pacdb

Pointer Authentication Code (Data B)

PACDB <Xd>, <Xn|SP>

Signs a data pointer using Key B.

Pseudocode Operation

modifier ← Xn | SP
Xd ← AddPAC(Xd, modifier, key_b, data_key)

Example

PACDB x0, x1

Encoding

Binary Layout

1

31

1

30

0

29

11010110

28:21

00001

20:16

00

15:14

0

13

011

12:10

Rn

9:5

Rd

4:0

 

Format Data Processing

Opcode 0xDAC10C00

Extension PAC (Security)

Operands

• Xd
  Ptr
• Xn
  Modifier

Related

Other forms of pacdb

• pacdb Pointer Authentication Code for Data Address (Key…

More in PAC (Security)

Reference

View in Arm A64 ISA Reference ↗ Arm A64 ISA

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0xDAC10C00	PACDB <Xd>, <Xn|SP>		A64		1 | 1 | 0 | 11010110 | 00001 | 00 | 0 | 011 | Rn | Rd

Description

Pointer Authentication Code for Data address, using key B. This instruction computes and inserts a pointer authentication code for a data address, using a modifier and key B. The address is in the general-purpose register that is specified by <Xd>. The modifier is:

Operation

if source_is_sp then
    X[d, 64] = AddPACDB(X[d, 64], SP[]);
else
    X[d, 64] = AddPACDB(X[d, 64], X[n, 64]);