From 0d14076c93ea0c5d220ce6956c67f0929d00f8b4 Mon Sep 17 00:00:00 2001
From: Daniel Kiss <daniel.kiss@arm.com>
Date: Mon, 16 Mar 2020 16:50:54 +0000
Subject: [PATCH] mm: smaps: Report arm64 guarded pages in smaps
The arm64 Branch Target Identification support is activated by marking
executable pages as guarded pages. Report pages mapped this way in
smaps to aid diagnostics.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Daniel Kiss <daniel.kiss@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
Documentation/filesystems/proc.txt | 1 +
fs/proc/task_mmu.c | 3 +++
2 files changed, 4 insertions(+)
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 99ca040e3f900..ed5465d0f4350 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -519,6 +519,7 @@ manner. The codes are the following:
hg - huge page advise flag
nh - no-huge page advise flag
mg - mergable advise flag
+ bt - arm64 BTI guarded page
Note that there is no guarantee that every flag and associated mnemonic will
be present in all further kernel releases. Things get changed, the flags may
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 3ba9ae83bff5a..1e3409c484d16 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -668,6 +668,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
[ilog2(VM_ARCH_1)] = "ar",
[ilog2(VM_WIPEONFORK)] = "wf",
[ilog2(VM_DONTDUMP)] = "dd",
+#ifdef CONFIG_ARM64_BTI
+ [ilog2(VM_ARM64_BTI)] = "bt",
+#endif
#ifdef CONFIG_MEM_SOFT_DIRTY
[ilog2(VM_SOFTDIRTY)] = "sd",
#endif
--
2.39.5