[IA64] kprobe opcode 16 bytes alignment on IA64

On IA64 instruction opcode must be 16 bytes alignment, in kprobe structure
there is one element to save original instruction, currently saved opcode
is not statically allocated in kprobe structure, that can not assure
16 bytes alignment. This patch dynamically allocated kprobe instruction
opcode to assure 16 bytes alignment.

Signed-off-by: bibo mao <bibo.mao@intel.com>
Acked-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 29 insertions, 26 deletions

diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
index 781960f80b6f..320cb7a91c9d 100644
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -136,10 +136,8 @@ static void __kprobes update_kprobe_inst_flag(uint template, uint  slot,
 static int __kprobes unsupported_inst(uint template, uint  slot,
                                       uint major_opcode,
                                       unsigned long kprobe_inst,
-                                      struct kprobe *p)
+                                      unsigned long addr)
 {
-        unsigned long addr = (unsigned long)p->addr;
-
         if (bundle_encoding[template][slot] == I) {
                 switch (major_opcode) {
                         case 0x0: //I_UNIT_MISC_OPCODE:
@@ -217,7 +215,7 @@ static void __kprobes prepare_break_inst(uint template, uint  slot,
                                          struct kprobe *p)
 {
         unsigned long break_inst = BREAK_INST;
-        bundle_t *bundle = &p->ainsn.insn.bundle;
+        bundle_t *bundle = &p->opcode.bundle;
 
         /*
          * Copy the original kprobe_inst qualifying predicate(qp)
@@ -423,11 +421,9 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
         unsigned long *kprobe_addr = (unsigned long *)(addr & ~0xFULL);
         unsigned long kprobe_inst=0;
         unsigned int slot = addr & 0xf, template, major_opcode = 0;
-        bundle_t *bundle = &p->ainsn.insn.bundle;
-
-        memcpy(&p->opcode.bundle, kprobe_addr, sizeof(bundle_t));
-        memcpy(&p->ainsn.insn.bundle, kprobe_addr, sizeof(bundle_t));
+        bundle_t *bundle;
 
+        bundle = &((kprobe_opcode_t *)kprobe_addr)->bundle;
         template = bundle->quad0.template;
 
         if(valid_kprobe_addr(template, slot, addr))
@@ -440,20 +436,19 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
         /* Get kprobe_inst and major_opcode from the bundle */
         get_kprobe_inst(bundle, slot, &kprobe_inst, &major_opcode);
 
-        if (unsupported_inst(template, slot, major_opcode, kprobe_inst, p))
+        if (unsupported_inst(template, slot, major_opcode, kprobe_inst, addr))
                         return -EINVAL;
 
-        prepare_break_inst(template, slot, major_opcode, kprobe_inst, p);
 
-        return 0;
-}
+        p->ainsn.insn = get_insn_slot();
+        if (!p->ainsn.insn)
+                return -ENOMEM;
+        memcpy(&p->opcode, kprobe_addr, sizeof(kprobe_opcode_t));
+        memcpy(p->ainsn.insn, kprobe_addr, sizeof(kprobe_opcode_t));
 
-void __kprobes flush_insn_slot(struct kprobe *p)
-{
-        unsigned long arm_addr;
+        prepare_break_inst(template, slot, major_opcode, kprobe_inst, p);
 
-        arm_addr = ((unsigned long)&p->opcode.bundle) & ~0xFULL;
-        flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
+        return 0;
 }
 
 void __kprobes arch_arm_kprobe(struct kprobe *p)
@@ -461,9 +456,10 @@ void __kprobes arch_arm_kprobe(struct kprobe *p)
         unsigned long addr = (unsigned long)p->addr;
         unsigned long arm_addr = addr & ~0xFULL;
 
-        flush_insn_slot(p);
-        memcpy((char *)arm_addr, &p->ainsn.insn.bundle, sizeof(bundle_t));
-        flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
+        flush_icache_range((unsigned long)p->ainsn.insn,
+                        (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t));
+        memcpy((char *)arm_addr, &p->opcode, sizeof(kprobe_opcode_t));
+        flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));
 }
 
 void __kprobes arch_disarm_kprobe(struct kprobe *p)
@@ -471,11 +467,18 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
         unsigned long addr = (unsigned long)p->addr;
         unsigned long arm_addr = addr & ~0xFULL;
 
-        /* p->opcode contains the original unaltered bundle */
-        memcpy((char *) arm_addr, (char *) &p->opcode.bundle, sizeof(bundle_t));
-        flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
+        /* p->ainsn.insn contains the original unaltered kprobe_opcode_t */
+        memcpy((char *) arm_addr, (char *) p->ainsn.insn,
+                                         sizeof(kprobe_opcode_t));
+        flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));
 }
 
+void __kprobes arch_remove_kprobe(struct kprobe *p)
+{
+        mutex_lock(&kprobe_mutex);
+        free_insn_slot(p->ainsn.insn);
+        mutex_unlock(&kprobe_mutex);
+}
 /*
  * We are resuming execution after a single step fault, so the pt_regs
  * structure reflects the register state after we executed the instruction
@@ -486,12 +489,12 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
  */
 static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
 {
-        unsigned long bundle_addr = ((unsigned long) (&p->opcode.bundle)) & ~0xFULL;
+        unsigned long bundle_addr = (unsigned long) (&p->ainsn.insn->bundle);
         unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL;
         unsigned long template;
         int slot = ((unsigned long)p->addr & 0xf);
 
-        template = p->opcode.bundle.quad0.template;
+        template = p->ainsn.insn->bundle.quad0.template;
 
         if (slot == 1 && bundle_encoding[template][1] == L)
                 slot = 2;
@@ -553,7 +556,7 @@ turn_ss_off:
 
 static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs)
 {
-        unsigned long bundle_addr = (unsigned long) &p->opcode.bundle;
+        unsigned long bundle_addr = (unsigned long) &p->ainsn.insn->bundle;
         unsigned long slot = (unsigned long)p->addr & 0xf;
 
         /* single step inline if break instruction */