Commit d47d1d8a authored by Anton Blanchard's avatar Anton Blanchard Committed by Benjamin Herrenschmidt

powerpc: Rework pseries machine check handler

Rework pseries machine check handler:

- If MSR_RI isn't set, we cannot recover even if the machine check was fully
  recovered

- Rename nonfatal to recovered

- Handle RTAS_DISP_LIMITED_RECOVERY

- Use BUS_MCEERR_AR instead of BUS_ADRERR

- Don't check all the RTAS error log fields when receiving a synchronous
  machine check. Recent versions of the pseries firmware do not fill them
  in during a machine check and instead send a follow up error log with
  the detailed information. If we see a synchronous machine check, and we
  came from userspace then kill the task.
Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent e49b1fae
......@@ -259,31 +259,43 @@ int pSeries_system_reset_exception(struct pt_regs *regs)
* Return 1 if corrected (or delivered a signal).
* Return 0 if there is nothing we can do.
*/
static int recover_mce(struct pt_regs *regs, struct rtas_error_log * err)
static int recover_mce(struct pt_regs *regs, struct rtas_error_log *err)
{
int nonfatal = 0;
int recovered = 0;
if (err->disposition == RTAS_DISP_FULLY_RECOVERED) {
if (!(regs->msr & MSR_RI)) {
/* If MSR_RI isn't set, we cannot recover */
recovered = 0;
} else if (err->disposition == RTAS_DISP_FULLY_RECOVERED) {
/* Platform corrected itself */
nonfatal = 1;
} else if ((regs->msr & MSR_RI) &&
user_mode(regs) &&
err->severity == RTAS_SEVERITY_ERROR_SYNC &&
err->disposition == RTAS_DISP_NOT_RECOVERED &&
err->target == RTAS_TARGET_MEMORY &&
err->type == RTAS_TYPE_ECC_UNCORR &&
!(current->pid == 0 || is_global_init(current))) {
/* Kill off a user process with an ECC error */
printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n",
current->pid);
/* XXX something better for ECC error? */
_exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
nonfatal = 1;
recovered = 1;
} else if (err->disposition == RTAS_DISP_LIMITED_RECOVERY) {
/* Platform corrected itself but could be degraded */
printk(KERN_ERR "MCE: limited recovery, system may "
"be degraded\n");
recovered = 1;
} else if (user_mode(regs) && !is_global_init(current) &&
err->severity == RTAS_SEVERITY_ERROR_SYNC) {
/*
* If we received a synchronous error when in userspace
* kill the task. Firmware may report details of the fail
* asynchronously, so we can't rely on the target and type
* fields being valid here.
*/
printk(KERN_ERR "MCE: uncorrectable error, killing task "
"%s:%d\n", current->comm, current->pid);
_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
recovered = 1;
}
log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
return nonfatal;
return recovered;
}
/*
......
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