Messages in this thread | | | Date | Sun, 23 Apr 2023 09:56:52 +0100 | From | Conor Dooley <> | Subject | Re: [PATCH RESEND] riscv: fix kprobe user string arg print fault issue |
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On 23 April 2023 02:29:12 IST, ruanjinjie <ruanjinjie@huawei.com> wrote: >On riscv qemu platform, when add kprobe event on do_sys_open() to show >filename string arg, it just print fault as follow: > >echo 'p:myprobe do_sys_open dfd=$arg1 filename=+0($arg2):string flags=$arg3 >mode=$arg4' > kprobe_events > >bash-166 [000] ...1. 360.195367: myprobe: (do_sys_open+0x0/0x84) >dfd=0xffffffffffffff9c filename=(fault) flags=0x8241 mode=0x1b6 > >bash-166 [000] ...1. 360.219369: myprobe: (do_sys_open+0x0/0x84) >dfd=0xffffffffffffff9c filename=(fault) flags=0x8241 mode=0x1b6 > >bash-191 [000] ...1. 360.378827: myprobe: (do_sys_open+0x0/0x84) >dfd=0xffffffffffffff9c filename=(fault) flags=0x98800 mode=0x0 > >As riscv do not select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE, >the +0($arg2) addr is processed as a kernel address though it is a >userspace address, cause the above filename=(fault) print. So select >ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE to avoid the issue, after that the >kprobe trace is ok as below: > >bash-166 [000] ...1. 96.767641: myprobe: (do_sys_open+0x0/0x84) >dfd=0xffffffffffffff9c filename="/dev/null" flags=0x8241 mode=0x1b6 > >bash-166 [000] ...1. 96.793751: myprobe: (do_sys_open+0x0/0x84) >dfd=0xffffffffffffff9c filename="/dev/null" flags=0x8241 mode=0x1b6 > >bash-177 [000] ...1. 96.962354: myprobe: (do_sys_open+0x0/0x84) >dfd=0xffffffffffffff9c filename="/sys/kernel/debug/tracing/events/kprobes/" >flags=0x98800 mode=0x0 > >Signed-off-by: ruanjinjie <ruanjinjie@huawei.com> >--- > arch/riscv/Kconfig | 1 + > 1 file changed, 1 insertion(+) > >diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >index eb7f29a412f8..c51f0d3227af 100644 >--- a/arch/riscv/Kconfig >+++ b/arch/riscv/Kconfig >@@ -26,6 +26,7 @@ config RISCV > select ARCH_HAS_KCOV > select ARCH_HAS_MMIOWB > select ARCH_HAS_PMEM_API >+ select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
Please add this in alphabetical order, thanks.
> select ARCH_HAS_PTE_SPECIAL > select ARCH_HAS_SET_DIRECT_MAP if MMU > select ARCH_HAS_SET_MEMORY if MMU
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