From 628d06a48f57c36abdc2a024930212e654a501b7 Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Mon, 27 Apr 2020 09:00:08 -0700 Subject: [PATCH] scs: Add page accounting for shadow call stack allocations This change adds accounting for the memory allocated for shadow stacks. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Acked-by: Will Deacon Signed-off-by: Will Deacon --- 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 38f8f31c9451..6d2f983ac54e 100644 --- a/kernel/scs.c +++ b/kernel/scs.c @@ -6,8 +6,10 @@ */ #include +#include #include #include +#include #include 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 = scs_alloc(node); @@ -49,6 +62,7 @@ int scs_prepare(struct task_struct *tsk, int node) task_scs(tsk) = s; task_scs_offset(tsk) = 0; + scs_account(tsk, 1); return 0; } @@ -61,5 +75,6 @@ void scs_release(struct task_struct *tsk) return; WARN(scs_corrupted(tsk), "corrupted shadow stack detected when freeing task\n"); + 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", -- 2.25.1