From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from zen.linaroharston ([51.148.130.216]) by smtp.gmail.com with ESMTPSA id a6sm15423797wrr.85.2019.09.12.04.18.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Sep 2019 04:18:12 -0700 (PDT) Received: from zen (localhost [127.0.0.1]) by zen.linaroharston (Postfix) with ESMTP id 8848C1FF87; Thu, 12 Sep 2019 12:18:11 +0100 (BST) References: <20190910144428.32597-1-peter.maydell@linaro.org> <20190910144428.32597-7-peter.maydell@linaro.org> User-agent: mu4e 1.3.4; emacs 27.0.50 From: Alex =?utf-8?Q?Benn=C3=A9e?= To: qemu-devel@nongnu.org Cc: qemu-arm@nongnu.org Subject: Re: [Qemu-devel] [PATCH 06/13] target/arm/arm-semi: Factor out implementation of SYS_WRITE In-reply-to: <20190910144428.32597-7-peter.maydell@linaro.org> Date: Thu, 12 Sep 2019 12:18:11 +0100 Message-ID: <87lfutzrt8.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-TUID: nFMIvivYCDpg Peter Maydell writes: > Factor out the implementation of SYS_WRITE via the > new function tables. > > The #ifdef around the declaration/initialization of the > local 'env' variable is unfortunate but necessary, because > the softmmu-semi.h version of lock_user implicitly uses 'env', > but the user-only version doesn't need it. heh - one reason I rewrote a local lock_user_string for semihost.c although of course it only has to worry about the softmmu case as you don't have re-direct-able char devices in linux-user. > Without the ifdefs > we'd get a warning about the unused variable for the user-only > compilation. > > Signed-off-by: Peter Maydell Reviewed-by: Alex Benn=C3=A9e > --- > target/arm/arm-semi.c | 53 ++++++++++++++++++++++++++++--------------- > 1 file changed, 35 insertions(+), 18 deletions(-) > > diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c > index f3e0bf77cd3..0dec4c04e2f 100644 > --- a/target/arm/arm-semi.c > +++ b/target/arm/arm-semi.c > @@ -345,27 +345,61 @@ static target_ulong arm_gdb_syscall(ARMCPU *cpu, gd= b_syscall_complete_cb cb, > * setting the guest errno if appropriate. > */ > typedef uint32_t sys_closefn(TaskState *ts, ARMCPU *cpu, GuestFD *gf); > +typedef uint32_t sys_writefn(TaskState *ts, ARMCPU *cpu, GuestFD *gf, > + target_ulong buf, uint32_t len); > > static uint32_t host_closefn(TaskState *ts, ARMCPU *cpu, GuestFD *gf) > { > return set_swi_errno(ts, close(gf->hostfd)); > } > > +static uint32_t host_writefn(TaskState *ts, ARMCPU *cpu, GuestFD *gf, > + target_ulong buf, uint32_t len) > +{ > + uint32_t ret; > +#ifndef CONFIG_USER_ONLY > + CPUARMState *env =3D &cpu->env; > +#endif > + char *s =3D lock_user(VERIFY_READ, buf, len, 1); > + if (!s) { > + /* Return bytes not written on error */ > + return len; > + } > + ret =3D set_swi_errno(ts, write(gf->hostfd, s, len)); > + unlock_user(s, buf, 0); > + if (ret =3D=3D (uint32_t)-1) { > + ret =3D 0; > + } > + /* Return bytes not written */ > + return len - ret; > +} > + > static uint32_t gdb_closefn(TaskState *ts, ARMCPU *cpu, GuestFD *gf) > { > return arm_gdb_syscall(cpu, arm_semi_cb, "close,%x", gf->hostfd); > } > > +static uint32_t gdb_writefn(TaskState *ts, ARMCPU *cpu, GuestFD *gf, > + target_ulong buf, uint32_t len) > +{ > + arm_semi_syscall_len =3D len; > + return arm_gdb_syscall(cpu, arm_semi_cb, "write,%x,%x,%x", > + gf->hostfd, buf, len); > +} > + > typedef struct GuestFDFunctions { > sys_closefn *closefn; > + sys_writefn *writefn; > } GuestFDFunctions; > > static const GuestFDFunctions guestfd_fns[] =3D { > [GuestFDHost] =3D { > .closefn =3D host_closefn, > + .writefn =3D host_writefn, > }, > [GuestFDGDB] =3D { > .closefn =3D gdb_closefn, > + .writefn =3D gdb_writefn, > }, > }; > > @@ -504,24 +538,7 @@ target_ulong do_arm_semihosting(CPUARMState *env) > return set_swi_errno(ts, -1); > } > > - if (use_gdb_syscalls()) { > - arm_semi_syscall_len =3D len; > - return arm_gdb_syscall(cpu, arm_semi_cb, "write,%x,%x,%x", > - gf->hostfd, arg1, len); > - } else { > - s =3D lock_user(VERIFY_READ, arg1, len, 1); > - if (!s) { > - /* Return bytes not written on error */ > - return len; > - } > - ret =3D set_swi_errno(ts, write(gf->hostfd, s, len)); > - unlock_user(s, arg1, 0); > - if (ret =3D=3D (uint32_t)-1) { > - ret =3D 0; > - } > - /* Return bytes not written */ > - return len - ret; > - } > + return guestfd_fns[gf->type].writefn(ts, cpu, gf, arg1, len); > case TARGET_SYS_READ: > GET_ARG(0); > GET_ARG(1); -- Alex Benn=C3=A9e