Date: Tue, 14 Sep 2021 23:54:08 +0100 From: Jessica Clarke <jrtc27@freebsd.org> To: Konstantin Belousov <kostikbel@gmail.com> Cc: Edward Tomasz Napierala <trasz@freebsd.org>, src-committers <src-committers@freebsd.org>, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: bdf0f24bb16d - main - linux: implement PTRACE_GET_SYSCALL_INFO Message-ID: <7C375F3A-889E-440F-A164-959A9A903733@freebsd.org> In-Reply-To: <YUEl/Ii%2Bve5I%2BUGe@kib.kiev.ua> References: <202109142041.18EKf6RU040962@gitrepo.freebsd.org> <YUEl/Ii%2Bve5I%2BUGe@kib.kiev.ua>
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On 14 Sep 2021, at 23:45, Konstantin Belousov <kostikbel@gmail.com> = wrote: >=20 > On Tue, Sep 14, 2021 at 08:41:06PM +0000, Edward Tomasz Napierala = wrote: >> The branch main has been updated by trasz: >>=20 >> URL: = https://cgit.FreeBSD.org/src/commit/?id=3Dbdf0f24bb16d556a5b1e01cdfc087d08= e91ac572 >>=20 >> commit bdf0f24bb16d556a5b1e01cdfc087d08e91ac572 >> Author: Edward Tomasz Napierala <trasz@FreeBSD.org> >> AuthorDate: 2021-09-12 11:31:10 +0000 >> Commit: Edward Tomasz Napierala <trasz@FreeBSD.org> >> CommitDate: 2021-09-14 20:19:55 +0000 >>=20 >> linux: implement PTRACE_GET_SYSCALL_INFO >>=20 >> This is one of the pieces required to make modern (ie Focal) >> strace(1) work. >>=20 >> Reviewed By: jhb (earlier version) >> Sponsored by: EPSRC >> Differential Revision: https://reviews.freebsd.org/D28212 >> --- >> lib/libsysdecode/mktables | 2 +- >> sys/amd64/linux/linux_ptrace.c | 98 = +++++++++++++++++++++++++++++++++-- >> sys/compat/freebsd32/freebsd32_misc.c | 3 ++ >> sys/kern/sys_process.c | 17 ++++++ >> sys/sys/ptrace.h | 4 ++ >> 5 files changed, 120 insertions(+), 4 deletions(-) >>=20 >> + case PT_GET_SC_ARGS_ALL: >> + CTR1(KTR_PTRACE, "PT_GET_SC_ARGS_ALL: pid %d", = p->p_pid); >> + if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) =3D=3D 0 >> +#ifdef COMPAT_FREEBSD32 >> + || (wrap32 && !safe) >> +#endif >> + ) { >> + error =3D EINVAL; >> + break; >> + } >> + bcopy(td2->td_sa.args, addr, sizeof(td2->td_sa.args)); >> + break; >=20 > This is awful, you already got that feedback in review, as I read it. > I strongly suggest to remove PT_GET_SC_ARGS_ALL, and instead checks = something > in the implementation of PT_GET_SC_ARGS to select either full copy or = just > nargs args. >=20 > Easiest thing for 'something' would be SV_PROC_ABI(p) =3D=3D = SV_ABI_LINUX. That is incorrect. The original review just changed PT_GET_SC_ARGS even for FreeBSD and that was what was described as horrible. John suggested two alternatives: this approach, and having the Linuxulator bypass kern_ptrace entirely by doing its own thing. Your option seems simpler but I don=E2=80=99t know if there=E2=80=99s a = good reason why that wasn=E2=80=99t suggested. Jess
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