Messages in this thread Patch in this message | | | From | Wei Gao <> | Subject | [PATCH v1] futex: Add compat_sys_futex_waitv for 32bit compatibility | Date | Thu, 23 Nov 2023 00:31:40 -0500 |
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From: wei gao <wegao@suse.com>
Current implementation lead LTP test case futex_waitv failed when compiled with -m32. This patch add new compat_sys_futex_waitv to handle m32 mode syscall.
The failure reason is futex_waitv in m32 mode will deliver kernel with struct old_timespec32 timeout, but this struct type can not directly used by current sys_futex_waitv implementation.
The new function copy main logic of current sys_futex_waitv, just update parameter type from "struct __kernel_timespec __user *" to "struct old_timespec32 __user *," and use get_old_timespec32 within the new function to get timeout value.
Signed-off-by: wei gao <wegao@suse.com> --- arch/x86/entry/syscalls/syscall_32.tbl | 2 +- kernel/futex/syscalls.c | 61 ++++++++++++++++++++++++++ 2 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index c8fac5205803..11bd927dd417 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -453,7 +453,7 @@ 446 i386 landlock_restrict_self sys_landlock_restrict_self 447 i386 memfd_secret sys_memfd_secret 448 i386 process_mrelease sys_process_mrelease -449 i386 futex_waitv sys_futex_waitv +449 i386 futex_waitv sys_futex_waitv compat_sys_futex_waitv 450 i386 set_mempolicy_home_node sys_set_mempolicy_home_node 451 i386 cachestat sys_cachestat 452 i386 fchmodat2 sys_fchmodat2 diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c index 4b6da9116aa6..62d69f8ec34c 100644 --- a/kernel/futex/syscalls.c +++ b/kernel/futex/syscalls.c @@ -486,6 +486,67 @@ COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid, return ret; } + +COMPAT_SYSCALL_DEFINE5(futex_waitv, struct futex_waitv __user *, waiters, + unsigned int, nr_futexes, unsigned int, flags, + struct old_timespec32 __user *, timeout, clockid_t, clockid) +{ + struct hrtimer_sleeper to; + struct futex_vector *futexv; + struct timespec64 ts; + ktime_t time; + int ret; + + /* This syscall supports no flags for now */ + if (flags) + return -EINVAL; + + if (!nr_futexes || nr_futexes > FUTEX_WAITV_MAX || !waiters) + return -EINVAL; + + if (timeout) { + int flag_clkid = 0, flag_init = 0; + + if (clockid == CLOCK_REALTIME) { + flag_clkid = FLAGS_CLOCKRT; + flag_init = FUTEX_CLOCK_REALTIME; + } + + if (clockid != CLOCK_REALTIME && clockid != CLOCK_MONOTONIC) + return -EINVAL; + + if (get_old_timespec32(&ts, timeout)) + return -EFAULT; + + /* + * Since there's no opcode for futex_waitv, use + * FUTEX_WAIT_BITSET that uses absolute timeout as well + */ + ret = futex_init_timeout(FUTEX_WAIT_BITSET, flag_init, &ts, &time); + if (ret) + return ret; + + futex_setup_timer(&time, &to, flag_clkid, 0); + } + + futexv = kcalloc(nr_futexes, sizeof(*futexv), GFP_KERNEL); + if (!futexv) { + ret = -ENOMEM; + goto destroy_timer; + } + + ret = futex_parse_waitv(futexv, waiters, nr_futexes, futex_wake_mark, + NULL); + if (!ret) + ret = futex_wait_multiple(futexv, nr_futexes, timeout ? &to : NULL); + + kfree(futexv); + +destroy_timer: + if (timeout) + futex2_destroy_timeout(&to); + return ret; +} #endif /* CONFIG_COMPAT */ #ifdef CONFIG_COMPAT_32BIT_TIME -- 2.34.1
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