uprobes/x86: move the UPROBE_FIX_{RIP,IP,CALL} code at the end of pre/post hooks

No functional changes. Preparation to simplify the review of the next
change. Just reorder the code in arch_uprobe_pre/post_xol() functions
so that UPROBE_FIX_{RIP_*,IP,CALL} logic goes to the end.

Also change arch_uprobe_pre_xol() to use utask instead of autask, to
make the code more symmetrical with arch_uprobe_post_xol().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>

diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index c52c30fa7871a3dec58b8cfdd126d13adbcda542..3bb4198aa5880b9a55f90873519b5803f7a604c7 100644 (file)
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -474,19 +474,18 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
  */
 int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
 {
-       struct arch_uprobe_task *autask;
+       struct uprobe_task *utask = current->utask;
 
-       autask = &current->utask->autask;
-       autask->saved_trap_nr = current->thread.trap_nr;
+       regs->ip = utask->xol_vaddr;
+       utask->autask.saved_trap_nr = current->thread.trap_nr;
        current->thread.trap_nr = UPROBE_TRAP_NR;
-       regs->ip = current->utask->xol_vaddr;
-       pre_xol_rip_insn(auprobe, regs, autask);
 
-       autask->saved_tf = !!(regs->flags & X86_EFLAGS_TF);
+       utask->autask.saved_tf = !!(regs->flags & X86_EFLAGS_TF);
        regs->flags |= X86_EFLAGS_TF;
        if (test_tsk_thread_flag(current, TIF_BLOCKSTEP))
                set_task_blockstep(current, false);
 
+       pre_xol_rip_insn(auprobe, regs, &utask->autask);
        return 0;
 }
 
@@ -560,22 +559,13 @@ bool arch_uprobe_xol_was_trapped(struct task_struct *t)
  */
 int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
 {
-       struct uprobe_task *utask;
+       struct uprobe_task *utask = current->utask;
        long correction;
        int result = 0;
 
        WARN_ON_ONCE(current->thread.trap_nr != UPROBE_TRAP_NR);
 
-       utask = current->utask;
        current->thread.trap_nr = utask->autask.saved_trap_nr;
-       correction = (long)(utask->vaddr - utask->xol_vaddr);
-       handle_riprel_post_xol(auprobe, regs, &correction);
-       if (auprobe->fixups & UPROBE_FIX_IP)
-               regs->ip += correction;
-
-       if (auprobe->fixups & UPROBE_FIX_CALL)
-               result = adjust_ret_addr(regs->sp, correction);
-
        /*
         * arch_uprobe_pre_xol() doesn't save the state of TIF_BLOCKSTEP
         * so we can get an extra SIGTRAP if we do not clear TF. We need
@@ -586,6 +576,14 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
        else if (!(auprobe->fixups & UPROBE_FIX_SETF))
                regs->flags &= ~X86_EFLAGS_TF;
 
+       correction = (long)(utask->vaddr - utask->xol_vaddr);
+       handle_riprel_post_xol(auprobe, regs, &correction);
+       if (auprobe->fixups & UPROBE_FIX_IP)
+               regs->ip += correction;
+
+       if (auprobe->fixups & UPROBE_FIX_CALL)
+               result = adjust_ret_addr(regs->sp, correction);
+
        return result;
 }