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-rw-r--r--kernel/compat.c292
1 files changed, 292 insertions, 0 deletions
diff --git a/kernel/compat.c b/kernel/compat.c
new file mode 100644
index 000000000..f9f7a79e0
--- /dev/null
+++ b/kernel/compat.c
@@ -0,0 +1,292 @@
+// 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);
+
+/*
+ * Allocate user-space memory for the duration of a single system call,
+ * in order to marshall parameters inside a compat thunk.
+ */
+void __user *compat_alloc_user_space(unsigned long len)
+{
+ void __user *ptr;
+
+ /* If len would occupy more than half of the entire compat space... */
+ if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
+ return NULL;
+
+ ptr = arch_compat_alloc_user_space(len);
+
+ if (unlikely(!access_ok(ptr, len)))
+ return NULL;
+
+ return ptr;
+}
+EXPORT_SYMBOL_GPL(compat_alloc_user_space);