bpf: remove bpf_priv_data

As various bpf commands need different data to save between entering
and exiting of the syscall, do not emulate union bpf_attr approach.

* bpf.c (struct bpf_priv_data): Remove.
(DECL_BPF_CMD_DECODER): Remove "struct bpf_priv_data *" argument.
(BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)): Use set_tcb_priv_ulong
and get_tcb_priv_ulong to keep bpf_attr.query.prog_cnt field.
(SYS_FUNC(bpf)): Remove priv variable, do not initialize it,
and do not pass it to bpf_cmd_decoders.

diff --git a/bpf.c b/bpf.c
index 3a8745fd997a8de24229bce48e864fe9e534a2bf..8e6fed087b8b859c9406c23a06f355c3f2eea560 100644 (file)
--- a/bpf.c
+++ b/bpf.c
@@ -50,19 +50,12 @@
 #include "xlat/ebpf_regs.h"
 #include "xlat/numa_node.h"
 
-/** Storage for all the data that is needed to be stored on entering. */
-struct bpf_priv_data {
-       bool     bpf_prog_query_stored;
-       uint32_t bpf_prog_query_prog_cnt;
-};
-
 #define DECL_BPF_CMD_DECODER(bpf_cmd_decoder)                          \
 int                                                                    \
 bpf_cmd_decoder(struct tcb *const tcp,                                 \
                const kernel_ulong_t addr,                              \
                const unsigned int size,                                \
-               void *const data,                                       \
-               struct bpf_priv_data *priv)                             \
+               void *const data)                                       \
 /* End of DECL_BPF_CMD_DECODER definition. */
 
 #define BEGIN_BPF_CMD_DECODER(bpf_cmd)                                 \
@@ -452,13 +445,7 @@ BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)
 
                tprints(", prog_ids=");
 
-               if (!priv)
-                       priv = xcalloc(1, sizeof(*priv));
-
-               priv->bpf_prog_query_stored = true;
-               priv->bpf_prog_query_prog_cnt = attr.prog_cnt;
-
-               set_tcb_priv_data(tcp, priv, free);
+               set_tcb_priv_ulong(tcp, attr.prog_cnt);
 
                return 0;
        }
@@ -469,9 +456,9 @@ BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)
                    print_uint32_array_member, 0);
 
        tprints(", prog_cnt=");
-       if (priv && priv->bpf_prog_query_stored
-           && priv->bpf_prog_query_prog_cnt != attr.prog_cnt)
-               tprintf("%" PRIu32 " => ", priv->bpf_prog_query_prog_cnt);
+       const uint32_t prog_cnt_entering = get_tcb_priv_ulong(tcp);
+       if (prog_cnt_entering != attr.prog_cnt)
+               tprintf("%" PRIu32 " => ", prog_cnt_entering);
        tprintf("%" PRIu32, attr.prog_cnt);
        tprints("}");
 }
@@ -514,30 +501,27 @@ SYS_FUNC(bpf)
                BPF_CMD_ENTRY(BPF_RAW_TRACEPOINT_OPEN),
        };
 
-       static char *buf;
-       struct bpf_priv_data *priv = NULL;
-
        const unsigned int cmd = tcp->u_arg[0];
        const kernel_ulong_t addr = tcp->u_arg[1];
        const unsigned int size = tcp->u_arg[2];
        int rc = RVAL_DECODED;
 
-       if (!buf)
-               buf = xmalloc(get_pagesize());
-
        if (entering(tcp)) {
                printxval_index(bpf_commands, cmd, "BPF_???");
                tprints(", ");
-       } else {
-               priv = get_tcb_priv_data(tcp);
        }
 
        if (size > 0
            && size <= get_pagesize()
            && cmd < ARRAY_SIZE(bpf_cmd_decoders)
            && bpf_cmd_decoders[cmd]) {
+               static char *buf;
+
+               if (!buf)
+                       buf = xmalloc(get_pagesize());
+
                if (!umoven_or_printaddr_ignore_syserror(tcp, addr, size, buf))
-                       rc = bpf_cmd_decoders[cmd](tcp, addr, size, buf, priv);
+                       rc = bpf_cmd_decoders[cmd](tcp, addr, size, buf);
        } else {
                printaddr(addr);
        }