Messages in this thread Patch in this message | | | From | Breno Leitao <> | Subject | [PATCH v6 12/13] x86/bugs: spectre_v2_user default mode depends on Kconfig | Date | Tue, 21 Nov 2023 08:07:39 -0800 |
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Change the default value of spectre v2 in user mode to respect the CONFIG_MITIGATION_SPECTRE_V2 config option.
Currently, user mode spectre v2 is set to auto (SPECTRE_V2_USER_CMD_AUTO) by default, even if CONFIG_MITIGATION_SPECTRE_V2 is disabled.
Set the Spectre_v2 value to auto (SPECTRE_V2_USER_CMD_AUTO) if the Spectre v2 config (CONFIG_MITIGATION_SPECTRE_V2) is enabled, otherwise set the value to none (SPECTRE_V2_USER_CMD_NONE).
Important to say the command line argument "spectre_v2_user" overwrites the default value in both cases.
Signed-off-by: Breno Leitao <leitao@debian.org> --- arch/x86/kernel/cpu/bugs.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 0172bb0f61fe..a99f8c064682 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1216,8 +1216,11 @@ static __ro_after_init enum spectre_v2_mitigation_cmd spectre_v2_cmd; static enum spectre_v2_user_cmd __init spectre_v2_parse_user_cmdline(void) { + int ret, i, mode; char arg[20]; - int ret, i; + + mode = IS_ENABLED(CONFIG_MITIGATION_SPECTRE_V2) ? + SPECTRE_V2_USER_CMD_AUTO : SPECTRE_V2_USER_CMD_NONE; switch (spectre_v2_cmd) { case SPECTRE_V2_CMD_NONE: @@ -1231,7 +1234,7 @@ spectre_v2_parse_user_cmdline(void) ret = cmdline_find_option(boot_command_line, "spectre_v2_user", arg, sizeof(arg)); if (ret < 0) - return SPECTRE_V2_USER_CMD_AUTO; + return mode; for (i = 0; i < ARRAY_SIZE(v2_user_options); i++) { if (match_option(arg, ret, v2_user_options[i].option)) { @@ -1241,8 +1244,8 @@ spectre_v2_parse_user_cmdline(void) } } - pr_err("Unknown user space protection option (%s). Switching to AUTO select\n", arg); - return SPECTRE_V2_USER_CMD_AUTO; + pr_err("Unknown user space protection option (%s). Switching to default\n", arg); + return mode; } static inline bool spectre_v2_in_ibrs_mode(enum spectre_v2_mitigation mode) -- 2.34.1
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