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Commit 15d6b7aa authored by Thomas Gleixner's avatar Thomas Gleixner
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x86/speculation: Reorder the spec_v2 code 

Reorder the code so it is better grouped. No functional change.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185004.707122879@linutronix.de
parent 130d6f94
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Inline Side-by-side
Showing with 84 additions and 84 deletions
arch/x86/kernel/cpu/bugs.c
View file @ 15d6b7aa
......@@ -124,29 +124,6 @@ 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_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 __ro_after_init =
SPECTRE_V2_NONE;
void
x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest)
{
......@@ -216,6 +193,12 @@ 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 __ro_after_init =
SPECTRE_V2_NONE;
#ifdef RETPOLINE
static bool spectre_v2_bad_module;
......@@ -237,18 +220,6 @@ static inline const char *spectre_v2_module_string(void)
static inline const char *spectre_v2_module_string(void) { return ""; }
#endif
static void __init spec2_print_if_insecure(const char *reason)
{
if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
pr_info("%s selected on command line.\n", reason);
}
static void __init spec2_print_if_secure(const char *reason)
{
if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
pr_info("%s selected on command line.\n", reason);
}
static inline bool match_option(const char *arg, int arglen, const char *opt)
{
int len = strlen(opt);
......@@ -256,24 +227,53 @@ static inline bool match_option(const char *arg, int arglen, const char *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_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 },
{ "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))
pr_info("%s selected on command line.\n", reason);
}
static void __init spec2_print_if_secure(const char *reason)
{
if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
pr_info("%s selected on command line.\n", reason);
}
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;
......@@ -317,48 +317,6 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
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();
......@@ -462,6 +420,48 @@ static void __init spectre_v2_select_mitigation(void)
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
......
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