Messages in this thread Patch in this message | | | From | Roland McGrath <> | Subject | Re: x86: do_debug && PTRACE_SINGLESTEP broken by 08d68323d1f0c34452e614263b212ca556dae47f | Date | Thu, 17 Dec 2009 17:40:21 -0800 (PST) |
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Comparing to the old (2.6.32) logic, I think it might be this (untested). I also note this is the sole use of get_si_code, seems like it should just be rolled in here.
Thanks, Roland
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 3339917..16a88f5 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -530,7 +530,6 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) { struct task_struct *tsk = current; unsigned long dr6; - int si_code; get_debugreg(dr6, 6); @@ -569,14 +568,15 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) * We already checked v86 mode above, so we can check for kernel mode * by just checking the CPL of CS. */ + dr6 = tsk->thread.debugreg6; if ((dr6 & DR_STEP) && !user_mode(regs)) { tsk->thread.debugreg6 &= ~DR_STEP; set_tsk_thread_flag(tsk, TIF_SINGLESTEP); regs->flags &= ~X86_EFLAGS_TF; + } else if (dr6 & (DR_STEP | DR_TRAP_BITS)) { + send_sigtrap(tsk, regs, error_code, get_si_code(dr6)); } - si_code = get_si_code(tsk->thread.debugreg6); - if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS)) - send_sigtrap(tsk, regs, error_code, si_code); + preempt_conditional_cli(regs); return;
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