From e2c95a61656d29ceaac97b6a975c8a1f26e26f15 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 26 Nov 2018 14:05:38 +0100 Subject: bpf, ppc64: generalize fetching subprog into bpf_jit_get_func_addr Make fetching of the BPF call address from ppc64 JIT generic. ppc64 was using a slightly different variant rather than through the insns' imm field encoding as the target address would not fit into that space. Therefore, the target subprog number was encoded into the insns' offset and fetched through fp->aux->func[off]->bpf_func instead. Given there are other JITs with this issue and the mechanism of fetching the address is JIT-generic, move it into the core as a helper instead. On the JIT side, we get information on whether the retrieved address is a fixed one, that is, not changing through JIT passes, or a dynamic one. For the former, JITs can optimize their imm emission because this doesn't change jump offsets throughout JIT process. Signed-off-by: Daniel Borkmann Reviewed-by: Sandipan Das Tested-by: Sandipan Das Signed-off-by: Alexei Starovoitov --- include/linux/filter.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/filter.h') diff --git a/include/linux/filter.h b/include/linux/filter.h index de629b706d1d..448dcc448f1f 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -866,6 +866,10 @@ void bpf_jit_binary_free(struct bpf_binary_header *hdr); void bpf_jit_free(struct bpf_prog *fp); +int bpf_jit_get_func_addr(const struct bpf_prog *prog, + const struct bpf_insn *insn, bool extra_pass, + u64 *func_addr, bool *func_addr_fixed); + struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); -- cgit From b7df9ada9a7700dbcca1ba53d217c01e3d48179c Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sat, 1 Dec 2018 01:18:53 +0100 Subject: bpf: fix pointer offsets in context for 32 bit Currently, pointer offsets in three BPF context structures are broken in two scenarios: i) 32 bit compiled applications running on 64 bit kernels, and ii) LLVM compiled BPF programs running on 32 bit kernels. The latter is due to BPF target machine being strictly 64 bit. So in each of the cases the offsets will mismatch in verifier when checking / rewriting context access. Fix this by providing a helper macro __bpf_md_ptr() that will enforce padding up to 64 bit and proper alignment, and for context access a macro bpf_ctx_range_ptr() which will cover full 64 bit member range on 32 bit archs. For flow_keys, we additionally need to force the size check to sizeof(__u64) as with other pointer types. Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") Fixes: 4f738adba30a ("bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX data") Fixes: 2dbb9b9e6df6 ("bpf: Introduce BPF_PROG_TYPE_SK_REUSEPORT") Reported-by: David S. Miller Signed-off-by: Daniel Borkmann Acked-by: David S. Miller Tested-by: David S. Miller Signed-off-by: Alexei Starovoitov --- include/linux/filter.h | 7 +++++++ include/uapi/linux/bpf.h | 17 ++++++++++++----- net/core/filter.c | 16 ++++++++-------- tools/include/uapi/linux/bpf.h | 17 ++++++++++++----- 4 files changed, 39 insertions(+), 18 deletions(-) (limited to 'include/linux/filter.h') diff --git a/include/linux/filter.h b/include/linux/filter.h index 448dcc448f1f..795ff0b869bb 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -449,6 +449,13 @@ struct sock_reuseport; offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2) \ offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1 +#if BITS_PER_LONG == 64 +# define bpf_ctx_range_ptr(TYPE, MEMBER) \ + offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1 +#else +# define bpf_ctx_range_ptr(TYPE, MEMBER) \ + offsetof(TYPE, MEMBER) ... offsetof(TYPE, MEMBER) + 8 - 1 +#endif /* BITS_PER_LONG == 64 */ #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE) \ ({ \ diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 852dc17ab47a..426b5c8a245b 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2422,6 +2422,12 @@ enum bpf_lwt_encap_mode { BPF_LWT_ENCAP_SEG6_INLINE }; +#define __bpf_md_ptr(type, name) \ +union { \ + type name; \ + __u64 :64; \ +} __attribute__((aligned(8))) + /* user accessible mirror of in-kernel sk_buff. * new fields can only be added to the end of this structure */ @@ -2456,7 +2462,7 @@ struct __sk_buff { /* ... here. */ __u32 data_meta; - struct bpf_flow_keys *flow_keys; + __bpf_md_ptr(struct bpf_flow_keys *, flow_keys); }; struct bpf_tunnel_key { @@ -2572,8 +2578,8 @@ enum sk_action { * be added to the end of this structure */ struct sk_msg_md { - void *data; - void *data_end; + __bpf_md_ptr(void *, data); + __bpf_md_ptr(void *, data_end); __u32 family; __u32 remote_ip4; /* Stored in network byte order */ @@ -2589,8 +2595,9 @@ struct sk_reuseport_md { * Start of directly accessible data. It begins from * the tcp/udp header. */ - void *data; - void *data_end; /* End of directly accessible data */ + __bpf_md_ptr(void *, data); + /* End of directly accessible data */ + __bpf_md_ptr(void *, data_end); /* * Total length of packet (starting from the tcp/udp header). * Note that the directly accessible bytes (data_end - data) diff --git a/net/core/filter.c b/net/core/filter.c index 9a1327eb25fa..6ee605da990f 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5435,8 +5435,8 @@ static bool bpf_skb_is_valid_access(int off, int size, enum bpf_access_type type if (size != size_default) return false; break; - case bpf_ctx_range(struct __sk_buff, flow_keys): - if (size != sizeof(struct bpf_flow_keys *)) + case bpf_ctx_range_ptr(struct __sk_buff, flow_keys): + if (size != sizeof(__u64)) return false; break; default: @@ -5464,7 +5464,7 @@ static bool sk_filter_is_valid_access(int off, int size, case bpf_ctx_range(struct __sk_buff, data): case bpf_ctx_range(struct __sk_buff, data_meta): case bpf_ctx_range(struct __sk_buff, data_end): - case bpf_ctx_range(struct __sk_buff, flow_keys): + case bpf_ctx_range_ptr(struct __sk_buff, flow_keys): case bpf_ctx_range_till(struct __sk_buff, family, local_port): return false; } @@ -5489,7 +5489,7 @@ static bool cg_skb_is_valid_access(int off, int size, switch (off) { case bpf_ctx_range(struct __sk_buff, tc_classid): case bpf_ctx_range(struct __sk_buff, data_meta): - case bpf_ctx_range(struct __sk_buff, flow_keys): + case bpf_ctx_range_ptr(struct __sk_buff, flow_keys): return false; case bpf_ctx_range(struct __sk_buff, data): case bpf_ctx_range(struct __sk_buff, data_end): @@ -5530,7 +5530,7 @@ static bool lwt_is_valid_access(int off, int size, case bpf_ctx_range(struct __sk_buff, tc_classid): case bpf_ctx_range_till(struct __sk_buff, family, local_port): case bpf_ctx_range(struct __sk_buff, data_meta): - case bpf_ctx_range(struct __sk_buff, flow_keys): + case bpf_ctx_range_ptr(struct __sk_buff, flow_keys): return false; } @@ -5756,7 +5756,7 @@ static bool tc_cls_act_is_valid_access(int off, int size, case bpf_ctx_range(struct __sk_buff, data_end): info->reg_type = PTR_TO_PACKET_END; break; - case bpf_ctx_range(struct __sk_buff, flow_keys): + case bpf_ctx_range_ptr(struct __sk_buff, flow_keys): case bpf_ctx_range_till(struct __sk_buff, family, local_port): return false; } @@ -5958,7 +5958,7 @@ static bool sk_skb_is_valid_access(int off, int size, switch (off) { case bpf_ctx_range(struct __sk_buff, tc_classid): case bpf_ctx_range(struct __sk_buff, data_meta): - case bpf_ctx_range(struct __sk_buff, flow_keys): + case bpf_ctx_range_ptr(struct __sk_buff, flow_keys): return false; } @@ -6039,7 +6039,7 @@ static bool flow_dissector_is_valid_access(int off, int size, case bpf_ctx_range(struct __sk_buff, data_end): info->reg_type = PTR_TO_PACKET_END; break; - case bpf_ctx_range(struct __sk_buff, flow_keys): + case bpf_ctx_range_ptr(struct __sk_buff, flow_keys): info->reg_type = PTR_TO_FLOW_KEYS; break; case bpf_ctx_range(struct __sk_buff, tc_classid): diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 852dc17ab47a..426b5c8a245b 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2422,6 +2422,12 @@ enum bpf_lwt_encap_mode { BPF_LWT_ENCAP_SEG6_INLINE }; +#define __bpf_md_ptr(type, name) \ +union { \ + type name; \ + __u64 :64; \ +} __attribute__((aligned(8))) + /* user accessible mirror of in-kernel sk_buff. * new fields can only be added to the end of this structure */ @@ -2456,7 +2462,7 @@ struct __sk_buff { /* ... here. */ __u32 data_meta; - struct bpf_flow_keys *flow_keys; + __bpf_md_ptr(struct bpf_flow_keys *, flow_keys); }; struct bpf_tunnel_key { @@ -2572,8 +2578,8 @@ enum sk_action { * be added to the end of this structure */ struct sk_msg_md { - void *data; - void *data_end; + __bpf_md_ptr(void *, data); + __bpf_md_ptr(void *, data_end); __u32 family; __u32 remote_ip4; /* Stored in network byte order */ @@ -2589,8 +2595,9 @@ struct sk_reuseport_md { * Start of directly accessible data. It begins from * the tcp/udp header. */ - void *data; - void *data_end; /* End of directly accessible data */ + __bpf_md_ptr(void *, data); + /* End of directly accessible data */ + __bpf_md_ptr(void *, data_end); /* * Total length of packet (starting from the tcp/udp header). * Note that the directly accessible bytes (data_end - data) -- cgit