This change adds accounting for the memory allocated for shadow stacks.
Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Will Deacon <will@xxxxxxxxxx>
---
drivers/base/node.c | 6 ++++++
fs/proc/meminfo.c | 4 ++++
include/linux/mmzone.h | 3 +++
kernel/scs.c | 15 +++++++++++++++
mm/page_alloc.c | 6 ++++++
mm/vmstat.c | 3 +++
6 files changed, 37 insertions(+)
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 10d7e818e118..50b8c0d43859 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -415,6 +415,9 @@ static ssize_t node_read_meminfo(struct device *dev,
"Node %d AnonPages: %8lu kB\n"
"Node %d Shmem: %8lu kB\n"
"Node %d KernelStack: %8lu kB\n"
+#ifdef CONFIG_SHADOW_CALL_STACK
+ "Node %d ShadowCallStack:%8lu kB\n"
+#endif
"Node %d PageTables: %8lu kB\n"
"Node %d NFS_Unstable: %8lu kB\n"
"Node %d Bounce: %8lu kB\n"
@@ -438,6 +441,9 @@ static ssize_t node_read_meminfo(struct device *dev,
nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
nid, K(i.sharedram),
nid, sum_zone_node_page_state(nid, NR_KERNEL_STACK_KB),
+#ifdef CONFIG_SHADOW_CALL_STACK
+ nid, sum_zone_node_page_state(nid, NR_KERNEL_SCS_KB),
+#endif
nid, K(sum_zone_node_page_state(nid, NR_PAGETABLE)),
nid, K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 8c1f1bb1a5ce..09cd51c8d23d 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -103,6 +103,10 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
show_val_kb(m, "SUnreclaim: ", sunreclaim);
seq_printf(m, "KernelStack: %8lu kB\n",
global_zone_page_state(NR_KERNEL_STACK_KB));
+#ifdef CONFIG_SHADOW_CALL_STACK
+ seq_printf(m, "ShadowCallStack:%8lu kB\n",
+ global_zone_page_state(NR_KERNEL_SCS_KB));
+#endif
show_val_kb(m, "PageTables: ",
global_zone_page_state(NR_PAGETABLE));
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 1b9de7d220fb..acffc3bc6178 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -156,6 +156,9 @@ enum zone_stat_item {
NR_MLOCK, /* mlock()ed pages found and moved off LRU */
NR_PAGETABLE, /* used for pagetables */
NR_KERNEL_STACK_KB, /* measured in KiB */
+#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
+ NR_KERNEL_SCS_KB, /* measured in KiB */
+#endif
/* Second 128 byte cacheline */
NR_BOUNCE,
#if IS_ENABLED(CONFIG_ZSMALLOC)
diff --git a/kernel/scs.c b/kernel/scs.c
index 43624be9ad90..8769016c714c 100644
--- a/kernel/scs.c
+++ b/kernel/scs.c
@@ -6,8 +6,10 @@
*/
#include <linux/kasan.h>
+#include <linux/mm.h>
#include <linux/scs.h>
#include <linux/slab.h>
+#include <linux/vmstat.h>
#include <asm/scs.h>
static struct kmem_cache *scs_cache;
@@ -40,6 +42,17 @@ void __init scs_init(void)
scs_cache = kmem_cache_create("scs_cache", SCS_SIZE, 0, 0, NULL);
}
+static struct page *__scs_page(struct task_struct *tsk)
+{
+ return virt_to_page(task_scs(tsk));
+}
+
+static void scs_account(struct task_struct *tsk, int account)
+{
+ mod_zone_page_state(page_zone(__scs_page(tsk)), NR_KERNEL_SCS_KB,
+ account * (SCS_SIZE / 1024));
+}
+
int scs_prepare(struct task_struct *tsk, int node)
{
void *s;
@@ -50,6 +63,7 @@ int scs_prepare(struct task_struct *tsk, int node)
task_scs(tsk) = s;
task_scs_offset(tsk) = 0;
+ scs_account(tsk, 1);
return 0;
}
@@ -64,5 +78,6 @@ void scs_release(struct task_struct *tsk)
WARN_ON(scs_corrupted(tsk));
+ scs_account(tsk, -1);
scs_free(s);
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 69827d4fa052..83743d7a6177 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5411,6 +5411,9 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
" managed:%lukB"
" mlocked:%lukB"
" kernel_stack:%lukB"
+#ifdef CONFIG_SHADOW_CALL_STACK
+ " shadow_call_stack:%lukB"
+#endif
" pagetables:%lukB"
" bounce:%lukB"
" free_pcp:%lukB"
@@ -5433,6 +5436,9 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
K(zone_managed_pages(zone)),
K(zone_page_state(zone, NR_MLOCK)),
zone_page_state(zone, NR_KERNEL_STACK_KB),
+#ifdef CONFIG_SHADOW_CALL_STACK
+ zone_page_state(zone, NR_KERNEL_SCS_KB),
+#endif
K(zone_page_state(zone, NR_PAGETABLE)),
K(zone_page_state(zone, NR_BOUNCE)),
K(free_pcp),
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 96d21a792b57..2435d2c24657 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1119,6 +1119,9 @@ const char * const vmstat_text[] = {
"nr_mlock",
"nr_page_table_pages",
"nr_kernel_stack",
+#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
+ "nr_shadow_call_stack",
+#endif
"nr_bounce",
#if IS_ENABLED(CONFIG_ZSMALLOC)
"nr_zspages",
--
2.26.2.303.gf8c07b1a785-goog
