From: Marco Elver <elver@google.com>
To: Alexander Potapenko <glider@google.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>,
Dmitry Vyukov <dvyukov@google.com>,
Linux Memory Management List <linux-mm@kvack.org>,
Al Viro <viro@zeniv.linux.org.uk>,
adilger.kernel@dilger.ca,
Andrew Morton <akpm@linux-foundation.org>,
Andrey Konovalov <andreyknvl@google.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Andy Lutomirski <luto@kernel.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Arnd Bergmann <arnd@arndb.de>,
hch@infradead.org, hch@lst.de, darrick.wong@oracle.com,
davem@davemloft.net, dmitry.torokhov@gmail.com,
ebiggers@google.com, Eric Dumazet <edumazet@google.com>,
ericvh@gmail.com, gregkh@linuxfoundation.org,
harry.wentland@amd.com, herbert@gondor.apana.org.au,
iii@linux.ibm.com, mingo@elte.hu, jasowang@redhat.com,
axboe@kernel.dk, m.szyprowski@samsung.com,
Mark Rutland <mark.rutland@arm.com>,
martin.petersen@oracle.com, schwidefsky@de.ibm.com,
Matthew Wilcox <willy@infradead.org>,
mst@redhat.com, monstr@monstr.eu, pmladek@suse.com,
Qian Cai <cai@lca.pw>, Randy Dunlap <rdunlap@infradead.org>,
robin.murphy@arm.com,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
tiwai@suse.com, tytso@mit.edu,
Thomas Gleixner <tglx@linutronix.de>,
gor@linux.ibm.com, wsa@the-dreams.de
Subject: Re: [PATCH RFC v3 04/36] stackdepot: reserve 5 extra bits in depot_stack_handle_t
Date: Wed, 27 Nov 2019 15:23:05 +0100 [thread overview]
Message-ID: <CANpmjNOh5Ey6QfKkWxjHENuQmjVyKsh4Zi5wkpmeuWRpyquTDw@mail.gmail.com> (raw)
In-Reply-To: <20191122112621.204798-5-glider@google.com>
On Fri, 22 Nov 2019 at 12:26, <glider@google.com> wrote:
[...]
> 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);
The function declaration mismatches its definition ('unsigned bits' vs 'u32').
> +unsigned int get_dsh_extra_bits(depot_stack_handle_t handle);
This also doesn't match the definition.
The abbreviation 'dsh' in these function names is not very readable.
Maybe just '{set,get}_stack_depot_extra' ?
> #endif
> diff --git a/lib/stackdepot.c b/lib/stackdepot.c
> index eb95197b8743..e2f000a9fad8 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;
Would a BUILD_BUG_ON somewhere to assert that the total bits do not
exceed DEPOT_STACK_BITS make sense?
> };
> };
>
> @@ -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;
>
> --
> 2.24.0.432.g9d3f5f5b63-goog
>
next prev parent reply other threads:[~2019-11-27 14:23 UTC|newest]
Thread overview: 120+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-22 11:25 [PATCH RFC v3 00/36] Add KernelMemorySanitizer infrastructure glider
2019-11-22 11:25 ` [PATCH RFC v3 01/36] stackdepot: check depot_index before accessing the stack slab glider
2019-11-27 14:22 ` Marco Elver
2019-11-22 11:25 ` [PATCH RFC v3 02/36] stackdepot: build with -fno-builtin glider
2019-11-27 14:22 ` Marco Elver
2019-11-22 11:25 ` [PATCH RFC v3 03/36] kasan: stackdepot: move filter_irq_stacks() to stackdepot.c glider
2019-11-27 14:22 ` Marco Elver
2019-11-27 14:56 ` Alexander Potapenko
2019-11-22 11:25 ` [PATCH RFC v3 04/36] stackdepot: reserve 5 extra bits in depot_stack_handle_t glider
2019-11-27 14:23 ` Marco Elver [this message]
2019-11-22 11:25 ` [PATCH RFC v3 05/36] kmsan: add ReST documentation glider
2019-11-27 14:22 ` Marco Elver
2019-12-03 12:42 ` Alexander Potapenko
2019-11-22 11:25 ` [PATCH RFC v3 06/36] kmsan: gfp: introduce __GFP_NO_KMSAN_SHADOW glider
2019-11-27 14:48 ` Marco Elver
2019-12-03 12:57 ` Alexander Potapenko
2019-11-22 11:25 ` [PATCH RFC v3 07/36] kmsan: introduce __no_sanitize_memory and __SANITIZE_MEMORY__ glider
2019-11-28 13:13 ` Marco Elver
2019-11-29 16:09 ` Andrey Konovalov
2019-12-16 11:35 ` Alexander Potapenko
2019-11-22 11:25 ` [PATCH RFC v3 08/36] kmsan: reduce vmalloc space glider
2019-11-28 13:30 ` Marco Elver
2019-11-22 11:25 ` [PATCH RFC v3 09/36] kmsan: add KMSAN bits to struct page and struct task_struct glider
2019-11-28 13:44 ` Marco Elver
2019-11-28 14:05 ` Alexander Potapenko
2019-11-22 11:25 ` [PATCH RFC v3 10/36] kmsan: add KMSAN runtime glider
2019-11-24 19:44 ` Wolfram Sang
2019-11-25 9:14 ` Alexander Potapenko
2019-11-29 16:07 ` Marco Elver
2019-12-19 14:16 ` Alexander Potapenko
2019-12-02 15:39 ` Andrey Konovalov
2019-12-20 18:58 ` Alexander Potapenko
2019-12-03 14:34 ` Andrey Konovalov
2019-11-22 11:25 ` [PATCH RFC v3 11/36] kmsan: stackdepot: don't allocate KMSAN metadata for stackdepot glider
2019-11-29 14:52 ` Andrey Konovalov
2019-12-03 14:27 ` Alexander Potapenko
2019-11-22 11:25 ` [PATCH RFC v3 12/36] kmsan: define READ_ONCE_NOCHECK() glider
2019-12-02 10:03 ` Marco Elver
2019-12-03 12:45 ` Alexander Potapenko
2019-11-22 11:25 ` [PATCH RFC v3 13/36] kmsan: make READ_ONCE_TASK_STACK() return initialized values glider
2019-12-02 10:07 ` Marco Elver
2019-12-05 15:52 ` Alexander Potapenko
2019-11-22 11:25 ` [PATCH RFC v3 14/36] kmsan: x86: sync metadata pages on page fault glider
2019-11-22 11:26 ` [PATCH RFC v3 15/36] kmsan: add tests for KMSAN glider
2019-11-29 14:14 ` Andrey Konovalov
2019-12-05 14:30 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 16/36] crypto: kmsan: disable accelerated configs under KMSAN glider
2019-12-02 13:25 ` Marco Elver
2019-12-05 14:51 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 17/36] kmsan: x86: disable UNWINDER_ORC " glider
2019-12-02 13:30 ` Marco Elver
2019-11-22 11:26 ` [PATCH RFC v3 18/36] kmsan: disable LOCK_DEBUGGING_SUPPORT glider
2019-12-02 13:33 ` Marco Elver
2019-12-03 14:34 ` Alexander Potapenko
2019-12-03 15:00 ` Qian Cai
2019-12-03 15:14 ` Alexander Potapenko
2019-12-03 18:02 ` Qian Cai
2019-12-03 18:38 ` Steven Rostedt
2019-12-04 8:41 ` Alexander Potapenko
2019-12-04 12:22 ` Petr Mladek
2019-12-04 13:12 ` Qian Cai
2019-12-04 16:24 ` Alexander Potapenko
2019-12-04 18:03 ` Qian Cai
2019-11-22 11:26 ` [PATCH RFC v3 20/36] kmsan: x86: increase stack sizes in KMSAN builds glider
2019-12-02 14:31 ` Marco Elver
2019-11-22 11:26 ` [PATCH RFC v3 21/36] kmsan: disable KMSAN instrumentation for certain kernel parts glider
2019-11-29 15:07 ` Andrey Konovalov
2019-12-10 10:35 ` Alexander Potapenko
2019-12-10 12:38 ` Alexander Potapenko
2019-12-10 12:43 ` Qian Cai
2019-11-22 11:26 ` [PATCH RFC v3 22/36] kmsan: mm: call KMSAN hooks from SLUB code glider
2019-12-02 15:36 ` Marco Elver
2019-12-10 12:07 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 23/36] kmsan: call KMSAN hooks where needed glider
2019-11-26 10:17 ` Petr Mladek
2019-11-26 10:52 ` Alexander Potapenko
2019-11-29 16:21 ` Andrey Konovalov
2019-12-16 11:30 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 24/36] kmsan: disable instrumentation of certain functions glider
2019-11-29 14:59 ` Andrey Konovalov
2019-12-18 10:02 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 25/36] kmsan: unpoison |tlb| in arch_tlb_gather_mmu() glider
2019-11-29 15:08 ` Andrey Konovalov
2019-12-03 14:19 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 26/36] kmsan: use __msan_memcpy() where possible glider
2019-11-29 15:13 ` Andrey Konovalov
2019-12-05 15:46 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 27/36] kmsan: hooks for copy_to_user() and friends glider
2019-11-29 15:34 ` Andrey Konovalov
2019-12-05 16:00 ` Alexander Potapenko
2019-12-05 16:44 ` Andrey Konovalov
2019-12-11 14:22 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 28/36] kmsan: enable KMSAN builds glider
2019-11-29 15:55 ` Andrey Konovalov
2019-12-11 12:51 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 29/36] kmsan: handle /dev/[u]random glider
2019-11-22 11:26 ` [PATCH RFC v3 30/36] kmsan: virtio: check/unpoison scatterlist in vring_map_one_sg() glider
2019-11-22 11:26 ` [PATCH RFC v3 31/36] kmsan: disable strscpy() optimization under KMSAN glider
2019-12-02 15:51 ` Marco Elver
2019-12-02 16:23 ` Alexander Potapenko
2019-12-03 11:19 ` Alexander Potapenko
2019-12-03 11:24 ` Marco Elver
2019-12-03 11:27 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 32/36] kmsan: add iomap support glider
2019-12-03 12:50 ` Marco Elver
2019-12-03 14:07 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 33/36] kmsan: dma: unpoison memory mapped by dma_direct_map_page() glider
2019-11-22 11:26 ` [PATCH RFC v3 34/36] kmsan: disable physical page merging in biovec glider
2019-12-03 12:54 ` Marco Elver
2019-12-03 13:38 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 35/36] kmsan: ext4: skip block merging logic in ext4_mpage_readpages for KMSAN glider
2019-11-25 16:05 ` Robin Murphy
2019-11-25 17:03 ` Alexander Potapenko
2019-12-03 14:22 ` Marco Elver
2019-12-05 14:31 ` Alexander Potapenko
2019-11-22 11:26 ` [PATCH RFC v3 36/36] net: kasan: kmsan: support CONFIG_GENERIC_CSUM on x86, enable it for KASAN/KMSAN glider
2019-12-03 14:17 ` Marco Elver
2019-12-05 14:37 ` Alexander Potapenko
2019-11-29 14:39 ` [PATCH RFC v3 00/36] Add KernelMemorySanitizer infrastructure Marco Elver
2019-12-02 16:02 ` Alexander Potapenko
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