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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@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
This commit is contained in:
Oleg Nesterov 2012-12-30 15:54:08 +01:00
parent cf31ec3f7f
commit 74e59dfc6b
3 changed files with 9 additions and 11 deletions
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1
arch/x86/kernel/uprobes.c
View File

@ -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;
}

15
kernel/events/uprobes.c
View File

@ -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);
}

4
kernel/trace/trace_uprobe.c
View File

@ -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);