@@ -39,7 +39,6 @@ static void bug_at(unsigned char *ip, int line)
static void __ref __jump_label_transform(struct jump_entry *entry,
enum jump_label_type type,
- void *(*poker)(void *, const void *, size_t),
int init)
{
union jump_code_union jmp;
@@ -52,14 +51,6 @@ static void __ref __jump_label_transform(struct jump_entry *entry,
jmp.offset = jump_entry_target(entry) -
(jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE);
- /*
- * As long as we're UP and not yet marked RO, we can use
- * text_poke_early; SYSTEM_BOOTING guarantees both, as we switch to
- * SYSTEM_SCHEDULING before going either.
- */
- if (system_state == SYSTEM_BOOTING)
- poker = text_poke_early;
-
if (type == JUMP_LABEL_JMP) {
if (init) {
expect = default_nop; line = __LINE__;
@@ -82,16 +73,17 @@ static void __ref __jump_label_transform(struct jump_entry *entry,
bug_at((void *)jump_entry_code(entry), line);
/*
- * Make text_poke_bp() a default fallback poker.
+ * As long as we're UP and not yet marked RO, we can use
+ * text_poke_early; SYSTEM_BOOTING guarantees both, as we switch to
+ * SYSTEM_SCHEDULING before going either.
*
* At the time the change is being done, just ignore whether we
* are doing nop -> jump or jump -> nop transition, and assume
* always nop being the 'currently valid' instruction
- *
*/
- if (poker) {
- (*poker)((void *)jump_entry_code(entry), code,
- JUMP_LABEL_NOP_SIZE);
+ if (init || system_state == SYSTEM_BOOTING) {
+ text_poke_early((void *)jump_entry_code(entry), code,
+ JUMP_LABEL_NOP_SIZE);
return;
}
@@ -103,7 +95,7 @@ void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
mutex_lock(&text_mutex);
- __jump_label_transform(entry, type, NULL, 0);
+ __jump_label_transform(entry, type, 0);
mutex_unlock(&text_mutex);
}
@@ -133,7 +125,7 @@ __init_or_module void arch_jump_label_transform_static(struct jump_entry *entry,
jlstate = JL_STATE_NO_UPDATE;
}
if (jlstate == JL_STATE_UPDATE)
- __jump_label_transform(entry, type, text_poke_early, 1);
+ __jump_label_transform(entry, type, 1);
}
#endif
There are only two types of poking: early and breakpoint based. The use of a function pointer to perform poking complicates the code and is probably inefficient due to the use of indirect branches. Cc: Andy Lutomirski <luto@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Nadav Amit <namit@vmware.com> --- arch/x86/kernel/jump_label.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-)