From b2a6f6043577e09d51a4b5577fff9fc9f5b14b1c Mon Sep 17 00:00:00 2001 From: Michal Suchanek Date: Wed, 27 Nov 2019 23:09:59 +0100 Subject: [PATCH] powerpc: add link stack flush mitigation status in debugfs. 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 [mpe: Update for change to link_stack_flush_type] Signed-off-by: Michael Ellerman 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 index e159d40..d96fd14 100644 --- 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, arch_debugfs_dir, NULL, &fops_count_cache_flush); + debugfs_create_file_unsafe("link_stack_flush", 0600, + arch_debugfs_dir, NULL, + &fops_link_stack_flush); return 0; } device_initcall(count_cache_flush_debugfs_init); -- 2.7.4