Messages in this thread | | | Date | Mon, 4 Jan 2021 11:59:04 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/3] MIPS: kernel: Support extracting off-line stack traces from user-space with perf |
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On Tue, Dec 29, 2020 at 08:55:59PM +0800, Tiezhu Yang wrote: > +u64 perf_reg_abi(struct task_struct *tsk) > +{ > + if (test_tsk_thread_flag(tsk, TIF_32BIT_REGS)) > + return PERF_SAMPLE_REGS_ABI_32; > + else > + return PERF_SAMPLE_REGS_ABI_64; > +}
So we recently changed this on x86 to not rely on TIF flags. IIRC the problem is that on x86 you can change the mode of a task without the kernel being aware of it. Is something like that possible on MIPS as well?
The thing x86 does today is look at it's pt_regs state to determine the actual state.
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