From 21559c09b39155d44f8997703a35211623a38689 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Mon, 1 Jun 2015 10:33:48 -0400
Subject: [PATCH] Partially revert "ma-setup: simplify"

copy_bytes() tries to do the write in chunks, but ima kernel code
needs every rule to be written in one write. Writing the whole file
at once avoids the issue.

http://lists.freedesktop.org/archives/systemd-devel/2015-June/032623.html
http://sourceforge.net/p/linux-ima/mailman/message/34145236/
https://bugzilla.redhat.com/show_bug.cgi?id=1226948
(cherry picked from commit 116b6c8687e1da25fcecf80ba6ac16866e308d50)

Cherry-picked from: 116b6c8
Resolves: #1222517
---
 src/core/ima-setup.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/core/ima-setup.c b/src/core/ima-setup.c
index 0e0d16a7c9..1d4acfa3b1 100644
--- a/src/core/ima-setup.c
+++ b/src/core/ima-setup.c
@@ -27,9 +27,10 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
 
 #include "ima-setup.h"
-#include "copy.h"
 #include "util.h"
 #include "log.h"
 
@@ -42,6 +43,8 @@ int ima_setup(void) {
 
 #ifdef HAVE_IMA
         _cleanup_close_ int policyfd = -1, imafd = -1;
+        struct stat st;
+        char *policy;
 
         if (access(IMA_SECFS_DIR, F_OK) < 0) {
                 log_debug("IMA support is disabled in the kernel, ignoring.");
@@ -66,12 +69,20 @@ int ima_setup(void) {
                 return 0;
         }
 
-        r = copy_bytes(policyfd, imafd, (off_t) -1, false);
+        if (fstat(policyfd, &st) < 0)
+                return log_error_errno(errno, "Failed to fstat "IMA_POLICY_PATH": %m");
+
+        policy = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, policyfd, 0);
+        if (policy == MAP_FAILED)
+                return log_error_errno(errno, "Failed to mmap "IMA_POLICY_PATH": %m");
+
+        r = loop_write(imafd, policy, (size_t) st.st_size, false);
         if (r < 0)
                 log_error_errno(r, "Failed to load the IMA custom policy file "IMA_POLICY_PATH": %m");
         else
                 log_info("Successfully loaded the IMA custom policy "IMA_POLICY_PATH".");
 
+        munmap(policy, st.st_size);
 #endif /* HAVE_IMA */
         return r;
 }