The patch titled
Subject: PM: hibernate: disable when there are active secretmem users
has been added to the -mm tree. Its filename is
pm-hibernate-disable-when-there-are-active-secretmem-users.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/pm-hibernate-disable-when-there-are-active-secretmem-users.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/pm-hibernate-disable-when-there-are-active-secretmem-users.patch
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------------------------------------------------------
From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Subject: PM: hibernate: disable when there are active secretmem users
It is unsafe to allow saving of secretmem areas to the hibernation snapshot
as they would be visible after the resume and this essentially will defeat
the purpose of secret memory mappings.
Prevent hibernation whenever there are active secret memory users.
Link: https://lkml.kernel.org/r/20201203062949.5484-9-rppt@xxxxxxxxxx
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christopher Lameter <cl@xxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Elena Reshetova <elena.reshetova@xxxxxxxxx>
Cc: Hagen Paul Pfeifer <hagen@xxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: James Bottomley <jejb@xxxxxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tycho Andersen <tycho@xxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/secretmem.h | 6 ++++++
kernel/power/hibernate.c | 5 ++++-
mm/secretmem.c | 15 +++++++++++++++
3 files changed, 25 insertions(+), 1 deletion(-)
--- a/include/linux/secretmem.h~pm-hibernate-disable-when-there-are-active-secretmem-users
+++ a/include/linux/secretmem.h
@@ -6,6 +6,7 @@
bool vma_is_secretmem(struct vm_area_struct *vma);
bool page_is_secretmem(struct page *page);
+bool secretmem_active(void);
#else
@@ -18,6 +19,11 @@ static inline bool page_is_secretmem(str
{
return false;
}
+
+static inline bool secretmem_active(void)
+{
+ return false;
+}
#endif /* CONFIG_SECRETMEM */
--- a/kernel/power/hibernate.c~pm-hibernate-disable-when-there-are-active-secretmem-users
+++ a/kernel/power/hibernate.c
@@ -31,6 +31,7 @@
#include <linux/genhd.h>
#include <linux/ktime.h>
#include <linux/security.h>
+#include <linux/secretmem.h>
#include <trace/events/power.h>
#include "power.h"
@@ -81,7 +82,9 @@ void hibernate_release(void)
bool hibernation_available(void)
{
- return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION);
+ return nohibernate == 0 &&
+ !security_locked_down(LOCKDOWN_HIBERNATION) &&
+ !secretmem_active();
}
/**
--- a/mm/secretmem.c~pm-hibernate-disable-when-there-are-active-secretmem-users
+++ a/mm/secretmem.c
@@ -45,6 +45,13 @@ struct secretmem_ctx {
static struct cma *secretmem_cma;
+static atomic_t secretmem_users;
+
+bool secretmem_active(void)
+{
+ return !!atomic_read(&secretmem_users);
+}
+
static int secretmem_account_pages(struct page *page, gfp_t gfp, int order)
{
int err;
@@ -179,6 +186,12 @@ static const struct vm_operations_struct
.fault = secretmem_fault,
};
+static int secretmem_release(struct inode *inode, struct file *file)
+{
+ atomic_dec(&secretmem_users);
+ return 0;
+}
+
static int secretmem_mmap(struct file *file, struct vm_area_struct *vma)
{
unsigned long len = vma->vm_end - vma->vm_start;
@@ -201,6 +214,7 @@ bool vma_is_secretmem(struct vm_area_str
}
static const struct file_operations secretmem_fops = {
+ .release = secretmem_release,
.mmap = secretmem_mmap,
};
@@ -318,6 +332,7 @@ SYSCALL_DEFINE1(memfd_secret, unsigned l
file->f_flags |= O_LARGEFILE;
fd_install(fd, file);
+ atomic_inc(&secretmem_users);
return fd;
err_put_fd:
_
Patches currently in -mm which might be from rppt@xxxxxxxxxxxxx are
alpha-switch-from-discontigmem-to-sparsemem.patch
ia64-remove-custom-__early_pfn_to_nid.patch
ia64-remove-ifdef-config_zone_dma32-statements.patch
ia64-discontig-paging_init-remove-local-max_pfn-calculation.patch
ia64-split-virtual-map-initialization-out-of-paging_init.patch
ia64-forbid-using-virtual_mem_map-with-flatmem.patch
ia64-make-sparsemem-default-and-disable-discontigmem.patch
arm-remove-config_arch_has_holes_memorymodel.patch
arm-arm64-move-free_unused_memmap-to-generic-mm.patch
arc-use-flatmem-with-freeing-of-unused-memory-map-instead-of-discontigmem.patch
m68k-mm-make-node-data-and-node-setup-depend-on-config_discontigmem.patch
m68k-mm-enable-use-of-generic-memory_modelh-for-discontigmem.patch
m68k-deprecate-discontigmem.patch
mm-introduce-debug_pagealloc_mapunmap_pages-helpers.patch
pm-hibernate-make-direct-map-manipulations-more-explicit.patch
arch-mm-restore-dependency-of-__kernel_map_pages-on-debug_pagealloc.patch
arch-mm-make-kernel_page_present-always-available.patch
mm-refactor-initialization-of-stuct-page-for-holes-in-memory-layout.patch
mm-refactor-initialization-of-stuct-page-for-holes-in-memory-layout-fix.patch
mm-add-definition-of-pmd_page_order.patch
mmap-make-mlock_future_check-global.patch
set_memory-allow-set_direct_map__noflush-for-multiple-pages.patch
set_memory-allow-querying-whether-set_direct_map_-is-actually-enabled.patch
mm-introduce-memfd_secret-system-call-to-create-secret-memory-areas.patch
secretmem-use-pmd-size-pages-to-amortize-direct-map-fragmentation.patch
secretmem-add-memcg-accounting.patch
pm-hibernate-disable-when-there-are-active-secretmem-users.patch
arch-mm-wire-up-memfd_secret-system-call-were-relevant.patch
secretmem-test-add-basic-selftest-for-memfd_secret2.patch
