[PATCH RFC rebase 9/9] powerpc/64: barrier_nospec: Add commandline trigger
From: Michal Suchanek <hidden>
Date: 2018-03-15 19:15:58
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Add commandline options spectre_v2 and nospectre_v2 These are named same as similar x86 options regardless of actual effect to not require platform-specific configuration. Supported options: nospectre_v2 or spectre_v2=off - speculation barrier not used spectre_v2=on or spectre_v2=auto - speculation barrier used Changing the settings after boot is not supported and VM migration may change requirements so auto is same as on. Based on s390 implementation Signed-off-by: Michal Suchanek <redacted> --- arch/powerpc/kernel/setup_64.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index f6678a7b6114..c74e656265df 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c@@ -840,6 +840,28 @@ static int __init handle_no_pti(char *p) } early_param("nopti", handle_no_pti); +static int __init nospectre_v2_setup_early(char *str) +{ + no_nospec = true; + return 0; +} +early_param("nospectre_v2", nospectre_v2_setup_early); + +static int __init spectre_v2_setup_early(char *str) +{ + if (str && !strncmp(str, "on", 2)) + no_nospec = false; + + if (str && !strncmp(str, "off", 3)) + no_nospec = true; + + if (str && !strncmp(str, "auto", 4)) + no_nospec = false; + + return 0; +} +early_param("spectre_v2", spectre_v2_setup_early); + static void do_nothing(void *unused) { /*
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2.13.6