Date: Fri, 20 May 2022 11:04:01 +0300 From: Dmitry Chagin <dchagin@freebsd.org> To: Justin Hibbits <chmeee@has.gonegalt.net> Cc: Justin Hibbits <jhibbits@freebsd.org>, src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 47a57144af25 - main - cpuset: Byte swap cpuset for compat32 on big endian architectures Message-ID: <YodLcRvKOM%2B59/0n@heemeyer.club> In-Reply-To: <20220519184421.Horde.UNKOq2mSBtGdAqdpeKzm5Xr@cloud.gonegalt.net> References: <20220519184421.Horde.UNKOq2mSBtGdAqdpeKzm5Xr@cloud.gonegalt.net>
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On Thu, May 19, 2022 at 06:44:21PM +0000, Justin Hibbits wrote: > > "Dmitry Chagin" dchagin@freebsd.org – May 19, 2022 12:49 PM > > On Thu, May 19, 2022 at 03:48:42PM +0000, Justin Hibbits wrote: > > > The branch main has been updated by jhibbits: > > > > > > URL: https://cgit.FreeBSD.org/src/commit/?id=47a57144af25a7bd768b29272d50a36fdf2874ba > > > > > > commit 47a57144af25a7bd768b29272d50a36fdf2874ba > > > Author: Justin Hibbits <jhibbits@FreeBSD.org> > > > AuthorDate: 2022-05-12 20:38:22 +0000 > > > Commit: Justin Hibbits <jhibbits@FreeBSD.org> > > > CommitDate: 2022-05-19 15:49:55 +0000 > > > > > > cpuset: Byte swap cpuset for compat32 on big endian architectures > > > > > > Summary: > > > BITSET uses long as its basic underlying type, which is dependent on the > > > compile type, meaning on 32-bit builds the basic type is 32 bits, but on > > > 64-bit builds it's 64 bits. On little endian architectures this doesn't > > > matter, because the LSB is always at the low bit, so the words get > > > effectively concatenated moving between 32-bit and 64-bit, but on > > > big-endian architectures it throws a wrench in, as setting bit 0 in > > > 32-bit mode is equivalent to setting bit 32 in 64-bit mode. To > > > demonstrate: > > > > > > 32-bit mode: > > > > > > BIT_SET(foo, 0): 0x00000001 > > > > > > 64-bit sees: 0x0000000100000000 > > > > > > cpuset is the only system interface that uses bitsets, so solve this > > > by swapping the integer sub-components at the copyin/copyout points. > > > > > > Reviewed by: kib > > > MFC after: 3 days > > > Sponsored by: Juniper Networks, Inc. > > > Differential Revision: https://reviews.freebsd.org/D35225 > > > --- > > > sys/compat/freebsd32/freebsd32_misc.c | 70 +++++++++++++++++++++++++++++++++-- > > > sys/kern/kern_cpuset.c | 32 ++++++++++------ > > > sys/sys/cpuset.h | 9 +++++ > > > sys/sys/syscallsubr.h | 10 +++-- > > > 4 files changed, 101 insertions(+), 20 deletions(-) > > > > > > diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c > > > index 25c7a4e17dc7..d4206fdd24aa 100644 > > > --- a/sys/compat/freebsd32/freebsd32_misc.c > > > +++ b/sys/compat/freebsd32/freebsd32_misc.c > > > @@ -3310,13 +3310,72 @@ freebsd32_cpuset_getid(struct thread *td, > > > PAIR32TO64(id_t, uap->id), uap->setid)); > > > } > > > > > > +static int > > > +copyin32_set(const void *u, void *k, size_t size) > > > +{ > > > +#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ > > > + int rv; > > > + struct bitset *kb = k; > > > + int *p; > > > + > > > + rv = copyin(u, k, size); > > > + if (rv != 0) > > > + return (rv); > > > + > > > + p = (int *)kb->__bits; > > > + /* Loop through swapping words. > > > + * `size' is in bytes, we need bits. */ > > > + for (int i = 0; i < __bitset_words(size * 8); i++) { > > > + int tmp = p[0]; > > > + p[0] = p[1]; > > > + p[1] = tmp; > > > + p += 2; > > > + } > > > + return (0); > > > +#else > > > + return (copyin(u, k, size)); > > > +#endif > > > +} > > > + > > > +static int > > > +copyout32_set(const void *k, void *u, size_t size) > > > +{ > > > +#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ > > > + const struct bitset *kb = k; > > > + struct bitset *ub = u; > > > + const int *kp = (const int *)kb->__bits; > > > + int *up = (int *)ub->__bits; > > > + int rv; > > > + > > > + for (int i = 0; i < __bitset_words(CPU_SETSIZE); i++) { > > > + /* `size' is in bytes, we need bits. */ > > > + for (int i = 0; i < __bitset_words(size * 8); i++) { > > > + rv = suword32(up, kp[1]); > > > + if (rv == 0) > > > + rv = suword32(up + 1, kp[0]); > > > + if (rv != 0) > > > + return (EFAULT); > > > + } > > > + } > > > + return (0); > > > +#else > > > + return (copyout(k, u, size)); > > > +#endif > > > +} > > > + > > > +static const struct cpuset_copy_cb cpuset_copy32_cb = { > > > + .copyin = copyin32_set, > > > + .copyout = copyout32_set > > > +}; > > > + > > > int > > > freebsd32_cpuset_getaffinity(struct thread *td, > > > struct freebsd32_cpuset_getaffinity_args *uap) > > > { > > > > > > return (kern_cpuset_getaffinity(td, uap->level, uap->which, > > > - PAIR32TO64(id_t,uap->id), uap->cpusetsize, uap->mask)); > > > + PAIR32TO64(id_t,uap->id), uap->cpusetsize, uap->mask, > > > + &cpuset_copy32_cb)); > > > } > > > > > > int > > > @@ -3325,7 +3384,8 @@ freebsd32_cpuset_setaffinity(struct thread *td, > > > { > > > > > > return (user_cpuset_setaffinity(td, uap->level, uap->which, > > > - PAIR32TO64(id_t,uap->id), uap->cpusetsize, uap->mask)); > > > + PAIR32TO64(id_t,uap->id), uap->cpusetsize, uap->mask, > > > + &cpuset_copy32_cb)); > > > } > > > > > > int > > > @@ -3334,7 +3394,8 @@ freebsd32_cpuset_getdomain(struct thread *td, > > > { > > > > > > return (kern_cpuset_getdomain(td, uap->level, uap->which, > > > - PAIR32TO64(id_t,uap->id), uap->domainsetsize, uap->mask, uap->policy)); > > > + PAIR32TO64(id_t,uap->id), uap->domainsetsize, uap->mask, uap->policy, > > > + &cpuset_copy32_cb)); > > > } > > > > > > int > > > @@ -3343,7 +3404,8 @@ freebsd32_cpuset_setdomain(struct thread *td, > > > { > > > > > > return (kern_cpuset_setdomain(td, uap->level, uap->which, > > > - PAIR32TO64(id_t,uap->id), uap->domainsetsize, uap->mask, uap->policy)); > > > + PAIR32TO64(id_t,uap->id), uap->domainsetsize, uap->mask, uap->policy, > > > + &cpuset_copy32_cb)); > > > } > > > > > > int > > > diff --git a/sys/kern/kern_cpuset.c b/sys/kern/kern_cpuset.c > > > index 56d92687a693..e21ec146bb00 100644 > > > --- a/sys/kern/kern_cpuset.c > > > +++ b/sys/kern/kern_cpuset.c > > > @@ -52,6 +52,7 @@ __FBSDID("$FreeBSD$"); > > > #include <sys/sched.h> > > > #include <sys/smp.h> > > > #include <sys/syscallsubr.h> > > > +#include <sys/sysent.h> > > > #include <sys/capsicum.h> > > > #include <sys/cpuset.h> > > > #include <sys/domainset.h> > > > @@ -1742,6 +1743,11 @@ cpuset_check_capabilities(struct thread *td, cpulevel_t level, cpuwhich_t which, > > > return (0); > > > } > > > > > > +static const struct cpuset_copy_cb copy_set = { > > > + .copyin = copyin, > > > + .copyout = copyout > > > +}; > > > + > > > #ifndef _SYS_SYSPROTO_H_ > > > struct cpuset_args { > > > cpusetid_t *setid; > > > @@ -1883,12 +1889,12 @@ sys_cpuset_getaffinity(struct thread *td, struct cpuset_getaffinity_args *uap) > > > { > > > > > > return (kern_cpuset_getaffinity(td, uap->level, uap->which, > > > - uap->id, uap->cpusetsize, uap->mask)); > > > + uap->id, uap->cpusetsize, uap->mask, ©_set)); > > > } > > > > > > int > > > kern_cpuset_getaffinity(struct thread *td, cpulevel_t level, cpuwhich_t which, > > > - id_t id, size_t cpusetsize, cpuset_t *maskp) > > > + id_t id, size_t cpusetsize, cpuset_t *maskp, const struct cpuset_copy_cb *cb) > > > { > > > > this broke the build, as Linuxulator also uses kern_cpuset_getaffinity, > > may be we need to move out the userspace related code from > > kern_cpuset_getaffinity to user_cpuset_getaffinity? > > > > Sorry, I didn't sanity test a full kernel build, only a kernel-only build. I see you fixed it with 89737eb, thanks. > np, this commit pointed me to the need to finish my affinity job in a better way))
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