From: glider@google.com
To: Vegard Nossum <vegard.nossum@oracle.com>,
Dmitry Vyukov <dvyukov@google.com>,
linux-mm@kvack.org
Cc: viro@zeniv.linux.org.uk, akpm@linux-foundation.org,
aryabinin@virtuozzo.com, luto@kernel.org,
ard.biesheuvel@linaro.org, arnd@arndb.de, hch@lst.de,
dmitry.torokhov@gmail.com, edumazet@google.com,
ericvh@gmail.com, gregkh@linuxfoundation.org,
harry.wentland@amd.com, herbert@gondor.apana.org.au,
mingo@elte.hu, axboe@kernel.dk, martin.petersen@oracle.com,
schwidefsky@de.ibm.com, mst@redhat.com, monstr@monstr.eu,
pmladek@suse.com, sergey.senozhatsky@gmail.com,
rostedt@goodmis.org, tiwai@suse.com, tytso@mit.edu,
tglx@linutronix.de, wsa@the-dreams.de, gor@linux.ibm.com,
iii@linux.ibm.com, mark.rutland@arm.com, willy@infradead.org,
rdunlap@infradead.org, andreyknvl@google.com, elver@google.com,
Alexander Potapenko <glider@google.com>
Subject: [PATCH RFC v2 04/25] stackdepot: reserve 5 extra bits in depot_stack_handle_t
Date: Wed, 30 Oct 2019 15:22:16 +0100 [thread overview]
Message-ID: <20191030142237.249532-5-glider@google.com> (raw)
In-Reply-To: <20191030142237.249532-1-glider@google.com>
Some users (currently only KMSAN) may want to use spare bits in
depot_stack_handle_t. Let them do so and provide get_dsh_extra_bits()
and set_dsh_extra_bits() to access those bits.
Signed-off-by: Alexander Potapenko <glider@google.com>
To: Alexander Potapenko <glider@google.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: linux-mm@kvack.org
---
Change-Id: I23580dbde85908eeda0bdd8f83a8c3882ab3e012
---
include/linux/stackdepot.h | 8 ++++++++
lib/stackdepot.c | 24 +++++++++++++++++++++++-
2 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h
index 24d49c732341..ac1b5a78d7f6 100644
--- a/include/linux/stackdepot.h
+++ b/include/linux/stackdepot.h
@@ -12,6 +12,11 @@
#define _LINUX_STACKDEPOT_H
typedef u32 depot_stack_handle_t;
+/*
+ * Number of bits in the handle that stack depot doesn't use. Users may store
+ * information in them.
+ */
+#define STACK_DEPOT_EXTRA_BITS 5
depot_stack_handle_t stack_depot_save(unsigned long *entries,
unsigned int nr_entries, gfp_t gfp_flags);
@@ -20,5 +25,8 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle,
unsigned long **entries);
unsigned int filter_irq_stacks(unsigned long *entries, unsigned int nr_entries);
+depot_stack_handle_t set_dsh_extra_bits(depot_stack_handle_t handle,
+ unsigned int bits);
+unsigned int get_dsh_extra_bits(depot_stack_handle_t handle);
#endif
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index decb1e073b58..460efd3ef742 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -40,8 +40,10 @@
#define STACK_ALLOC_ALIGN 4
#define STACK_ALLOC_OFFSET_BITS (STACK_ALLOC_ORDER + PAGE_SHIFT - \
STACK_ALLOC_ALIGN)
+
#define STACK_ALLOC_INDEX_BITS (DEPOT_STACK_BITS - \
- STACK_ALLOC_NULL_PROTECTION_BITS - STACK_ALLOC_OFFSET_BITS)
+ STACK_ALLOC_NULL_PROTECTION_BITS - \
+ STACK_ALLOC_OFFSET_BITS - STACK_DEPOT_EXTRA_BITS)
#define STACK_ALLOC_SLABS_CAP 8192
#define STACK_ALLOC_MAX_SLABS \
(((1LL << (STACK_ALLOC_INDEX_BITS)) < STACK_ALLOC_SLABS_CAP) ? \
@@ -54,6 +56,7 @@ union handle_parts {
u32 slabindex : STACK_ALLOC_INDEX_BITS;
u32 offset : STACK_ALLOC_OFFSET_BITS;
u32 valid : STACK_ALLOC_NULL_PROTECTION_BITS;
+ u32 extra : STACK_DEPOT_EXTRA_BITS;
};
};
@@ -72,6 +75,24 @@ static int next_slab_inited;
static size_t depot_offset;
static DEFINE_SPINLOCK(depot_lock);
+depot_stack_handle_t set_dsh_extra_bits(depot_stack_handle_t handle,
+ u32 bits)
+{
+ union handle_parts parts = { .handle = handle };
+
+ parts.extra = bits & ((1U << STACK_DEPOT_EXTRA_BITS) - 1);
+ return parts.handle;
+}
+EXPORT_SYMBOL_GPL(set_dsh_extra_bits);
+
+u32 get_dsh_extra_bits(depot_stack_handle_t handle)
+{
+ union handle_parts parts = { .handle = handle };
+
+ return parts.extra;
+}
+EXPORT_SYMBOL_GPL(get_dsh_extra_bits);
+
static bool init_stack_slab(void **prealloc)
{
if (!*prealloc)
@@ -132,6 +153,7 @@ static struct stack_record *depot_alloc_stack(unsigned long *entries, int size,
stack->handle.slabindex = depot_index;
stack->handle.offset = depot_offset >> STACK_ALLOC_ALIGN;
stack->handle.valid = 1;
+ stack->handle.extra = 0;
memcpy(stack->entries, entries, size * sizeof(unsigned long));
depot_offset += required_size;
--
2.24.0.rc0.303.g954a862665-goog
next prev parent reply other threads:[~2019-10-30 14:22 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-30 14:22 [PATCH RFC v2 00/25] Add KernelMemorySanitizer infrastructure glider
2019-10-30 14:22 ` [PATCH RFC v2 01/25] stackdepot: check depot_index before accessing the stack slab glider
2019-10-30 14:22 ` [PATCH RFC v2 02/25] stackdepot: prevent Clang from optimizing away stackdepot_memcmp() glider
2019-11-01 5:50 ` Sergey Senozhatsky
2019-11-06 11:43 ` Alexander Potapenko
2019-11-07 6:08 ` Sergey Senozhatsky
2019-11-07 9:04 ` Arnd Bergmann
2019-11-07 9:22 ` Alexander Potapenko
2019-11-07 9:28 ` Arnd Bergmann
2019-11-07 9:43 ` Alexander Potapenko
[not found] ` <47fdac13-fa2c-2acd-2480-5e6d4db208f8@virtuozzo.com>
2019-11-07 10:00 ` Arnd Bergmann
[not found] ` <6875c6e6-2f1f-f8e6-e5d7-d451c48397ff@virtuozzo.com>
2019-11-07 10:30 ` Alexander Potapenko
2019-10-30 14:22 ` [PATCH RFC v2 03/25] kasan: stackdepot: move filter_irq_stacks() to stackdepot.c glider
2019-10-30 14:22 ` glider [this message]
2019-10-30 14:22 ` [PATCH RFC v2 05/25] kmsan: add ReST documentation glider
2019-10-30 14:22 ` [PATCH RFC v2 06/25] kmsan: gfp: introduce __GFP_NO_KMSAN_SHADOW glider
2019-10-30 14:22 ` [PATCH RFC v2 07/25] kmsan: introduce __no_sanitize_memory and __SANITIZE_MEMORY__ glider
2019-10-30 15:50 ` Andrey Konovalov
2019-11-01 12:52 ` Alexander Potapenko
2019-10-30 14:22 ` [PATCH RFC v2 08/25] kmsan: reduce vmalloc space glider
2019-10-30 14:22 ` [PATCH RFC v2 09/25] kmsan: add KMSAN runtime glider
2019-11-08 12:08 ` Dmitry Vyukov
2019-11-08 12:17 ` Dmitry Vyukov
2019-11-21 12:06 ` Alexander Potapenko
2019-11-13 8:13 ` Wolfram Sang
2019-11-21 12:01 ` Alexander Potapenko
2019-10-30 14:22 ` [PATCH RFC v2 10/25] kmsan: define READ_ONCE_NOCHECK() glider
2019-11-05 14:21 ` Mark Rutland
2019-11-21 12:08 ` Alexander Potapenko
2019-10-30 14:22 ` [PATCH RFC v2 11/25] kmsan: x86: sync metadata pages on page fault glider
2019-10-30 14:22 ` [PATCH RFC v2 12/25] kmsan: add tests for KMSAN glider
2019-10-30 14:22 ` [PATCH RFC v2 13/25] kmsan: make READ_ONCE_TASK_STACK() return initialized values glider
2019-10-30 14:22 ` [PATCH RFC v2 14/25] kmsan: Kconfig changes to disable options incompatible with KMSAN glider
2019-10-30 14:34 ` Qian Cai
2019-10-30 14:34 ` Christoph Hellwig
2019-10-30 14:22 ` [PATCH RFC v2 15/25] kmsan: Changing existing files to enable KMSAN builds glider
2019-10-30 14:36 ` Christoph Hellwig
2019-10-30 14:22 ` [PATCH RFC v2 16/25] kmsan: disable KMSAN instrumentation for certain kernel parts glider
2019-10-30 14:22 ` [PATCH RFC v2 17/25] kmsan: mm: call KMSAN hooks from SLUB code glider
2019-10-30 16:07 ` Andrey Konovalov
2019-10-30 14:22 ` [PATCH RFC v2 18/25] kmsan: call KMSAN hooks where needed glider
2019-10-31 11:49 ` Petr Mladek
2019-11-01 8:26 ` Sergey Senozhatsky
2019-11-05 14:12 ` Alexander Potapenko
2019-11-06 9:04 ` Petr Mladek
2019-11-06 9:07 ` Sergey Senozhatsky
2019-10-30 14:22 ` [PATCH RFC v2 19/25] kmsan: disable instrumentation of certain functions glider
2019-10-30 14:22 ` [PATCH RFC v2 20/25] kmsan: unpoison |tlb| in arch_tlb_gather_mmu() glider
2019-10-30 14:22 ` [PATCH RFC v2 21/25] kmsan: use __msan_memcpy() where possible glider
2019-10-30 14:22 ` [PATCH RFC v2 22/25] kmsan: unpoisoning buffers from devices etc glider
2019-10-30 14:38 ` Christoph Hellwig
2019-11-05 15:02 ` Alexander Potapenko
2019-11-07 13:00 ` Alexander Potapenko
2019-11-13 11:07 ` Alexander Potapenko
2019-10-30 14:22 ` [PATCH RFC v2 23/25] kmsan: hooks for copy_to_user() and friends glider
2019-10-30 14:22 ` [PATCH RFC v2 24/25] kmsan: disable strscpy() optimization under KMSAN glider
2019-10-30 14:22 ` [PATCH RFC v2 25/25] net: kasan: kmsan: support CONFIG_GENERIC_CSUM on x86, enable it for KASAN/KMSAN glider
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