+ s390-implement-the-architecture-specific-kmsan-functions.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: s390: implement the architecture-specific kmsan functions
has been added to the -mm mm-unstable branch.  Its filename is
     s390-implement-the-architecture-specific-kmsan-functions.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/s390-implement-the-architecture-specific-kmsan-functions.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Ilya Leoshkevich <iii@linux.ibm.com>
Subject: s390: implement the architecture-specific kmsan functions
Date: Thu, 14 Dec 2023 00:24:53 +0100

arch_kmsan_get_meta_or_null() finds the lowcore shadow by querying the
prefix and calling kmsan_get_metadata() again.

kmsan_virt_addr_valid() delegates to virt_addr_valid().

Link: https://lkml.kernel.org/r/20231213233605.661251-34-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/s390/include/asm/kmsan.h |   43 ++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

--- /dev/null
+++ a/arch/s390/include/asm/kmsan.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_KMSAN_H
+#define _ASM_S390_KMSAN_H
+
+#include <asm/lowcore.h>
+#include <asm/page.h>
+#include <linux/kmsan.h>
+#include <linux/mmzone.h>
+#include <linux/stddef.h>
+
+#ifndef MODULE
+
+static inline bool is_lowcore_addr(void *addr)
+{
+	return addr >= (void *)&S390_lowcore &&
+	       addr < (void *)(&S390_lowcore + 1);
+}
+
+static inline void *arch_kmsan_get_meta_or_null(void *addr, bool is_origin)
+{
+	if (is_lowcore_addr(addr)) {
+		/*
+		 * Different lowcores accessed via S390_lowcore are described
+		 * by the same struct page. Resolve the prefix manually in
+		 * order to get a distinct struct page.
+		 */
+		addr += (void *)lowcore_ptr[raw_smp_processor_id()] -
+			(void *)&S390_lowcore;
+		if (WARN_ON_ONCE(is_lowcore_addr(addr)))
+			return NULL;
+		return kmsan_get_metadata(addr, is_origin);
+	}
+	return NULL;
+}
+
+static inline bool kmsan_virt_addr_valid(void *addr)
+{
+	return virt_addr_valid(addr);
+}
+
+#endif /* !MODULE */
+
+#endif /* _ASM_S390_KMSAN_H */
_

Patches currently in -mm which might be from iii@linux.ibm.com are

ftrace-unpoison-ftrace_regs-in-ftrace_ops_list_func.patch
kmsan-make-the-tests-compatible-with-kmsanpanic=1.patch
kmsan-disable-kmsan-when-deferred_struct_page_init-is-enabled.patch
kmsan-increase-the-maximum-store-size-to-4096.patch
kmsan-fix-is_bad_asm_addr-on-arches-with-overlapping-address-spaces.patch
kmsan-fix-kmsan_copy_to_user-on-arches-with-overlapping-address-spaces.patch
kmsan-remove-a-useless-assignment-from-kmsan_vmap_pages_range_noflush.patch
kmsan-remove-an-x86-specific-include-from-kmsanh.patch
kmsan-expose-kmsan_get_metadata.patch
kmsan-export-panic_on_kmsan.patch
kmsan-allow-disabling-kmsan-checks-for-the-current-task.patch
kmsan-support-slab_poison.patch
kmsan-use-align_down-in-kmsan_get_metadata.patch
mm-slub-let-kmsan-access-metadata.patch
mm-slub-unpoison-the-memchr_inv-return-value.patch
mm-kfence-disable-kmsan-when-checking-the-canary.patch
lib-zlib-unpoison-dfltcc-output-buffers.patch
kmsan-accept-ranges-starting-with-0-on-s390.patch
s390-turn-off-kmsan-for-boot-vdso-and-purgatory.patch
s390-use-a-larger-stack-for-kmsan.patch
s390-boot-add-the-kmsan-runtime-stub.patch
s390-checksum-add-a-kmsan-check.patch
s390-cpacf-unpoison-the-results-of-cpacf_trng.patch
s390-cpumf-unpoison-stcctm-output-buffer.patch
s390-diag-unpoison-diag224-output-buffer.patch
s390-ftrace-unpoison-ftrace_regs-in-kprobe_ftrace_handler.patch
s390-irqflags-do-not-instrument-arch_local_irq_-with-kmsan.patch
s390-mm-define-kmsan-metadata-for-vmalloc-and-modules.patch
s390-string-add-kmsan-support.patch
s390-traps-unpoison-the-kernel_stack_overflows-pt_regs.patch
s390-uaccess-add-kmsan-support-to-put_user-and-get_user.patch
s390-unwind-disable-kmsan-checks.patch
s390-implement-the-architecture-specific-kmsan-functions.patch
kmsan-enable-on-s390.patch