When loading a pointer to register we need to use the appropriate
32 or 64bit instruction to preserve the pointers' top 32bits.
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Daniel Borkmann <dborkman@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Markos Chandras <markos.chandras@xxxxxxxxxx>
---
Changes since v1:
- Change function name to make it clear that we are loading a
pointer to a register, not an address
---
arch/mips/net/bpf_jit.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index 4505e2e6ab53..6e3963425b64 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -453,6 +453,17 @@ static inline void emit_wsbh(unsigned int dst, unsigned int src,
emit_instr(ctx, wsbh, dst, src);
}
+/* load pointer to register */
+static inline void emit_load_ptr(unsigned int dst, unsigned int src,
+ int imm, struct jit_ctx *ctx)
+{
+ /* src contains the base addr of the 32/64-pointer */
+ if (config_enabled(CONFIG_64BIT))
+ emit_instr(ctx, ld, dst, imm, src);
+ else
+ emit_instr(ctx, lw, dst, imm, src);
+}
+
/* load a function pointer to register */
static inline void emit_load_func(unsigned int reg, ptr imm,
struct jit_ctx *ctx)
@@ -1277,7 +1288,8 @@ jmp_cmp:
/* A = skb->dev->ifindex */
ctx->flags |= SEEN_SKB | SEEN_A | SEEN_S0;
off = offsetof(struct sk_buff, dev);
- emit_load(r_s0, r_skb, off, ctx);
+ /* Load *dev pointer */
+ emit_load_ptr(r_s0, r_skb, off, ctx);
/* error (0) in the delay slot */
emit_bcond(MIPS_COND_EQ, r_s0, r_zero,
b_imm(prog->len, ctx), ctx);
--
2.0.0
