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-rw-r--r--bcache_fix.patch129
1 files changed, 0 insertions, 129 deletions
diff --git a/bcache_fix.patch b/bcache_fix.patch
deleted file mode 100644
index f5c94a5..0000000
--- a/bcache_fix.patch
+++ /dev/null
@@ -1,129 +0,0 @@
-From 9e50f5f4ef401c4a5cd286ee3218fcc625ef6f77 Mon Sep 17 00:00:00 2001
-From: Coly Li <colyli@suse.de>
-Date: Mon, 10 Jun 2019 06:13:34 +0800
-Subject: bcache: fix stack corruption by PRECEDING_KEY()
-
-Recently people report bcache code compiled with gcc9 is broken, one of
-the buggy behavior I observe is that two adjacent 4KB I/Os should merge
-into one but they don't. Finally it turns out to be a stack corruption
-caused by macro PRECEDING_KEY().
-
-See how PRECEDING_KEY() is defined in bset.h,
-437 #define PRECEDING_KEY(_k) \
-438 ({ \
-439 struct bkey *_ret = NULL; \
-440 \
-441 if (KEY_INODE(_k) || KEY_OFFSET(_k)) { \
-442 _ret = &KEY(KEY_INODE(_k), KEY_OFFSET(_k), 0); \
-443 \
-444 if (!_ret->low) \
-445 _ret->high--; \
-446 _ret->low--; \
-447 } \
-448 \
-449 _ret; \
-450 })
-
-At line 442, _ret points to address of a on-stack variable combined by
-KEY(), the life range of this on-stack variable is in line 442-446,
-once _ret is returned to bch_btree_insert_key(), the returned address
-points to an invalid stack address and this address is overwritten in
-the following called bch_btree_iter_init(). Then argument 'search' of
-bch_btree_iter_init() points to some address inside stackframe of
-bch_btree_iter_init(), exact address depends on how the compiler
-allocates stack space. Now the stack is corrupted.
-
-Fixes: 0eacac22034c ("bcache: PRECEDING_KEY()")
-Signed-off-by: Coly Li <colyli@suse.de>
-Reviewed-by: Rolf Fokkens <rolf@rolffokkens.nl>
-Reviewed-by: Pierre JUHEN <pierre.juhen@orange.fr>
-Tested-by: Shenghui Wang <shhuiw@foxmail.com>
-Tested-by: Pierre JUHEN <pierre.juhen@orange.fr>
-Cc: Kent Overstreet <kent.overstreet@gmail.com>
-Cc: Nix <nix@esperi.org.uk>
-Cc: stable@vger.kernel.org
-Signed-off-by: Jens Axboe <axboe@kernel.dk>
----
- drivers/md/bcache/bset.c | 16 +++++++++++++---
- drivers/md/bcache/bset.h | 34 ++++++++++++++++++++--------------
- 2 files changed, 33 insertions(+), 17 deletions(-)
-
-diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
-index 8f07fa6e1739..268f1b685084 100644
---- a/drivers/md/bcache/bset.c
-+++ b/drivers/md/bcache/bset.c
-@@ -887,12 +887,22 @@ unsigned int bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
- struct bset *i = bset_tree_last(b)->data;
- struct bkey *m, *prev = NULL;
- struct btree_iter iter;
-+ struct bkey preceding_key_on_stack = ZERO_KEY;
-+ struct bkey *preceding_key_p = &preceding_key_on_stack;
-
- BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
-
-- m = bch_btree_iter_init(b, &iter, b->ops->is_extents
-- ? PRECEDING_KEY(&START_KEY(k))
-- : PRECEDING_KEY(k));
-+ /*
-+ * If k has preceding key, preceding_key_p will be set to address
-+ * of k's preceding key; otherwise preceding_key_p will be set
-+ * to NULL inside preceding_key().
-+ */
-+ if (b->ops->is_extents)
-+ preceding_key(&START_KEY(k), &preceding_key_p);
-+ else
-+ preceding_key(k, &preceding_key_p);
-+
-+ m = bch_btree_iter_init(b, &iter, preceding_key_p);
-
- if (b->ops->insert_fixup(b, k, &iter, replace_key))
- return status;
-diff --git a/drivers/md/bcache/bset.h b/drivers/md/bcache/bset.h
-index bac76aabca6d..c71365e7c1fa 100644
---- a/drivers/md/bcache/bset.h
-+++ b/drivers/md/bcache/bset.h
-@@ -434,20 +434,26 @@ static inline bool bch_cut_back(const struct bkey *where, struct bkey *k)
- return __bch_cut_back(where, k);
- }
-
--#define PRECEDING_KEY(_k) \
--({ \
-- struct bkey *_ret = NULL; \
-- \
-- if (KEY_INODE(_k) || KEY_OFFSET(_k)) { \
-- _ret = &KEY(KEY_INODE(_k), KEY_OFFSET(_k), 0); \
-- \
-- if (!_ret->low) \
-- _ret->high--; \
-- _ret->low--; \
-- } \
-- \
-- _ret; \
--})
-+/*
-+ * Pointer '*preceding_key_p' points to a memory object to store preceding
-+ * key of k. If the preceding key does not exist, set '*preceding_key_p' to
-+ * NULL. So the caller of preceding_key() needs to take care of memory
-+ * which '*preceding_key_p' pointed to before calling preceding_key().
-+ * Currently the only caller of preceding_key() is bch_btree_insert_key(),
-+ * and it points to an on-stack variable, so the memory release is handled
-+ * by stackframe itself.
-+ */
-+static inline void preceding_key(struct bkey *k, struct bkey **preceding_key_p)
-+{
-+ if (KEY_INODE(k) || KEY_OFFSET(k)) {
-+ (**preceding_key_p) = KEY(KEY_INODE(k), KEY_OFFSET(k), 0);
-+ if (!(*preceding_key_p)->low)
-+ (*preceding_key_p)->high--;
-+ (*preceding_key_p)->low--;
-+ } else {
-+ (*preceding_key_p) = NULL;
-+ }
-+}
-
- static inline bool bch_ptr_invalid(struct btree_keys *b, const struct bkey *k)
- {
---
-cgit v1.2.1-1-g437b
-
-