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cpuset: Byte swap cpuset for compat32 on big endian architectures

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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
This commit is contained in:
Justin Hibbits 2022-05-12 15:38:22 -05:00
parent 21add93b58
commit 47a57144af
4 changed files with 101 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

70
sys/compat/freebsd32/freebsd32_misc.c
View File

@ -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

32
sys/kern/kern_cpuset.c
View File

@ -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, &copy_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)
{
struct thread *ttd;
struct cpuset *nset;
@ -1977,7 +1983,7 @@ kern_cpuset_getaffinity(struct thread *td, cpulevel_t level, cpuwhich_t which,
goto out;
}
size = min(cpusetsize, sizeof(cpuset_t));
error = copyout(mask, maskp, size);
error = cb->copyout(mask, maskp, size);
if (error != 0)
goto out;
if (cpusetsize > size) {
@ -2021,7 +2027,7 @@ sys_cpuset_setaffinity(struct thread *td, struct cpuset_setaffinity_args *uap)
{
return (user_cpuset_setaffinity(td, uap->level, uap->which,
uap->id, uap->cpusetsize, uap->mask));
uap->id, uap->cpusetsize, uap->mask, &copy_set));
}
int
@ -2109,7 +2115,7 @@ kern_cpuset_setaffinity(struct thread *td, cpulevel_t level, cpuwhich_t which,
int
user_cpuset_setaffinity(struct thread *td, cpulevel_t level, cpuwhich_t which,
id_t id, size_t cpusetsize, const cpuset_t *maskp)
id_t id, size_t cpusetsize, const cpuset_t *maskp, const struct cpuset_copy_cb *cb)
{
cpuset_t *mask;
int error;
@ -2117,7 +2123,7 @@ user_cpuset_setaffinity(struct thread *td, cpulevel_t level, cpuwhich_t which,
size = min(cpusetsize, sizeof(cpuset_t));
mask = malloc(sizeof(cpuset_t), M_TEMP, M_WAITOK | M_ZERO);
error = copyin(maskp, mask, size);
error = cb->copyin(maskp, mask, size);
if (error)
goto out;
/*
@ -2165,12 +2171,13 @@ sys_cpuset_getdomain(struct thread *td, struct cpuset_getdomain_args *uap)
{
return (kern_cpuset_getdomain(td, uap->level, uap->which,
uap->id, uap->domainsetsize, uap->mask, uap->policy));
uap->id, uap->domainsetsize, uap->mask, uap->policy, &copy_set));
}
int
kern_cpuset_getdomain(struct thread *td, cpulevel_t level, cpuwhich_t which,
id_t id, size_t domainsetsize, domainset_t *maskp, int *policyp)
id_t id, size_t domainsetsize, domainset_t *maskp, int *policyp,
const struct cpuset_copy_cb *cb)
{
struct domainset outset;
struct thread *ttd;
@ -2268,7 +2275,7 @@ kern_cpuset_getdomain(struct thread *td, cpulevel_t level, cpuwhich_t which,
}
DOMAINSET_COPY(&outset.ds_mask, mask);
if (error == 0)
error = copyout(mask, maskp, domainsetsize);
error = cb->copyout(mask, maskp, domainsetsize);
if (error == 0)
if (suword32(policyp, outset.ds_policy) != 0)
error = EFAULT;
@ -2292,12 +2299,13 @@ sys_cpuset_setdomain(struct thread *td, struct cpuset_setdomain_args *uap)
{
return (kern_cpuset_setdomain(td, uap->level, uap->which,
uap->id, uap->domainsetsize, uap->mask, uap->policy));
uap->id, uap->domainsetsize, uap->mask, uap->policy, &copy_set));
}
int
kern_cpuset_setdomain(struct thread *td, cpulevel_t level, cpuwhich_t which,
id_t id, size_t domainsetsize, const domainset_t *maskp, int policy)
id_t id, size_t domainsetsize, const domainset_t *maskp, int policy,
const struct cpuset_copy_cb *cb)
{
struct cpuset *nset;
struct cpuset *set;
@ -2318,7 +2326,7 @@ kern_cpuset_setdomain(struct thread *td, cpulevel_t level, cpuwhich_t which,
return (error);
memset(&domain, 0, sizeof(domain));
mask = malloc(domainsetsize, M_TEMP, M_WAITOK | M_ZERO);
error = copyin(maskp, mask, domainsetsize);
error = cb->copyin(maskp, mask, domainsetsize);
if (error)
goto out;
/*

9
sys/sys/cpuset.h
View File

@ -154,6 +154,15 @@ struct prison;
struct proc;
struct thread;
/*
* Callbacks for copying in/out a cpuset or domainset. Used for alternate
* ABIs, like compat32.
*/
struct cpuset_copy_cb {
int (*copyin)(const void *, void *, size_t);
int (*copyout)(const void *, void *, size_t);
};
struct cpuset *cpuset_thread0(void);
struct cpuset *cpuset_ref(struct cpuset *);
void cpuset_rel(struct cpuset *);

10
sys/sys/syscallsubr.h
View File

@ -39,6 +39,7 @@
#include <sys/_uio.h>
struct __wrusage;
struct cpuset_copy_cb;
struct file;
struct filecaps;
enum idtype;
@ -119,18 +120,19 @@ int kern_connectat(struct thread *td, int dirfd, int fd,
int kern_copy_file_range(struct thread *td, int infd, off_t *inoffp,
int outfd, off_t *outoffp, size_t len, unsigned int flags);
int kern_cpuset_getaffinity(struct thread *td, cpulevel_t level,
cpuwhich_t which, id_t id, size_t cpusetsize, cpuset_t *maskp);
cpuwhich_t which, id_t id, size_t cpusetsize, cpuset_t *maskp,
const struct cpuset_copy_cb *cb);
int kern_cpuset_setaffinity(struct thread *td, cpulevel_t level,
cpuwhich_t which, id_t id, cpuset_t *maskp);
int user_cpuset_setaffinity(struct thread *td, cpulevel_t level,
cpuwhich_t which, id_t id, size_t cpusetsize,
const cpuset_t *maskp);
const cpuset_t *maskp, const struct cpuset_copy_cb *cb);
int kern_cpuset_getdomain(struct thread *td, cpulevel_t level,
cpuwhich_t which, id_t id, size_t domainsetsize,
domainset_t *maskp, int *policyp);
domainset_t *maskp, int *policyp, const struct cpuset_copy_cb *cb);
int kern_cpuset_setdomain(struct thread *td, cpulevel_t level,
cpuwhich_t which, id_t id, size_t domainsetsize,
const domainset_t *maskp, int policy);
const domainset_t *maskp, int policy, const struct cpuset_copy_cb *cb);
int kern_cpuset_getid(struct thread *td, cpulevel_t level,
cpuwhich_t which, id_t id, cpusetid_t *setid);
int kern_cpuset_setid(struct thread *td, cpuwhich_t which,