mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

bsd-user upstreaming: read, write and exit

Browse Source 
This series of patches continues the effort to get system calls working
 upstream. This series was cleaved off a prior series to give me time to rework
 based on the feedback from the first time I posted these. read, write and exit
 are implemented, along with a few helper functions and tracing.
 -----BEGIN PGP SIGNATURE-----
 Comment: GPGTools - https://gpgtools.org
 
 iQIzBAABCgAdFiEEIDX4lLAKo898zeG3bBzRKH2wEQAFAmKknqsACgkQbBzRKH2w
 EQDJFhAA3ARnphfxKUvKHzi6ARza8YRFNJs/X48l78xugW8Fx2+UFxn/oPzVYuM3
 TUIIRNIXQxYDWP5rNN4zNfYjn1F32qx4PrLzzHw4t/0pNvNDvbVKyw+OB1pNUVI9
 6hNH7jTLczi4OwZFPC4bJdFFHI55t4PCHxPaMQQO76lEsFzz3+9OcNNj3/j5aTBH
 kY3FsmOIKFEFuqDANjdn13lBlkNNWj5WMIsEQd+k1TPTfG3EWDlfHVJVezx9j5uH
 KMUjRRqBANLVJuqhog7sVAdkR6o/aKuq16nPVAgkLeJrsjwljoO1bGL3DTFWzhAo
 v3+S3a5gCReLXA/Z+dGCuJysmimsm+XdJWHyNIwDCV/UUg9tXc9/BI/eBSK7MLbz
 hvURY3cRSSVY+xiu5ts1OCp1bbqMaYbpIrv1mLZMA/32Y1KNv0LwSI0ClGag0MJ1
 rSVC3i/TGYn8Dk7TlfKkrKn751ZCCDsxZGROEcPlTV84Mc7080lpgYZKlgLCPJNT
 WWaVSBs9YhHhmoG3R3GurfsHnnRr8Y8iZkmndoCJdeSlmZh/1oD31PWKhnydsPa9
 jQCENkAM0dOM/r+hV+paFxOPkgklu7KLtjqGnVRxgB4j37jA9KDyw+UXLmjipP0K
 IwPlsNIfk1LujID3o5nJVgf/K+TJpXS7JDcUsuB9+FvlkeEMWm8=
 =nOc2
 -----END PGP SIGNATURE-----

Merge tag 'bsd-user-preen-2022q2-pull-request' of ssh://github.com/qemu-bsd-user/qemu-bsd-user into staging

bsd-user upstreaming: read, write and exit

This series of patches continues the effort to get system calls working
upstream. This series was cleaved off a prior series to give me time to rework
based on the feedback from the first time I posted these. read, write and exit
are implemented, along with a few helper functions and tracing.

# -----BEGIN PGP SIGNATURE-----
# Comment: GPGTools - https://gpgtools.org
#
# iQIzBAABCgAdFiEEIDX4lLAKo898zeG3bBzRKH2wEQAFAmKknqsACgkQbBzRKH2w
# EQDJFhAA3ARnphfxKUvKHzi6ARza8YRFNJs/X48l78xugW8Fx2+UFxn/oPzVYuM3
# TUIIRNIXQxYDWP5rNN4zNfYjn1F32qx4PrLzzHw4t/0pNvNDvbVKyw+OB1pNUVI9
# 6hNH7jTLczi4OwZFPC4bJdFFHI55t4PCHxPaMQQO76lEsFzz3+9OcNNj3/j5aTBH
# kY3FsmOIKFEFuqDANjdn13lBlkNNWj5WMIsEQd+k1TPTfG3EWDlfHVJVezx9j5uH
# KMUjRRqBANLVJuqhog7sVAdkR6o/aKuq16nPVAgkLeJrsjwljoO1bGL3DTFWzhAo
# v3+S3a5gCReLXA/Z+dGCuJysmimsm+XdJWHyNIwDCV/UUg9tXc9/BI/eBSK7MLbz
# hvURY3cRSSVY+xiu5ts1OCp1bbqMaYbpIrv1mLZMA/32Y1KNv0LwSI0ClGag0MJ1
# rSVC3i/TGYn8Dk7TlfKkrKn751ZCCDsxZGROEcPlTV84Mc7080lpgYZKlgLCPJNT
# WWaVSBs9YhHhmoG3R3GurfsHnnRr8Y8iZkmndoCJdeSlmZh/1oD31PWKhnydsPa9
# jQCENkAM0dOM/r+hV+paFxOPkgklu7KLtjqGnVRxgB4j37jA9KDyw+UXLmjipP0K
# IwPlsNIfk1LujID3o5nJVgf/K+TJpXS7JDcUsuB9+FvlkeEMWm8=
# =nOc2
# -----END PGP SIGNATURE-----
# gpg: Signature made Sat 11 Jun 2022 06:54:51 AM PDT
# gpg:                using RSA key 2035F894B00AA3CF7CCDE1B76C1CD1287DB01100
# gpg: Good signature from "Warner Losh <wlosh@netflix.com>" [unknown]
# gpg:                 aka "Warner Losh <imp@bsdimp.com>" [unknown]
# gpg:                 aka "Warner Losh <imp@freebsd.org>" [unknown]
# gpg:                 aka "Warner Losh <imp@village.org>" [unknown]
# gpg:                 aka "Warner Losh <wlosh@bsdimp.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 2035 F894 B00A A3CF 7CCD  E1B7 6C1C D128 7DB0 1100

* tag 'bsd-user-preen-2022q2-pull-request' of ssh://github.com/qemu-bsd-user/qemu-bsd-user:
  bsd-user/freebsd/os-syscall.c: Implement exit
  bsd-user/bsd-file.h: Meat of the write system calls
  bsd-user/bsd-file.h: Add implementations for read, pread, readv and preadv
  bsd-user/freebsd/os-syscall.c: Tracing and error boilerplate
  bsd-user/freebsd/os-syscall.c: unlock_iovec
  bsd-user/freebsd/os-syscall.c: lock_iovec

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2022-06-11 20:51:18 -07:00
commit b871cc83d6
3 changed files with 418 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

163
bsd-user/bsd-file.h
View File

@ -27,4 +27,167 @@ extern struct iovec *lock_iovec(int type, abi_ulong target_addr, int count,
extern void unlock_iovec(struct iovec *vec, abi_ulong target_addr, int count,
int copy);
ssize_t safe_read(int fd, void *buf, size_t nbytes);
ssize_t safe_pread(int fd, void *buf, size_t nbytes, off_t offset);
ssize_t safe_readv(int fd, const struct iovec *iov, int iovcnt);
ssize_t safe_preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset);
ssize_t safe_write(int fd, void *buf, size_t nbytes);
ssize_t safe_pwrite(int fd, void *buf, size_t nbytes, off_t offset);
ssize_t safe_writev(int fd, const struct iovec *iov, int iovcnt);
ssize_t safe_pwritev(int fd, const struct iovec *iov, int iovcnt, off_t offset);
/* read(2) */
static abi_long do_bsd_read(abi_long arg1, abi_long arg2, abi_long arg3)
{
abi_long ret;
void *p;
p = lock_user(VERIFY_WRITE, arg2, arg3, 0);
if (p == NULL) {
return -TARGET_EFAULT;
}
ret = get_errno(safe_read(arg1, p, arg3));
unlock_user(p, arg2, ret);
return ret;
}
/* pread(2) */
static abi_long do_bsd_pread(void *cpu_env, abi_long arg1,
abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6)
{
abi_long ret;
void *p;
p = lock_user(VERIFY_WRITE, arg2, arg3, 0);
if (p == NULL) {
return -TARGET_EFAULT;
}
if (regpairs_aligned(cpu_env) != 0) {
arg4 = arg5;
arg5 = arg6;
}
ret = get_errno(safe_pread(arg1, p, arg3, target_arg64(arg4, arg5)));
unlock_user(p, arg2, ret);
return ret;
}
/* readv(2) */
static abi_long do_bsd_readv(abi_long arg1, abi_long arg2, abi_long arg3)
{
abi_long ret;
struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 0);
if (vec != NULL) {
ret = get_errno(safe_readv(arg1, vec, arg3));
unlock_iovec(vec, arg2, arg3, 1);
} else {
ret = -host_to_target_errno(errno);
}
return ret;
}
/* preadv(2) */
static abi_long do_bsd_preadv(void *cpu_env, abi_long arg1,
abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6)
{
abi_long ret;
struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 1);
if (vec != NULL) {
if (regpairs_aligned(cpu_env) != 0) {
arg4 = arg5;
arg5 = arg6;
}
ret = get_errno(safe_preadv(arg1, vec, arg3, target_arg64(arg4, arg5)));
unlock_iovec(vec, arg2, arg3, 0);
} else {
ret = -host_to_target_errno(errno);
}
return ret;
}
/* write(2) */
static abi_long do_bsd_write(abi_long arg1, abi_long arg2, abi_long arg3)
{
abi_long nbytes, ret;
void *p;
/* nbytes < 0 implies that it was larger than SIZE_MAX. */
nbytes = arg3;
if (nbytes < 0) {
return -TARGET_EINVAL;
}
p = lock_user(VERIFY_READ, arg2, nbytes, 1);
if (p == NULL) {
return -TARGET_EFAULT;
}
ret = get_errno(safe_write(arg1, p, arg3));
unlock_user(p, arg2, 0);
return ret;
}
/* pwrite(2) */
static abi_long do_bsd_pwrite(void *cpu_env, abi_long arg1,
abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6)
{
abi_long ret;
void *p;
p = lock_user(VERIFY_READ, arg2, arg3, 1);
if (p == NULL) {
return -TARGET_EFAULT;
}
if (regpairs_aligned(cpu_env) != 0) {
arg4 = arg5;
arg5 = arg6;
}
ret = get_errno(safe_pwrite(arg1, p, arg3, target_arg64(arg4, arg5)));
unlock_user(p, arg2, 0);
return ret;
}
/* writev(2) */
static abi_long do_bsd_writev(abi_long arg1, abi_long arg2, abi_long arg3)
{
abi_long ret;
struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1);
if (vec != NULL) {
ret = get_errno(safe_writev(arg1, vec, arg3));
unlock_iovec(vec, arg2, arg3, 0);
} else {
ret = -host_to_target_errno(errno);
}
return ret;
}
/* pwritev(2) */
static abi_long do_bsd_pwritev(void *cpu_env, abi_long arg1,
abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6)
{
abi_long ret;
struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1);
if (vec != NULL) {
if (regpairs_aligned(cpu_env) != 0) {
arg4 = arg5;
arg5 = arg6;
}
ret = get_errno(safe_pwritev(arg1, vec, arg3, target_arg64(arg4, arg5)));
unlock_iovec(vec, arg2, arg3, 0);
} else {
ret = -host_to_target_errno(errno);
}
return ret;
}
#endif /* BSD_FILE_H */

42
bsd-user/bsd-proc.h Normal file
View File

@ -0,0 +1,42 @@
/*
* process related system call shims and definitions
*
* Copyright (c) 2013-2014 Stacey D. Son
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef BSD_PROC_H_
#define BSD_PROC_H_
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
/* exit(2) */
static inline abi_long do_bsd_exit(void *cpu_env, abi_long arg1)
{
#ifdef TARGET_GPROF
_mcleanup();
#endif
gdb_exit(arg1);
qemu_plugin_user_exit();
_exit(arg1);
return 0;
}
#endif /* !BSD_PROC_H_ */

217
bsd-user/freebsd/os-syscall.c
View File

@ -41,6 +41,22 @@
#include "user/syscall-trace.h"
#include "bsd-file.h"
#include "bsd-proc.h"
/* I/O */
safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes);
safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t,
offset);
safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt);
safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt,
off_t, offset);
safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes);
safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t,
offset);
safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt);
safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt,
off_t, offset);
void target_set_brk(abi_ulong new_brk)
{
@ -74,16 +90,209 @@ bool is_error(abi_long ret)
}
/*
* do_syscall() should always have a single exit point at the end so that
* actions, such as logging of syscall results, can be performed. All errnos
* that do_syscall() returns must be -TARGET_<errcode>.
* Unlocks a iovec. Unlike unlock_iovec, it assumes the tvec array itself is
* already locked from target_addr. It will be unlocked as well as all the iovec
* elements.
*/
static void helper_unlock_iovec(struct target_iovec *target_vec,
abi_ulong target_addr, struct iovec *vec,
int count, int copy)
{
for (int i = 0; i < count; i++) {
abi_ulong base = tswapal(target_vec[i].iov_base);
if (vec[i].iov_base) {
unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
}
}
unlock_user(target_vec, target_addr, 0);
}
struct iovec *lock_iovec(int type, abi_ulong target_addr,
int count, int copy)
{
struct target_iovec *target_vec;
struct iovec *vec;
abi_ulong total_len, max_len;
int i;
int err = 0;
if (count == 0) {
errno = 0;
return NULL;
}
if (count < 0 || count > IOV_MAX) {
errno = EINVAL;
return NULL;
}
vec = g_try_new0(struct iovec, count);
if (vec == NULL) {
errno = ENOMEM;
return NULL;
}
target_vec = lock_user(VERIFY_READ, target_addr,
count * sizeof(struct target_iovec), 1);
if (target_vec == NULL) {
err = EFAULT;
goto fail2;
}
max_len = 0x7fffffff & MIN(TARGET_PAGE_MASK, PAGE_MASK);
total_len = 0;
for (i = 0; i < count; i++) {
abi_ulong base = tswapal(target_vec[i].iov_base);
abi_long len = tswapal(target_vec[i].iov_len);
if (len < 0) {
err = EINVAL;
goto fail;
} else if (len == 0) {
/* Zero length pointer is ignored. */
vec[i].iov_base = 0;
} else {
vec[i].iov_base = lock_user(type, base, len, copy);
/*
* If the first buffer pointer is bad, this is a fault. But
* subsequent bad buffers will result in a partial write; this is
* realized by filling the vector with null pointers and zero
* lengths.
*/
if (!vec[i].iov_base) {
if (i == 0) {
err = EFAULT;
goto fail;
} else {
/*
* Fail all the subsequent addresses, they are already
* zero'd.
*/
goto out;
}
}
if (len > max_len - total_len) {
len = max_len - total_len;
}
}
vec[i].iov_len = len;
total_len += len;
}
out:
unlock_user(target_vec, target_addr, 0);
return vec;
fail:
helper_unlock_iovec(target_vec, target_addr, vec, i, copy);
fail2:
g_free(vec);
errno = err;
return NULL;
}
void unlock_iovec(struct iovec *vec, abi_ulong target_addr,
int count, int copy)
{
struct target_iovec *target_vec;
target_vec = lock_user(VERIFY_READ, target_addr,
count * sizeof(struct target_iovec), 1);
if (target_vec) {
helper_unlock_iovec(target_vec, target_addr, vec, count, copy);
}
g_free(vec);
}
/*
* All errnos that freebsd_syscall() returns must be -TARGET_<errcode>.
*/
static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
abi_long arg2, abi_long arg3, abi_long arg4,
abi_long arg5, abi_long arg6, abi_long arg7,
abi_long arg8)
{
abi_long ret;
switch (num) {
/*
* process system calls
*/
case TARGET_FREEBSD_NR_exit: /* exit(2) */
ret = do_bsd_exit(cpu_env, arg1);
break;
/*
* File system calls.
*/
case TARGET_FREEBSD_NR_read: /* read(2) */
ret = do_bsd_read(arg1, arg2, arg3);
break;
case TARGET_FREEBSD_NR_pread: /* pread(2) */
ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
break;
case TARGET_FREEBSD_NR_readv: /* readv(2) */
ret = do_bsd_readv(arg1, arg2, arg3);
break;
case TARGET_FREEBSD_NR_preadv: /* preadv(2) */
ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
case TARGET_FREEBSD_NR_write: /* write(2) */
ret = do_bsd_write(arg1, arg2, arg3);
break;
case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */
ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
break;
case TARGET_FREEBSD_NR_writev: /* writev(2) */
ret = do_bsd_writev(arg1, arg2, arg3);
break;
case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */
ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
break;
default:
qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
ret = -TARGET_ENOSYS;
break;
}
return ret;
}
/*
* do_freebsd_syscall() should always have a single exit point at the end so
* that actions, such as logging of syscall results, can be performed. This
* as a wrapper around freebsd_syscall() so that actually happens. Since
* that is a singleton, modern compilers will inline it anyway...
*/
abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
abi_long arg2, abi_long arg3, abi_long arg4,
abi_long arg5, abi_long arg6, abi_long arg7,
abi_long arg8)
{
return 0;
CPUState *cpu = env_cpu(cpu_env);
int ret;
trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
if (do_strace) {
print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
}
ret = freebsd_syscall(cpu_env, num, arg1, arg2, arg3, arg4, arg5, arg6,
arg7, arg8);
if (do_strace) {
print_freebsd_syscall_ret(num, ret);
}
trace_guest_user_syscall_ret(cpu, num, ret);
return ret;
}
void syscall_init(void)