/* * When a BNDSTX instruction attempts to save bounds to a bounds * table, it will first attempt to look up the table in the * first-level bounds directory. If it does not find a table in * the directory, a #BR is generated and we get here in order to * allocate a new table. * * With 32-bit mode, the size of BD is 4MB, and the size of each * bound table is 16KB. With 64-bit mode, the size of BD is 2GB, * and the size of each bound table is 4MB. */ static int do_mpx_bt_fault(void) { unsigned long bd_entry, bd_base; const struct bndcsr *bndcsr; struct mm_struct *mm = current->mm; bndcsr = get_xsave_field_ptr(XSTATE_BNDCSR); if (!bndcsr) return -EINVAL; /* * Mask off the preserve and enable bits */ bd_base = bndcsr->bndcfgu & MPX_BNDCFG_ADDR_MASK; /* * The hardware provides the address of the missing or invalid * entry via BNDSTATUS, so we don't have to go look it up. */ bd_entry = bndcsr->bndstatus & MPX_BNDSTA_ADDR_MASK; /* * Make sure the directory entry is within where we think * the directory is. */ if ((bd_entry < bd_base) || (bd_entry >= bd_base + mpx_bd_size_bytes(mm))) return -EINVAL; return allocate_bt(mm, (long __user *)bd_entry); }
/* * When a BNDSTX instruction attempts to save bounds to a bounds * table, it will first attempt to look up the table in the * first-level bounds directory. If it does not find a table in * the directory, a #BR is generated and we get here in order to * allocate a new table. * * With 32-bit mode, the size of BD is 4MB, and the size of each * bound table is 16KB. With 64-bit mode, the size of BD is 2GB, * and the size of each bound table is 4MB. */ static int do_mpx_bt_fault(struct xsave_struct *xsave_buf) { unsigned long bd_entry, bd_base; struct bndcsr *bndcsr; bndcsr = get_xsave_addr(xsave_buf, XSTATE_BNDCSR); if (!bndcsr) return -EINVAL; /* * Mask off the preserve and enable bits */ bd_base = bndcsr->bndcfgu & MPX_BNDCFG_ADDR_MASK; /* * The hardware provides the address of the missing or invalid * entry via BNDSTATUS, so we don't have to go look it up. */ bd_entry = bndcsr->bndstatus & MPX_BNDSTA_ADDR_MASK; /* * Make sure the directory entry is within where we think * the directory is. */ if ((bd_entry < bd_base) || (bd_entry >= bd_base + MPX_BD_SIZE_BYTES)) return -EINVAL; return allocate_bt((long __user *)bd_entry); }