Messages in this thread | | | Date | Tue, 3 Oct 2017 11:33:44 +0200 | From | Ingo Molnar <> | Subject | Re: [BUGFIX PATCH] kprobes/x86: Remove IRQ disabling from jprobe handlers |
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* Masami Hiramatsu <mhiramat@kernel.org> wrote:
> Jprobe actually doesn't need to disable IRQs while calling > handlers, because Documentation/kprobes.txt says: > > ----- > Probe handlers are run with preemption disabled. Depending on the > architecture and optimization state, handlers may also run with > interrupts disabled (e.g., kretprobe handlers and optimized kprobe > handlers run without interrupt disabled on x86/x86-64). > ----- > > So let's remove IRQ disabling from jprobes too. > > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> > --- > arch/x86/kernel/kprobes/core.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c > index b48e0efd668e..bd36f3c33cd0 100644 > --- a/arch/x86/kernel/kprobes/core.c > +++ b/arch/x86/kernel/kprobes/core.c > @@ -1099,8 +1099,6 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) > * raw stack chunk with redzones: > */ > __memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr, MIN_STACK_SIZE(addr)); > - regs->flags &= ~X86_EFLAGS_IF; > - trace_hardirqs_off(); > regs->ip = (unsigned long)(jp->entry); > > /*
Could you please also do a patch that disables jprobes permanently, in preparation of eventually removing them later?
Thanks,
Ingo
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