On 5/1/22 3:00 PM, Yonghong Song wrote: > Currently, the 64bit relocation value in the instruction > is computed as follows: > __u64 imm = insn[0].imm + ((__u64)insn[1].imm << 32) > > Suppose insn[0].imm = -1 (0xffffffff) and insn[1].imm = 1. > With the above computation, insn[0].imm will first sign-extend > to 64bit -1 (0xffffffffFFFFFFFF) and then add 0x1FFFFFFFF, > producing incorrect value 0xFFFFFFFF. The correct value > should be 0x1FFFFFFFF. > > Changing insn[0].imm to __u32 first will prevent 64bit sign > extension and fix the issue. > > Signed-off-by: Yonghong Song <yhs@xxxxxx> > --- > tools/lib/bpf/relo_core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > Signed-off-by: Dave Marchevsky <davemarchevsky@xxxxxx>
