patch-2_6_7-vs1_9_1_12

[linux-2.6.git] / arch / x86_64 / kernel / mce.c

diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c
index 922d62f..3bb678f 100644 (file)
--- a/arch/x86_64/kernel/mce.c
+++ b/arch/x86_64/kernel/mce.c
@@ -25,8 +25,9 @@
 #define NR_BANKS 5
 
 static int mce_disabled __initdata;
-/* 0: always panic, 1: panic if deadlock possible, 2: try to avoid panic */ 
-static int tolerant = 2;
+/* 0: always panic, 1: panic if deadlock possible, 2: try to avoid panic,
+   3: never panic or exit (for testing only) */
+static int tolerant = 1;
 static int banks;
 static unsigned long bank[NR_BANKS] = { [0 ... NR_BANKS-1] = ~0UL };
 
@@ -96,7 +97,8 @@ static void mce_panic(char *msg, struct mce *backup, unsigned long start)
        int i;
        oops_begin();
        for (i = 0; i < MCE_LOG_LEN; i++) {
-               if (mcelog.entry[i].tsc < start)
+               unsigned long tsc = mcelog.entry[i].tsc;
+               if (time_before(tsc, start))
                        continue;
                print_mce(&mcelog.entry[i]); 
                if (mcelog.entry[i].tsc == backup->tsc)
@@ -104,7 +106,10 @@ static void mce_panic(char *msg, struct mce *backup, unsigned long start)
        }
        if (backup)
                print_mce(backup);
-       panic(msg);
+       if (tolerant >= 3)
+               printk("Fake panic: %s\n", msg);
+       else
+               panic(msg);
 } 
 
 static int mce_available(struct cpuinfo_x86 *c)
@@ -120,8 +125,8 @@ static int mce_available(struct cpuinfo_x86 *c)
 
 void do_machine_check(struct pt_regs * regs, long error_code)
 {
-       struct mce m;
-       int nowayout = 0;
+       struct mce m, panicm;
+       int nowayout = (tolerant < 1); 
        int kill_it = 0;
        u64 mcestart;
        int i;
@@ -149,13 +154,31 @@ void do_machine_check(struct pt_regs * regs, long error_code)
        for (i = 0; i < banks; i++) {
                if (!bank[i])
                        continue;
+               
+               m.misc = 0; 
+               m.addr = 0;
 
                rdmsrl(MSR_IA32_MC0_STATUS + i*4, m.status);
                if ((m.status & MCI_STATUS_VAL) == 0)
                        continue;
+               /* Should be implied by the banks check above, but
+                  check it anyways */
+               if ((m.status & MCI_STATUS_EN) == 0)
+                       continue;
 
-               nowayout |= (tolerant < 1); 
-               nowayout |= !!(m.status & (MCI_STATUS_OVER|MCI_STATUS_PCC));
+               /* Did this bank cause the exception? */
+               /* Assume that the bank with uncorrectable errors did it,
+                  and that there is only a single one. */
+               if (m.status & MCI_STATUS_UC) {
+                       panicm = m;
+               } else {
+                       m.rip = 0;
+                       m.cs = 0;
+               }
+
+               /* In theory _OVER could be a nowayout too, but
+                  assume any overflowed errors were no fatal. */
+               nowayout |= !!(m.status & MCI_STATUS_PCC);
                kill_it |= !!(m.status & MCI_STATUS_UC);
                m.bank = i;
 
@@ -176,7 +199,10 @@ void do_machine_check(struct pt_regs * regs, long error_code)
        if (nowayout)
                mce_panic("Machine check", &m, mcestart);
        if (kill_it) {
-               int user_space = (m.rip && (m.cs & 3));
+               int user_space = 0;
+
+               if (m.mcgstatus & MCG_STATUS_RIPV)
+                       user_space = m.rip && (m.cs & 3);
                
                /* When the machine was in user space and the CPU didn't get
                   confused it's normally not necessary to panic, unless you 
@@ -187,11 +213,12 @@ void do_machine_check(struct pt_regs * regs, long error_code)
                   it is best to just halt the machine. */
                if ((!user_space && (panic_on_oops || tolerant < 2)) ||
                    (unsigned)current->pid <= 1)
-                       mce_panic("Uncorrected machine check", &m, mcestart);
+                       mce_panic("Uncorrected machine check", &panicm, mcestart);
 
                /* do_exit takes an awful lot of locks and has as slight risk 
                   of deadlocking. If you don't want that don't set tolerant >= 2 */
-               do_exit(SIGBUS);
+               if (tolerant < 3)
+                       do_exit(SIGBUS);
        }
 }
 
@@ -207,7 +234,7 @@ static void mce_clear_all(void)
  * Periodic polling timer for "silent" machine check errors.
  */
 
-static int check_interval = 3600; /* one hour */
+static int check_interval = 5 * 60; /* 5 minutes */
 static void mcheck_timer(void *data);
 static DECLARE_WORK(mcheck_work, mcheck_timer, NULL);
 
@@ -297,12 +324,12 @@ static void collect_tscs(void *data)
        rdtscll(cpu_tsc[smp_processor_id()]);
 } 
 
-static ssize_t mce_read(struct file *filp, char *ubuf, size_t usize, loff_t *off)
+static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize, loff_t *off)
 {
        unsigned long cpu_tsc[NR_CPUS];
        static DECLARE_MUTEX(mce_read_sem);
        unsigned next;
-       char *buf = ubuf;
+       char __user *buf = ubuf;
        int i, err;
 
        down(&mce_read_sem); 
@@ -348,19 +375,20 @@ static ssize_t mce_read(struct file *filp, char *ubuf, size_t usize, loff_t *off
 
 static int mce_ioctl(struct inode *i, struct file *f,unsigned int cmd, unsigned long arg)
 {
+       int __user *p = (int __user *)arg;
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM; 
        switch (cmd) {
        case MCE_GET_RECORD_LEN: 
-               return put_user(sizeof(struct mce), (int *)arg);
+               return put_user(sizeof(struct mce), p);
        case MCE_GET_LOG_LEN:
-               return put_user(MCE_LOG_LEN, (int *)arg);               
+               return put_user(MCE_LOG_LEN, p);                
        case MCE_GETCLEAR_FLAGS: {
                unsigned flags;
                do { 
                        flags = mcelog.flags;
                } while (cmpxchg(&mcelog.flags, flags, 0) != flags); 
-               return put_user(flags, (int *)arg); 
+               return put_user(flags, p); 
        }
        default:
                return -ENOTTY;