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-rw-r--r--arch/x86/include/asm/mce.h7
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce_64.c129
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce_amd_64.c2
3 files changed, 116 insertions, 22 deletions
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 048b71d9387..225cdb5d2bf 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -112,6 +112,13 @@ void mce_log_therm_throt_event(__u64 status);
extern atomic_t mce_entry;
extern void do_machine_check(struct pt_regs *, long);
+
+enum mcp_flags {
+ MCP_TIMESTAMP = (1 << 0), /* log time stamp */
+ MCP_UC = (1 << 1), /* log uncorrected errors */
+};
+extern void machine_check_poll(enum mcp_flags flags);
+
extern int mce_notify_user(void);
#endif /* !CONFIG_X86_32 */
diff --git a/arch/x86/kernel/cpu/mcheck/mce_64.c b/arch/x86/kernel/cpu/mcheck/mce_64.c
index fed875742b1..268b05edade 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_64.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_64.c
@@ -3,6 +3,8 @@
* K8 parts Copyright 2002,2003 Andi Kleen, SuSE Labs.
* Rest from unknown author(s).
* 2004 Andi Kleen. Rewrote most of it.
+ * Copyright 2008 Intel Corporation
+ * Author: Andi Kleen
*/
#include <linux/init.h>
@@ -189,7 +191,77 @@ static inline void mce_get_rip(struct mce *m, struct pt_regs *regs)
}
/*
- * The actual machine check handler
+ * Poll for corrected events or events that happened before reset.
+ * Those are just logged through /dev/mcelog.
+ *
+ * This is executed in standard interrupt context.
+ */
+void machine_check_poll(enum mcp_flags flags)
+{
+ struct mce m;
+ int i;
+
+ mce_setup(&m);
+
+ rdmsrl(MSR_IA32_MCG_STATUS, m.mcgstatus);
+ for (i = 0; i < banks; i++) {
+ if (!bank[i])
+ continue;
+
+ m.misc = 0;
+ m.addr = 0;
+ m.bank = i;
+ m.tsc = 0;
+
+ barrier();
+ rdmsrl(MSR_IA32_MC0_STATUS + i*4, m.status);
+ if (!(m.status & MCI_STATUS_VAL))
+ continue;
+
+ /*
+ * Uncorrected events are handled by the exception handler
+ * when it is enabled. But when the exception is disabled log
+ * everything.
+ *
+ * TBD do the same check for MCI_STATUS_EN here?
+ */
+ if ((m.status & MCI_STATUS_UC) && !(flags & MCP_UC))
+ continue;
+
+ if (m.status & MCI_STATUS_MISCV)
+ rdmsrl(MSR_IA32_MC0_MISC + i*4, m.misc);
+ if (m.status & MCI_STATUS_ADDRV)
+ rdmsrl(MSR_IA32_MC0_ADDR + i*4, m.addr);
+
+ if (!(flags & MCP_TIMESTAMP))
+ m.tsc = 0;
+ /*
+ * Don't get the IP here because it's unlikely to
+ * have anything to do with the actual error location.
+ */
+
+ mce_log(&m);
+ add_taint(TAINT_MACHINE_CHECK);
+
+ /*
+ * Clear state for this bank.
+ */
+ wrmsrl(MSR_IA32_MC0_STATUS+4*i, 0);
+ }
+
+ /*
+ * Don't clear MCG_STATUS here because it's only defined for
+ * exceptions.
+ */
+}
+
+/*
+ * The actual machine check handler. This only handles real
+ * exceptions when something got corrupted coming in through int 18.
+ *
+ * This is executed in NMI context not subject to normal locking rules. This
+ * implies that most kernel services cannot be safely used. Don't even
+ * think about putting a printk in there!
*/
void do_machine_check(struct pt_regs * regs, long error_code)
{
@@ -207,13 +279,14 @@ void do_machine_check(struct pt_regs * regs, long error_code)
* error.
*/
int kill_it = 0;
+ DECLARE_BITMAP(toclear, MAX_NR_BANKS);
atomic_inc(&mce_entry);
- if ((regs
- && notify_die(DIE_NMI, "machine check", regs, error_code,
+ if (notify_die(DIE_NMI, "machine check", regs, error_code,
18, SIGKILL) == NOTIFY_STOP)
- || !banks)
+ goto out2;
+ if (!banks)
goto out2;
mce_setup(&m);
@@ -227,6 +300,7 @@ void do_machine_check(struct pt_regs * regs, long error_code)
barrier();
for (i = 0; i < banks; i++) {
+ __clear_bit(i, toclear);
if (!bank[i])
continue;
@@ -238,6 +312,20 @@ void do_machine_check(struct pt_regs * regs, long error_code)
if ((m.status & MCI_STATUS_VAL) == 0)
continue;
+ /*
+ * Non uncorrected errors are handled by machine_check_poll
+ * Leave them alone.
+ */
+ if ((m.status & MCI_STATUS_UC) == 0)
+ continue;
+
+ /*
+ * Set taint even when machine check was not enabled.
+ */
+ add_taint(TAINT_MACHINE_CHECK);
+
+ __set_bit(i, toclear);
+
if (m.status & MCI_STATUS_EN) {
/* if PCC was set, there's no way out */
no_way_out |= !!(m.status & MCI_STATUS_PCC);
@@ -251,6 +339,12 @@ void do_machine_check(struct pt_regs * regs, long error_code)
no_way_out = 1;
kill_it = 1;
}
+ } else {
+ /*
+ * Machine check event was not enabled. Clear, but
+ * ignore.
+ */
+ continue;
}
if (m.status & MCI_STATUS_MISCV)
@@ -259,10 +353,7 @@ void do_machine_check(struct pt_regs * regs, long error_code)
rdmsrl(MSR_IA32_MC0_ADDR + i*4, m.addr);
mce_get_rip(&m, regs);
- if (error_code < 0)
- m.tsc = 0;
- if (error_code != -2)
- mce_log(&m);
+ mce_log(&m);
/* Did this bank cause the exception? */
/* Assume that the bank with uncorrectable errors did it,
@@ -271,14 +362,8 @@ void do_machine_check(struct pt_regs * regs, long error_code)
panicm = m;
panicm_found = 1;
}
-
- add_taint(TAINT_MACHINE_CHECK);
}
- /* Never do anything final in the polling timer */
- if (!regs)
- goto out;
-
/* If we didn't find an uncorrectable error, pick
the last one (shouldn't happen, just being safe). */
if (!panicm_found)
@@ -325,10 +410,11 @@ void do_machine_check(struct pt_regs * regs, long error_code)
/* notify userspace ASAP */
set_thread_flag(TIF_MCE_NOTIFY);
- out:
/* the last thing we do is clear state */
- for (i = 0; i < banks; i++)
- wrmsrl(MSR_IA32_MC0_STATUS+4*i, 0);
+ for (i = 0; i < banks; i++) {
+ if (test_bit(i, toclear))
+ wrmsrl(MSR_IA32_MC0_STATUS+4*i, 0);
+ }
wrmsrl(MSR_IA32_MCG_STATUS, 0);
out2:
atomic_dec(&mce_entry);
@@ -377,7 +463,7 @@ static void mcheck_timer(unsigned long data)
WARN_ON(smp_processor_id() != data);
if (mce_available(&current_cpu_data))
- do_machine_check(NULL, 0);
+ machine_check_poll(MCP_TIMESTAMP);
/*
* Alert userspace if needed. If we logged an MCE, reduce the
@@ -494,9 +580,10 @@ static void mce_init(void *dummy)
u64 cap;
int i;
- /* Log the machine checks left over from the previous reset.
- This also clears all registers */
- do_machine_check(NULL, mce_bootlog ? -1 : -2);
+ /*
+ * Log the machine checks left over from the previous reset.
+ */
+ machine_check_poll(MCP_UC);
set_in_cr4(X86_CR4_MCE);
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd_64.c b/arch/x86/kernel/cpu/mcheck/mce_amd_64.c
index 75d9dd25e3d..0069c653f4e 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd_64.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd_64.c
@@ -231,7 +231,7 @@ asmlinkage void mce_threshold_interrupt(void)
/* Log the machine check that caused the threshold
event. */
- do_machine_check(NULL, 0);
+ machine_check_poll(MCP_TIMESTAMP);
if (high & MASK_OVERFLOW_HI) {
rdmsrl(address, m.misc);
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-26 14:08:31 +0000