From: Thomas Gleixner <t...@linutronix.de> commit 15d6b7aab0793b2de8a05d8a828777dd24db424e upstream.
Reorder the code so it is better grouped. No functional change. Signed-off-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: Ingo Molnar <mi...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Andy Lutomirski <l...@kernel.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Jiri Kosina <jkos...@suse.cz> Cc: Tom Lendacky <thomas.lenda...@amd.com> Cc: Josh Poimboeuf <jpoim...@redhat.com> Cc: Andrea Arcangeli <aarca...@redhat.com> Cc: David Woodhouse <d...@amazon.co.uk> Cc: Tim Chen <tim.c.c...@linux.intel.com> Cc: Andi Kleen <a...@linux.intel.com> Cc: Dave Hansen <dave.han...@intel.com> Cc: Casey Schaufler <casey.schauf...@intel.com> Cc: Asit Mallick <asit.k.mall...@intel.com> Cc: Arjan van de Ven <ar...@linux.intel.com> Cc: Jon Masters <j...@redhat.com> Cc: Waiman Long <longman9...@gmail.com> Cc: Greg KH <gre...@linuxfoundation.org> Cc: Dave Stewart <david.c.stew...@intel.com> Cc: Kees Cook <keesc...@chromium.org> Link: https://lkml.kernel.org/r/20181125185004.707122...@linutronix.de [bwh: Backported to 4.4: - We still have the minimal mitigation modes - Adjust context] Signed-off-by: Ben Hutchings <b...@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- arch/x86/kernel/cpu/bugs.c | 174 ++++++++++++++++++++++----------------------- 1 file changed, 87 insertions(+), 87 deletions(-) --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -115,30 +115,6 @@ void __init check_bugs(void) #endif } -/* The kernel command line selection */ -enum spectre_v2_mitigation_cmd { - SPECTRE_V2_CMD_NONE, - SPECTRE_V2_CMD_AUTO, - SPECTRE_V2_CMD_FORCE, - SPECTRE_V2_CMD_RETPOLINE, - SPECTRE_V2_CMD_RETPOLINE_GENERIC, - SPECTRE_V2_CMD_RETPOLINE_AMD, -}; - -static const char *spectre_v2_strings[] = { - [SPECTRE_V2_NONE] = "Vulnerable", - [SPECTRE_V2_RETPOLINE_MINIMAL] = "Vulnerable: Minimal generic ASM retpoline", - [SPECTRE_V2_RETPOLINE_MINIMAL_AMD] = "Vulnerable: Minimal AMD ASM retpoline", - [SPECTRE_V2_RETPOLINE_GENERIC] = "Mitigation: Full generic retpoline", - [SPECTRE_V2_RETPOLINE_AMD] = "Mitigation: Full AMD retpoline", - [SPECTRE_V2_IBRS_ENHANCED] = "Mitigation: Enhanced IBRS", -}; - -#undef pr_fmt -#define pr_fmt(fmt) "Spectre V2 : " fmt - -static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE; - void x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest) { @@ -208,6 +184,11 @@ static void x86_amd_ssb_disable(void) wrmsrl(MSR_AMD64_LS_CFG, msrval); } +#undef pr_fmt +#define pr_fmt(fmt) "Spectre V2 : " fmt + +static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE; + #ifdef RETPOLINE static bool spectre_v2_bad_module; @@ -229,6 +210,45 @@ static inline const char *spectre_v2_mod static inline const char *spectre_v2_module_string(void) { return ""; } #endif +static inline bool match_option(const char *arg, int arglen, const char *opt) +{ + int len = strlen(opt); + + return len == arglen && !strncmp(arg, opt, len); +} + +/* The kernel command line selection for spectre v2 */ +enum spectre_v2_mitigation_cmd { + SPECTRE_V2_CMD_NONE, + SPECTRE_V2_CMD_AUTO, + SPECTRE_V2_CMD_FORCE, + SPECTRE_V2_CMD_RETPOLINE, + SPECTRE_V2_CMD_RETPOLINE_GENERIC, + SPECTRE_V2_CMD_RETPOLINE_AMD, +}; + +static const char *spectre_v2_strings[] = { + [SPECTRE_V2_NONE] = "Vulnerable", + [SPECTRE_V2_RETPOLINE_MINIMAL] = "Vulnerable: Minimal generic ASM retpoline", + [SPECTRE_V2_RETPOLINE_MINIMAL_AMD] = "Vulnerable: Minimal AMD ASM retpoline", + [SPECTRE_V2_RETPOLINE_GENERIC] = "Mitigation: Full generic retpoline", + [SPECTRE_V2_RETPOLINE_AMD] = "Mitigation: Full AMD retpoline", + [SPECTRE_V2_IBRS_ENHANCED] = "Mitigation: Enhanced IBRS", +}; + +static const struct { + const char *option; + enum spectre_v2_mitigation_cmd cmd; + bool secure; +} mitigation_options[] = { + { "off", SPECTRE_V2_CMD_NONE, false }, + { "on", SPECTRE_V2_CMD_FORCE, true }, + { "retpoline", SPECTRE_V2_CMD_RETPOLINE, false }, + { "retpoline,amd", SPECTRE_V2_CMD_RETPOLINE_AMD, false }, + { "retpoline,generic", SPECTRE_V2_CMD_RETPOLINE_GENERIC, false }, + { "auto", SPECTRE_V2_CMD_AUTO, false }, +}; + static void __init spec2_print_if_insecure(const char *reason) { if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) @@ -246,31 +266,11 @@ static inline bool retp_compiler(void) return __is_defined(RETPOLINE); } -static inline bool match_option(const char *arg, int arglen, const char *opt) -{ - int len = strlen(opt); - - return len == arglen && !strncmp(arg, opt, len); -} - -static const struct { - const char *option; - enum spectre_v2_mitigation_cmd cmd; - bool secure; -} mitigation_options[] = { - { "off", SPECTRE_V2_CMD_NONE, false }, - { "on", SPECTRE_V2_CMD_FORCE, true }, - { "retpoline", SPECTRE_V2_CMD_RETPOLINE, false }, - { "retpoline,amd", SPECTRE_V2_CMD_RETPOLINE_AMD, false }, - { "retpoline,generic", SPECTRE_V2_CMD_RETPOLINE_GENERIC, false }, - { "auto", SPECTRE_V2_CMD_AUTO, false }, -}; - static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void) { + enum spectre_v2_mitigation_cmd cmd = SPECTRE_V2_CMD_AUTO; char arg[20]; int ret, i; - enum spectre_v2_mitigation_cmd cmd = SPECTRE_V2_CMD_AUTO; if (cmdline_find_option_bool(boot_command_line, "nospectre_v2")) return SPECTRE_V2_CMD_NONE; @@ -313,48 +313,6 @@ static enum spectre_v2_mitigation_cmd __ return cmd; } -static bool stibp_needed(void) -{ - if (spectre_v2_enabled == SPECTRE_V2_NONE) - return false; - - /* Enhanced IBRS makes using STIBP unnecessary. */ - if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED) - return false; - - if (!boot_cpu_has(X86_FEATURE_STIBP)) - return false; - - return true; -} - -static void update_stibp_msr(void *info) -{ - wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base); -} - -void arch_smt_update(void) -{ - u64 mask; - - if (!stibp_needed()) - return; - - mutex_lock(&spec_ctrl_mutex); - - mask = x86_spec_ctrl_base & ~SPEC_CTRL_STIBP; - if (sched_smt_active()) - mask |= SPEC_CTRL_STIBP; - - if (mask != x86_spec_ctrl_base) { - pr_info("Spectre v2 cross-process SMT mitigation: %s STIBP\n", - mask & SPEC_CTRL_STIBP ? "Enabling" : "Disabling"); - x86_spec_ctrl_base = mask; - on_each_cpu(update_stibp_msr, NULL, 1); - } - mutex_unlock(&spec_ctrl_mutex); -} - static void __init spectre_v2_select_mitigation(void) { enum spectre_v2_mitigation_cmd cmd = spectre_v2_parse_cmdline(); @@ -459,6 +417,48 @@ specv2_set_mode: arch_smt_update(); } +static bool stibp_needed(void) +{ + if (spectre_v2_enabled == SPECTRE_V2_NONE) + return false; + + /* Enhanced IBRS makes using STIBP unnecessary. */ + if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED) + return false; + + if (!boot_cpu_has(X86_FEATURE_STIBP)) + return false; + + return true; +} + +static void update_stibp_msr(void *info) +{ + wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base); +} + +void arch_smt_update(void) +{ + u64 mask; + + if (!stibp_needed()) + return; + + mutex_lock(&spec_ctrl_mutex); + + mask = x86_spec_ctrl_base & ~SPEC_CTRL_STIBP; + if (sched_smt_active()) + mask |= SPEC_CTRL_STIBP; + + if (mask != x86_spec_ctrl_base) { + pr_info("Spectre v2 cross-process SMT mitigation: %s STIBP\n", + mask & SPEC_CTRL_STIBP ? "Enabling" : "Disabling"); + x86_spec_ctrl_base = mask; + on_each_cpu(update_stibp_msr, NULL, 1); + } + mutex_unlock(&spec_ctrl_mutex); +} + #undef pr_fmt #define pr_fmt(fmt) "Speculative Store Bypass: " fmt
