[PATCH bpf-next] selftests/bpf: Enable signed division and modulo overflow tests for LoongArch

[Tiezhu Yang]

The LoongArch hardware divider handles signed overflow boundaries (such
as INT_MIN/-1 or LLONG_MIN/-1) natively and perfectly well on physical
silicon: (1)for division operations, it naturally returns the dividend
itself; (2)for modulo operations, it returns 0. Thus enable the signed
division and modulo overflow tests for LoongArch in verifier_sdiv.c.

Before:

  $ sudo ./test_progs -t verifier_sdiv | grep "MIN/-1"
  #731/121 verifier_sdiv/SDIV64, overflow r/r, LLONG_MIN/-1:SKIP
  #731/123 verifier_sdiv/SDIV64, overflow r/i, LLONG_MIN/-1:SKIP
  #731/125 verifier_sdiv/SDIV32, overflow r/r, INT_MIN/-1:SKIP
  #731/127 verifier_sdiv/SDIV32, overflow r/i, INT_MIN/-1:SKIP
  #731/129 verifier_sdiv/SMOD64, overflow r/r, LLONG_MIN/-1:SKIP
  #731/131 verifier_sdiv/SMOD64, overflow r/i, LLONG_MIN/-1:SKIP
  #731/133 verifier_sdiv/SMOD32, overflow r/r, INT_MIN/-1:SKIP
  #731/135 verifier_sdiv/SMOD32, overflow r/i, INT_MIN/-1:SKIP

After:

  $ sudo ./test_progs -t verifier_sdiv | grep "MIN/-1"
  #731/121 verifier_sdiv/SDIV64, overflow r/r, LLONG_MIN/-1:OK
  #731/123 verifier_sdiv/SDIV64, overflow r/i, LLONG_MIN/-1:OK
  #731/125 verifier_sdiv/SDIV32, overflow r/r, INT_MIN/-1:OK
  #731/127 verifier_sdiv/SDIV32, overflow r/i, INT_MIN/-1:OK
  #731/129 verifier_sdiv/SMOD64, overflow r/r, LLONG_MIN/-1:OK
  #731/131 verifier_sdiv/SMOD64, overflow r/i, LLONG_MIN/-1:OK
  #731/133 verifier_sdiv/SMOD32, overflow r/r, INT_MIN/-1:OK
  #731/135 verifier_sdiv/SMOD32, overflow r/i, INT_MIN/-1:OK

Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
 tools/testing/selftests/bpf/progs/verifier_sdiv.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/testing/selftests/bpf/progs/verifier_sdiv.c b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
index d6cbe1e27fd6..5e8bf781e073 100644
--- a/tools/testing/selftests/bpf/progs/verifier_sdiv.c
+++ b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
@@ -775,6 +775,7 @@ SEC("socket")
 __description("SDIV64, overflow r/r, LLONG_MIN/-1")
 __success __retval(1)
 __arch_x86_64
+__arch_loongarch
 __xlated("0: r2 = 0x8000000000000000")
 __xlated("2: r3 = -1")
 __xlated("3: r4 = r2")
@@ -839,6 +840,7 @@ SEC("socket")
 __description("SDIV64, overflow r/i, LLONG_MIN/-1")
 __success __retval(1)
 __arch_x86_64
+__arch_loongarch
 __xlated("0: r2 = 0x8000000000000000")
 __xlated("2: r4 = r2")
 __xlated("3: r2 = -r2")
@@ -887,6 +889,7 @@ SEC("socket")
 __description("SDIV32, overflow r/r, INT_MIN/-1")
 __success __retval(1)
 __arch_x86_64
+__arch_loongarch
 __xlated("0: w2 = -2147483648")
 __xlated("1: w3 = -1")
 __xlated("2: w4 = w2")
@@ -953,6 +956,7 @@ SEC("socket")
 __description("SDIV32, overflow r/i, INT_MIN/-1")
 __success __retval(1)
 __arch_x86_64
+__arch_loongarch
 __xlated("0: w2 = -2147483648")
 __xlated("1: w4 = w2")
 __xlated("2: w2 = -w2")
@@ -1001,6 +1005,7 @@ SEC("socket")
 __description("SMOD64, overflow r/r, LLONG_MIN/-1")
 __success __retval(0)
 __arch_x86_64
+__arch_loongarch
 __xlated("0: r2 = 0x8000000000000000")
 __xlated("2: r3 = -1")
 __xlated("3: r4 = r2")
@@ -1061,6 +1066,7 @@ SEC("socket")
 __description("SMOD64, overflow r/i, LLONG_MIN/-1")
 __success __retval(0)
 __arch_x86_64
+__arch_loongarch
 __xlated("0: r2 = 0x8000000000000000")
 __xlated("2: r4 = r2")
 __xlated("3: w2 = 0")
@@ -1105,6 +1111,7 @@ SEC("socket")
 __description("SMOD32, overflow r/r, INT_MIN/-1")
 __success __retval(0)
 __arch_x86_64
+__arch_loongarch
 __xlated("0: w2 = -2147483648")
 __xlated("1: w3 = -1")
 __xlated("2: w4 = w2")
@@ -1169,6 +1176,7 @@ SEC("socket")
 __description("SMOD32, overflow r/i, INT_MIN/-1")
 __success __retval(0)
 __arch_x86_64
+__arch_loongarch
 __xlated("0: w2 = -2147483648")
 __xlated("1: w4 = w2")
 __xlated("2: w2 = 0")
-- 
2.42.0