[1/2] xen/flask: Fix Python 3 problems with gen-policy.py

Commit Message

Andrew Cooper Dec. 7, 2019, 4:52 p.m. UTC

The script is Python 2 specific, and fails with string/binary issues with
Python 3:

  Traceback (most recent call last):
    File "gen-policy.py", line 14, in <module>
      for char in sys.stdin.read():
    File "/usr/lib/python3.5/codecs.py", line 321, in decode
      (result, consumed) = self._buffer_decode(data, self.errors, final)
  UnicodeDecodeError: 'utf-8' codec can't decode byte 0x8c in position 0: invalid start byte

Fixing the script to be compatible isn't hard, but using python here is
wasteful.  Drop the script entirely, and write a short flask-policy.S instead.

Signed-off-by: Andrew Cooper <[e-mail]>
---
CC: Daniel De Graaf <[e-mail]>
CC: Juergen Gross <[e-mail]>

For 4.13.  This is a blocker to our intent to by Py3-clean in this release

Discovered entirely accidently when testing the following patch.
---
 xen/xsm/flask/Makefile       |  6 ++----
 xen/xsm/flask/flask-policy.S | 20 ++++++++++++++++++++
 xen/xsm/flask/gen-policy.py  | 23 -----------------------
 3 files changed, 22 insertions(+), 27 deletions(-)
 create mode 100644 xen/xsm/flask/flask-policy.S
 delete mode 100644 xen/xsm/flask/gen-policy.py

Patch

diff --git a/xen/xsm/flask/Makefile b/xen/xsm/flask/Makefile
index f5ffab1226..7c3f381287 100644
--- a/xen/xsm/flask/Makefile
+++ b/xen/xsm/flask/Makefile
@@ -27,7 +27,8 @@  $(FLASK_H_FILES): $(FLASK_H_DEPEND)
 $(AV_H_FILES): $(AV_H_DEPEND)
 	$(CONFIG_SHELL) policy/mkaccess_vector.sh $(AWK) $(AV_H_DEPEND)
 
-obj-$(CONFIG_XSM_FLASK_POLICY) += policy.o
+obj-bin-$(CONFIG_XSM_FLASK_POLICY) += flask-policy.o
+flask-policy.o: policy.bin
 
 FLASK_BUILD_DIR := $(CURDIR)
 POLICY_SRC := $(FLASK_BUILD_DIR)/xenpolicy-$(XEN_FULLVERSION)
@@ -36,9 +37,6 @@  policy.bin: FORCE
 	$(MAKE) -f $(XEN_ROOT)/tools/flask/policy/Makefile.common -C $(XEN_ROOT)/tools/flask/policy FLASK_BUILD_DIR=$(FLASK_BUILD_DIR)
 	cmp -s $(POLICY_SRC) $@ || cp $(POLICY_SRC) $@
 
-policy.c: policy.bin gen-policy.py
-	$(PYTHON) gen-policy.py < $< > $@
-
 .PHONY: clean
 clean::
 	rm -f $(ALL_H_FILES) *.o $(DEPS_RM) policy.* $(POLICY_SRC)
diff --git a/xen/xsm/flask/flask-policy.S b/xen/xsm/flask/flask-policy.S
new file mode 100644
index 0000000000..d78ce77fd6
--- /dev/null
+++ b/xen/xsm/flask/flask-policy.S
@@ -0,0 +1,20 @@ 
+        .section .init.rodata, "a", @progbits
+
+/* const unsigned char xsm_flask_init_policy[] __initconst */
+	.align 4
+        .global xsm_flask_init_policy
+xsm_flask_init_policy:
+        .incbin "policy.bin"
+.Lend:
+
+        .type xsm_flask_init_policy, @object
+        .size xsm_flask_init_policy, . - xsm_flask_init_policy
+
+/* const unsigned int __initconst xsm_flask_init_policy_size */
+	.align 4
+        .global xsm_flask_init_policy_size
+xsm_flask_init_policy_size:
+        .long .Lend - xsm_flask_init_policy
+
+        .type xsm_flask_init_policy_size, @object
+        .size xsm_flask_init_policy_size, . - xsm_flask_init_policy_size
diff --git a/xen/xsm/flask/gen-policy.py b/xen/xsm/flask/gen-policy.py
deleted file mode 100644
index c7501e4614..0000000000
--- a/xen/xsm/flask/gen-policy.py
+++ /dev/null
@@ -1,23 +0,0 @@ 
-#!/usr/bin/env python
-import sys
-
-policy_size = 0
-
-sys.stdout.write("""
-/* This file is autogenerated by gen_policy.py */
-#include <xen/init.h>
-#include <xsm/xsm.h>
-
-const unsigned char xsm_flask_init_policy[] __initconst = {
-""")
-
-for char in sys.stdin.read():
-    sys.stdout.write(" 0x%02x," % ord(char))
-    policy_size = policy_size + 1
-    if policy_size % 13 == 0:
-        sys.stdout.write("\n")
-
-sys.stdout.write("""
-};
-const unsigned int __initconst xsm_flask_init_policy_size = %d;
-""" % policy_size)