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authorDaniel Borkmann <daniel@iogearbox.net>2016-12-18 01:52:57 +0100
committerDavid S. Miller <davem@davemloft.net>2016-12-17 21:27:44 -0500
commitaafe6ae9cee32df85eb5e8bb6dd1d918e6807b09 (patch)
tree4aa9958d1ddf599f4ed32d491f8ab217c9747056 /include
parent40e972ab652f3e9b84a8f24f517345b460962c29 (diff)
bpf: dynamically allocate digest scratch buffer
Geert rightfully complained that 7bd509e311f4 ("bpf: add prog_digest and expose it via fdinfo/netlink") added a too large allocation of variable 'raw' from bss section, and should instead be done dynamically: # ./scripts/bloat-o-meter kernel/bpf/core.o.1 kernel/bpf/core.o.2 add/remove: 3/0 grow/shrink: 0/0 up/down: 33291/0 (33291) function old new delta raw - 32832 +32832 [...] Since this is only relevant during program creation path, which can be considered slow-path anyway, lets allocate that dynamically and be not implicitly dependent on verifier mutex. Move bpf_prog_calc_digest() at the beginning of replace_map_fd_with_map_ptr() and also error handling stays straight forward. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/linux/bpf.h2
-rw-r--r--include/linux/filter.h14
2 files changed, 12 insertions, 4 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 8796ff03f472..201eb483c46f 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -216,7 +216,7 @@ u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
-void bpf_prog_calc_digest(struct bpf_prog *fp);
+int bpf_prog_calc_digest(struct bpf_prog *fp);
const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
diff --git a/include/linux/filter.h b/include/linux/filter.h
index af8a1804cac6..702314253797 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -57,9 +57,6 @@ struct bpf_prog_aux;
/* BPF program can access up to 512 bytes of stack space. */
#define MAX_BPF_STACK 512
-/* Maximum BPF program size in bytes. */
-#define MAX_BPF_SIZE (BPF_MAXINSNS * sizeof(struct bpf_insn))
-
/* Helper macros for filter block array initializers. */
/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
@@ -517,6 +514,17 @@ static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
return BPF_PROG_RUN(prog, xdp);
}
+static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
+{
+ return prog->len * sizeof(struct bpf_insn);
+}
+
+static inline u32 bpf_prog_digest_scratch_size(const struct bpf_prog *prog)
+{
+ return round_up(bpf_prog_insn_size(prog) +
+ sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
+}
+
static inline unsigned int bpf_prog_size(unsigned int proglen)
{
return max(sizeof(struct bpf_prog),