Commit-ID: 9d778782266f95e5c6ec43ed8195ba331c821018
Gitweb: http://git.kernel.org/tip/9d778782266f95e5c6ec43ed8195ba331c821018
Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
AuthorDate: Tue, 7 Aug 2012 18:12:28 +0200
Committer: Oleg Nesterov <oleg@xxxxxxxxxx>
CommitDate: Sat, 15 Sep 2012 17:37:28 +0200
uprobes: Introduce arch_uprobe_enable/disable_step()
As Oleg pointed out in [0] uprobe should not use the ptrace interface
for enabling/disabling single stepping.
[0] http://lkml.kernel.org/r/20120730141638.GA5306@xxxxxxxxxx
Add the new "__weak arch" helpers which simply call user_*_single_step()
as a preparation. This is only needed to not break the powerpc port, we
will fold this logic into arch_uprobe_pre/post_xol() hooks later.
We should also change handle_singlestep(), _disable_step(&uprobe->arch)
should be called before put_uprobe().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
---
include/linux/uprobes.h | 2 ++
kernel/events/uprobes.c | 14 ++++++++++++--
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 6d4fe79..e6f0331 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -112,6 +112,8 @@ extern void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm);
extern void uprobe_free_utask(struct task_struct *t);
extern void uprobe_copy_process(struct task_struct *t);
extern unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs);
+extern void __weak arch_uprobe_enable_step(struct arch_uprobe *arch);
+extern void __weak arch_uprobe_disable_step(struct arch_uprobe *arch);
extern int uprobe_post_sstep_notifier(struct pt_regs *regs);
extern int uprobe_pre_sstep_notifier(struct pt_regs *regs);
extern void uprobe_notify_resume(struct pt_regs *regs);
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index e4a906c..912ef48 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1444,6 +1444,16 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
return uprobe;
}
+void __weak arch_uprobe_enable_step(struct arch_uprobe *arch)
+{
+ user_enable_single_step(current);
+}
+
+void __weak arch_uprobe_disable_step(struct arch_uprobe *arch)
+{
+ user_disable_single_step(current);
+}
+
/*
* Run handler and ask thread to singlestep.
* Ensure all non-fatal signals cannot interrupt thread while it singlesteps.
@@ -1490,7 +1500,7 @@ static void handle_swbp(struct pt_regs *regs)
utask->state = UTASK_SSTEP;
if (!pre_ssout(uprobe, regs, bp_vaddr)) {
- user_enable_single_step(current);
+ arch_uprobe_enable_step(&uprobe->arch);
return;
}
@@ -1526,10 +1536,10 @@ static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs)
else
WARN_ON_ONCE(1);
+ arch_uprobe_disable_step(&uprobe->arch);
put_uprobe(uprobe);
utask->active_uprobe = NULL;
utask->state = UTASK_RUNNING;
- user_disable_single_step(current);
xol_free_insn_slot(current);
spin_lock_irq(¤t->sighand->siglock);
--
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