2019-11-27 22:12:18

by Michal Suchánek

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 <[email protected]>
---
arch/powerpc/kernel/security.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index 7d4b2080a658..56dce4798a4d 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -446,14 +446,26 @@ static int count_cache_flush_get(void *data, u64 *val)
return 0;
}

+static int link_stack_flush_get(void *data, u64 *val)
+{
+ *val = link_stack_flush_enabled;
+
+ 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);
--
2.23.0

2022-02-15 07:31:10

by Michael Ellerman

Subject: Re: [PATCH] powerpc: add link stack flush mitigation status in debugfs.

On Wed, 27 Nov 2019 23:09:59 +0100, Michal Suchanek wrote:
> 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.
>
>

Applied to powerpc/next.

[1/1] powerpc: add link stack flush mitigation status in debugfs.
https://git.kernel.org/powerpc/c/b2a6f6043577e09d51a4b5577fff9fc9f5b14b1c

cheers