epoll_pwait2 is the same as epoll_pwait but with timeout being
(a pointer to) struct timespec instead of an integer.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3210
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
---
linux-user/syscall.c | 29 +++++++++++++++++++++++------
1 file changed, 23 insertions(+), 6 deletions(-)
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index d89c36382e..7269476b40 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -708,8 +708,11 @@ safe_syscall5(int, ppoll, struct pollfd *, ufds, unsigned int, nfds,
size_t, sigsetsize)
#endif
safe_syscall6(int, epoll_pwait, int, epfd, struct epoll_event *, events,
- int, maxevents, int, timeout, const sigset_t *, sigmask,
- size_t, sigsetsize)
+ int, maxevents, int, timeout,
+ const sigset_t *, sigmask, size_t, sigsetsize)
+safe_syscall6(int, epoll_pwait2, int, epfd, struct epoll_event *, events,
+ int, maxevents, struct timespec *, timeout_ts,
+ const sigset_t *, sigmask, size_t, sigsetsize)
#if defined(__NR_futex)
safe_syscall6(int,futex,int *,uaddr,int,op,int,val, \
const struct timespec *,timeout,int *,uaddr2,int,val3)
@@ -13619,12 +13622,20 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
case TARGET_NR_epoll_wait:
#endif
case TARGET_NR_epoll_pwait:
+ case TARGET_NR_epoll_pwait2:
{
struct target_epoll_event *target_ep;
struct epoll_event *ep;
int epfd = arg1;
int maxevents = arg3;
- int timeout = arg4;
+ struct timespec ts, *timeout_ts = NULL;
+
+ if (num == TARGET_NR_epoll_pwait2 && arg4 != 0) {
+ if (target_to_host_timespec(&ts, arg4)) {
+ return -TARGET_EFAULT;
+ }
+ timeout_ts = &ts;
+ }
if (maxevents <= 0 || maxevents > TARGET_EP_MAX_EVENTS) {
return -TARGET_EINVAL;
@@ -13644,6 +13655,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
switch (num) {
case TARGET_NR_epoll_pwait:
+ case TARGET_NR_epoll_pwait2:
{
sigset_t *set = NULL;
@@ -13654,8 +13666,13 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
}
}
- ret = get_errno(safe_epoll_pwait(epfd, ep, maxevents, timeout,
- set, SIGSET_T_SIZE));
+ if (num == TARGET_NR_epoll_pwait) {
+ ret = safe_epoll_pwait(epfd, ep, maxevents, arg4,
+ set, SIGSET_T_SIZE);
+ } else {
+ ret = safe_epoll_pwait2(epfd, ep, maxevents, timeout_ts,
+ set, SIGSET_T_SIZE);
+ }
if (set) {
finish_sigsuspend_mask(ret);
@@ -13664,7 +13681,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
}
#if defined(TARGET_NR_epoll_wait)
case TARGET_NR_epoll_wait:
- ret = get_errno(safe_epoll_pwait(epfd, ep, maxevents, timeout,
+ ret = get_errno(safe_epoll_pwait(epfd, ep, maxevents, arg4,
NULL, 0));
break;
#endif
--
2.47.3On 1/8/26 20:43, Michael Tokarev wrote:
> epoll_pwait2 is the same as epoll_pwait but with timeout being
> (a pointer to) struct timespec instead of an integer.
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3210
I failed to realize there was a previous attempt to implement
the same syscall by Zixing Liu - it was even submitted through my tree,
but it was badly reviewed - I failed to notice a memory leak in there.
> @@ -13654,8 +13666,13 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
> }
> }
>
> - ret = get_errno(safe_epoll_pwait(epfd, ep, maxevents, timeout,
> - set, SIGSET_T_SIZE));
> + if (num == TARGET_NR_epoll_pwait) {
> + ret = safe_epoll_pwait(epfd, ep, maxevents, arg4,
> + set, SIGSET_T_SIZE);
> + } else {
> + ret = safe_epoll_pwait2(epfd, ep, maxevents, timeout_ts,
> + set, SIGSET_T_SIZE);
> + }
>
And this is wrong - I forgot get_errno() in the new version.
Fixed now:
@@ -13654,8 +13666,13 @@ static abi_long do_syscall1(CPUArchState
*cpu_env, int num, abi_long arg1,
}
}
- ret = get_errno(safe_epoll_pwait(epfd, ep, maxevents, timeout,
- set, SIGSET_T_SIZE));
+ if (num == TARGET_NR_epoll_pwait) {
+ ret = get_errno(safe_epoll_pwait(epfd, ep, maxevents, arg4,
+ set, SIGSET_T_SIZE));
+ } else {
+ ret = get_errno(safe_epoll_pwait2(epfd, ep, maxevents,
timeout_ts,
+ set, SIGSET_T_SIZE));
+ }
if (set) {
finish_sigsuspend_mask(ret);
The previous attempt were not successful, because it failed build on
armhf. I checked why it failed -- it is rather fun, the failure to
build was because qemu carried old/incomplete linux-headers for 32bit
arm. These headers weren't needed since v5.0.0, and were removed in
v10.0.0-2612-g99c6e970a4 "linux-headers: Remove the 32-bit arm headers" -
after what commit, the patch by Zixing Liu would've worked (modulo the
memory leak).
But I think my version is better, in the end (after fixing get_errno()).
Thanks,
/mjt
On 1/8/26 9:43 AM, Michael Tokarev wrote: > epoll_pwait2 is the same as epoll_pwait but with timeout being > (a pointer to) struct timespec instead of an integer. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3210 > Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> > --- > linux-user/syscall.c | 29 +++++++++++++++++++++++------ > 1 file changed, 23 insertions(+), 6 deletions(-) > Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
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