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| author | Cupertino Miranda <cupertino.miranda@oracle.com> | 2025-12-02 18:02:20 +0000 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-12-10 00:12:09 -0800 |
| commit | a5b4867fad18e72fd5fc442c16be83723776283b (patch) | |
| tree | bbfa87c0a8d8203313f775e9fed466cbd788fee4 | |
| parent | d18dec4b8990048ce75f0ece32bb96b3fbd3f422 (diff) | |
selftests/bpf: add verifier sign extension bound computation tests.
This commit adds 3 tests to verify a common compiler generated
pattern for sign extension (r1 <<= 32; r1 s>>= 32).
The tests make sure the register bounds are correctly computed both for
positive and negative register values.
Signed-off-by: Cupertino Miranda <cupertino.miranda@oracle.com>
Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Cc: David Faust <david.faust@oracle.com>
Cc: Jose Marchesi <jose.marchesi@oracle.com>
Cc: Elena Zannoni <elena.zannoni@oracle.com>
Link: https://lore.kernel.org/r/20251202180220.11128-3-cupertino.miranda@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_subreg.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_subreg.c b/tools/testing/selftests/bpf/progs/verifier_subreg.c index 8613ea160dcd..b3e1c3eef9ae 100644 --- a/tools/testing/selftests/bpf/progs/verifier_subreg.c +++ b/tools/testing/selftests/bpf/progs/verifier_subreg.c @@ -532,6 +532,74 @@ __naked void arsh32_imm_zero_extend_check(void) } SEC("socket") +__description("arsh32 imm sign positive extend check") +__success __retval(0) +__log_level(2) +__msg("2: (57) r6 &= 4095 ; R6=scalar(smin=smin32=0,smax=umax=smax32=umax32=4095,var_off=(0x0; 0xfff))") +__msg("3: (67) r6 <<= 32 ; R6=scalar(smin=smin32=0,smax=umax=0xfff00000000,smax32=umax32=0,var_off=(0x0; 0xfff00000000))") +__msg("4: (c7) r6 s>>= 32 ; R6=scalar(smin=smin32=0,smax=umax=smax32=umax32=4095,var_off=(0x0; 0xfff))") +__naked void arsh32_imm_sign_extend_positive_check(void) +{ + asm volatile (" \ + call %[bpf_get_prandom_u32]; \ + r6 = r0; \ + r6 &= 4095; \ + r6 <<= 32; \ + r6 s>>= 32; \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +SEC("socket") +__description("arsh32 imm sign negative extend check") +__success __retval(0) +__log_level(2) +__msg("3: (17) r6 -= 4095 ; R6=scalar(smin=smin32=-4095,smax=smax32=0)") +__msg("4: (67) r6 <<= 32 ; R6=scalar(smin=0xfffff00100000000,smax=smax32=umax32=0,umax=0xffffffff00000000,smin32=0,var_off=(0x0; 0xffffffff00000000))") +__msg("5: (c7) r6 s>>= 32 ; R6=scalar(smin=smin32=-4095,smax=smax32=0)") +__naked void arsh32_imm_sign_extend_negative_check(void) +{ + asm volatile (" \ + call %[bpf_get_prandom_u32]; \ + r6 = r0; \ + r6 &= 4095; \ + r6 -= 4095; \ + r6 <<= 32; \ + r6 s>>= 32; \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +SEC("socket") +__description("arsh32 imm sign extend check") +__success __retval(0) +__log_level(2) +__msg("3: (17) r6 -= 2047 ; R6=scalar(smin=smin32=-2047,smax=smax32=2048)") +__msg("4: (67) r6 <<= 32 ; R6=scalar(smin=0xfffff80100000000,smax=0x80000000000,umax=0xffffffff00000000,smin32=0,smax32=umax32=0,var_off=(0x0; 0xffffffff00000000))") +__msg("5: (c7) r6 s>>= 32 ; R6=scalar(smin=smin32=-2047,smax=smax32=2048)") +__naked void arsh32_imm_sign_extend_check(void) +{ + asm volatile (" \ + call %[bpf_get_prandom_u32]; \ + r6 = r0; \ + r6 &= 4095; \ + r6 -= 2047; \ + r6 <<= 32; \ + r6 s>>= 32; \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +SEC("socket") __description("end16 (to_le) reg zero extend check") __success __success_unpriv __retval(0) __naked void le_reg_zero_extend_check_1(void) |