| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2025 Isovalent */ |
| |
| #include <linux/bpf.h> |
| #include <bpf/bpf_helpers.h> |
| #include "bpf_misc.h" |
| #include "../../../include/linux/filter.h" |
| |
| #if defined(__TARGET_ARCH_x86) || defined(__TARGET_ARCH_arm64) |
| |
| #define DEFINE_SIMPLE_JUMP_TABLE_PROG(NAME, SRC_REG, OFF, IMM, OUTCOME) \ |
| \ |
| SEC("socket") \ |
| OUTCOME \ |
| __naked void jump_table_ ## NAME(void) \ |
| { \ |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .size jt0_%=, 16; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 += 8; \ |
| r0 = *(u64 *)(r0 + 0); \ |
| .8byte %[gotox_r0]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_0, (SRC_REG), (OFF) , (IMM))) \ |
| : __clobber_all); \ |
| } |
| |
| /* |
| * The first program which doesn't use reserved fields |
| * loads and works properly. The rest fail to load. |
| */ |
| DEFINE_SIMPLE_JUMP_TABLE_PROG(ok, BPF_REG_0, 0, 0, __success __retval(1)) |
| DEFINE_SIMPLE_JUMP_TABLE_PROG(reserved_field_src_reg, BPF_REG_1, 0, 0, __failure __msg("BPF_JA|BPF_X uses reserved fields")) |
| DEFINE_SIMPLE_JUMP_TABLE_PROG(reserved_field_non_zero_off, BPF_REG_0, 1, 0, __failure __msg("BPF_JA|BPF_X uses reserved fields")) |
| DEFINE_SIMPLE_JUMP_TABLE_PROG(reserved_field_non_zero_imm, BPF_REG_0, 0, 1, __failure __msg("BPF_JA|BPF_X uses reserved fields")) |
| |
| /* |
| * Gotox is forbidden when there is no jump table loaded |
| * which points to the sub-function where the gotox is used |
| */ |
| SEC("socket") |
| __failure __msg("no jump tables found for subprog starting at 0") |
| __naked void jump_table_no_jump_table(void) |
| { |
| asm volatile (" \ |
| .8byte %[gotox_r0]; \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_0, 0, 0 , 0)) |
| : __clobber_all); |
| } |
| |
| /* |
| * Incorrect type of the target register, only PTR_TO_INSN allowed |
| */ |
| SEC("socket") |
| __failure __msg("R1 has type scalar, expected PTR_TO_INSN") |
| __naked void jump_table_incorrect_dst_reg_type(void) |
| { |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .size jt0_%=, 16; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 += 8; \ |
| r0 = *(u64 *)(r0 + 0); \ |
| r1 = 42; \ |
| .8byte %[gotox_r1]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_r1, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_1, 0, 0 , 0)) |
| : __clobber_all); |
| } |
| |
| #define DEFINE_INVALID_SIZE_PROG(READ_SIZE, OUTCOME) \ |
| \ |
| SEC("socket") \ |
| OUTCOME \ |
| __naked void jump_table_invalid_read_size_ ## READ_SIZE(void) \ |
| { \ |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .size jt0_%=, 16; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 += 8; \ |
| r0 = *(" #READ_SIZE " *)(r0 + 0); \ |
| .8byte %[gotox_r0]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_0, 0, 0 , 0)) \ |
| : __clobber_all); \ |
| } |
| |
| DEFINE_INVALID_SIZE_PROG(u32, __failure __msg("Invalid read of 4 bytes from insn_array")) |
| DEFINE_INVALID_SIZE_PROG(u16, __failure __msg("Invalid read of 2 bytes from insn_array")) |
| DEFINE_INVALID_SIZE_PROG(u8, __failure __msg("Invalid read of 1 bytes from insn_array")) |
| |
| SEC("socket") |
| __failure __msg("misaligned value access off 0+1+0 size 8") |
| __naked void jump_table_misaligned_access(void) |
| { |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .size jt0_%=, 16; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 += 1; \ |
| r0 = *(u64 *)(r0 + 0); \ |
| .8byte %[gotox_r0]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_0, 0, 0 , 0)) |
| : __clobber_all); |
| } |
| |
| SEC("socket") |
| __failure __msg("invalid access to map value, value_size=16 off=24 size=8") |
| __naked void jump_table_invalid_mem_acceess_pos(void) |
| { |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .size jt0_%=, 16; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 += 24; \ |
| r0 = *(u64 *)(r0 + 0); \ |
| .8byte %[gotox_r0]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_0, 0, 0 , 0)) |
| : __clobber_all); |
| } |
| |
| SEC("socket") |
| __failure __msg("invalid access to map value, value_size=16 off=-24 size=8") |
| __naked void jump_table_invalid_mem_acceess_neg(void) |
| { |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .size jt0_%=, 16; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 -= 24; \ |
| r0 = *(u64 *)(r0 + 0); \ |
| .8byte %[gotox_r0]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_0, 0, 0 , 0)) |
| : __clobber_all); |
| } |
| |
| SEC("socket") |
| __success __retval(1) |
| __naked void jump_table_add_sub_ok(void) |
| { |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .size jt0_%=, 16; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 -= 24; \ |
| r0 += 32; \ |
| r0 = *(u64 *)(r0 + 0); \ |
| .8byte %[gotox_r0]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_0, 0, 0 , 0)) |
| : __clobber_all); |
| } |
| |
| SEC("socket") |
| __failure __msg("write into map forbidden, value_size=16 off=8 size=8") |
| __naked void jump_table_no_writes(void) |
| { |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .size jt0_%=, 16; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 += 8; \ |
| r1 = 0xbeef; \ |
| *(u64 *)(r0 + 0) = r1; \ |
| .8byte %[gotox_r0]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_0, 0, 0 , 0)) |
| : __clobber_all); |
| } |
| |
| #define DEFINE_JUMP_TABLE_USE_REG(REG) \ |
| SEC("socket") \ |
| __success __retval(1) \ |
| __naked void jump_table_use_reg_r ## REG(void) \ |
| { \ |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .size jt0_%=, 16; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 += 8; \ |
| r" #REG " = *(u64 *)(r0 + 0); \ |
| .8byte %[gotox_rX]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_rX, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_ ## REG, 0, 0 , 0)) \ |
| : __clobber_all); \ |
| } |
| |
| DEFINE_JUMP_TABLE_USE_REG(0) |
| DEFINE_JUMP_TABLE_USE_REG(1) |
| DEFINE_JUMP_TABLE_USE_REG(2) |
| DEFINE_JUMP_TABLE_USE_REG(3) |
| DEFINE_JUMP_TABLE_USE_REG(4) |
| DEFINE_JUMP_TABLE_USE_REG(5) |
| DEFINE_JUMP_TABLE_USE_REG(6) |
| DEFINE_JUMP_TABLE_USE_REG(7) |
| DEFINE_JUMP_TABLE_USE_REG(8) |
| DEFINE_JUMP_TABLE_USE_REG(9) |
| |
| __used static int test_subprog(void) |
| { |
| return 0; |
| } |
| |
| SEC("socket") |
| __failure __msg("jump table for insn 4 points outside of the subprog [0,10]") |
| __naked void jump_table_outside_subprog(void) |
| { |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .quad ret_out_%= - socket; \ |
| .size jt0_%=, 24; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 += 8; \ |
| r0 = *(u64 *)(r0 + 0); \ |
| .8byte %[gotox_r0]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| call test_subprog; \ |
| exit; \ |
| ret_out_%=: \ |
| " : \ |
| : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_0, 0, 0 , 0)) |
| : __clobber_all); |
| } |
| |
| SEC("socket") |
| __success __retval(1) |
| __naked void jump_table_contains_non_unique_values(void) |
| { |
| asm volatile (" \ |
| .pushsection .jumptables,\"\",@progbits; \ |
| jt0_%=: \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .quad ret0_%= - socket; \ |
| .quad ret1_%= - socket; \ |
| .size jt0_%=, 80; \ |
| .global jt0_%=; \ |
| .popsection; \ |
| \ |
| r0 = jt0_%= ll; \ |
| r0 += 8; \ |
| r0 = *(u64 *)(r0 + 0); \ |
| .8byte %[gotox_r0]; \ |
| ret0_%=: \ |
| r0 = 0; \ |
| exit; \ |
| ret1_%=: \ |
| r0 = 1; \ |
| exit; \ |
| " : \ |
| : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_0, 0, 0 , 0)) |
| : __clobber_all); |
| } |
| |
| #endif /* __TARGET_ARCH_x86 || __TARGET_ARCH_arm64 */ |
| |
| char _license[] SEC("license") = "GPL"; |
