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authorIlya Leoshkevich <iii@linux.ibm.com>2021-09-07 11:58:59 +0200
committerVasily Gorbik <gor@linux.ibm.com>2021-09-16 10:39:55 +0200
commit1511df6f5e9ef32826f20db2ee81f8527154dc14 (patch)
tree14f1385f7edd9c645bcf29fc8e8903e8187b4564 /arch/s390
parent6880fa6c56601bb8ed59df6c30fd390cc5f6dd8f (diff)
s390/bpf: Fix branch shortening during codegen pass
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>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/net/bpf_jit_comp.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 88419263a89a..c3bd630e9b43 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); \