[PATCH v7 11/14] x86/jump-label: remove support for custom poker
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
Cc: Kees Cook
Cc: Peter Zijlstra
Cc: Dave Hansen
Cc: Masami Hiramatsu
Signed-off-by: Nadav Amit
---
arch/x86/kernel/jump_label.c | 24
1 file changed, 8 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c
index ed5fe274a7d8..994c13e2867d 100644
--- a/arch/x86/kernel/jump_label.c
+++ b/arch/x86/kernel/jump_label.c
@@ -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(_mutex);
- __jump_label_transform(entry, type, NULL, 0);
+ __jump_label_transform(entry, type, 0);
mutex_unlock(_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
--
2.17.1
[PATCH v7 11/14] x86/jump-label: remove support for custom poker
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
Cc: Kees Cook
Cc: Peter Zijlstra
Cc: Dave Hansen
Cc: Masami Hiramatsu
Signed-off-by: Nadav Amit
---
arch/x86/kernel/jump_label.c | 24
1 file changed, 8 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c
index ed5fe274a7d8..994c13e2867d 100644
--- a/arch/x86/kernel/jump_label.c
+++ b/arch/x86/kernel/jump_label.c
@@ -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(_mutex);
- __jump_label_transform(entry, type, NULL, 0);
+ __jump_label_transform(entry, type, 0);
mutex_unlock(_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
--
2.17.1
