Messages in this thread Patch in this message | | | Date | Thu, 10 May 2018 11:20:13 +0800 | From | Wang YanQing <> | Subject | [PATCH] bpf, arm32: Correct check_imm24 |
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imm24 is signed, so the right range is: [-(2<<(24 - 1)), (2<<(24 - 1)) - 1]
Note:this patch also fix a typo.
Signed-off-by: Wang YanQing <udknight@gmail.com> --- arch/arm/net/bpf_jit_32.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index c0b4124..19c6d77 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -84,7 +84,7 @@ * * 1. First argument is passed using the arm 32bit registers and rest of the * arguments are passed on stack scratch space. - * 2. First callee-saved arugument is mapped to arm 32 bit registers and rest + * 2. First callee-saved argument is mapped to arm 32 bit registers and rest * arguments are mapped to scratch space on stack. * 3. We need two 64 bit temp registers to do complex operations on eBPF * registers. @@ -1198,15 +1198,14 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) u8 rd, rt, rm, rn; s32 jmp_offset; -#define check_imm(bits, imm) do { \ - if ((((imm) > 0) && ((imm) >> (bits))) || \ - (((imm) < 0) && (~(imm) >> (bits)))) { \ - pr_info("[%2d] imm=%d(0x%x) out of range\n", \ - i, imm, imm); \ +#define check_imm_range(min, max, imm) do { \ + if (imm < min || imm > max) { \ + pr_info("[%2d] imm=%d is out of range\n", \ + i, imm); \ return -EINVAL; \ } \ } while (0) -#define check_imm24(imm) check_imm(24, imm) +#define check_imm24(imm) check_imm_range(-16777216, 16777215, imm) switch (code) { /* ALU operations */ -- 1.8.5.6.2.g3d8a54e.dirty
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