static inline void set_fs(mm_segment_t fs)
{
current_thread_info()->addr_limit = fs;
+
+ /*
+ * Prevent a mispredicted conditional call to set_fs from forwarding
+ * the wrong address limit to access_ok under speculation.
+ */
+ dsb(nsh);
+ isb();
+
modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
}
__typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
/*
+ * Sanitise a uaccess pointer such that it becomes NULL if addr+size
+ * is above the current addr_limit.
+ */
+#define uaccess_mask_range_ptr(ptr, size) \
+ ((__typeof__(ptr))__uaccess_mask_range_ptr(ptr, size))
+static inline void __user *__uaccess_mask_range_ptr(const void __user *ptr,
+ size_t size)
+{
+ void __user *safe_ptr = (void __user *)ptr;
+ unsigned long tmp;
+
+ asm volatile(
+ " sub %1, %3, #1\n"
+ " subs %1, %1, %0\n"
+ " addhs %1, %1, #1\n"
+ " subhss %1, %1, %2\n"
+ " movlo %0, #0\n"
+ : "+r" (safe_ptr), "=&r" (tmp)
+ : "r" (size), "r" (current_thread_info()->addr_limit)
+ : "cc");
+
+ csdb();
+ return safe_ptr;
+}
+
+/*
* Single-value transfer routines. They automatically use the right
* size if we just have the right pointer type. Note that the functions
* which read from user space (*get_*) need to take care not to leak
__pu_err; \
})
+#ifdef CONFIG_CPU_SPECTRE
+/*
+ * When mitigating Spectre variant 1.1, all accessors need to include
+ * verification of the address space.
+ */
+#define __put_user(x, ptr) put_user(x, ptr)
+
+#else
#define __put_user(x, ptr) \
({ \
long __pu_err = 0; \
__pu_err; \
})
-#define __put_user_error(x, ptr, err) \
-({ \
- __put_user_switch((x), (ptr), (err), __put_user_nocheck); \
- (void) 0; \
-})
-
#define __put_user_nocheck(x, __pu_ptr, __err, __size) \
do { \
unsigned long __pu_addr = (unsigned long)__pu_ptr; \
: "r" (x), "i" (-EFAULT) \
: "cc")
+#endif /* !CONFIG_CPU_SPECTRE */
#ifdef CONFIG_MMU
extern unsigned long __must_check
kframe->magic = IWMMXT_MAGIC;
kframe->size = IWMMXT_STORAGE_SIZE;
iwmmxt_task_copy(current_thread_info(), &kframe->storage);
-
- err = __copy_to_user(frame, kframe, sizeof(*frame));
} else {
/*
* For bug-compatibility with older kernels, some space
* Set the magic and size appropriately so that properly
* written userspace can skip it reliably:
*/
- __put_user_error(DUMMY_MAGIC, &frame->magic, err);
- __put_user_error(IWMMXT_STORAGE_SIZE, &frame->size, err);
+ *kframe = (struct iwmmxt_sigframe) {
+ .magic = DUMMY_MAGIC,
+ .size = IWMMXT_STORAGE_SIZE,
+ };
}
+ err = __copy_to_user(frame, kframe, sizeof(*kframe));
+
return err;
}
static int preserve_vfp_context(struct vfp_sigframe __user *frame)
{
- const unsigned long magic = VFP_MAGIC;
- const unsigned long size = VFP_STORAGE_SIZE;
+ struct vfp_sigframe kframe;
int err = 0;
- __put_user_error(magic, &frame->magic, err);
- __put_user_error(size, &frame->size, err);
+ memset(&kframe, 0, sizeof(kframe));
+ kframe.magic = VFP_MAGIC;
+ kframe.size = VFP_STORAGE_SIZE;
+ err = vfp_preserve_user_clear_hwstate(&kframe.ufp, &kframe.ufp_exc);
if (err)
- return -EFAULT;
+ return err;
- return vfp_preserve_user_clear_hwstate(&frame->ufp, &frame->ufp_exc);
+ return __copy_to_user(frame, &kframe, sizeof(kframe));
}
static int restore_vfp_context(char __user **auxp)
setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
{
struct aux_sigframe __user *aux;
+ struct sigcontext context;
int err = 0;
- __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
- __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
- __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
- __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
- __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
- __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
- __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
- __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
- __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
- __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
- __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
- __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
- __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
- __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
- __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
- __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
- __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
-
- __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err);
- __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err);
- __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err);
- __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
+ context = (struct sigcontext) {
+ .arm_r0 = regs->ARM_r0,
+ .arm_r1 = regs->ARM_r1,
+ .arm_r2 = regs->ARM_r2,
+ .arm_r3 = regs->ARM_r3,
+ .arm_r4 = regs->ARM_r4,
+ .arm_r5 = regs->ARM_r5,
+ .arm_r6 = regs->ARM_r6,
+ .arm_r7 = regs->ARM_r7,
+ .arm_r8 = regs->ARM_r8,
+ .arm_r9 = regs->ARM_r9,
+ .arm_r10 = regs->ARM_r10,
+ .arm_fp = regs->ARM_fp,
+ .arm_ip = regs->ARM_ip,
+ .arm_sp = regs->ARM_sp,
+ .arm_lr = regs->ARM_lr,
+ .arm_pc = regs->ARM_pc,
+ .arm_cpsr = regs->ARM_cpsr,
+
+ .trap_no = current->thread.trap_no,
+ .error_code = current->thread.error_code,
+ .fault_address = current->thread.address,
+ .oldmask = set->sig[0],
+ };
+
+ err |= __copy_to_user(&sf->uc.uc_mcontext, &context, sizeof(context));
err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
if (err == 0)
err |= preserve_vfp_context(&aux->vfp);
#endif
- __put_user_error(0, &aux->end_magic, err);
+ err |= __put_user(0, &aux->end_magic);
return err;
}
/*
* Set uc.uc_flags to a value which sc.trap_no would never have.
*/
- __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
+ err = __put_user(0x5ac3c35a, &frame->uc.uc_flags);
err |= setup_sigframe(frame, regs, set);
if (err == 0)
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
- __put_user_error(0, &frame->sig.uc.uc_flags, err);
- __put_user_error(NULL, &frame->sig.uc.uc_link, err);
+ err |= __put_user(0, &frame->sig.uc.uc_flags);
+ err |= __put_user(NULL, &frame->sig.uc.uc_link);
err |= __save_altstack(&frame->sig.uc.uc_stack, regs->ARM_sp);
err |= setup_sigframe(&frame->sig, regs, set);
* Save the current VFP state into the provided structures and prepare
* for entry into a new function (signal handler).
*/
-int vfp_preserve_user_clear_hwstate(struct user_vfp __user *ufp,
- struct user_vfp_exc __user *ufp_exc)
+int vfp_preserve_user_clear_hwstate(struct user_vfp *ufp,
+ struct user_vfp_exc *ufp_exc)
{
struct thread_info *thread = current_thread_info();
struct vfp_hard_struct *hwstate = &thread->vfpstate.hard;
- int err = 0;
/* Ensure that the saved hwstate is up-to-date. */
vfp_sync_hwstate(thread);
* Copy the floating point registers. There can be unused
* registers see asm/hwcap.h for details.
*/
- err |= __copy_to_user(&ufp->fpregs, &hwstate->fpregs,
- sizeof(hwstate->fpregs));
+ memcpy(&ufp->fpregs, &hwstate->fpregs, sizeof(hwstate->fpregs));
+
/*
* Copy the status and control register.
*/
- __put_user_error(hwstate->fpscr, &ufp->fpscr, err);
+ ufp->fpscr = hwstate->fpscr;
/*
* Copy the exception registers.
*/
- __put_user_error(hwstate->fpexc, &ufp_exc->fpexc, err);
- __put_user_error(hwstate->fpinst, &ufp_exc->fpinst, err);
- __put_user_error(hwstate->fpinst2, &ufp_exc->fpinst2, err);
-
- if (err)
- return -EFAULT;
+ ufp_exc->fpexc = hwstate->fpexc;
+ ufp_exc->fpinst = hwstate->fpinst;
+ ufp_exc->fpinst2 = ufp_exc->fpinst2;
/* Ensure that VFP is disabled. */
vfp_flush_hwstate(thread);
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