+ return;
+
+ switch (len) {
+ case 4:
+ *pstart = be32dec(start_data);
+ *pend = be32dec(end_data);
+ break;
+ case 8:
+ *pstart = be64dec(start_data);
+ *pend = be64dec(end_data);
+ break;
+ default:
+ printf("Unsupported len %d for /chosen/efirng-start\n", len);
+ return;
+ }
+}
+
+static struct krndsource efirng_source;
+
+static void
+fdt_setup_efirng(void)
+{
+ const uint64_t efirng_size = efirng_end - efirng_start;
+ const paddr_t startpa = trunc_page(efirng_start);
+ const paddr_t endpa = round_page(efirng_end);
+ paddr_t pa;
+ vaddr_t va;
+ void *efirng;
+
+ if (efirng_size == 0)
+ return;
+
+ va = uvm_km_alloc(kernel_map, endpa - startpa, 0,
+ UVM_KMF_VAONLY | UVM_KMF_NOWAIT);
+ if (va == 0) {
+ printf("Failed to allocate VA for efirng\n");
+ return;
+ }
+ efirng = (void *)va;
+
+ for (pa = startpa; pa < endpa; pa += PAGE_SIZE, va += PAGE_SIZE)
+ pmap_kenter_pa(va, pa, VM_PROT_READ|VM_PROT_WRITE, 0);
+ pmap_update(pmap_kernel());
+
+ rnd_attach_source(&efirng_source, "efirng", RND_TYPE_RNG,
+ RND_FLAG_DEFAULT);
+ rnd_add_data(&efirng_source, efirng, efirng_size, 0);
+ explicit_memset(efirng, 0, efirng_size);
+}
+
#ifdef EFI_RUNTIME
static void
fdt_map_efi_runtime(const char *prop, enum arm_efirt_mem_type type)
@@ -579,8 +649,9 @@ initarm(void *arg)
/* Parse ramdisk info */
fdt_probe_initrd(&initrd_start, &initrd_end);
- /* Parse rndseed */
+ /* Parse our on-disk rndseed and the firmware's RNG from EFI */
fdt_probe_rndseed(&rndseed_start, &rndseed_end);
+ fdt_probe_efirng(&efirng_start, &efirng_end);
/*
* Populate bootconfig structure for the benefit of
@@ -699,6 +770,7 @@ cpu_startup_hook(void)
fdtbus_intr_init();
fdt_setup_rndseed();
+ fdt_setup_efirng();
}
void
