From: glider@google.com
To: Alexander Potapenko <glider@google.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>,
Dmitry Vyukov <dvyukov@google.com>,
linux-mm@kvack.org
Subject: [PATCH RFC v1 14/26] kmsan: make READ_ONCE_TASK_STACK() return initialized values
Date: Fri, 18 Oct 2019 11:42:52 +0200 [thread overview]
Message-ID: <20191018094304.37056-15-glider@google.com> (raw)
In-Reply-To: <20191018094304.37056-1-glider@google.com>
To avoid false positives, assume that reading from the task stack
always produces initialized values.
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: Ie73e5a41fdc8195699928e65f5cbe0d3d3c9e2fa
---
arch/x86/include/asm/unwind.h | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h
index 499578f7e6d7..f60c2bd1ddf2 100644
--- a/arch/x86/include/asm/unwind.h
+++ b/arch/x86/include/asm/unwind.h
@@ -100,9 +100,10 @@ void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
#endif
/*
- * This disables KASAN checking when reading a value from another task's stack,
- * since the other task could be running on another CPU and could have poisoned
- * the stack in the meantime.
+ * This disables KASAN/KMSAN checking when reading a value from another task's
+ * stack, since the other task could be running on another CPU and could have
+ * poisoned the stack in the meantime. Frame pointers are uninitialized by
+ * default, so for KMSAN we mark the return value initialized unconditionally.
*/
#define READ_ONCE_TASK_STACK(task, x) \
({ \
@@ -111,7 +112,7 @@ void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
val = READ_ONCE(x); \
else \
val = READ_ONCE_NOCHECK(x); \
- val; \
+ KMSAN_INIT_VALUE(val); \
})
static inline bool task_on_another_cpu(struct task_struct *task)
--
2.23.0.866.gb869b98d4c-goog
next prev parent reply other threads:[~2019-10-18 9:43 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-18 9:42 [PATCH RFC v1 00/26] Add KernelMemorySanitizer infrastructure glider
2019-10-18 9:42 ` [PATCH RFC v1 01/26] stackdepot: check depot_index before accessing the stack slab glider
2019-10-18 9:42 ` [PATCH RFC v1 02/26] stackdepot: prevent Clang from optimizing away stackdepot_memcmp() glider
2019-10-18 9:42 ` [PATCH RFC v1 03/26] kasan: stackdepot: move filter_irq_stacks() to stackdepot.c glider
2019-10-18 9:42 ` [PATCH RFC v1 04/26] stackdepot: reserve 5 extra bits in depot_stack_handle_t glider
2019-10-18 9:42 ` [PATCH RFC v1 05/26] printk_safe: externalize printk_context glider
2019-10-21 9:09 ` Petr Mladek
2019-10-23 17:57 ` Alexander Potapenko
2019-10-23 18:00 ` Alexander Potapenko
2019-10-24 12:46 ` Petr Mladek
2019-10-28 13:09 ` Alexander Potapenko
2019-10-29 12:02 ` Petr Mladek
2019-10-29 12:45 ` Alexander Potapenko
2019-10-18 9:42 ` [PATCH RFC v1 06/26] kasan: compiler.h: rename __no_kasan_or_inline into __no_memory_tool_or_inline glider
2019-10-18 9:42 ` [PATCH RFC v1 07/26] kmsan: add ReST documentation glider
2019-10-18 9:42 ` [PATCH RFC v1 08/26] kmsan: gfp: introduce __GFP_NO_KMSAN_SHADOW glider
2019-10-18 9:42 ` [PATCH RFC v1 09/26] kmsan: introduce __no_sanitize_memory and __SANITIZE_MEMORY__ glider
2019-10-18 9:42 ` [PATCH RFC v1 10/26] kmsan: reduce vmalloc space glider
2019-10-18 9:42 ` [PATCH RFC v1 11/26] kmsan: add KMSAN runtime glider
2019-10-18 9:42 ` [PATCH RFC v1 12/26] kmsan: x86: sync metadata pages on page fault glider
2019-10-18 9:42 ` [PATCH RFC v1 13/26] kmsan: add tests for KMSAN glider
2019-10-18 9:42 ` glider [this message]
2019-10-18 9:42 ` [PATCH RFC v1 15/26] kmsan: Kconfig changes to disable options incompatible with KMSAN glider
2019-10-21 14:11 ` Harry Wentland
2019-10-18 9:42 ` [PATCH RFC v1 16/26] kmsan: Changing existing files to enable KMSAN builds glider
2019-10-18 9:42 ` [PATCH RFC v1 17/26] kmsan: disable KMSAN instrumentation for certain kernel parts glider
2019-10-18 9:42 ` [PATCH RFC v1 18/26] kmsan: mm: call KMSAN hooks from SLUB code glider
2019-10-18 13:22 ` Qian Cai
2019-10-18 13:33 ` Alexander Potapenko
2019-10-18 13:41 ` Qian Cai
2019-10-18 13:55 ` Alexander Potapenko
2019-10-18 14:42 ` Qian Cai
2019-10-18 14:54 ` Alexander Potapenko
2019-10-18 15:13 ` Qian Cai
2019-10-18 15:30 ` Alexander Potapenko
2019-10-18 16:08 ` Qian Cai
2019-10-18 9:42 ` [PATCH RFC v1 19/26] kmsan: call KMSAN hooks where needed glider
2019-10-18 15:02 ` Qian Cai
2019-10-29 14:09 ` Alexander Potapenko
2019-10-29 14:56 ` Qian Cai
2019-10-21 9:25 ` Petr Mladek
2019-10-29 13:59 ` Alexander Potapenko
2019-10-18 9:42 ` [PATCH RFC v1 20/26] kmsan: disable instrumentation of certain functions glider
2019-10-18 9:42 ` [PATCH RFC v1 21/26] kmsan: unpoison |tlb| in arch_tlb_gather_mmu() glider
2019-10-18 9:43 ` [PATCH RFC v1 22/26] kmsan: use __msan_memcpy() where possible glider
2019-10-18 9:43 ` [PATCH RFC v1 23/26] kmsan: unpoisoning buffers from devices etc glider
2019-10-18 15:27 ` Christoph Hellwig
2019-10-18 16:22 ` Matthew Wilcox
2019-10-29 14:45 ` Alexander Potapenko
2019-10-30 12:43 ` Alexander Potapenko
2019-10-18 9:43 ` [PATCH RFC v1 24/26] kmsan: hooks for copy_to_user() and friends glider
2019-10-18 9:43 ` [PATCH RFC v1 25/26] kmsan: disable strscpy() optimization under KMSAN glider
2019-10-18 9:43 ` [PATCH RFC v1 26/26] net: kasan: kmsan: support CONFIG_GENERIC_CSUM on x86, enable it for KASAN/KMSAN glider
2019-10-19 3:20 ` Randy Dunlap
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