bpf: rename poke descriptor's 'ip' member to 'tailcall_target'

Reflect the actual purpose of poke->ip and rename it to
poke->tailcall_target so that it will not the be confused with another
poke target that will be introduced in next commit.

While at it, do the same thing with poke->ip_stable - rename it to
poke->tailcall_target_stable.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 6fb8c94..7b0ff16 100644 (file)
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -434,7 +434,7 @@ static void emit_bpf_tail_call_direct(struct bpf_jit_poke_descriptor *poke,
        EMIT3(0x83, 0xC0, 0x01);                      /* add eax, 1 */
        EMIT2_off32(0x89, 0x85, -36 - MAX_BPF_STACK); /* mov dword ptr [rbp -548], eax */
 
-       poke->ip = image + (addr - X86_PATCH_SIZE);
+       poke->tailcall_target = image + (addr - X86_PATCH_SIZE);
        poke->adj_off = PROLOGUE_SIZE;
 
        memcpy(prog, ideal_nops[NOP_ATOMIC5], X86_PATCH_SIZE);
@@ -453,7 +453,7 @@ static void bpf_tail_call_direct_fixup(struct bpf_prog *prog)
 
        for (i = 0; i < prog->aux->size_poke_tab; i++) {
                poke = &prog->aux->poke_tab[i];
-               WARN_ON_ONCE(READ_ONCE(poke->ip_stable));
+               WARN_ON_ONCE(READ_ONCE(poke->tailcall_target_stable));
 
                if (poke->reason != BPF_POKE_REASON_TAIL_CALL)
                        continue;
@@ -464,18 +464,20 @@ static void bpf_tail_call_direct_fixup(struct bpf_prog *prog)
                if (target) {
                        /* Plain memcpy is used when image is not live yet
                         * and still not locked as read-only. Once poke
-                        * location is active (poke->ip_stable), any parallel
-                        * bpf_arch_text_poke() might occur still on the
-                        * read-write image until we finally locked it as
-                        * read-only. Both modifications on the given image
-                        * are under text_mutex to avoid interference.
+                        * location is active (poke->tailcall_target_stable),
+                        * any parallel bpf_arch_text_poke() might occur
+                        * still on the read-write image until we finally
+                        * locked it as read-only. Both modifications on
+                        * the given image are under text_mutex to avoid
+                        * interference.
                         */
-                       ret = __bpf_arch_text_poke(poke->ip, BPF_MOD_JUMP, NULL,
+                       ret = __bpf_arch_text_poke(poke->tailcall_target,
+                                                  BPF_MOD_JUMP, NULL,
                                                   (u8 *)target->bpf_func +
                                                   poke->adj_off, false);
                        BUG_ON(ret < 0);
                }
-               WRITE_ONCE(poke->ip_stable, true);
+               WRITE_ONCE(poke->tailcall_target_stable, true);
                mutex_unlock(&array->aux->poke_mutex);
        }
 }

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index a23e5eb..f3790c9 100644 (file)
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -697,14 +697,14 @@ enum bpf_jit_poke_reason {
 
 /* Descriptor of pokes pointing /into/ the JITed image. */
 struct bpf_jit_poke_descriptor {
-       void *ip;
+       void *tailcall_target;
        union {
                struct {
                        struct bpf_map *map;
                        u32 key;
                } tail_call;
        };
-       bool ip_stable;
+       bool tailcall_target_stable;
        u8 adj_off;
        u16 reason;
        u32 insn_idx;

diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index e046fb7..60abf7f 100644 (file)
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -918,12 +918,13 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
                         *    there could be danger of use after free otherwise.
                         * 2) Initially when we start tracking aux, the program
                         *    is not JITed yet and also does not have a kallsyms
-                        *    entry. We skip these as poke->ip_stable is not
-                        *    active yet. The JIT will do the final fixup before
-                        *    setting it stable. The various poke->ip_stable are
-                        *    successively activated, so tail call updates can
-                        *    arrive from here while JIT is still finishing its
-                        *    final fixup for non-activated poke entries.
+                        *    entry. We skip these as poke->tailcall_target_stable
+                        *    is not active yet. The JIT will do the final fixup
+                        *    before setting it stable. The various
+                        *    poke->tailcall_target_stable are successively
+                        *    activated, so tail call updates can arrive from here
+                        *    while JIT is still finishing its final fixup for
+                        *    non-activated poke entries.
                         * 3) On program teardown, the program's kallsym entry gets
                         *    removed out of RCU callback, but we can only untrack
                         *    from sleepable context, therefore bpf_arch_text_poke()
@@ -940,7 +941,7 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
                         * 5) Any other error happening below from bpf_arch_text_poke()
                         *    is a unexpected bug.
                         */
-                       if (!READ_ONCE(poke->ip_stable))
+                       if (!READ_ONCE(poke->tailcall_target_stable))
                                continue;
                        if (poke->reason != BPF_POKE_REASON_TAIL_CALL)
                                continue;
@@ -948,7 +949,7 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
                            poke->tail_call.key != key)
                                continue;
 
-                       ret = bpf_arch_text_poke(poke->ip, BPF_MOD_JUMP,
+                       ret = bpf_arch_text_poke(poke->tailcall_target, BPF_MOD_JUMP,
                                                 old ? (u8 *)old->bpf_func +
                                                 poke->adj_off : NULL,
                                                 new ? (u8 *)new->bpf_func +

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 2a20c28..2e00ac0 100644 (file)
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -775,7 +775,8 @@ int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
 
        if (size > poke_tab_max)
                return -ENOSPC;
-       if (poke->ip || poke->ip_stable || poke->adj_off)
+       if (poke->tailcall_target || poke->tailcall_target_stable ||
+           poke->adj_off)
                return -EINVAL;
 
        switch (poke->reason) {