Commit 4ac95c65efea for kernel

commit 4ac95c65efeaf0c010199b2b2f5f78b06f28dab6
Author: Jenny Guanni Qu <qguanni@gmail.com>
Date:   Wed Mar 11 01:11:16 2026 +0000

    selftests/bpf: Add tests for sdiv32/smod32 with INT_MIN dividend

    Add tests to verify that signed 32-bit division and modulo operations
    produce correct results when the dividend is INT_MIN (0x80000000).

    The bug fixed in the previous commit only affects the BPF interpreter
    path. When JIT is enabled (the default on most architectures), the
    native CPU division instruction produces the correct result and these
    tests pass regardless. With bpf_jit_enable=0, the interpreter is used
    and without the previous fix, INT_MIN / 2 incorrectly returns
    0x40000000 instead of 0xC0000000 due to abs(S32_MIN) undefined
    behavior, causing these tests to fail.

    Test cases:
      - SDIV32 INT_MIN / 2 = -1073741824 (imm and reg divisor)
      - SMOD32 INT_MIN % 2 = 0 (positive and negative divisor)

    Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
    Acked-by: Yonghong Song <yonghong.song@linux.dev>
    Signed-off-by: Jenny Guanni Qu <qguanni@gmail.com>
    Link: https://lore.kernel.org/r/20260311011116.2108005-3-qguanni@gmail.com
    Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/progs/verifier_sdiv.c b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
index 148d2299e5b4..fd59d57e8e37 100644
--- a/tools/testing/selftests/bpf/progs/verifier_sdiv.c
+++ b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
@@ -1209,6 +1209,64 @@ __naked void smod32_ri_divisor_neg_1(void)
 	: __clobber_all);
 }

+SEC("socket")
+__description("SDIV32, INT_MIN divided by 2, imm")
+__success __success_unpriv __retval(-1073741824)
+__naked void sdiv32_int_min_div_2_imm(void)
+{
+	asm volatile ("					\
+	w0 = %[int_min];				\
+	w0 s/= 2;					\
+	exit;						\
+"	:
+	: __imm_const(int_min, INT_MIN)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("SDIV32, INT_MIN divided by 2, reg")
+__success __success_unpriv __retval(-1073741824)
+__naked void sdiv32_int_min_div_2_reg(void)
+{
+	asm volatile ("					\
+	w0 = %[int_min];				\
+	w1 = 2;						\
+	w0 s/= w1;					\
+	exit;						\
+"	:
+	: __imm_const(int_min, INT_MIN)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("SMOD32, INT_MIN modulo 2, imm")
+__success __success_unpriv __retval(0)
+__naked void smod32_int_min_mod_2_imm(void)
+{
+	asm volatile ("					\
+	w0 = %[int_min];				\
+	w0 s%%= 2;					\
+	exit;						\
+"	:
+	: __imm_const(int_min, INT_MIN)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("SMOD32, INT_MIN modulo -2, imm")
+__success __success_unpriv __retval(0)
+__naked void smod32_int_min_mod_neg2_imm(void)
+{
+	asm volatile ("					\
+	w0 = %[int_min];				\
+	w0 s%%= -2;					\
+	exit;						\
+"	:
+	: __imm_const(int_min, INT_MIN)
+	: __clobber_all);
+}
+
+
 #else

 SEC("socket")