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author | Kees Cook <keescook@chromium.org> | 2016-08-17 14:42:10 -0700 |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-10-31 13:01:57 -0700 |
commit | 0cd340dcb05c4a43742fe156f36737bb2a321bfd (patch) | |
tree | 1e45dac53b3a090f28e2e11a5328f0f5a8b4d6a0 /lib/list_debug.c | |
parent | 54acd4397d7e7a725c94101180cd9f38ef701acc (diff) | |
download | linux-0cd340dcb05c4a43742fe156f36737bb2a321bfd.tar.gz linux-0cd340dcb05c4a43742fe156f36737bb2a321bfd.tar.bz2 linux-0cd340dcb05c4a43742fe156f36737bb2a321bfd.zip |
list: Split list_del() debug checking into separate function
Similar to the list_add() debug consolidation, this commit consolidates
the debug checking performed during CONFIG_DEBUG_LIST into a new
__list_del_entry_valid() function, and stops list updates when corruption
is found.
Refactored from same hardening in PaX and Grsecurity.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Diffstat (limited to 'lib/list_debug.c')
-rw-r--r-- | lib/list_debug.c | 53 |
1 files changed, 23 insertions, 30 deletions
diff --git a/lib/list_debug.c b/lib/list_debug.c index d0b89b9d0736..276565fca2a6 100644 --- a/lib/list_debug.c +++ b/lib/list_debug.c @@ -39,41 +39,34 @@ bool __list_add_valid(struct list_head *new, struct list_head *prev, } EXPORT_SYMBOL(__list_add_valid); -void __list_del_entry(struct list_head *entry) +bool __list_del_entry_valid(struct list_head *entry) { struct list_head *prev, *next; prev = entry->prev; next = entry->next; - if (WARN(next == LIST_POISON1, - "list_del corruption, %p->next is LIST_POISON1 (%p)\n", - entry, LIST_POISON1) || - WARN(prev == LIST_POISON2, - "list_del corruption, %p->prev is LIST_POISON2 (%p)\n", - entry, LIST_POISON2) || - WARN(prev->next != entry, - "list_del corruption. prev->next should be %p, " - "but was %p\n", entry, prev->next) || - WARN(next->prev != entry, - "list_del corruption. next->prev should be %p, " - "but was %p\n", entry, next->prev)) - return; - - __list_del(prev, next); -} -EXPORT_SYMBOL(__list_del_entry); + if (unlikely(next == LIST_POISON1)) { + WARN(1, "list_del corruption, %p->next is LIST_POISON1 (%p)\n", + entry, LIST_POISON1); + return false; + } + if (unlikely(prev == LIST_POISON2)) { + WARN(1, "list_del corruption, %p->prev is LIST_POISON2 (%p)\n", + entry, LIST_POISON2); + return false; + } + if (unlikely(prev->next != entry)) { + WARN(1, "list_del corruption. prev->next should be %p, but was %p\n", + entry, prev->next); + return false; + } + if (unlikely(next->prev != entry)) { + WARN(1, "list_del corruption. next->prev should be %p, but was %p\n", + entry, next->prev); + return false; + } + return true; -/** - * list_del - deletes entry from list. - * @entry: the element to delete from the list. - * Note: list_empty on entry does not return true after this, the entry is - * in an undefined state. - */ -void list_del(struct list_head *entry) -{ - __list_del_entry(entry); - entry->next = LIST_POISON1; - entry->prev = LIST_POISON2; } -EXPORT_SYMBOL(list_del); +EXPORT_SYMBOL(__list_del_entry_valid); |