summaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
authorGeert Uytterhoeven <geert@linux-m68k.org>2019-05-16 09:09:35 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-07-03 13:14:46 +0200
commitb78ad2169282ae469eebfb35bfba9615f0d9c6cc (patch)
tree5b3178a6c392d2c5fd33b1920146bb67e9303952 /kernel
parent27380331755f1b17a49cb3d2c7db43d10ec8749a (diff)
downloadlinux-stable-b78ad2169282ae469eebfb35bfba9615f0d9c6cc.tar.gz
linux-stable-b78ad2169282ae469eebfb35bfba9615f0d9c6cc.tar.bz2
linux-stable-b78ad2169282ae469eebfb35bfba9615f0d9c6cc.zip
cpu/speculation: Warn on unsupported mitigations= parameter
commit 1bf72720281770162c87990697eae1ba2f1d917a upstream. 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 <geert@linux-m68k.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190516070935.22546-1-geert@linux-m68k.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpu.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 5d65eae893bd..46aefe5c0e35 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -2289,6 +2289,9 @@ static int __init mitigations_parse_cmdline(char *arg)
cpu_mitigations = CPU_MITIGATIONS_AUTO;
else if (!strcmp(arg, "auto,nosmt"))
cpu_mitigations = CPU_MITIGATIONS_AUTO_NOSMT;
+ else
+ pr_crit("Unsupported mitigations=%s, system may still be vulnerable\n",
+ arg);
return 0;
}