diff options
| -rw-r--r-- | kernel/bpf/core.c | 22 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_sdiv.c | 58 |
2 files changed, 72 insertions, 8 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 9e126be33755..7b675a451ec8 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1757,6 +1757,12 @@ bool bpf_opcode_in_insntable(u8 code) } #ifndef CONFIG_BPF_JIT_ALWAYS_ON +/* Absolute value of s32 without undefined behavior for S32_MIN */ +static u32 abs_s32(s32 x) +{ + return x >= 0 ? (u32)x : -(u32)x; +} + /** * ___bpf_prog_run - run eBPF program on a given context * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers @@ -1921,8 +1927,8 @@ select_insn: DST = do_div(AX, (u32) SRC); break; case 1: - AX = abs((s32)DST); - AX = do_div(AX, abs((s32)SRC)); + AX = abs_s32((s32)DST); + AX = do_div(AX, abs_s32((s32)SRC)); if ((s32)DST < 0) DST = (u32)-AX; else @@ -1949,8 +1955,8 @@ select_insn: DST = do_div(AX, (u32) IMM); break; case 1: - AX = abs((s32)DST); - AX = do_div(AX, abs((s32)IMM)); + AX = abs_s32((s32)DST); + AX = do_div(AX, abs_s32((s32)IMM)); if ((s32)DST < 0) DST = (u32)-AX; else @@ -1976,8 +1982,8 @@ select_insn: DST = (u32) AX; break; case 1: - AX = abs((s32)DST); - do_div(AX, abs((s32)SRC)); + AX = abs_s32((s32)DST); + do_div(AX, abs_s32((s32)SRC)); if (((s32)DST < 0) == ((s32)SRC < 0)) DST = (u32)AX; else @@ -2003,8 +2009,8 @@ select_insn: DST = (u32) AX; break; case 1: - AX = abs((s32)DST); - do_div(AX, abs((s32)IMM)); + AX = abs_s32((s32)DST); + do_div(AX, abs_s32((s32)IMM)); if (((s32)DST < 0) == ((s32)IMM < 0)) DST = (u32)AX; else 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") |