在 2020/6/4 上午9:17, Maciej W. Rozycki 写道: > On Fri, 29 May 2020, WANG Xuerui wrote: > >> On 2020/5/29 17:29, yuanjunqing wrote: >> >>>> diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S >>>> index cff52b283e03..cd5545764e5f 100644 >>>> --- a/arch/mips/kernel/mcount.S >>>> +++ b/arch/mips/kernel/mcount.S >>>> @@ -87,8 +87,15 @@ EXPORT_SYMBOL(_mcount) >>>> PTR_LA t1, _etext >>>> sltu t3, t1, a0 /* t3 = (a0 > _etext) */ >>>> or t1, t2, t3 >>>> + PTR_LA t2, stlab-4 /* t2: "function:stacktrace" return address */ >>>> + move a1, AT /* arg2: parent's return address */ >>>> beqz t1, ftrace_call >>>> - nop >>>> + nop /* "function:stacktrace" return address */ >>>> +stlab: >>>> + PTR_LA t2, stlab-4 >>>> + /* ftrace_call_end: ftrace_call return address */ >>>> + beq t2,ra, ftrace_call_end >>>> + nop > Broken delay slot indentation.
Thank you for your reply. For this question that you mentioned about the delay slot, I will modify my patch again. > >>>> #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT) >>>> PTR_SUBU a0, a0, 16 /* arg1: adjust to module's recorded callsite */ >>>> #else >>>> @@ -98,7 +105,9 @@ EXPORT_SYMBOL(_mcount) >>>> .globl ftrace_call >>>> ftrace_call: >>>> nop /* a placeholder for the call to a real tracing function */ >>>> - move a1, AT /* arg2: parent's return address */ >>>> + move ra, t2 /* t2: "function:stacktrace" return address */ > Likewise. NB I haven't investigated if the change makes sense. A more > detailed explanation in the change description is certainly needed. I will attach a specific description for further explanation about the second patch later. > > Maciej
