Commit-ID: 74e59dfc6b19e3472a7c16ad57bc831e6e647895
Gitweb: http://git.kernel.org/tip/74e59dfc6b19e3472a7c16ad57bc831e6e647895
Author: Oleg Nesterov <oleg@xxxxxxxxxx>
AuthorDate: Sun, 30 Dec 2012 15:54:08 +0100
Committer: Oleg Nesterov <oleg@xxxxxxxxxx>
CommitDate: Fri, 8 Feb 2013 17:47:11 +0100
uprobes: Change handle_swbp() to expose bp_vaddr to handler_chain()
Change handle_swbp() to set regs->ip = bp_vaddr in advance, this is
what consumer->handler() needs but uprobe_get_swbp_addr() is not
exported.
This also simplifies the code and makes it more consistent across
the supported architectures. handle_swbp() becomes the only caller
of uprobe_get_swbp_addr().
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
---
arch/x86/kernel/uprobes.c | 1 -
kernel/events/uprobes.c | 15 +++++++--------
kernel/trace/trace_uprobe.c | 4 ++--
3 files changed, 9 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 4e33a35d..0ba4cfb 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -681,7 +681,6 @@ static bool __skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
continue;
if (auprobe->insn[i] == 0x90) {
- regs->ip = uprobe_get_swbp_addr(regs);
regs->ip += i + 1;
return true;
}
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 04c104a..f1b8078 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1504,6 +1504,10 @@ static void handle_swbp(struct pt_regs *regs)
}
return;
}
+
+ /* change it in advance for ->handler() and restart */
+ instruction_pointer_set(regs, bp_vaddr);
+
/*
* TODO: move copy_insn/etc into _register and remove this hack.
* After we hit the bp, _unregister + _register can install the
@@ -1511,14 +1515,14 @@ static void handle_swbp(struct pt_regs *regs)
*/
smp_rmb(); /* pairs with wmb() in install_breakpoint() */
if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags)))
- goto restart;
+ goto out;
utask = current->utask;
if (!utask) {
utask = add_utask();
/* Cannot allocate; re-execute the instruction. */
if (!utask)
- goto restart;
+ goto out;
}
handler_chain(uprobe, regs);
@@ -1531,12 +1535,7 @@ static void handle_swbp(struct pt_regs *regs)
return;
}
-restart:
- /*
- * cannot singlestep; cannot skip instruction;
- * re-execute the instruction.
- */
- instruction_pointer_set(regs, bp_vaddr);
+ /* can_skip_sstep() succeeded, or restart if can't singlestep */
out:
put_uprobe(uprobe);
}
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index e668024..17d9b2b 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -492,7 +492,7 @@ static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
return;
entry = ring_buffer_event_data(event);
- entry->ip = uprobe_get_swbp_addr(task_pt_regs(current));
+ entry->ip = instruction_pointer(task_pt_regs(current));
data = (u8 *)&entry[1];
for (i = 0; i < tu->nr_args; i++)
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
@@ -667,7 +667,7 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
if (!entry)
goto out;
- entry->ip = uprobe_get_swbp_addr(task_pt_regs(current));
+ entry->ip = instruction_pointer(task_pt_regs(current));
data = (u8 *)&entry[1];
for (i = 0; i < tu->nr_args; i++)
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
--
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