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Diffstat (limited to 'arch/x86/kernel/cpu/mce/inject.c')
-rw-r--r--arch/x86/kernel/cpu/mce/inject.c117
1 files changed, 106 insertions, 11 deletions
diff --git a/arch/x86/kernel/cpu/mce/inject.c b/arch/x86/kernel/cpu/mce/inject.c
index 3413b41b8d55..12cf2e7ca33c 100644
--- a/arch/x86/kernel/cpu/mce/inject.c
+++ b/arch/x86/kernel/cpu/mce/inject.c
@@ -33,6 +33,8 @@
#include "internal.h"
+static bool hw_injection_possible = true;
+
/*
* Collect all the MCi_XXX settings
*/
@@ -88,12 +90,28 @@ MCE_INJECT_GET(status);
MCE_INJECT_GET(misc);
MCE_INJECT_GET(addr);
MCE_INJECT_GET(synd);
+MCE_INJECT_GET(ipid);
DEFINE_SIMPLE_ATTRIBUTE(status_fops, inj_status_get, inj_status_set, "%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(misc_fops, inj_misc_get, inj_misc_set, "%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(addr_fops, inj_addr_get, inj_addr_set, "%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(synd_fops, inj_synd_get, inj_synd_set, "%llx\n");
+/* Use the user provided IPID value on a sw injection. */
+static int inj_ipid_set(void *data, u64 val)
+{
+ struct mce *m = (struct mce *)data;
+
+ if (cpu_feature_enabled(X86_FEATURE_SMCA)) {
+ if (inj_type == SW_INJ)
+ m->ipid = val;
+ }
+
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(ipid_fops, inj_ipid_get, inj_ipid_set, "%llx\n");
+
static void setup_inj_struct(struct mce *m)
{
memset(m, 0, sizeof(struct mce));
@@ -146,9 +164,9 @@ static void raise_exception(struct mce *m, struct pt_regs *pregs)
regs.cs = m->cs;
pregs = &regs;
}
- /* in mcheck exeception handler, irq will be disabled */
+ /* do_machine_check() expects interrupts disabled -- at least */
local_irq_save(flags);
- do_machine_check(pregs, 0);
+ do_machine_check(pregs);
local_irq_restore(flags);
m->finished = 0;
}
@@ -199,7 +217,7 @@ static int raise_local(void)
* calling irq_enter, but the necessary
* machinery isn't exported currently.
*/
- /*FALL THROUGH*/
+ fallthrough;
case MCJ_CTX_PROCESS:
raise_exception(m, NULL);
break;
@@ -232,7 +250,7 @@ static void __maybe_unused raise_mce(struct mce *m)
unsigned long start;
int cpu;
- get_online_cpus();
+ cpus_read_lock();
cpumask_copy(mce_inject_cpumask, cpu_online_mask);
cpumask_clear_cpu(get_cpu(), mce_inject_cpumask);
for_each_online_cpu(cpu) {
@@ -266,7 +284,7 @@ static void __maybe_unused raise_mce(struct mce *m)
}
raise_local();
put_cpu();
- put_online_cpus();
+ cpus_read_unlock();
} else {
preempt_disable();
raise_local();
@@ -323,6 +341,8 @@ static int __set_inj(const char *buf)
for (i = 0; i < N_INJ_TYPES; i++) {
if (!strncmp(flags_options[i], buf, strlen(flags_options[i]))) {
+ if (i > SW_INJ && !hw_injection_possible)
+ continue;
inj_type = i;
return 0;
}
@@ -347,7 +367,7 @@ static ssize_t flags_write(struct file *filp, const char __user *ubuf,
char buf[MAX_FLAG_OPT_SIZE], *__buf;
int err;
- if (cnt > MAX_FLAG_OPT_SIZE)
+ if (!cnt || cnt > MAX_FLAG_OPT_SIZE)
return -EINVAL;
if (copy_from_user(&buf, ubuf, cnt))
@@ -487,6 +507,8 @@ static void do_inject(void)
i_mce.tsc = rdtsc_ordered();
+ i_mce.status |= MCI_STATUS_VAL;
+
if (i_mce.misc)
i_mce.status |= MCI_STATUS_MISCV;
@@ -511,7 +533,7 @@ static void do_inject(void)
*/
if (inj_type == DFR_INT_INJ) {
i_mce.status |= MCI_STATUS_DEFERRED;
- i_mce.status |= (i_mce.status & ~MCI_STATUS_UC);
+ i_mce.status &= ~MCI_STATUS_UC;
}
/*
@@ -522,11 +544,11 @@ static void do_inject(void)
if (boot_cpu_has(X86_FEATURE_AMD_DCM) &&
b == 4 &&
boot_cpu_data.x86 < 0x17) {
- toggle_nb_mca_mst_cpu(amd_get_nb_id(cpu));
- cpu = get_nbc_for_node(amd_get_nb_id(cpu));
+ toggle_nb_mca_mst_cpu(topology_die_id(cpu));
+ cpu = get_nbc_for_node(topology_die_id(cpu));
}
- get_online_cpus();
+ cpus_read_lock();
if (!cpu_online(cpu))
goto err;
@@ -550,7 +572,7 @@ static void do_inject(void)
}
err:
- put_online_cpus();
+ cpus_read_unlock();
}
@@ -574,6 +596,33 @@ static int inj_bank_set(void *data, u64 val)
}
m->bank = val;
+
+ /*
+ * sw-only injection allows to write arbitrary values into the MCA
+ * registers because it tests only the decoding paths.
+ */
+ if (inj_type == SW_INJ)
+ goto inject;
+
+ /*
+ * Read IPID value to determine if a bank is populated on the target
+ * CPU.
+ */
+ if (cpu_feature_enabled(X86_FEATURE_SMCA)) {
+ u64 ipid;
+
+ if (rdmsrl_on_cpu(m->extcpu, MSR_AMD64_SMCA_MCx_IPID(val), &ipid)) {
+ pr_err("Error reading IPID on CPU%d\n", m->extcpu);
+ return -EINVAL;
+ }
+
+ if (!ipid) {
+ pr_err("Cannot inject into unpopulated bank %llu\n", val);
+ return -ENODEV;
+ }
+ }
+
+inject:
do_inject();
/* Reset injection struct */
@@ -629,6 +678,8 @@ static const char readme_msg[] =
"\t is present in hardware. \n"
"\t - \"th\": Trigger APIC interrupt for Threshold errors. Causes threshold \n"
"\t APIC interrupt handler to handle the error. \n"
+"\n"
+"ipid:\t IPID (AMD-specific)\n"
"\n";
static ssize_t
@@ -652,6 +703,7 @@ static struct dfs_node {
{ .name = "misc", .fops = &misc_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "addr", .fops = &addr_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "synd", .fops = &synd_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "ipid", .fops = &ipid_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "bank", .fops = &bank_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "flags", .fops = &flags_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "cpu", .fops = &extcpu_fops, .perm = S_IRUSR | S_IWUSR },
@@ -669,11 +721,54 @@ static void __init debugfs_init(void)
&i_mce, dfs_fls[i].fops);
}
+static void check_hw_inj_possible(void)
+{
+ int cpu;
+ u8 bank;
+
+ /*
+ * This behavior exists only on SMCA systems though its not directly
+ * related to SMCA.
+ */
+ if (!cpu_feature_enabled(X86_FEATURE_SMCA))
+ return;
+
+ cpu = get_cpu();
+
+ for (bank = 0; bank < MAX_NR_BANKS; ++bank) {
+ u64 status = MCI_STATUS_VAL, ipid;
+
+ /* Check whether bank is populated */
+ rdmsrl(MSR_AMD64_SMCA_MCx_IPID(bank), ipid);
+ if (!ipid)
+ continue;
+
+ toggle_hw_mce_inject(cpu, true);
+
+ wrmsrl_safe(mca_msr_reg(bank, MCA_STATUS), status);
+ rdmsrl_safe(mca_msr_reg(bank, MCA_STATUS), &status);
+
+ if (!status) {
+ hw_injection_possible = false;
+ pr_warn("Platform does not allow *hardware* error injection."
+ "Try using APEI EINJ instead.\n");
+ }
+
+ toggle_hw_mce_inject(cpu, false);
+
+ break;
+ }
+
+ put_cpu();
+}
+
static int __init inject_init(void)
{
if (!alloc_cpumask_var(&mce_inject_cpumask, GFP_KERNEL))
return -ENOMEM;
+ check_hw_inj_possible();
+
debugfs_init();
register_nmi_handler(NMI_LOCAL, mce_raise_notify, 0, "mce_notify");
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.