Messages in this thread | | | Date | Tue, 8 Jun 2021 16:14:57 +0800 | From | Jisheng Zhang <> | Subject | Re: [PATCH] riscv: code patching only works on !XIP_KERNEL |
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On Tue, 8 Jun 2021 09:50:00 +0200 Vitaly Wool <vitaly.wool@konsulko.com> wrote:
> > > Hi Jisheng, > > On Tue, Jun 8, 2021 at 9:24 AM Jisheng Zhang > <Jisheng.Zhang@synaptics.com> wrote: > > > > On Mon, 24 May 2021 21:32:38 +0200 > > Vitaly Wool <vitaly.wool@konsulko.com> wrote: > > > > > > > > > > > > > On Sat, May 22, 2021 at 7:15 PM Palmer Dabbelt <palmer@dabbelt.com> wrote: > > > > > > > > On Mon, 10 May 2021 11:19:30 PDT (-0700), vitaly.wool@konsulko.com wrote: > > > > > On Mon, May 10, 2021 at 6:35 PM Jisheng Zhang <jszhang3@mail.ustc.edu.cn> wrote: > > > > >> > > > > >> From: Jisheng Zhang <jszhang@kernel.org> > > > > >> > > > > >> Some features which need code patching such as KPROBES, DYNAMIC_FTRACE > > > > >> KGDB can only work on !XIP_KERNEL. Add dependencies for these features > > > > >> that rely on code patching. > > > > > > > > > > Since we can define extra RW sections to place some tiny code bits in > > > > > RAM, I would suggest that you hold back this patch for a while. > > > > > I am not going to support the idea of e. g. compiling KGDB support > > > > > into a XIP kernel, but disabling the whole HAVE_ARCH_JUMP_LABEL is > > > > > hardly the way to go. > > > > > > > > Do you have any updates on this? The SOC_SIFIVE disable thread floated > > > > back to the top of my inbox and I didn't see anything there. I'd prefer > > > > to avoid chasing around Kconfig disables for a bunch of stuff that we're > > > > just going to fix soon, but if this is going to be a big change then > > > > it's likely for next cycle anyway so in that case I'll start picking up > > > > these compile disable patches. > > > > > > Sorry, was caught up in fixing other stuff but now I'm on it so expect > > > some updates soon. > > > > Hi Vitaly, > > > > Based on your "[PATCH] riscv: xip: support runtime trap patching", IMHO, it > > solves ERRATA patching issue(And it makes use of the fact that the ERRATA > > only touches traps at the moment), but can't make code patching tech such as > > KPROBES, DYNAMIC_FTRACE etc. work properly, so my patch is still needed. > > At this point it is needed, yes. > > The thing is, I thought I'd go with one problem at a time, so I posted > the patch which solves build issues for SOC_SIFIVE and XIP, and > runtime patching for ERRATA (and I hope it gets accepted and makes its > way into -stable, too). > I gathered that addressing your issue had lower priority and so it's
It's at lower priority, in fact I didn't have XIP riscv platform ;)
> still underway. All in all, I don't mind going on with your patch, > when the initial issue is addressed, we may want to revert some part > of it but I guess that would be ok with you, wouldn't it?
We could revert some part of it later although I suspect the incompatibility between code patching tech and XIP could be addressed, take the KPROBES for example, it needs an ability to patch almost *every* can_be_kprobed insn this isn't achievable/necessary in XIP case.
Thanks
> > Best regards, > Vitaly > > > What do you think? > > > > Regards > > > > > > > > Best regards, > > > Vitaly > > > > > > > Not trying to rush any thing here, just don't want to have a bunch of > > > > broken configs. > > > > > > > > > > > > > > Best regards, > > > > > Vitaly > > > > > > > > > >> Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > > > > >> --- > > > > >> Hi, > > > > >> > > > > >> Currently, the RISCV_ERRATA_ALTERNATIVE also only works on !XIP_KERNEL > > > > >> but from the maillist it seem there's effort to make the co-exist, so > > > > >> I drop RISCV_ERRATA_ALTERNATIVE dependency on !XIP_KERNEL. > > > > >> > > > > >> Thanks > > > > >> > > > > >> arch/riscv/Kconfig | 18 +++++++++--------- > > > > >> 1 file changed, 9 insertions(+), 9 deletions(-) > > > > >> > > > > >> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > > > >> index a8ad8eb76120..61320b94ef97 100644 > > > > >> --- a/arch/riscv/Kconfig > > > > >> +++ b/arch/riscv/Kconfig > > > > >> @@ -60,11 +60,11 @@ config RISCV > > > > >> select GENERIC_TIME_VSYSCALL if MMU && 64BIT > > > > >> select HANDLE_DOMAIN_IRQ > > > > >> select HAVE_ARCH_AUDITSYSCALL > > > > >> - select HAVE_ARCH_JUMP_LABEL > > > > >> - select HAVE_ARCH_JUMP_LABEL_RELATIVE > > > > >> + select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL > > > > >> + select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL > > > > >> select HAVE_ARCH_KASAN if MMU && 64BIT > > > > >> select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT > > > > >> - select HAVE_ARCH_KGDB > > > > >> + select HAVE_ARCH_KGDB if !XIP_KERNEL > > > > >> select HAVE_ARCH_KGDB_QXFER_PKT > > > > >> select HAVE_ARCH_MMAP_RND_BITS if MMU > > > > >> select HAVE_ARCH_SECCOMP_FILTER > > > > >> @@ -79,9 +79,9 @@ config RISCV > > > > >> select HAVE_GCC_PLUGINS > > > > >> select HAVE_GENERIC_VDSO if MMU && 64BIT > > > > >> select HAVE_IRQ_TIME_ACCOUNTING > > > > >> - select HAVE_KPROBES > > > > >> - select HAVE_KPROBES_ON_FTRACE > > > > >> - select HAVE_KRETPROBES > > > > >> + select HAVE_KPROBES if !XIP_KERNEL > > > > >> + select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL > > > > >> + select HAVE_KRETPROBES if !XIP_KERNEL > > > > >> select HAVE_PCI > > > > >> select HAVE_PERF_EVENTS > > > > >> select HAVE_PERF_REGS > > > > >> @@ -230,11 +230,11 @@ config ARCH_RV64I > > > > >> bool "RV64I" > > > > >> select 64BIT > > > > >> select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000 > > > > >> - select HAVE_DYNAMIC_FTRACE if MMU && $(cc-option,-fpatchable-function-entry=8) > > > > >> + select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8) > > > > >> select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE > > > > >> - select HAVE_FTRACE_MCOUNT_RECORD > > > > >> + select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL > > > > >> select HAVE_FUNCTION_GRAPH_TRACER > > > > >> - select HAVE_FUNCTION_TRACER > > > > >> + select HAVE_FUNCTION_TRACER if !XIP_KERNEL > > > > >> select SWIOTLB if MMU > > > > >> > > > > >> endchoice > > > > >> -- > > > > >> 2.31.0 > > > > >> > > > > >> > > > > >> > > > > >> _______________________________________________
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