+ schedh-drop-in_ubsan-field-when-ubsan-is-in-trap-mode.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: sched.h: drop in_ubsan field when UBSAN is in trap mode
has been added to the -mm tree.  Its filename is
     schedh-drop-in_ubsan-field-when-ubsan-is-in-trap-mode.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/schedh-drop-in_ubsan-field-when-ubsan-is-in-trap-mode.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/schedh-drop-in_ubsan-field-when-ubsan-is-in-trap-mode.patch

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------------------------------------------------------
From: Elena Petrova <lenaptr@google.com>
Subject: sched.h: drop in_ubsan field when UBSAN is in trap mode

in_ubsan field of task_struct is only used in lib/ubsan.c, which in its
turn is used only `ifneq ($(CONFIG_UBSAN_TRAP),y)`.

Removing unnecessary field from a task_struct will help preserve the ABI
between vanilla and CONFIG_UBSAN_TRAP'ed kernels.  In particular, this
will help enabling bounds sanitizer transparently for Android's GKI.

Link: https://lkml.kernel.org/r/20200910134802.3160311-1-lenaptr@google.com
Signed-off-by: Elena Petrova <lenaptr@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/sched.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/linux/sched.h~schedh-drop-in_ubsan-field-when-ubsan-is-in-trap-mode
+++ a/include/linux/sched.h
@@ -1009,7 +1009,7 @@ struct task_struct {
 	struct held_lock		held_locks[MAX_LOCK_DEPTH];
 #endif
 
-#ifdef CONFIG_UBSAN
+#if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
 	unsigned int			in_ubsan;
 #endif
 
_

Patches currently in -mm which might be from lenaptr@google.com are

schedh-drop-in_ubsan-field-when-ubsan-is-in-trap-mode.patch