diff options
| author | Sami Tolvanen <samitolvanen@google.com> | 2019-01-16 11:28:49 -0800 |
|---|---|---|
| committer | Sami Tolvanen <samitolvanen@google.com> | 2019-01-23 15:06:27 -0800 |
| commit | 046daa57dd626d70a334e3210566c0eb6b515176 (patch) | |
| tree | 05052f5c419e8d0b47d782f050e1def7f504d374 | |
| parent | f9b2849005dae73b1814ffdecdb9af792c83af59 (diff) | |
ANDROID: cfi: fix shadow rebasing
If the module area base address changes when loading a new module, the
new CFI shadow will only cover the first allocated page for each existing
module. This will cause cross-DSO look-ups to functions elsewhere in the
module to fall back to a red-black tree, which may be slower.
Bug: 122963951
Change-Id: I9262034d39351afcd42590ead8d6384fc30a8ce8
Reported-by: Wu,Le <wule01@baidu.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
| -rw-r--r-- | kernel/cfi.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/cfi.c b/kernel/cfi.c index 6951c25d311b..b29bdaf8c566 100644 --- a/kernel/cfi.c +++ b/kernel/cfi.c @@ -87,6 +87,14 @@ static inline unsigned long shadow_to_ptr(const struct cfi_shadow *s, return (s->r.min_page + s->shadow[index]) << PAGE_SHIFT; } +static inline unsigned long shadow_to_page(const struct cfi_shadow *s, + int index) +{ + BUG_ON(index < 0 || index >= SHADOW_SIZE); + + return (s->r.min_page + index) << PAGE_SHIFT; +} + static void prepare_next_shadow(const struct cfi_shadow __rcu *prev, struct cfi_shadow *next) { @@ -109,7 +117,7 @@ static void prepare_next_shadow(const struct cfi_shadow __rcu *prev, if (prev->shadow[i] == SHADOW_INVALID) continue; - index = ptr_to_shadow(next, shadow_to_ptr(prev, i)); + index = ptr_to_shadow(next, shadow_to_page(prev, i)); if (index < 0) continue; |