imm24 is signed, so the right range is:
[-(1<<(24 - 1)), (1<<(24 - 1)) - 1]
Note:this patch also fix a typo.
Signed-off-by: Wang YanQing <udkni...@gmail.com>
---
Changes
v1-v2:
1:Rewrite the patch, I make a mistake, the v1 is wrong totally,
reported by Russell King.
I use the fix suggested by Russell King instead of myself which
use the exact number range [-8388608, 8388607].
2:Fix the error in changelog.
Thanks!
arch/arm/net/bpf_jit_32.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index caccc78..316bc08 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.
@@ -1199,8 +1199,8 @@ static int build_insn(const struct bpf_insn *insn, struct
jit_ctx *ctx)
s32 jmp_offset;
#define check_imm(bits, imm) do { \
- if ((((imm) > 0) && ((imm) >> (bits))) || \
- (((imm) < 0) && (~(imm) >> (bits)))) { \
+ if ((imm) >= (1 << ((bits) - 1)) || \
+ (imm) < -(1 << ((bits) - 1))) { \
pr_info("[%2d] imm=%d(0x%x) out of range\n", \
i, imm, imm); \
return -EINVAL; \
--
1.8.5.6.2.g3d8a54e.dirty
