diff options
| author |   Björn Töpel <bjorn.topel@intel.com> | 2019-12-13 18:51:07 +0100 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2019-12-13 13:09:32 -0800 |
| commit | 98e8627efcada18ac043a77b9101b4b4c768090b (patch) | |
| tree | 78bddd4e10be8b09a0a0703129ff112e8ee012f4 /kernel | |
| parent | selftests/bpf: Fix perf_buffer test on systems w/ offline CPUs (diff) | |
| download | linux-dev-98e8627efcada18ac043a77b9101b4b4c768090b.tar.xz linux-dev-98e8627efcada18ac043a77b9101b4b4c768090b.zip | |
bpf: Move trampoline JIT image allocation to a function
Refactor the image allocation in the BPF trampoline code into a
separate function, so it can be shared with the BPF dispatcher in
upcoming commits.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191213175112.30208-2-bjorn.topel@gmail.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/trampoline.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 7e89f1f49d77..5ee301ddbd00 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -13,6 +13,22 @@ static struct hlist_head trampoline_table[TRAMPOLINE_TABLE_SIZE]; /* serializes access to trampoline_table */ static DEFINE_MUTEX(trampoline_mutex); +void *bpf_jit_alloc_exec_page(void) +{ + void *image; + + image = bpf_jit_alloc_exec(PAGE_SIZE); + if (!image) + return NULL; + + set_vm_flush_reset_perms(image); + /* Keep image as writeable. The alternative is to keep flipping ro/rw + * everytime new program is attached or detached. + */ + set_memory_x((long)image, 1); + return image; +} + struct bpf_trampoline *bpf_trampoline_lookup(u64 key) { struct bpf_trampoline *tr; @@ -33,7 +49,7 @@ struct bpf_trampoline *bpf_trampoline_lookup(u64 key) goto out; /* is_root was checked earlier. No need for bpf_jit_charge_modmem() */ - image = bpf_jit_alloc_exec(PAGE_SIZE); + image = bpf_jit_alloc_exec_page(); if (!image) { kfree(tr); tr = NULL; @@ -47,12 +63,6 @@ struct bpf_trampoline *bpf_trampoline_lookup(u64 key) mutex_init(&tr->mutex); for (i = 0; i < BPF_TRAMP_MAX; i++) INIT_HLIST_HEAD(&tr->progs_hlist[i]); - - set_vm_flush_reset_perms(image); - /* Keep image as writeable. The alternative is to keep flipping ro/rw - * everytime new program is attached or detached. - */ - set_memory_x((long)image, 1); tr->image = image; out: mutex_unlock(&trampoline_mutex); |