diff options
| author | Andrey Konovalov <andreyknvl@google.com> | 2022-09-06 00:05:47 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-10-04 00:03:02 +0300 |
| commit | 80b92bfe3bb75aa6688f58af9df356757a46f659 (patch) | |
| tree | 03827a0d4725b1ad461ff9f57e9919f7c0b33ad3 /mm/kasan/tags.c | |
| parent | 7ebfce33125100e3f0c5e059845a019a1401433d (diff) | |
| download | linux-80b92bfe3bb75aa6688f58af9df356757a46f659.tar.xz | |
kasan: dynamically allocate stack ring entries
Instead of using a large static array, allocate the stack ring dynamically
via memblock_alloc().
The size of the stack ring is controlled by a new kasan.stack_ring_size
command-line parameter. When kasan.stack_ring_size is not provided, the
default value of 32 << 10 is used.
When the stack trace collection is disabled via kasan.stacktrace=off, the
stack ring is not allocated.
Link: https://lkml.kernel.org/r/03b82ab60db53427e9818e0b0c1971baa10c3cbc.1662411800.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/kasan/tags.c')
| -rw-r--r-- | mm/kasan/tags.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index dd929ab166fb..67a222586846 100644 --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -10,6 +10,7 @@ #include <linux/init.h> #include <linux/kasan.h> #include <linux/kernel.h> +#include <linux/memblock.h> #include <linux/memory.h> #include <linux/mm.h> #include <linux/static_key.h> @@ -19,6 +20,8 @@ #include "kasan.h" #include "../slab.h" +#define KASAN_STACK_RING_SIZE_DEFAULT (32 << 10) + enum kasan_arg_stacktrace { KASAN_ARG_STACKTRACE_DEFAULT, KASAN_ARG_STACKTRACE_OFF, @@ -54,6 +57,16 @@ static int __init early_kasan_flag_stacktrace(char *arg) } early_param("kasan.stacktrace", early_kasan_flag_stacktrace); +/* kasan.stack_ring_size=<number of entries> */ +static int __init early_kasan_flag_stack_ring_size(char *arg) +{ + if (!arg) + return -EINVAL; + + return kstrtoul(arg, 0, &stack_ring.size); +} +early_param("kasan.stack_ring_size", early_kasan_flag_stack_ring_size); + void __init kasan_init_tags(void) { switch (kasan_arg_stacktrace) { @@ -67,6 +80,16 @@ void __init kasan_init_tags(void) static_branch_enable(&kasan_flag_stacktrace); break; } + + if (kasan_stack_collection_enabled()) { + if (!stack_ring.size) + stack_ring.size = KASAN_STACK_RING_SIZE_DEFAULT; + stack_ring.entries = memblock_alloc( + sizeof(stack_ring.entries[0]) * stack_ring.size, + SMP_CACHE_BYTES); + if (WARN_ON(!stack_ring.entries)) + static_branch_disable(&kasan_flag_stacktrace); + } } static void save_stack_info(struct kmem_cache *cache, void *object, @@ -88,7 +111,7 @@ static void save_stack_info(struct kmem_cache *cache, void *object, next: pos = atomic64_fetch_add(1, &stack_ring.pos); - entry = &stack_ring.entries[pos % KASAN_STACK_RING_SIZE]; + entry = &stack_ring.entries[pos % stack_ring.size]; /* Detect stack ring entry slots that are being written to. */ old_ptr = READ_ONCE(entry->ptr); |