diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/verifier_scalar_ids.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_scalar_ids.c | 323 |
1 files changed, 247 insertions, 76 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_scalar_ids.c b/tools/testing/selftests/bpf/progs/verifier_scalar_ids.c index 13b29a7faa71..7c5e5e6d10eb 100644 --- a/tools/testing/selftests/bpf/progs/verifier_scalar_ids.c +++ b/tools/testing/selftests/bpf/progs/verifier_scalar_ids.c @@ -5,18 +5,27 @@ #include "bpf_misc.h" /* Check that precision marks propagate through scalar IDs. - * Registers r{0,1,2} have the same scalar ID at the moment when r0 is - * marked to be precise, this mark is immediately propagated to r{1,2}. + * Registers r{0,1,2} have the same scalar ID. + * Range information is propagated for scalars sharing same ID. + * Check that precision mark for r0 causes precision marks for r{1,2} + * when range information is propagated for 'if <reg> <op> <const>' insn. */ SEC("socket") __success __log_level(2) -__msg("frame0: regs=r0,r1,r2 stack= before 4: (bf) r3 = r10") +/* first 'if' branch */ +__msg("6: (0f) r3 += r0") +__msg("frame0: regs=r0 stack= before 4: (25) if r1 > 0x7 goto pc+0") +__msg("frame0: parent state regs=r0,r1,r2 stack=:") __msg("frame0: regs=r0,r1,r2 stack= before 3: (bf) r2 = r0") -__msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0") -__msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255") -__msg("frame0: regs=r0 stack= before 0: (85) call bpf_ktime_get_ns") +/* second 'if' branch */ +__msg("from 4 to 5: ") +__msg("6: (0f) r3 += r0") +__msg("frame0: regs=r0 stack= before 5: (bf) r3 = r10") +__msg("frame0: regs=r0 stack= before 4: (25) if r1 > 0x7 goto pc+0") +/* parent state already has r{0,1,2} as precise */ +__msg("frame0: parent state regs= stack=:") __flag(BPF_F_TEST_STATE_FREQ) -__naked void precision_same_state(void) +__naked void linked_regs_bpf_k(void) { asm volatile ( /* r0 = random number up to 0xff */ @@ -25,7 +34,8 @@ __naked void precision_same_state(void) /* tie r0.id == r1.id == r2.id */ "r1 = r0;" "r2 = r0;" - /* force r0 to be precise, this immediately marks r1 and r2 as + "if r1 > 7 goto +0;" + /* force r0 to be precise, this eventually marks r1 and r2 as * precise as well because of shared IDs */ "r3 = r10;" @@ -37,22 +47,17 @@ __naked void precision_same_state(void) : __clobber_all); } -/* Same as precision_same_state, but mark propagates through state / - * parent state boundary. +/* Registers r{0,1,2} share same ID when 'if r1 > ...' insn is processed, + * check that verifier marks r{1,2} as precise while backtracking + * 'if r1 > ...' with r0 already marked. */ SEC("socket") __success __log_level(2) -__msg("frame0: last_idx 6 first_idx 5 subseq_idx -1") -__msg("frame0: regs=r0,r1,r2 stack= before 5: (bf) r3 = r10") -__msg("frame0: parent state regs=r0,r1,r2 stack=:") -__msg("frame0: regs=r0,r1,r2 stack= before 4: (05) goto pc+0") -__msg("frame0: regs=r0,r1,r2 stack= before 3: (bf) r2 = r0") -__msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0") -__msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255") -__msg("frame0: parent state regs=r0 stack=:") -__msg("frame0: regs=r0 stack= before 0: (85) call bpf_ktime_get_ns") __flag(BPF_F_TEST_STATE_FREQ) -__naked void precision_cross_state(void) +__msg("frame0: regs=r0 stack= before 5: (2d) if r1 > r3 goto pc+0") +__msg("frame0: parent state regs=r0,r1,r2,r3 stack=:") +__msg("frame0: regs=r0,r1,r2,r3 stack= before 4: (b7) r3 = 7") +__naked void linked_regs_bpf_x_src(void) { asm volatile ( /* r0 = random number up to 0xff */ @@ -61,13 +66,13 @@ __naked void precision_cross_state(void) /* tie r0.id == r1.id == r2.id */ "r1 = r0;" "r2 = r0;" - /* force checkpoint */ - "goto +0;" - /* force r0 to be precise, this immediately marks r1 and r2 as + "r3 = 7;" + "if r1 > r3 goto +0;" + /* force r0 to be precise, this eventually marks r1 and r2 as * precise as well because of shared IDs */ - "r3 = r10;" - "r3 += r0;" + "r4 = r10;" + "r4 += r0;" "r0 = 0;" "exit;" : @@ -75,19 +80,17 @@ __naked void precision_cross_state(void) : __clobber_all); } -/* Same as precision_same_state, but break one of the - * links, note that r1 is absent from regs=... in __msg below. +/* Registers r{0,1,2} share same ID when 'if r1 > r3' insn is processed, + * check that verifier marks r{0,1,2} as precise while backtracking + * 'if r1 > r3' with r3 already marked. */ SEC("socket") __success __log_level(2) -__msg("frame0: regs=r0,r2 stack= before 5: (bf) r3 = r10") -__msg("frame0: regs=r0,r2 stack= before 4: (b7) r1 = 0") -__msg("frame0: regs=r0,r2 stack= before 3: (bf) r2 = r0") -__msg("frame0: regs=r0 stack= before 2: (bf) r1 = r0") -__msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255") -__msg("frame0: regs=r0 stack= before 0: (85) call bpf_ktime_get_ns") __flag(BPF_F_TEST_STATE_FREQ) -__naked void precision_same_state_broken_link(void) +__msg("frame0: regs=r3 stack= before 5: (2d) if r1 > r3 goto pc+0") +__msg("frame0: parent state regs=r0,r1,r2,r3 stack=:") +__msg("frame0: regs=r0,r1,r2,r3 stack= before 4: (b7) r3 = 7") +__naked void linked_regs_bpf_x_dst(void) { asm volatile ( /* r0 = random number up to 0xff */ @@ -96,15 +99,13 @@ __naked void precision_same_state_broken_link(void) /* tie r0.id == r1.id == r2.id */ "r1 = r0;" "r2 = r0;" - /* break link for r1, this is the only line that differs - * compared to the previous test - */ - "r1 = 0;" - /* force r0 to be precise, this immediately marks r1 and r2 as + "r3 = 7;" + "if r1 > r3 goto +0;" + /* force r0 to be precise, this eventually marks r1 and r2 as * precise as well because of shared IDs */ - "r3 = r10;" - "r3 += r0;" + "r4 = r10;" + "r4 += r3;" "r0 = 0;" "exit;" : @@ -112,22 +113,18 @@ __naked void precision_same_state_broken_link(void) : __clobber_all); } -/* Same as precision_same_state_broken_link, but with state / - * parent state boundary. +/* Same as linked_regs_bpf_k, but break one of the + * links, note that r1 is absent from regs=... in __msg below. */ SEC("socket") __success __log_level(2) -__msg("frame0: regs=r0,r2 stack= before 6: (bf) r3 = r10") -__msg("frame0: regs=r0,r2 stack= before 5: (b7) r1 = 0") -__msg("frame0: parent state regs=r0,r2 stack=:") -__msg("frame0: regs=r0,r1,r2 stack= before 4: (05) goto pc+0") -__msg("frame0: regs=r0,r1,r2 stack= before 3: (bf) r2 = r0") -__msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0") -__msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255") +__msg("7: (0f) r3 += r0") +__msg("frame0: regs=r0 stack= before 6: (bf) r3 = r10") __msg("frame0: parent state regs=r0 stack=:") -__msg("frame0: regs=r0 stack= before 0: (85) call bpf_ktime_get_ns") +__msg("frame0: regs=r0 stack= before 5: (25) if r0 > 0x7 goto pc+0") +__msg("frame0: parent state regs=r0,r2 stack=:") __flag(BPF_F_TEST_STATE_FREQ) -__naked void precision_cross_state_broken_link(void) +__naked void linked_regs_broken_link(void) { asm volatile ( /* r0 = random number up to 0xff */ @@ -136,18 +133,13 @@ __naked void precision_cross_state_broken_link(void) /* tie r0.id == r1.id == r2.id */ "r1 = r0;" "r2 = r0;" - /* force checkpoint, although link between r1 and r{0,2} is - * broken by the next statement current precision tracking - * algorithm can't react to it and propagates mark for r1 to - * the parent state. - */ - "goto +0;" /* break link for r1, this is the only line that differs - * compared to precision_cross_state() + * compared to the previous test */ "r1 = 0;" - /* force r0 to be precise, this immediately marks r1 and r2 as - * precise as well because of shared IDs + "if r0 > 7 goto +0;" + /* force r0 to be precise, + * this eventually marks r2 as precise because of shared IDs */ "r3 = r10;" "r3 += r0;" @@ -164,10 +156,16 @@ __naked void precision_cross_state_broken_link(void) */ SEC("socket") __success __log_level(2) -__msg("11: (0f) r2 += r1") +__msg("12: (0f) r2 += r1") /* Current state */ -__msg("frame2: last_idx 11 first_idx 10 subseq_idx -1") -__msg("frame2: regs=r1 stack= before 10: (bf) r2 = r10") +__msg("frame2: last_idx 12 first_idx 11 subseq_idx -1 ") +__msg("frame2: regs=r1 stack= before 11: (bf) r2 = r10") +__msg("frame2: parent state regs=r1 stack=") +__msg("frame1: parent state regs= stack=") +__msg("frame0: parent state regs= stack=") +/* Parent state */ +__msg("frame2: last_idx 10 first_idx 10 subseq_idx 11 ") +__msg("frame2: regs=r1 stack= before 10: (25) if r1 > 0x7 goto pc+0") __msg("frame2: parent state regs=r1 stack=") /* frame1.r{6,7} are marked because mark_precise_scalar_ids() * looks for all registers with frame2.r1.id in the current state @@ -192,7 +190,7 @@ __msg("frame1: regs=r1 stack= before 4: (85) call pc+1") __msg("frame0: parent state regs=r1,r6 stack=") /* Parent state */ __msg("frame0: last_idx 3 first_idx 1 subseq_idx 4") -__msg("frame0: regs=r0,r1,r6 stack= before 3: (bf) r6 = r0") +__msg("frame0: regs=r1,r6 stack= before 3: (bf) r6 = r0") __msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0") __msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255") __flag(BPF_F_TEST_STATE_FREQ) @@ -230,7 +228,8 @@ static __naked __noinline __used void precision_many_frames__bar(void) { asm volatile ( - /* force r1 to be precise, this immediately marks: + "if r1 > 7 goto +0;" + /* force r1 to be precise, this eventually marks: * - bar frame r1 * - foo frame r{1,6,7} * - main frame r{1,6} @@ -247,14 +246,16 @@ void precision_many_frames__bar(void) */ SEC("socket") __success __log_level(2) +__msg("11: (0f) r2 += r1") /* foo frame */ -__msg("frame1: regs=r1 stack=-8,-16 before 9: (bf) r2 = r10") +__msg("frame1: regs=r1 stack= before 10: (bf) r2 = r10") +__msg("frame1: regs=r1 stack= before 9: (25) if r1 > 0x7 goto pc+0") __msg("frame1: regs=r1 stack=-8,-16 before 8: (7b) *(u64 *)(r10 -16) = r1") __msg("frame1: regs=r1 stack=-8 before 7: (7b) *(u64 *)(r10 -8) = r1") __msg("frame1: regs=r1 stack= before 4: (85) call pc+2") /* main frame */ -__msg("frame0: regs=r0,r1 stack=-8 before 3: (7b) *(u64 *)(r10 -8) = r1") -__msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0") +__msg("frame0: regs=r1 stack=-8 before 3: (7b) *(u64 *)(r10 -8) = r1") +__msg("frame0: regs=r1 stack= before 2: (bf) r1 = r0") __msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255") __flag(BPF_F_TEST_STATE_FREQ) __naked void precision_stack(void) @@ -283,7 +284,8 @@ void precision_stack__foo(void) */ "*(u64*)(r10 - 8) = r1;" "*(u64*)(r10 - 16) = r1;" - /* force r1 to be precise, this immediately marks: + "if r1 > 7 goto +0;" + /* force r1 to be precise, this eventually marks: * - foo frame r1,fp{-8,-16} * - main frame r1,fp{-8} */ @@ -299,15 +301,17 @@ void precision_stack__foo(void) SEC("socket") __success __log_level(2) /* r{6,7} */ -__msg("11: (0f) r3 += r7") -__msg("frame0: regs=r6,r7 stack= before 10: (bf) r3 = r10") +__msg("12: (0f) r3 += r7") +__msg("frame0: regs=r7 stack= before 11: (bf) r3 = r10") +__msg("frame0: regs=r7 stack= before 9: (25) if r7 > 0x7 goto pc+0") /* ... skip some insns ... */ __msg("frame0: regs=r6,r7 stack= before 3: (bf) r7 = r0") __msg("frame0: regs=r0,r6 stack= before 2: (bf) r6 = r0") /* r{8,9} */ -__msg("12: (0f) r3 += r9") -__msg("frame0: regs=r8,r9 stack= before 11: (0f) r3 += r7") +__msg("13: (0f) r3 += r9") +__msg("frame0: regs=r9 stack= before 12: (0f) r3 += r7") /* ... skip some insns ... */ +__msg("frame0: regs=r9 stack= before 10: (25) if r9 > 0x7 goto pc+0") __msg("frame0: regs=r8,r9 stack= before 7: (bf) r9 = r0") __msg("frame0: regs=r0,r8 stack= before 6: (bf) r8 = r0") __flag(BPF_F_TEST_STATE_FREQ) @@ -328,8 +332,9 @@ __naked void precision_two_ids(void) "r9 = r0;" /* clear r0 id */ "r0 = 0;" - /* force checkpoint */ - "goto +0;" + /* propagate equal scalars precision */ + "if r7 > 7 goto +0;" + "if r9 > 7 goto +0;" "r3 = r10;" /* force r7 to be precise, this also marks r6 */ "r3 += r7;" @@ -341,6 +346,105 @@ __naked void precision_two_ids(void) : __clobber_all); } +SEC("socket") +__success __log_level(2) +__flag(BPF_F_TEST_STATE_FREQ) +/* check thar r0 and r6 have different IDs after 'if', + * collect_linked_regs() can't tie more than 6 registers for a single insn. + */ +__msg("8: (25) if r0 > 0x7 goto pc+0 ; R0=scalar(id=1") +__msg("9: (bf) r6 = r6 ; R6_w=scalar(id=2") +/* check that r{0-5} are marked precise after 'if' */ +__msg("frame0: regs=r0 stack= before 8: (25) if r0 > 0x7 goto pc+0") +__msg("frame0: parent state regs=r0,r1,r2,r3,r4,r5 stack=:") +__naked void linked_regs_too_many_regs(void) +{ + asm volatile ( + /* r0 = random number up to 0xff */ + "call %[bpf_ktime_get_ns];" + "r0 &= 0xff;" + /* tie r{0-6} IDs */ + "r1 = r0;" + "r2 = r0;" + "r3 = r0;" + "r4 = r0;" + "r5 = r0;" + "r6 = r0;" + /* propagate range for r{0-6} */ + "if r0 > 7 goto +0;" + /* make r6 appear in the log */ + "r6 = r6;" + /* force r0 to be precise, + * this would cause r{0-4} to be precise because of shared IDs + */ + "r7 = r10;" + "r7 += r0;" + "r0 = 0;" + "exit;" + : + : __imm(bpf_ktime_get_ns) + : __clobber_all); +} + +SEC("socket") +__failure __log_level(2) +__flag(BPF_F_TEST_STATE_FREQ) +__msg("regs=r7 stack= before 5: (3d) if r8 >= r0") +__msg("parent state regs=r0,r7,r8") +__msg("regs=r0,r7,r8 stack= before 4: (25) if r0 > 0x1") +__msg("div by zero") +__naked void linked_regs_broken_link_2(void) +{ + asm volatile ( + "call %[bpf_get_prandom_u32];" + "r7 = r0;" + "r8 = r0;" + "call %[bpf_get_prandom_u32];" + "if r0 > 1 goto +0;" + /* r7.id == r8.id, + * thus r7 precision implies r8 precision, + * which implies r0 precision because of the conditional below. + */ + "if r8 >= r0 goto 1f;" + /* break id relation between r7 and r8 */ + "r8 += r8;" + /* make r7 precise */ + "if r7 == 0 goto 1f;" + "r0 /= 0;" +"1:" + "r0 = 42;" + "exit;" + : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +/* Check that mark_chain_precision() for one of the conditional jump + * operands does not trigger equal scalars precision propagation. + */ +SEC("socket") +__success __log_level(2) +__msg("3: (25) if r1 > 0x100 goto pc+0") +__msg("frame0: regs=r1 stack= before 2: (bf) r1 = r0") +__naked void cjmp_no_linked_regs_trigger(void) +{ + asm volatile ( + /* r0 = random number up to 0xff */ + "call %[bpf_ktime_get_ns];" + "r0 &= 0xff;" + /* tie r0.id == r1.id */ + "r1 = r0;" + /* the jump below would be predicted, thus r1 would be marked precise, + * this should not imply precision mark for r0 + */ + "if r1 > 256 goto +0;" + "r0 = 0;" + "exit;" + : + : __imm(bpf_ktime_get_ns) + : __clobber_all); +} + /* Verify that check_ids() is used by regsafe() for scalars. * * r9 = ... some pointer with range X ... @@ -656,4 +760,71 @@ __naked void two_old_ids_one_cur_id(void) : __clobber_all); } +SEC("socket") +/* Note the flag, see verifier.c:opt_subreg_zext_lo32_rnd_hi32() */ +__flag(BPF_F_TEST_RND_HI32) +__success +/* This test was added because of a bug in verifier.c:sync_linked_regs(), + * upon range propagation it destroyed subreg_def marks for registers. + * The subreg_def mark is used to decide whether zero extension instructions + * are needed when register is read. When BPF_F_TEST_RND_HI32 is set it + * also causes generation of statements to randomize upper halves of + * read registers. + * + * The test is written in a way to return an upper half of a register + * that is affected by range propagation and must have it's subreg_def + * preserved. This gives a return value of 0 and leads to undefined + * return value if subreg_def mark is not preserved. + */ +__retval(0) +/* Check that verifier believes r1/r0 are zero at exit */ +__log_level(2) +__msg("4: (77) r1 >>= 32 ; R1_w=0") +__msg("5: (bf) r0 = r1 ; R0_w=0 R1_w=0") +__msg("6: (95) exit") +__msg("from 3 to 4") +__msg("4: (77) r1 >>= 32 ; R1_w=0") +__msg("5: (bf) r0 = r1 ; R0_w=0 R1_w=0") +__msg("6: (95) exit") +/* Verify that statements to randomize upper half of r1 had not been + * generated. + */ +__xlated("call unknown") +__xlated("r0 &= 2147483647") +__xlated("w1 = w0") +/* This is how disasm.c prints BPF_ZEXT_REG at the moment, x86 and arm + * are the only CI archs that do not need zero extension for subregs. + */ +#if !defined(__TARGET_ARCH_x86) && !defined(__TARGET_ARCH_arm64) +__xlated("w1 = w1") +#endif +__xlated("if w0 < 0xa goto pc+0") +__xlated("r1 >>= 32") +__xlated("r0 = r1") +__xlated("exit") +__naked void linked_regs_and_subreg_def(void) +{ + asm volatile ( + "call %[bpf_ktime_get_ns];" + /* make sure r0 is in 32-bit range, otherwise w1 = w0 won't + * assign same IDs to registers. + */ + "r0 &= 0x7fffffff;" + /* link w1 and w0 via ID */ + "w1 = w0;" + /* 'if' statement propagates range info from w0 to w1, + * but should not affect w1->subreg_def property. + */ + "if w0 < 10 goto +0;" + /* r1 is read here, on archs that require subreg zero + * extension this would cause zext patch generation. + */ + "r1 >>= 32;" + "r0 = r1;" + "exit;" + : + : __imm(bpf_ktime_get_ns) + : __clobber_all); +} + char _license[] SEC("license") = "GPL"; |