On 6/30/21 4:40 AM, Daniel Axtens wrote:
If the 'ibm,secure-boot' property of the root node is 2 or greater,
enter lockdown.
Signed-off-by: Daniel Axtens <d...@axtens.net>
Reviewed-by: Stefan Berger <stef...@linux.ibm.com>
---
docs/grub.texi | 4 ++--
grub-core/Makefile.core.def | 1 +
grub-core/kern/ieee1275/init.c | 27 +++++++++++++++++++++++++++
include/grub/lockdown.h | 3 ++-
4 files changed, 32 insertions(+), 3 deletions(-)
diff --git a/docs/grub.texi b/docs/grub.texi
index 02fcda11e3bd..b13316cdb491 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -6189,8 +6189,8 @@ Measured boot is currently only supported on EFI
platforms.
@section Lockdown when booting on a secure setup
The GRUB can be locked down when booted on a secure boot environment, for example
-if the UEFI secure boot is enabled. On a locked down configuration, the GRUB
will
-be restricted and some operations/commands cannot be executed.
+if UEFI or Power secure boot is enabled. On a locked down configuration, the
+GRUB will be restricted and some operations/commands cannot be executed.
The @samp{lockdown} variable is set to @samp{y} when the GRUB is locked down.
Otherwise it does not exit.
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 4aa4cf263d94..775a031f1843 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -317,6 +317,7 @@ kernel = {
powerpc_ieee1275 = kern/powerpc/cache.S;
powerpc_ieee1275 = kern/powerpc/dl.c;
powerpc_ieee1275 = kern/powerpc/compiler-rt.S;
+ powerpc_ieee1275 = kern/lockdown.c;
sparc64_ieee1275 = kern/sparc64/cache.S;
sparc64_ieee1275 = kern/sparc64/dl.c;
diff --git a/grub-core/kern/ieee1275/init.c b/grub-core/kern/ieee1275/init.c
index 4586bec939b2..5faf4e736074 100644
--- a/grub-core/kern/ieee1275/init.c
+++ b/grub-core/kern/ieee1275/init.c
@@ -44,6 +44,7 @@
#ifdef __sparc__
#include <grub/machine/kernel.h>
#endif
+#include <grub/lockdown.h>
/* The maximum heap size we're going to claim. Not used by sparc.
We allocate 1/4 of the available memory under 4G, up to this limit. */
@@ -442,6 +443,30 @@ grub_parse_cmdline (void)
}
}
+static void
+grub_get_ieee1275_secure_boot (void)
+{
+ grub_ieee1275_phandle_t root;
+ int rc;
+ grub_uint32_t is_sb;
+
+ grub_ieee1275_finddevice ("/", &root);
+
+ rc = grub_ieee1275_get_integer_property (root, "ibm,secure-boot", &is_sb,
+ sizeof (is_sb), 0);
+
+ /* ibm,secure-boot:
+ * 0 - disabled
+ * 1 - audit
+ * 2 - enforce
+ * 3 - enforce + OS-specific behaviour
+ *
+ * We only support enforce.
+ */
+ if (rc >= 0 && is_sb >= 2)
+ grub_lockdown ();
+}
+
grub_addr_t grub_modbase;
void
@@ -467,6 +492,8 @@ grub_machine_init (void)
#else
grub_install_get_time_ms (grub_rtc_get_time_ms);
#endif
+
+ grub_get_ieee1275_secure_boot ();
}
void
diff --git a/include/grub/lockdown.h b/include/grub/lockdown.h
index 40531fa823bf..ebfee4bf06e7 100644
--- a/include/grub/lockdown.h
+++ b/include/grub/lockdown.h
@@ -24,7 +24,8 @@
#define GRUB_LOCKDOWN_DISABLED 0
#define GRUB_LOCKDOWN_ENABLED 1
-#ifdef GRUB_MACHINE_EFI
+#if defined(GRUB_MACHINE_EFI) || \
+ (defined(__powerpc__) && defined(GRUB_MACHINE_IEEE1275))
extern void
EXPORT_FUNC (grub_lockdown) (void);
extern int
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