diff options
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 42 |
1 files changed, 40 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 8adffc17fa8b..7c23f0397390 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -10,6 +10,7 @@ #include <linux/thread_info.h> #include <linux/init.h> #include <linux/uaccess.h> +#include <linux/delay.h> #include <asm/cpufeature.h> #include <asm/msr.h> @@ -41,6 +42,7 @@ enum split_lock_detect_state { sld_off = 0, sld_warn, sld_fatal, + sld_ratelimit, }; /* @@ -997,13 +999,30 @@ static const struct { { "off", sld_off }, { "warn", sld_warn }, { "fatal", sld_fatal }, + { "ratelimit:", sld_ratelimit }, }; +static struct ratelimit_state bld_ratelimit; + static inline bool match_option(const char *arg, int arglen, const char *opt) { - int len = strlen(opt); + int len = strlen(opt), ratelimit; + + if (strncmp(arg, opt, len)) + return false; + + /* + * Min ratelimit is 1 bus lock/sec. + * Max ratelimit is 1000 bus locks/sec. + */ + if (sscanf(arg, "ratelimit:%d", &ratelimit) == 1 && + ratelimit > 0 && ratelimit <= 1000) { + ratelimit_state_init(&bld_ratelimit, HZ, ratelimit); + ratelimit_set_flags(&bld_ratelimit, RATELIMIT_MSG_ON_RELEASE); + return true; + } - return len == arglen && !strncmp(arg, opt, len); + return len == arglen; } static bool split_lock_verify_msr(bool on) @@ -1082,6 +1101,15 @@ static void sld_update_msr(bool on) static void split_lock_init(void) { + /* + * #DB for bus lock handles ratelimit and #AC for split lock is + * disabled. + */ + if (sld_state == sld_ratelimit) { + split_lock_verify_msr(false); + return; + } + if (cpu_model_supports_sld) split_lock_verify_msr(sld_state != sld_off); } @@ -1154,6 +1182,12 @@ void handle_bus_lock(struct pt_regs *regs) switch (sld_state) { case sld_off: break; + case sld_ratelimit: + /* Enforce no more than bld_ratelimit bus locks/sec. */ + while (!__ratelimit(&bld_ratelimit)) + msleep(20); + /* Warn on the bus lock. */ + fallthrough; case sld_warn: pr_warn_ratelimited("#DB: %s/%d took a bus_lock trap at address: 0x%lx\n", current->comm, current->pid, regs->ip); @@ -1259,6 +1293,10 @@ static void sld_state_show(void) " from non-WB" : ""); } break; + case sld_ratelimit: + if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) + pr_info("#DB: setting system wide bus lock rate limit to %u/sec\n", bld_ratelimit.burst); + break; } } |