[lkml]   [2019]   [May]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH] cpu/speculation: Warn on unsupported mitigations= parameter
Currently, if the user specifies an unsupported mitigation strategy on
the kernel command line, it will be ignored silently. The code will
fall back to the default strategy, possibly leaving the system more
vulnerable than expected.

This may happen due to e.g. a simple typo, or, for a stable kernel
release, because not all mitigation strategies have been backported.

Inform the user by printing a message.

Fixes: 98af8452945c5565 ("cpu/speculation: Add 'mitigations=' cmdline option")
Signed-off-by: Geert Uytterhoeven <>
kernel/cpu.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index f2ef10460698e9ec..8458fda00e6ddb88 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -2339,6 +2339,9 @@ static int __init mitigations_parse_cmdline(char *arg)
cpu_mitigations = CPU_MITIGATIONS_AUTO;
else if (!strcmp(arg, "auto,nosmt"))
+ else
+ pr_crit("Unsupported mitigations=%s, system may still be vulnerable\n",
+ arg);

return 0;
 \ /
  Last update: 2019-05-16 09:10    [W:0.028 / U:1.480 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site