summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/text-patching.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/include/asm/text-patching.h')
-rw-r--r--arch/x86/include/asm/text-patching.h86
1 files changed, 67 insertions, 19 deletions
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
index 23c626a742e8..67315fa3956a 100644
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -25,14 +25,6 @@ static inline void apply_paravirt(struct paravirt_patch_site *start,
*/
#define POKE_MAX_OPCODE_SIZE 5
-struct text_poke_loc {
- void *addr;
- int len;
- s32 rel32;
- u8 opcode;
- const u8 text[POKE_MAX_OPCODE_SIZE];
-};
-
extern void text_poke_early(void *addr, const void *opcode, size_t len);
/*
@@ -50,21 +42,13 @@ extern void text_poke_early(void *addr, const void *opcode, size_t len);
* an inconsistent instruction while you patch.
*/
extern void *text_poke(void *addr, const void *opcode, size_t len);
+extern void text_poke_sync(void);
extern void *text_poke_kgdb(void *addr, const void *opcode, size_t len);
extern int poke_int3_handler(struct pt_regs *regs);
extern void text_poke_bp(void *addr, const void *opcode, size_t len, const void *emulate);
-extern void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries);
-extern void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
- const void *opcode, size_t len, const void *emulate);
-extern int after_bootmem;
-extern __ro_after_init struct mm_struct *poking_mm;
-extern __ro_after_init unsigned long poking_addr;
-#ifndef CONFIG_UML_X86
-static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
-{
- regs->ip = ip;
-}
+extern void text_poke_queue(void *addr, const void *opcode, size_t len, const void *emulate);
+extern void text_poke_finish(void);
#define INT3_INSN_SIZE 1
#define INT3_INSN_OPCODE 0xCC
@@ -78,6 +62,67 @@ static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
#define JMP8_INSN_SIZE 2
#define JMP8_INSN_OPCODE 0xEB
+#define DISP32_SIZE 4
+
+static inline int text_opcode_size(u8 opcode)
+{
+ int size = 0;
+
+#define __CASE(insn) \
+ case insn##_INSN_OPCODE: size = insn##_INSN_SIZE; break
+
+ switch(opcode) {
+ __CASE(INT3);
+ __CASE(CALL);
+ __CASE(JMP32);
+ __CASE(JMP8);
+ }
+
+#undef __CASE
+
+ return size;
+}
+
+union text_poke_insn {
+ u8 text[POKE_MAX_OPCODE_SIZE];
+ struct {
+ u8 opcode;
+ s32 disp;
+ } __attribute__((packed));
+};
+
+static __always_inline
+void *text_gen_insn(u8 opcode, const void *addr, const void *dest)
+{
+ static union text_poke_insn insn; /* per instance */
+ int size = text_opcode_size(opcode);
+
+ insn.opcode = opcode;
+
+ if (size > 1) {
+ insn.disp = (long)dest - (long)(addr + size);
+ if (size == 2) {
+ /*
+ * Ensure that for JMP9 the displacement
+ * actually fits the signed byte.
+ */
+ BUG_ON((insn.disp >> 31) != (insn.disp >> 7));
+ }
+ }
+
+ return &insn.text;
+}
+
+extern int after_bootmem;
+extern __ro_after_init struct mm_struct *poking_mm;
+extern __ro_after_init unsigned long poking_addr;
+
+#ifndef CONFIG_UML_X86
+static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
{
/*
@@ -85,6 +130,9 @@ static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
* stack where the break point happened, and the saving of
* pt_regs. We can extend the original stack because of
* this gap. See the idtentry macro's create_gap option.
+ *
+ * Similarly entry_32.S will have a gap on the stack for (any) hardware
+ * exception and pt_regs; see FIXUP_FRAME.
*/
regs->sp -= sizeof(unsigned long);
*(unsigned long *)regs->sp = val;