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Re: [PATCH v2 1/2] linux-user: Add support for ppoll_time64() and pselec
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From: |
Laurent Vivier |
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Subject: |
Re: [PATCH v2 1/2] linux-user: Add support for ppoll_time64() and pselect6_time64() |
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Date: |
Tue, 25 Aug 2020 09:17:57 +0200 |
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User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 |
Le 25/08/2020 à 00:30, Filip Bozuta a écrit :
> This patch introduces functionality for following time64 syscalls:
>
> *ppoll_time64
>
> This is a year 2038 safe variant of:
>
> int poll(struct pollfd *fds, nfds_t nfds, int timeout)
> -- wait for some event on a file descriptor --
> man page: https://man7.org/linux/man-pages/man2/ppoll.2.html
>
> *pselect6_time64
>
> This is a year 2038 safe variant of:
>
> int pselect6(int nfds, fd_set *readfds, fd_set *writefds,
> fd_set *exceptfds, const struct timespec *timeout,
> const sigset_t *sigmask);
> -- synchronous I/O multiplexing --
> man page: https://man7.org/linux/man-pages/man2/pselect6.2.html
>
> Implementation notes:
>
> Year 2038 safe syscalls in this patch were implemented
> with the same code as their regular variants (ppoll() and pselect()).
> This code was moved to new functions ('do_ppoll()' and 'do_pselect6()')
> that take a 'bool time64' from which a right 'struct timespec' converting
> function is called.
> (target_to_host/host_to_target_timespec() for regular and
> target_to_host/host_to_target_timespec64() for time64 variants)
>
> Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
> ---
> linux-user/syscall.c | 462 +++++++++++++++++++++++--------------------
> 1 file changed, 251 insertions(+), 211 deletions(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 1211e759c2..fc6a6e32e4 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -397,7 +397,7 @@ static int sys_getcwd1(char *buf, size_t size)
> return strlen(buf)+1;
> }
>
> -#ifdef TARGET_NR_utimensat
> +#if defined(TARGET_NR_utimensat)
> #if defined(__NR_utimensat)
> #define __NR_sys_utimensat __NR_utimensat
> _syscall4(int,sys_utimensat,int,dirfd,const char *,pathname,
> @@ -763,11 +763,11 @@ safe_syscall5(int, waitid, idtype_t, idtype, id_t, id,
> siginfo_t *, infop, \
> int, options, struct rusage *, rusage)
> safe_syscall3(int, execve, const char *, filename, char **, argv, char **,
> envp)
> #if defined(TARGET_NR_select) || defined(TARGET_NR__newselect) || \
> - defined(TARGET_NR_pselect6)
> + defined(TARGET_NR_pselect6) || defined(TARGET_NR_pselect6_time64)
> safe_syscall6(int, pselect6, int, nfds, fd_set *, readfds, fd_set *,
> writefds, \
> fd_set *, exceptfds, struct timespec *, timeout, void *, sig)
> #endif
> -#if defined(TARGET_NR_ppoll) || defined(TARGET_NR_poll)
> +#if defined(TARGET_NR_ppoll) || defined(TARGET_NR_ppoll_time64)
> safe_syscall5(int, ppoll, struct pollfd *, ufds, unsigned int, nfds,
> struct timespec *, tsp, const sigset_t *, sigmask,
> size_t, sigsetsize)
> @@ -984,7 +984,7 @@ abi_long do_brk(abi_ulong new_brk)
> }
>
> #if defined(TARGET_NR_select) || defined(TARGET_NR__newselect) || \
> - defined(TARGET_NR_pselect6)
> + defined(TARGET_NR_pselect6) || defined(TARGET_NR_pselect6_time64)
> static inline abi_long copy_from_user_fdset(fd_set *fds,
> abi_ulong target_fds_addr,
> int n)
> @@ -1252,7 +1252,8 @@ static inline abi_long target_to_host_timespec(struct
> timespec *host_ts,
> }
> #endif
>
> -#if defined(TARGET_NR_clock_settime64) || defined(TARGET_NR_futex_time64)
> +#if defined(TARGET_NR_clock_settime64) || defined(TARGET_NR_futex_time64) ||
> \
> + defined(TARGET_NR_pselect6_time64) || defined(TARGET_NR_ppoll_time64)
> static inline abi_long target_to_host_timespec64(struct timespec *host_ts,
> abi_ulong target_addr)
> {
> @@ -1458,6 +1459,237 @@ static abi_long do_old_select(abi_ulong arg1)
> #endif
> #endif
>
> +#if defined(TARGET_NR_pselect6) || defined(TARGET_NR_pselect6_time64)
> +static abi_long do_pselect6(abi_long arg1, abi_long arg2, abi_long arg3,
> + abi_long arg4, abi_long arg5, abi_long arg6,
> + bool time64)
> +{
> + abi_long rfd_addr, wfd_addr, efd_addr, n, ts_addr;
> + fd_set rfds, wfds, efds;
> + fd_set *rfds_ptr, *wfds_ptr, *efds_ptr;
> + struct timespec ts, *ts_ptr;
> + abi_long ret;
> +
> + /*
> + * The 6th arg is actually two args smashed together,
> + * so we cannot use the C library.
> + */
> + sigset_t set;
> + struct {
> + sigset_t *set;
> + size_t size;
> + } sig, *sig_ptr;
> +
> + abi_ulong arg_sigset, arg_sigsize, *arg7;
> + target_sigset_t *target_sigset;
> +
> + n = arg1;
> + rfd_addr = arg2;
> + wfd_addr = arg3;
> + efd_addr = arg4;
> + ts_addr = arg5;
> +
> + ret = copy_from_user_fdset_ptr(&rfds, &rfds_ptr, rfd_addr, n);
> + if (ret) {
> + return ret;
> + }
> + ret = copy_from_user_fdset_ptr(&wfds, &wfds_ptr, wfd_addr, n);
> + if (ret) {
> + return ret;
> + }
> + ret = copy_from_user_fdset_ptr(&efds, &efds_ptr, efd_addr, n);
> + if (ret) {
> + return ret;
> + }
> +
> + /*
> + * This takes a timespec, and not a timeval, so we cannot
> + * use the do_select() helper ...
> + */
> + if (ts_addr) {
> + if (time64) {
> + if (target_to_host_timespec64(&ts, ts_addr)) {
> + return -TARGET_EFAULT;
> + }
> + } else {
> + if (target_to_host_timespec(&ts, ts_addr)) {
> + return -TARGET_EFAULT;
> + }
> + }
> + ts_ptr = &ts;
> + } else {
> + ts_ptr = NULL;
> + }
> +
> + /* Extract the two packed args for the sigset */
> + if (arg6) {
> + sig_ptr = &sig;
> + sig.size = SIGSET_T_SIZE;
> +
> + arg7 = lock_user(VERIFY_READ, arg6, sizeof(*arg7) * 2, 1);
> + if (!arg7) {
> + return -TARGET_EFAULT;
> + }
> + arg_sigset = tswapal(arg7[0]);
> + arg_sigsize = tswapal(arg7[1]);
> + unlock_user(arg7, arg6, 0);
> +
> + if (arg_sigset) {
> + sig.set = &set;
> + if (arg_sigsize != sizeof(*target_sigset)) {
> + /* Like the kernel, we enforce correct size sigsets */
> + return -TARGET_EINVAL;
> + }
> + target_sigset = lock_user(VERIFY_READ, arg_sigset,
> + sizeof(*target_sigset), 1);
> + if (!target_sigset) {
> + return -TARGET_EFAULT;
> + }
> + target_to_host_sigset(&set, target_sigset);
> + unlock_user(target_sigset, arg_sigset, 0);
> + } else {
> + sig.set = NULL;
> + }
> + } else {
> + sig_ptr = NULL;
> + }
> +
> + ret = get_errno(safe_pselect6(n, rfds_ptr, wfds_ptr, efds_ptr,
> + ts_ptr, sig_ptr));
> +
> + if (!is_error(ret)) {
> + if (rfd_addr && copy_to_user_fdset(rfd_addr, &rfds, n)) {
> + return -TARGET_EFAULT;
> + }
> + if (wfd_addr && copy_to_user_fdset(wfd_addr, &wfds, n)) {
> + return -TARGET_EFAULT;
> + }
> + if (efd_addr && copy_to_user_fdset(efd_addr, &efds, n)) {
> + return -TARGET_EFAULT;
> + }
> + if (time64) {
> + if (ts_addr && host_to_target_timespec(ts_addr, &ts)) {
> + return -TARGET_EFAULT;
> + }
> + } else {
> + if (ts_addr && host_to_target_timespec64(ts_addr, &ts)) {
> + return -TARGET_EFAULT;
> + }
> + }
> + }
> + return ret;
> +}
> +#endif
> +
> +#if defined(TARGET_NR_poll) || defined(TARGET_NR_ppoll) || \
> + defined(TARGET_NR_ppoll_time64)
> +static abi_long do_ppoll(abi_long arg1, abi_long arg2, abi_long arg3,
> + abi_long arg4, abi_long arg5, bool ppoll, bool
> time64)
> +{
> + struct target_pollfd *target_pfd;
> + unsigned int nfds = arg2;
> + struct pollfd *pfd;
> + unsigned int i;
> + abi_long ret;
> +
> + pfd = NULL;
> + target_pfd = NULL;
> + if (nfds) {
> + if (nfds > (INT_MAX / sizeof(struct target_pollfd))) {
> + return -TARGET_EINVAL;
> + }
> + target_pfd = lock_user(VERIFY_WRITE, arg1,
> + sizeof(struct target_pollfd) * nfds, 1);
> + if (!target_pfd) {
> + return -TARGET_EFAULT;
> + }
> +
> + pfd = alloca(sizeof(struct pollfd) * nfds);
> + for (i = 0; i < nfds; i++) {
> + pfd[i].fd = tswap32(target_pfd[i].fd);
> + pfd[i].events = tswap16(target_pfd[i].events);
> + }
> + }
> + if (ppoll) {
> + struct timespec _timeout_ts, *timeout_ts = &_timeout_ts;
> + target_sigset_t *target_set;
> + sigset_t _set, *set = &_set;
> +
> + if (arg3) {
> + if (time64) {
> + if (target_to_host_timespec64(timeout_ts, arg3)) {
> + unlock_user(target_pfd, arg1, 0);
> + return -TARGET_EFAULT;
> + }
> + } else {
> + if (target_to_host_timespec(timeout_ts, arg3)) {
> + unlock_user(target_pfd, arg1, 0);
> + return -TARGET_EFAULT;
> + }
> + }
> + } else {
> + timeout_ts = NULL;
> + }
> +
> + if (arg4) {
> + if (arg5 != sizeof(target_sigset_t)) {
> + unlock_user(target_pfd, arg1, 0);
> + return -TARGET_EINVAL;
> + }
> +
> + target_set = lock_user(VERIFY_READ, arg4,
> + sizeof(target_sigset_t), 1);
> + if (!target_set) {
> + unlock_user(target_pfd, arg1, 0);
> + return -TARGET_EFAULT;
> + }
> + target_to_host_sigset(set, target_set);
> + } else {
> + set = NULL;
> + }
> +
> + ret = get_errno(safe_ppoll(pfd, nfds, timeout_ts,
> + set, SIGSET_T_SIZE));
> +
> + if (!is_error(ret) && arg3) {
> + if (time64) {
> + if (host_to_target_timespec64(arg3, timeout_ts)) {
> + return -TARGET_EFAULT;
> + }
> + } else {
> + if (host_to_target_timespec(arg3, timeout_ts)) {
> + return -TARGET_EFAULT;
> + }
> + }
> + }
> + if (arg4) {
> + unlock_user(target_set, arg4, 0);
> + }
> + } else {
> + struct timespec ts, *pts;
> +
> + if (arg3 >= 0) {
> + /* Convert ms to secs, ns */
> + ts.tv_sec = arg3 / 1000;
> + ts.tv_nsec = (arg3 % 1000) * 1000000LL;
> + pts = &ts;
> + } else {
> + /* -ve poll() timeout means "infinite" */
> + pts = NULL;
> + }
> + ret = get_errno(safe_ppoll(pfd, nfds, pts, NULL, 0));
> + }
> +
> + if (!is_error(ret)) {
> + for (i = 0; i < nfds; i++) {
> + target_pfd[i].revents = tswap16(pfd[i].revents);
> + }
> + }
> + unlock_user(target_pfd, arg1, sizeof(struct target_pollfd) * nfds);
> + return ret;
> +}
> +#endif
> +
> static abi_long do_pipe2(int host_pipe[], int flags)
> {
> #ifdef CONFIG_PIPE2
> @@ -9045,106 +9277,11 @@ static abi_long do_syscall1(void *cpu_env, int num,
> abi_long arg1,
> #endif
> #ifdef TARGET_NR_pselect6
> case TARGET_NR_pselect6:
> - {
> - abi_long rfd_addr, wfd_addr, efd_addr, n, ts_addr;
> - fd_set rfds, wfds, efds;
> - fd_set *rfds_ptr, *wfds_ptr, *efds_ptr;
> - struct timespec ts, *ts_ptr;
> -
> - /*
> - * The 6th arg is actually two args smashed together,
> - * so we cannot use the C library.
> - */
> - sigset_t set;
> - struct {
> - sigset_t *set;
> - size_t size;
> - } sig, *sig_ptr;
> -
> - abi_ulong arg_sigset, arg_sigsize, *arg7;
> - target_sigset_t *target_sigset;
> -
> - n = arg1;
> - rfd_addr = arg2;
> - wfd_addr = arg3;
> - efd_addr = arg4;
> - ts_addr = arg5;
> -
> - ret = copy_from_user_fdset_ptr(&rfds, &rfds_ptr, rfd_addr, n);
> - if (ret) {
> - return ret;
> - }
> - ret = copy_from_user_fdset_ptr(&wfds, &wfds_ptr, wfd_addr, n);
> - if (ret) {
> - return ret;
> - }
> - ret = copy_from_user_fdset_ptr(&efds, &efds_ptr, efd_addr, n);
> - if (ret) {
> - return ret;
> - }
> -
> - /*
> - * This takes a timespec, and not a timeval, so we cannot
> - * use the do_select() helper ...
> - */
> - if (ts_addr) {
> - if (target_to_host_timespec(&ts, ts_addr)) {
> - return -TARGET_EFAULT;
> - }
> - ts_ptr = &ts;
> - } else {
> - ts_ptr = NULL;
> - }
> -
> - /* Extract the two packed args for the sigset */
> - if (arg6) {
> - sig_ptr = &sig;
> - sig.size = SIGSET_T_SIZE;
> -
> - arg7 = lock_user(VERIFY_READ, arg6, sizeof(*arg7) * 2, 1);
> - if (!arg7) {
> - return -TARGET_EFAULT;
> - }
> - arg_sigset = tswapal(arg7[0]);
> - arg_sigsize = tswapal(arg7[1]);
> - unlock_user(arg7, arg6, 0);
> -
> - if (arg_sigset) {
> - sig.set = &set;
> - if (arg_sigsize != sizeof(*target_sigset)) {
> - /* Like the kernel, we enforce correct size sigsets
> */
> - return -TARGET_EINVAL;
> - }
> - target_sigset = lock_user(VERIFY_READ, arg_sigset,
> - sizeof(*target_sigset), 1);
> - if (!target_sigset) {
> - return -TARGET_EFAULT;
> - }
> - target_to_host_sigset(&set, target_sigset);
> - unlock_user(target_sigset, arg_sigset, 0);
> - } else {
> - sig.set = NULL;
> - }
> - } else {
> - sig_ptr = NULL;
> - }
> -
> - ret = get_errno(safe_pselect6(n, rfds_ptr, wfds_ptr, efds_ptr,
> - ts_ptr, sig_ptr));
> -
> - if (!is_error(ret)) {
> - if (rfd_addr && copy_to_user_fdset(rfd_addr, &rfds, n))
> - return -TARGET_EFAULT;
> - if (wfd_addr && copy_to_user_fdset(wfd_addr, &wfds, n))
> - return -TARGET_EFAULT;
> - if (efd_addr && copy_to_user_fdset(efd_addr, &efds, n))
> - return -TARGET_EFAULT;
> -
> - if (ts_addr && host_to_target_timespec(ts_addr, &ts))
> - return -TARGET_EFAULT;
> - }
> - }
> - return ret;
> + return do_pselect6(arg1, arg2, arg3, arg4, arg5, arg6, false);
> +#endif
> +#ifdef TARGET_NR_pselect6_time64
> + case TARGET_NR_pselect6_time64:
> + return do_pselect6(arg1, arg2, arg3, arg4, arg5, arg6, true);
> #endif
> #ifdef TARGET_NR_symlink
> case TARGET_NR_symlink:
> @@ -10076,114 +10213,17 @@ static abi_long do_syscall1(void *cpu_env, int
> num, abi_long arg1,
> case TARGET_NR__newselect:
> return do_select(arg1, arg2, arg3, arg4, arg5);
> #endif
> -#if defined(TARGET_NR_poll) || defined(TARGET_NR_ppoll)
> -# ifdef TARGET_NR_poll
> +#ifdef TARGET_NR_poll
> case TARGET_NR_poll:
> -# endif
> -# ifdef TARGET_NR_ppoll
> + return do_ppoll(arg1, arg2, arg3, arg4, arg5, false, false);
> +#endif
> +#ifdef TARGET_NR_ppoll
> case TARGET_NR_ppoll:
> -# endif
> - {
> - struct target_pollfd *target_pfd;
> - unsigned int nfds = arg2;
> - struct pollfd *pfd;
> - unsigned int i;
> -
> - pfd = NULL;
> - target_pfd = NULL;
> - if (nfds) {
> - if (nfds > (INT_MAX / sizeof(struct target_pollfd))) {
> - return -TARGET_EINVAL;
> - }
> -
> - target_pfd = lock_user(VERIFY_WRITE, arg1,
> - sizeof(struct target_pollfd) * nfds,
> 1);
> - if (!target_pfd) {
> - return -TARGET_EFAULT;
> - }
> -
> - pfd = alloca(sizeof(struct pollfd) * nfds);
> - for (i = 0; i < nfds; i++) {
> - pfd[i].fd = tswap32(target_pfd[i].fd);
> - pfd[i].events = tswap16(target_pfd[i].events);
> - }
> - }
> -
> - switch (num) {
> -# ifdef TARGET_NR_ppoll
> - case TARGET_NR_ppoll:
> - {
> - struct timespec _timeout_ts, *timeout_ts = &_timeout_ts;
> - target_sigset_t *target_set;
> - sigset_t _set, *set = &_set;
> -
> - if (arg3) {
> - if (target_to_host_timespec(timeout_ts, arg3)) {
> - unlock_user(target_pfd, arg1, 0);
> - return -TARGET_EFAULT;
> - }
> - } else {
> - timeout_ts = NULL;
> - }
> -
> - if (arg4) {
> - if (arg5 != sizeof(target_sigset_t)) {
> - unlock_user(target_pfd, arg1, 0);
> - return -TARGET_EINVAL;
> - }
> -
> - target_set = lock_user(VERIFY_READ, arg4,
> sizeof(target_sigset_t), 1);
> - if (!target_set) {
> - unlock_user(target_pfd, arg1, 0);
> - return -TARGET_EFAULT;
> - }
> - target_to_host_sigset(set, target_set);
> - } else {
> - set = NULL;
> - }
> -
> - ret = get_errno(safe_ppoll(pfd, nfds, timeout_ts,
> - set, SIGSET_T_SIZE));
> -
> - if (!is_error(ret) && arg3) {
> - host_to_target_timespec(arg3, timeout_ts);
> - }
> - if (arg4) {
> - unlock_user(target_set, arg4, 0);
> - }
> - break;
> - }
> -# endif
> -# ifdef TARGET_NR_poll
> - case TARGET_NR_poll:
> - {
> - struct timespec ts, *pts;
> -
> - if (arg3 >= 0) {
> - /* Convert ms to secs, ns */
> - ts.tv_sec = arg3 / 1000;
> - ts.tv_nsec = (arg3 % 1000) * 1000000LL;
> - pts = &ts;
> - } else {
> - /* -ve poll() timeout means "infinite" */
> - pts = NULL;
> - }
> - ret = get_errno(safe_ppoll(pfd, nfds, pts, NULL, 0));
> - break;
> - }
> -# endif
> - default:
> - g_assert_not_reached();
> - }
> -
> - if (!is_error(ret)) {
> - for(i = 0; i < nfds; i++) {
> - target_pfd[i].revents = tswap16(pfd[i].revents);
> - }
> - }
> - unlock_user(target_pfd, arg1, sizeof(struct target_pollfd) *
> nfds);
> - }
> - return ret;
> + return do_ppoll(arg1, arg2, arg3, arg4, arg5, true, false);
> +#endif
> +#ifdef TARGET_NR_ppoll_time64
> + case TARGET_NR_ppoll_time64:
> + return do_ppoll(arg1, arg2, arg3, arg4, arg5, true, true);
> #endif
> case TARGET_NR_flock:
> /* NOTE: the flock constant seems to be the same for every
>
Applied to my linux-user-for-5.2 branch.
Thanks,
Laurent