x86, vmlinux.lds: add copyright

[safe/jmp/linux-2.6] / arch / x86 / kernel / kprobes.c

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index cc8ae90..7b5169d 100644 (file)
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -193,6 +193,9 @@ static int __kprobes can_boost(kprobe_opcode_t *opcodes)
        kprobe_opcode_t opcode;
        kprobe_opcode_t *orig_opcodes = opcodes;
 
+       if (search_exception_tables((unsigned long)opcodes))
+               return 0;       /* Page fault may occur on this address. */
+
 retry:
        if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1)
                return 0;
@@ -376,9 +379,10 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
 
 void __kprobes arch_remove_kprobe(struct kprobe *p)
 {
-       mutex_lock(&kprobe_mutex);
-       free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1));
-       mutex_unlock(&kprobe_mutex);
+       if (p->ainsn.insn) {
+               free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1));
+               p->ainsn.insn = NULL;
+       }
 }
 
 static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
@@ -431,7 +435,6 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
                regs->ip = (unsigned long)p->ainsn.insn;
 }
 
-/* Called with kretprobe_lock held */
 void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
                                      struct pt_regs *regs)
 {
@@ -446,7 +449,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
 static void __kprobes setup_singlestep(struct kprobe *p, struct pt_regs *regs,
                                       struct kprobe_ctlblk *kcb)
 {
-#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PM)
+#if !defined(CONFIG_PREEMPT) || defined(CONFIG_FREEZER)
        if (p->ainsn.boostable == 1 && !p->post_handler) {
                /* Boost up -- we can execute copied instructions directly */
                reset_current_kprobe();
@@ -489,7 +492,7 @@ static int __kprobes reenter_kprobe(struct kprobe *p, struct pt_regs *regs,
                break;
        case KPROBE_HIT_SS:
                if (p == kprobe_running()) {
-                       regs->flags &= ~TF_MASK;
+                       regs->flags &= ~X86_EFLAGS_TF;
                        regs->flags |= kcb->kprobe_saved_flags;
                        return 0;
                } else {
@@ -635,13 +638,13 @@ static void __used __kprobes kretprobe_trampoline_holder(void)
 #else
                        "       pushf\n"
                        /*
-                        * Skip cs, ip, orig_ax.
+                        * Skip cs, ip, orig_ax and gs.
                         * trampoline_handler() will plug in these values
                         */
-                       "       subl $12, %esp\n"
+                       "       subl $16, %esp\n"
                        "       pushl %fs\n"
-                       "       pushl %ds\n"
                        "       pushl %es\n"
+                       "       pushl %ds\n"
                        "       pushl %eax\n"
                        "       pushl %ebp\n"
                        "       pushl %edi\n"
@@ -652,10 +655,10 @@ static void __used __kprobes kretprobe_trampoline_holder(void)
                        "       movl %esp, %eax\n"
                        "       call trampoline_handler\n"
                        /* Move flags to cs */
-                       "       movl 52(%esp), %edx\n"
-                       "       movl %edx, 48(%esp)\n"
+                       "       movl 56(%esp), %edx\n"
+                       "       movl %edx, 52(%esp)\n"
                        /* Replace saved flags with true return address. */
-                       "       movl %eax, 52(%esp)\n"
+                       "       movl %eax, 56(%esp)\n"
                        "       popl %ebx\n"
                        "       popl %ecx\n"
                        "       popl %edx\n"
@@ -663,8 +666,8 @@ static void __used __kprobes kretprobe_trampoline_holder(void)
                        "       popl %edi\n"
                        "       popl %ebp\n"
                        "       popl %eax\n"
-                       /* Skip ip, orig_ax, es, ds, fs */
-                       "       addl $20, %esp\n"
+                       /* Skip ds, es, fs, gs, orig_ax and ip */
+                       "       addl $24, %esp\n"
                        "       popf\n"
 #endif
                        "       ret\n");
@@ -682,13 +685,13 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
        unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
 
        INIT_HLIST_HEAD(&empty_rp);
-       spin_lock_irqsave(&kretprobe_lock, flags);
-       head = kretprobe_inst_table_head(current);
+       kretprobe_hash_lock(current, &head, &flags);
        /* fixup registers */
 #ifdef CONFIG_X86_64
        regs->cs = __KERNEL_CS;
 #else
        regs->cs = __KERNEL_CS | get_kernel_rpl();
+       regs->gs = 0;
 #endif
        regs->ip = trampoline_address;
        regs->orig_ax = ~0UL;
@@ -696,7 +699,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
        /*
         * It is possible to have multiple instances associated with a given
         * task either because multiple functions in the call path have
-        * return probes installed on them, and/or more then one
+        * return probes installed on them, and/or more than one
         * return probe was registered for a target function.
         *
         * We can handle this because:
@@ -732,7 +735,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
 
        kretprobe_assert(ri, orig_ret_address, trampoline_address);
 
-       spin_unlock_irqrestore(&kretprobe_lock, flags);
+       kretprobe_hash_unlock(current, &flags);
 
        hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
                hlist_del(&ri->hlist);
@@ -860,7 +863,6 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs)
 
        resume_execution(cur, regs, kcb);
        regs->flags |= kcb->kprobe_saved_flags;
-       trace_hardirqs_fixup_flags(regs->flags);
 
        if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
                kcb->kprobe_status = KPROBE_HIT_SSDONE;