[tip: x86/microcode] platform/x86/intel/ifs: Remove memory allocation from load path

tip-bot2 for Jithu Joseph
2022-11-19T16:25:08Z

The following commit has been merged into the x86/microcode branch of tip:

Commit-ID: cb5eceee816bf05667089869d822b9cbc919465a
Gitweb: https://git.kernel.org/tip/cb5eceee816bf05667089869d822b9cbc919465a
Author: Jithu Joseph <jithu.joseph@intel.com>
AuthorDate: Thu, 17 Nov 2022 11:59:57 -08:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Fri, 18 Nov 2022 21:43:18 +01:00

platform/x86/intel/ifs: Remove memory allocation from load path

IFS requires tests to be authenticated once for each CPU socket on a
system.

scan_chunks_sanity_check() was dynamically allocating memory to store
the state of whether tests have been authenticated on each socket for
every load operation.

Move the memory allocation to init path and store the pointer in
ifs_data struct.

Also rearrange the adjacent error checking in init for a more simplified
and natural flow.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20221117195957.28225-1-jithu.joseph@intel.com
---
drivers/platform/x86/intel/ifs/core.c | 20 ++++++++++++++++----
drivers/platform/x86/intel/ifs/ifs.h | 2 ++
drivers/platform/x86/intel/ifs/load.c | 14 ++++----------
3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/drivers/platform/x86/intel/ifs/core.c b/drivers/platform/x86/intel/ifs/core.c
index 5fb7f65..943eb2a 100644
--- a/drivers/platform/x86/intel/ifs/core.c
+++ b/drivers/platform/x86/intel/ifs/core.c
@@ -4,6 +4,7 @@
#include <linux/module.h>
#include <linux/kdev_t.h>
#include <linux/semaphore.h>
+#include <linux/slab.h>

#include <asm/cpu_device_id.h>

@@ -34,6 +35,7 @@ static int __init ifs_init(void)
{
const struct x86_cpu_id *m;
u64 msrval;
+ int ret;

m = x86_match_cpu(ifs_cpu_ids);
if (!m)
@@ -50,16 +52,26 @@ static int __init ifs_init(void)

ifs_device.misc.groups = ifs_get_groups();

- if ((msrval & BIT(ifs_device.data.integrity_cap_bit)) &&
- !misc_register(&ifs_device.misc))
- return 0;
+ if (!(msrval & BIT(ifs_device.data.integrity_cap_bit)))
+ return -ENODEV;
+
+ ifs_device.data.pkg_auth = kmalloc_array(topology_max_packages(), sizeof(bool), GFP_KERNEL);
+ if (!ifs_device.data.pkg_auth)
+ return -ENOMEM;
+
+ ret = misc_register(&ifs_device.misc);
+ if (ret) {
+ kfree(ifs_device.data.pkg_auth);
+ return ret;
+ }

- return -ENODEV;
+ return 0;
}

static void __exit ifs_exit(void)
{
misc_deregister(&ifs_device.misc);
+ kfree(ifs_device.data.pkg_auth);
}

module_init(ifs_init);
diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
index 3ff1d9a..8de1952 100644
--- a/drivers/platform/x86/intel/ifs/ifs.h
+++ b/drivers/platform/x86/intel/ifs/ifs.h
@@ -191,6 +191,7 @@ union ifs_status {
* struct ifs_data - attributes related to intel IFS driver
* @integrity_cap_bit: MSR_INTEGRITY_CAPS bit enumerating this test
* @loaded_version: stores the currently loaded ifs image version.
+ * @pkg_auth: array of bool storing per package auth status
* @loaded: If a valid test binary has been loaded into the memory
* @loading_error: Error occurred on another CPU while loading image
* @valid_chunks: number of chunks which could be validated.
@@ -199,6 +200,7 @@ union ifs_status {
*/
struct ifs_data {
int integrity_cap_bit;
+ bool *pkg_auth;
int loaded_version;
bool loaded;
bool loading_error;
diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
index 89ce265..8423c48 100644
--- a/drivers/platform/x86/intel/ifs/load.c
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -3,7 +3,6 @@

#include <linux/firmware.h>
#include <asm/cpu.h>
-#include <linux/slab.h>
#include <asm/microcode_intel.h>

#include "ifs.h"
@@ -118,16 +117,12 @@ done:
*/
static int scan_chunks_sanity_check(struct device *dev)
{
- int metadata_size, curr_pkg, cpu, ret = -ENOMEM;
+ int metadata_size, curr_pkg, cpu, ret;
struct ifs_data *ifsd = ifs_get_data(dev);
- bool *package_authenticated;
struct ifs_work local_work;
char *test_ptr;

- package_authenticated = kcalloc(topology_max_packages(), sizeof(bool), GFP_KERNEL);
- if (!package_authenticated)
- return ret;
-
+ memset(ifsd->pkg_auth, 0, (topology_max_packages() * sizeof(bool)));
metadata_size = ifs_header_ptr->metadata_size;

/* Spec says that if the Meta Data Size = 0 then it should be treated as 2000 */
@@ -150,7 +145,7 @@ static int scan_chunks_sanity_check(struct device *dev)
cpus_read_lock();
for_each_online_cpu(cpu) {
curr_pkg = topology_physical_package_id(cpu);
- if (package_authenticated[curr_pkg])
+ if (ifsd->pkg_auth[curr_pkg])
continue;
reinit_completion(&ifs_done);
local_work.dev = dev;
@@ -161,12 +156,11 @@ static int scan_chunks_sanity_check(struct device *dev)
ret = -EIO;
goto out;
}
- package_authenticated[curr_pkg] = 1;
+ ifsd->pkg_auth[curr_pkg] = 1;
}
ret = 0;
out:
cpus_read_unlock();
- kfree(package_authenticated);

return ret;
}