From: Ilya Leoshkevich <iii@linux.ibm.com> stable inclusion from stable-5.10.68 commit ab7cf225016159bc2c3590be6fa12965565d903b bugzilla: 182671 https://gitee.com/openeuler/kernel/issues/I4EWUH Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 1511df6f5e9ef32826f20db2ee81f8527154dc14 upstream. EMIT6_PCREL() macro assumes that the previous pass generated 6 bytes of code, which is not the case if branch shortening took place. Fix by using jit->prg, like all the other EMIT6_PCREL_*() macros. Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Fixes: 4e9b4a6883dd ("s390/bpf: Use relative long branches") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- arch/s390/net/bpf_jit_comp.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index cba6e9825fb8..8d9047d2d1e1 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -248,8 +248,7 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1) #define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask) \ ({ \ - /* Branch instruction needs 6 bytes */ \ - int rel = (addrs[(i) + (off) + 1] - (addrs[(i) + 1] - 6)) / 2;\ + int rel = (addrs[(i) + (off) + 1] - jit->prg) / 2; \ _EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), (op2) | (mask));\ REG_SET_SEEN(b1); \ REG_SET_SEEN(b2); \ -- 2.20.1