[PATCH v2 2/6] x86/mce: Make mce=nobootlog work again

From: Jan H. SchÃnherr
Date: Fri Jan 03 2020 - 10:08:16 EST


Since commit 8b38937b7ab5 ("x86/mce: Do not enter deferred errors into
the generic pool twice") the mce=nobootlog option has become mostly
ineffective (after being only slightly ineffective before), as the
code is taking actions on MCEs left over from boot when they have a
usable address.

Move the check for MCP_DONTLOG a bit outward to make it effective again.

Also, since commit 011d82611172 ("RAS: Add a Corrected Errors Collector")
the two branches of the remaining "if" the bottom of machine_check_poll()
do same. Unify them.

Signed-off-by: Jan H. SchÃnherr <jschoenh@xxxxxxxxx>
---
Changes v1->v2:
- remove an indentation level in favor of a goto (requested by Boris)
- don't mention Linux version (per remark from Boris)
---
arch/x86/kernel/cpu/mce/core.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 16134ce587fd..0ccd6cf3402d 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -750,26 +750,22 @@ bool machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
log_it:
error_seen = true;

- mce_read_aux(&m, i);
+ if (flags & MCP_DONTLOG)
+ goto clear_it;

+ mce_read_aux(&m, i);
m.severity = mce_severity(&m, mca_cfg.tolerant, NULL, false);
-
/*
* Don't get the IP here because it's unlikely to
* have anything to do with the actual error location.
*/
- if (!(flags & MCP_DONTLOG) && !mca_cfg.dont_log_ce)
- mce_log(&m);
- else if (mce_usable_address(&m)) {
- /*
- * Although we skipped logging this, we still want
- * to take action. Add to the pool so the registered
- * notifiers will see it.
- */
- if (!mce_gen_pool_add(&m))
- mce_schedule_work();
- }

+ if (mca_cfg.dont_log_ce && !mce_usable_address(&m))
+ goto clear_it;
+
+ mce_log(&m);
+
+clear_it:
/*
* Clear state for this bank.
*/
--
2.22.0.3.gb49bb57c8208.dirty