diff options
Diffstat (limited to 'kernel/compat.c')
| -rw-r--r-- | kernel/compat.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/kernel/compat.c b/kernel/compat.c new file mode 100644 index 0000000000..fb50f29d9b --- /dev/null +++ b/kernel/compat.c @@ -0,0 +1,271 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/kernel/compat.c + * + * Kernel compatibililty routines for e.g. 32 bit syscall support + * on 64 bit kernels. + * + * Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation + */ + +#include <linux/linkage.h> +#include <linux/compat.h> +#include <linux/errno.h> +#include <linux/time.h> +#include <linux/signal.h> +#include <linux/sched.h> /* for MAX_SCHEDULE_TIMEOUT */ +#include <linux/syscalls.h> +#include <linux/unistd.h> +#include <linux/security.h> +#include <linux/export.h> +#include <linux/migrate.h> +#include <linux/posix-timers.h> +#include <linux/times.h> +#include <linux/ptrace.h> +#include <linux/gfp.h> + +#include <linux/uaccess.h> + +#ifdef __ARCH_WANT_SYS_SIGPROCMASK + +/* + * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the + * blocked set of signals to the supplied signal set + */ +static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set) +{ + memcpy(blocked->sig, &set, sizeof(set)); +} + +COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how, + compat_old_sigset_t __user *, nset, + compat_old_sigset_t __user *, oset) +{ + old_sigset_t old_set, new_set; + sigset_t new_blocked; + + old_set = current->blocked.sig[0]; + + if (nset) { + if (get_user(new_set, nset)) + return -EFAULT; + new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); + + new_blocked = current->blocked; + + switch (how) { + case SIG_BLOCK: + sigaddsetmask(&new_blocked, new_set); + break; + case SIG_UNBLOCK: + sigdelsetmask(&new_blocked, new_set); + break; + case SIG_SETMASK: + compat_sig_setmask(&new_blocked, new_set); + break; + default: + return -EINVAL; + } + + set_current_blocked(&new_blocked); + } + + if (oset) { + if (put_user(old_set, oset)) + return -EFAULT; + } + + return 0; +} + +#endif + +int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru) +{ + struct compat_rusage r32; + memset(&r32, 0, sizeof(r32)); + r32.ru_utime.tv_sec = r->ru_utime.tv_sec; + r32.ru_utime.tv_usec = r->ru_utime.tv_usec; + r32.ru_stime.tv_sec = r->ru_stime.tv_sec; + r32.ru_stime.tv_usec = r->ru_stime.tv_usec; + r32.ru_maxrss = r->ru_maxrss; + r32.ru_ixrss = r->ru_ixrss; + r32.ru_idrss = r->ru_idrss; + r32.ru_isrss = r->ru_isrss; + r32.ru_minflt = r->ru_minflt; + r32.ru_majflt = r->ru_majflt; + r32.ru_nswap = r->ru_nswap; + r32.ru_inblock = r->ru_inblock; + r32.ru_oublock = r->ru_oublock; + r32.ru_msgsnd = r->ru_msgsnd; + r32.ru_msgrcv = r->ru_msgrcv; + r32.ru_nsignals = r->ru_nsignals; + r32.ru_nvcsw = r->ru_nvcsw; + r32.ru_nivcsw = r->ru_nivcsw; + if (copy_to_user(ru, &r32, sizeof(r32))) + return -EFAULT; + return 0; +} + +static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr, + unsigned len, struct cpumask *new_mask) +{ + unsigned long *k; + + if (len < cpumask_size()) + memset(new_mask, 0, cpumask_size()); + else if (len > cpumask_size()) + len = cpumask_size(); + + k = cpumask_bits(new_mask); + return compat_get_bitmap(k, user_mask_ptr, len * 8); +} + +COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid, + unsigned int, len, + compat_ulong_t __user *, user_mask_ptr) +{ + cpumask_var_t new_mask; + int retval; + + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) + return -ENOMEM; + + retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask); + if (retval) + goto out; + + retval = sched_setaffinity(pid, new_mask); +out: + free_cpumask_var(new_mask); + return retval; +} + +COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len, + compat_ulong_t __user *, user_mask_ptr) +{ + int ret; + cpumask_var_t mask; + + if ((len * BITS_PER_BYTE) < nr_cpu_ids) + return -EINVAL; + if (len & (sizeof(compat_ulong_t)-1)) + return -EINVAL; + + if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) + return -ENOMEM; + + ret = sched_getaffinity(pid, mask); + if (ret == 0) { + unsigned int retlen = min(len, cpumask_size()); + + if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8)) + ret = -EFAULT; + else + ret = retlen; + } + free_cpumask_var(mask); + + return ret; +} + +/* + * We currently only need the following fields from the sigevent + * structure: sigev_value, sigev_signo, sig_notify and (sometimes + * sigev_notify_thread_id). The others are handled in user mode. + * We also assume that copying sigev_value.sival_int is sufficient + * to keep all the bits of sigev_value.sival_ptr intact. + */ +int get_compat_sigevent(struct sigevent *event, + const struct compat_sigevent __user *u_event) +{ + memset(event, 0, sizeof(*event)); + return (!access_ok(u_event, sizeof(*u_event)) || + __get_user(event->sigev_value.sival_int, + &u_event->sigev_value.sival_int) || + __get_user(event->sigev_signo, &u_event->sigev_signo) || + __get_user(event->sigev_notify, &u_event->sigev_notify) || + __get_user(event->sigev_notify_thread_id, + &u_event->sigev_notify_thread_id)) + ? -EFAULT : 0; +} + +long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, + unsigned long bitmap_size) +{ + unsigned long nr_compat_longs; + + /* align bitmap up to nearest compat_long_t boundary */ + bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); + nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); + + if (!user_read_access_begin(umask, bitmap_size / 8)) + return -EFAULT; + + while (nr_compat_longs > 1) { + compat_ulong_t l1, l2; + unsafe_get_user(l1, umask++, Efault); + unsafe_get_user(l2, umask++, Efault); + *mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1; + nr_compat_longs -= 2; + } + if (nr_compat_longs) + unsafe_get_user(*mask, umask++, Efault); + user_read_access_end(); + return 0; + +Efault: + user_read_access_end(); + return -EFAULT; +} + +long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, + unsigned long bitmap_size) +{ + unsigned long nr_compat_longs; + + /* align bitmap up to nearest compat_long_t boundary */ + bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); + nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); + + if (!user_write_access_begin(umask, bitmap_size / 8)) + return -EFAULT; + + while (nr_compat_longs > 1) { + unsigned long m = *mask++; + unsafe_put_user((compat_ulong_t)m, umask++, Efault); + unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault); + nr_compat_longs -= 2; + } + if (nr_compat_longs) + unsafe_put_user((compat_ulong_t)*mask, umask++, Efault); + user_write_access_end(); + return 0; +Efault: + user_write_access_end(); + return -EFAULT; +} + +int +get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat) +{ +#ifdef __BIG_ENDIAN + compat_sigset_t v; + if (copy_from_user(&v, compat, sizeof(compat_sigset_t))) + return -EFAULT; + switch (_NSIG_WORDS) { + case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 ); + fallthrough; + case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 ); + fallthrough; + case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 ); + fallthrough; + case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 ); + } +#else + if (copy_from_user(set, compat, sizeof(compat_sigset_t))) + return -EFAULT; +#endif + return 0; +} +EXPORT_SYMBOL_GPL(get_compat_sigset); |