[PATCH v1 1/1] /proc/pid/smaps: add mseal info for vma

From: jeffxu
Date: Fri Jun 14 2024 - 14:24:32 EST


From: Jeff Xu <jeffxu@xxxxxxxxxxxx>

Add sp in /proc/pid/smaps to indicate vma is sealed

Signed-off-by: Jeff Xu <jeffxu@xxxxxxxxxxxx>
---
Documentation/filesystems/proc.rst | 1 +
fs/proc/task_mmu.c | 3 +++
include/linux/mm.h | 5 +++++
mm/internal.h | 5 -----
4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 7c3a565ffbef..400217a1589c 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -571,6 +571,7 @@ encoded manner. The codes are the following:
um userfaultfd missing tracking
uw userfaultfd wr-protect tracking
ss shadow stack page
+ sp sealed page
== =======================================

Note that there is no guarantee that every flag and associated mnemonic will
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 6ed1f56b32b4..ba2db75ca22a 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -711,6 +711,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
#ifdef CONFIG_X86_USER_SHADOW_STACK
[ilog2(VM_SHADOW_STACK)] = "ss",
+#endif
+#ifdef CONFIG_64BIT
+ [ilog2(VM_SEALED)] = "sp",
#endif
};
size_t i;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 587d34879865..8600564898fa 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -314,6 +314,11 @@ extern unsigned int kobjsize(const void *objp);
#define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */
#define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */

+#ifdef CONFIG_64BIT
+/* VM is sealed, in vm_flags */
+#define VM_SEALED _BITUL(63)
+#endif
+
#ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS
#define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */
#define VM_HIGH_ARCH_BIT_1 33 /* bit only usable on 64-bit architectures */
diff --git a/mm/internal.h b/mm/internal.h
index fd68c43664d5..72f7c110d563 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1509,11 +1509,6 @@ void __meminit __init_single_page(struct page *page, unsigned long pfn,
unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,
int priority);

-#ifdef CONFIG_64BIT
-/* VM is sealed, in vm_flags */
-#define VM_SEALED _BITUL(63)
-#endif
-
#ifdef CONFIG_64BIT
static inline int can_do_mseal(unsigned long flags)
{
--
2.45.2.627.g7a2c4fd464-goog