Commit-ID: 4dc316c64594d1a5ef2d61fba5ae0fe7fe18cdca
Gitweb: http://git.kernel.org/tip/4dc316c64594d1a5ef2d61fba5ae0fe7fe18cdca
Author: Oleg Nesterov <oleg@xxxxxxxxxx>
AuthorDate: Sun, 28 Oct 2012 17:57:30 +0100
Committer: Oleg Nesterov <oleg@xxxxxxxxxx>
CommitDate: Sat, 3 Nov 2012 17:15:12 +0100
uprobes/x86: Cleanup the single-stepping code
No functional changes.
Now that default arch_uprobe_enable/disable_step() helpers do nothing,
x86 has no reason to reimplement them. Change arch_uprobe_*_xol() hooks
to do the necessary work and remove the x86-specific hooks.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/uprobes.c | 54 +++++++++++++++++------------------------------
1 file changed, 19 insertions(+), 35 deletions(-)
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index aafa555..c71025b 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -478,6 +478,11 @@ int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
regs->ip = current->utask->xol_vaddr;
pre_xol_rip_insn(auprobe, regs, autask);
+ 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);
+
return 0;
}
@@ -603,6 +608,16 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
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
+ * to examine the opcode to make it right.
+ */
+ if (utask->autask.saved_tf)
+ send_sig(SIGTRAP, current, 0);
+ else if (!(auprobe->fixups & UPROBE_FIX_SETF))
+ regs->flags &= ~X86_EFLAGS_TF;
+
return result;
}
@@ -647,6 +662,10 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
current->thread.trap_nr = utask->autask.saved_trap_nr;
handle_riprel_post_xol(auprobe, regs, NULL);
instruction_pointer_set(regs, utask->vaddr);
+
+ /* clear TF if it was set by us in arch_uprobe_pre_xol() */
+ if (!utask->autask.saved_tf)
+ regs->flags &= ~X86_EFLAGS_TF;
}
/*
@@ -676,38 +695,3 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
send_sig(SIGTRAP, current, 0);
return ret;
}
-
-void arch_uprobe_enable_step(struct arch_uprobe *auprobe)
-{
- struct task_struct *task = current;
- struct arch_uprobe_task *autask = &task->utask->autask;
- struct pt_regs *regs = task_pt_regs(task);
-
- autask->saved_tf = !!(regs->flags & X86_EFLAGS_TF);
-
- regs->flags |= X86_EFLAGS_TF;
- if (test_tsk_thread_flag(task, TIF_BLOCKSTEP))
- set_task_blockstep(task, false);
-}
-
-void arch_uprobe_disable_step(struct arch_uprobe *auprobe)
-{
- struct task_struct *task = current;
- struct arch_uprobe_task *autask = &task->utask->autask;
- bool trapped = (task->utask->state == UTASK_SSTEP_TRAPPED);
- struct pt_regs *regs = task_pt_regs(task);
- /*
- * The state of TIF_BLOCKSTEP was not saved so we can get an extra
- * SIGTRAP if we do not clear TF. We need to examine the opcode to
- * make it right.
- */
- if (unlikely(trapped)) {
- if (!autask->saved_tf)
- regs->flags &= ~X86_EFLAGS_TF;
- } else {
- if (autask->saved_tf)
- send_sig(SIGTRAP, task, 0);
- else if (!(auprobe->fixups & UPROBE_FIX_SETF))
- regs->flags &= ~X86_EFLAGS_TF;
- }
-}
--
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