From b2a6f6043577e09d51a4b5577fff9fc9f5b14b1c Mon Sep 17 00:00:00 2001
From: Michal Suchanek <msuchanek@suse.de>
Date: Wed, 27 Nov 2019 23:09:59 +0100
Subject: [PATCH] powerpc: add link stack flush mitigation status in debugfs.

References: bsc#1157038 bsc#1157923 ltc#182612 git-fixes
Patch-mainline: v5.18-rc1
Git-commit: b2a6f6043577e09d51a4b5577fff9fc9f5b14b1c

The link stack flush status is not visible in debugfs. It can be enabled
even when count cache flush is disabled. Add separate file for its
status.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
[mpe: Update for change to link_stack_flush_type]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191127220959.6208-1-msuchanek@suse.de
---
 arch/powerpc/kernel/security.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -747,14 +747,29 @@ static int count_cache_flush_get(void *data, u64 *val)
 	return 0;
 }
 
+static int link_stack_flush_get(void *data, u64 *val)
+{
+	if (link_stack_flush_type == BRANCH_CACHE_FLUSH_NONE)
+		*val = 0;
+	else
+		*val = 1;
+
+	return 0;
+}
+
 DEFINE_DEBUGFS_ATTRIBUTE(fops_count_cache_flush, count_cache_flush_get,
 			 count_cache_flush_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_link_stack_flush, link_stack_flush_get,
+			 count_cache_flush_set, "%llu\n");
 
 static __init int count_cache_flush_debugfs_init(void)
 {
 	debugfs_create_file_unsafe("count_cache_flush", 0600,
 				   powerpc_debugfs_root, NULL,
 				   &fops_count_cache_flush);
+	debugfs_create_file_unsafe("link_stack_flush", 0600,
+				   powerpc_debugfs_root, NULL,
+				   &fops_link_stack_flush);
 	return 0;
 }
 device_initcall(count_cache_flush_debugfs_init);
-- 
2.31.1