selftests/bpf: Add tests for sdiv/smod overflow cases

Subtests are added to exercise the patched code which handles
  - LLONG_MIN/-1
  - INT_MIN/-1
  - LLONG_MIN%-1
  - INT_MIN%-1
where -1 could be an immediate or in a register.
Without the previous patch, all these cases will crash the kernel on
x86_64 platform.

Additional tests are added to use small values (e.g. -5/-1, 5%-1, etc.)
in order to exercise the additional logic with patched insns.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240913150332.1188102-1-yonghong.song@linux.dev
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 2a2271cf0294108dea4b55cae9587725ac6e51aa..148d2299e5b4c82a2de571df195024580174652f 100644 (file)
--- a/tools/testing/selftests/bpf/progs/verifier_sdiv.c
+++ b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include <linux/bpf.h>
+#include <limits.h>
 #include <bpf/bpf_helpers.h>
 #include "bpf_misc.h"
 
@@ -770,6 +771,444 @@ __naked void smod64_zero_divisor(void)
 "      ::: __clobber_all);
 }
 
+SEC("socket")
+__description("SDIV64, overflow r/r, LLONG_MIN/-1")
+__success __retval(1)
+__arch_x86_64
+__xlated("0: r2 = 0x8000000000000000")
+__xlated("2: r3 = -1")
+__xlated("3: r4 = r2")
+__xlated("4: r11 = r3")
+__xlated("5: r11 += 1")
+__xlated("6: if r11 > 0x1 goto pc+4")
+__xlated("7: if r11 == 0x0 goto pc+1")
+__xlated("8: r2 = 0")
+__xlated("9: r2 = -r2")
+__xlated("10: goto pc+1")
+__xlated("11: r2 s/= r3")
+__xlated("12: r0 = 0")
+__xlated("13: if r2 != r4 goto pc+1")
+__xlated("14: r0 = 1")
+__xlated("15: exit")
+__naked void sdiv64_overflow_rr(void)
+{
+       asm volatile ("                                 \
+       r2 = %[llong_min] ll;                           \
+       r3 = -1;                                        \
+       r4 = r2;                                        \
+       r2 s/= r3;                                      \
+       r0 = 0;                                         \
+       if r2 != r4 goto +1;                            \
+       r0 = 1;                                         \
+       exit;                                           \
+"      :
+       : __imm_const(llong_min, LLONG_MIN)
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SDIV64, r/r, small_val/-1")
+__success __retval(-5)
+__arch_x86_64
+__xlated("0: r2 = 5")
+__xlated("1: r3 = -1")
+__xlated("2: r11 = r3")
+__xlated("3: r11 += 1")
+__xlated("4: if r11 > 0x1 goto pc+4")
+__xlated("5: if r11 == 0x0 goto pc+1")
+__xlated("6: r2 = 0")
+__xlated("7: r2 = -r2")
+__xlated("8: goto pc+1")
+__xlated("9: r2 s/= r3")
+__xlated("10: r0 = r2")
+__xlated("11: exit")
+__naked void sdiv64_rr_divisor_neg_1(void)
+{
+       asm volatile ("                                 \
+       r2 = 5;                                         \
+       r3 = -1;                                        \
+       r2 s/= r3;                                      \
+       r0 = r2;                                        \
+       exit;                                           \
+"      :
+       :
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SDIV64, overflow r/i, LLONG_MIN/-1")
+__success __retval(1)
+__arch_x86_64
+__xlated("0: r2 = 0x8000000000000000")
+__xlated("2: r4 = r2")
+__xlated("3: r2 = -r2")
+__xlated("4: r0 = 0")
+__xlated("5: if r2 != r4 goto pc+1")
+__xlated("6: r0 = 1")
+__xlated("7: exit")
+__naked void sdiv64_overflow_ri(void)
+{
+       asm volatile ("                                 \
+       r2 = %[llong_min] ll;                           \
+       r4 = r2;                                        \
+       r2 s/= -1;                                      \
+       r0 = 0;                                         \
+       if r2 != r4 goto +1;                            \
+       r0 = 1;                                         \
+       exit;                                           \
+"      :
+       : __imm_const(llong_min, LLONG_MIN)
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SDIV64, r/i, small_val/-1")
+__success __retval(-5)
+__arch_x86_64
+__xlated("0: r2 = 5")
+__xlated("1: r4 = r2")
+__xlated("2: r2 = -r2")
+__xlated("3: r0 = r2")
+__xlated("4: exit")
+__naked void sdiv64_ri_divisor_neg_1(void)
+{
+       asm volatile ("                                 \
+       r2 = 5;                                         \
+       r4 = r2;                                        \
+       r2 s/= -1;                                      \
+       r0 = r2;                                        \
+       exit;                                           \
+"      :
+       :
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SDIV32, overflow r/r, INT_MIN/-1")
+__success __retval(1)
+__arch_x86_64
+__xlated("0: w2 = -2147483648")
+__xlated("1: w3 = -1")
+__xlated("2: w4 = w2")
+__xlated("3: r11 = r3")
+__xlated("4: w11 += 1")
+__xlated("5: if w11 > 0x1 goto pc+4")
+__xlated("6: if w11 == 0x0 goto pc+1")
+__xlated("7: w2 = 0")
+__xlated("8: w2 = -w2")
+__xlated("9: goto pc+1")
+__xlated("10: w2 s/= w3")
+__xlated("11: r0 = 0")
+__xlated("12: if w2 != w4 goto pc+1")
+__xlated("13: r0 = 1")
+__xlated("14: exit")
+__naked void sdiv32_overflow_rr(void)
+{
+       asm volatile ("                                 \
+       w2 = %[int_min];                                \
+       w3 = -1;                                        \
+       w4 = w2;                                        \
+       w2 s/= w3;                                      \
+       r0 = 0;                                         \
+       if w2 != w4 goto +1;                            \
+       r0 = 1;                                         \
+       exit;                                           \
+"      :
+       : __imm_const(int_min, INT_MIN)
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SDIV32, r/r, small_val/-1")
+__success __retval(5)
+__arch_x86_64
+__xlated("0: w2 = -5")
+__xlated("1: w3 = -1")
+__xlated("2: w4 = w2")
+__xlated("3: r11 = r3")
+__xlated("4: w11 += 1")
+__xlated("5: if w11 > 0x1 goto pc+4")
+__xlated("6: if w11 == 0x0 goto pc+1")
+__xlated("7: w2 = 0")
+__xlated("8: w2 = -w2")
+__xlated("9: goto pc+1")
+__xlated("10: w2 s/= w3")
+__xlated("11: w0 = w2")
+__xlated("12: exit")
+__naked void sdiv32_rr_divisor_neg_1(void)
+{
+       asm volatile ("                                 \
+       w2 = -5;                                        \
+       w3 = -1;                                        \
+       w4 = w2;                                        \
+       w2 s/= w3;                                      \
+       w0 = w2;                                        \
+       exit;                                           \
+"      :
+       :
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SDIV32, overflow r/i, INT_MIN/-1")
+__success __retval(1)
+__arch_x86_64
+__xlated("0: w2 = -2147483648")
+__xlated("1: w4 = w2")
+__xlated("2: w2 = -w2")
+__xlated("3: r0 = 0")
+__xlated("4: if w2 != w4 goto pc+1")
+__xlated("5: r0 = 1")
+__xlated("6: exit")
+__naked void sdiv32_overflow_ri(void)
+{
+       asm volatile ("                                 \
+       w2 = %[int_min];                                \
+       w4 = w2;                                        \
+       w2 s/= -1;                                      \
+       r0 = 0;                                         \
+       if w2 != w4 goto +1;                            \
+       r0 = 1;                                         \
+       exit;                                           \
+"      :
+       : __imm_const(int_min, INT_MIN)
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SDIV32, r/i, small_val/-1")
+__success __retval(-5)
+__arch_x86_64
+__xlated("0: w2 = 5")
+__xlated("1: w4 = w2")
+__xlated("2: w2 = -w2")
+__xlated("3: w0 = w2")
+__xlated("4: exit")
+__naked void sdiv32_ri_divisor_neg_1(void)
+{
+       asm volatile ("                                 \
+       w2 = 5;                                         \
+       w4 = w2;                                        \
+       w2 s/= -1;                                      \
+       w0 = w2;                                        \
+       exit;                                           \
+"      :
+       :
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SMOD64, overflow r/r, LLONG_MIN/-1")
+__success __retval(0)
+__arch_x86_64
+__xlated("0: r2 = 0x8000000000000000")
+__xlated("2: r3 = -1")
+__xlated("3: r4 = r2")
+__xlated("4: r11 = r3")
+__xlated("5: r11 += 1")
+__xlated("6: if r11 > 0x1 goto pc+3")
+__xlated("7: if r11 == 0x1 goto pc+3")
+__xlated("8: w2 = 0")
+__xlated("9: goto pc+1")
+__xlated("10: r2 s%= r3")
+__xlated("11: r0 = r2")
+__xlated("12: exit")
+__naked void smod64_overflow_rr(void)
+{
+       asm volatile ("                                 \
+       r2 = %[llong_min] ll;                           \
+       r3 = -1;                                        \
+       r4 = r2;                                        \
+       r2 s%%= r3;                                     \
+       r0 = r2;                                        \
+       exit;                                           \
+"      :
+       : __imm_const(llong_min, LLONG_MIN)
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SMOD64, r/r, small_val/-1")
+__success __retval(0)
+__arch_x86_64
+__xlated("0: r2 = 5")
+__xlated("1: r3 = -1")
+__xlated("2: r4 = r2")
+__xlated("3: r11 = r3")
+__xlated("4: r11 += 1")
+__xlated("5: if r11 > 0x1 goto pc+3")
+__xlated("6: if r11 == 0x1 goto pc+3")
+__xlated("7: w2 = 0")
+__xlated("8: goto pc+1")
+__xlated("9: r2 s%= r3")
+__xlated("10: r0 = r2")
+__xlated("11: exit")
+__naked void smod64_rr_divisor_neg_1(void)
+{
+       asm volatile ("                                 \
+       r2 = 5;                                         \
+       r3 = -1;                                        \
+       r4 = r2;                                        \
+       r2 s%%= r3;                                     \
+       r0 = r2;                                        \
+       exit;                                           \
+"      :
+       :
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SMOD64, overflow r/i, LLONG_MIN/-1")
+__success __retval(0)
+__arch_x86_64
+__xlated("0: r2 = 0x8000000000000000")
+__xlated("2: r4 = r2")
+__xlated("3: w2 = 0")
+__xlated("4: r0 = r2")
+__xlated("5: exit")
+__naked void smod64_overflow_ri(void)
+{
+       asm volatile ("                                 \
+       r2 = %[llong_min] ll;                           \
+       r4 = r2;                                        \
+       r2 s%%= -1;                                     \
+       r0 = r2;                                        \
+       exit;                                           \
+"      :
+       : __imm_const(llong_min, LLONG_MIN)
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SMOD64, r/i, small_val/-1")
+__success __retval(0)
+__arch_x86_64
+__xlated("0: r2 = 5")
+__xlated("1: r4 = r2")
+__xlated("2: w2 = 0")
+__xlated("3: r0 = r2")
+__xlated("4: exit")
+__naked void smod64_ri_divisor_neg_1(void)
+{
+       asm volatile ("                                 \
+       r2 = 5;                                         \
+       r4 = r2;                                        \
+       r2 s%%= -1;                                     \
+       r0 = r2;                                        \
+       exit;                                           \
+"      :
+       :
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SMOD32, overflow r/r, INT_MIN/-1")
+__success __retval(0)
+__arch_x86_64
+__xlated("0: w2 = -2147483648")
+__xlated("1: w3 = -1")
+__xlated("2: w4 = w2")
+__xlated("3: r11 = r3")
+__xlated("4: w11 += 1")
+__xlated("5: if w11 > 0x1 goto pc+3")
+__xlated("6: if w11 == 0x1 goto pc+4")
+__xlated("7: w2 = 0")
+__xlated("8: goto pc+1")
+__xlated("9: w2 s%= w3")
+__xlated("10: goto pc+1")
+__xlated("11: w2 = w2")
+__xlated("12: r0 = r2")
+__xlated("13: exit")
+__naked void smod32_overflow_rr(void)
+{
+       asm volatile ("                                 \
+       w2 = %[int_min];                                \
+       w3 = -1;                                        \
+       w4 = w2;                                        \
+       w2 s%%= w3;                                     \
+       r0 = r2;                                        \
+       exit;                                           \
+"      :
+       : __imm_const(int_min, INT_MIN)
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SMOD32, r/r, small_val/-1")
+__success __retval(0)
+__arch_x86_64
+__xlated("0: w2 = -5")
+__xlated("1: w3 = -1")
+__xlated("2: w4 = w2")
+__xlated("3: r11 = r3")
+__xlated("4: w11 += 1")
+__xlated("5: if w11 > 0x1 goto pc+3")
+__xlated("6: if w11 == 0x1 goto pc+4")
+__xlated("7: w2 = 0")
+__xlated("8: goto pc+1")
+__xlated("9: w2 s%= w3")
+__xlated("10: goto pc+1")
+__xlated("11: w2 = w2")
+__xlated("12: r0 = r2")
+__xlated("13: exit")
+__naked void smod32_rr_divisor_neg_1(void)
+{
+       asm volatile ("                                 \
+       w2 = -5;                                \
+       w3 = -1;                                        \
+       w4 = w2;                                        \
+       w2 s%%= w3;                                     \
+       r0 = r2;                                        \
+       exit;                                           \
+"      :
+       :
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SMOD32, overflow r/i, INT_MIN/-1")
+__success __retval(0)
+__arch_x86_64
+__xlated("0: w2 = -2147483648")
+__xlated("1: w4 = w2")
+__xlated("2: w2 = 0")
+__xlated("3: r0 = r2")
+__xlated("4: exit")
+__naked void smod32_overflow_ri(void)
+{
+       asm volatile ("                                 \
+       w2 = %[int_min];                                \
+       w4 = w2;                                        \
+       w2 s%%= -1;                                     \
+       r0 = r2;                                        \
+       exit;                                           \
+"      :
+       : __imm_const(int_min, INT_MIN)
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("SMOD32, r/i, small_val/-1")
+__success __retval(0)
+__arch_x86_64
+__xlated("0: w2 = 5")
+__xlated("1: w4 = w2")
+__xlated("2: w2 = 0")
+__xlated("3: w0 = w2")
+__xlated("4: exit")
+__naked void smod32_ri_divisor_neg_1(void)
+{
+       asm volatile ("                                 \
+       w2 = 5;                                         \
+       w4 = w2;                                        \
+       w2 s%%= -1;                                     \
+       w0 = w2;                                        \
+       exit;                                           \
+"      :
+       :
+       : __clobber_all);
+}
+
 #else
 
 SEC("socket")