summaryrefslogtreecommitdiffstats
path: root/kernel/bpf/trampoline.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/bpf/trampoline.c')
-rw-r--r--kernel/bpf/trampoline.c101
1 files changed, 76 insertions, 25 deletions
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index e97aeda3a8..d382f5ebe0 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -115,10 +115,10 @@ bool bpf_prog_has_trampoline(const struct bpf_prog *prog)
(ptype == BPF_PROG_TYPE_LSM && eatype == BPF_LSM_MAC);
}
-void bpf_image_ksym_add(void *data, struct bpf_ksym *ksym)
+void bpf_image_ksym_add(void *data, unsigned int size, struct bpf_ksym *ksym)
{
ksym->start = (unsigned long) data;
- ksym->end = ksym->start + PAGE_SIZE;
+ ksym->end = ksym->start + size;
bpf_ksym_add(ksym);
perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,
PAGE_SIZE, false, ksym->name);
@@ -254,8 +254,8 @@ bpf_trampoline_get_progs(const struct bpf_trampoline *tr, int *total, bool *ip_a
static void bpf_tramp_image_free(struct bpf_tramp_image *im)
{
bpf_image_ksym_del(&im->ksym);
- bpf_jit_free_exec(im->image);
- bpf_jit_uncharge_modmem(PAGE_SIZE);
+ arch_free_bpf_trampoline(im->image, im->size);
+ bpf_jit_uncharge_modmem(im->size);
percpu_ref_exit(&im->pcref);
kfree_rcu(im, rcu);
}
@@ -349,7 +349,7 @@ static void bpf_tramp_image_put(struct bpf_tramp_image *im)
call_rcu_tasks_trace(&im->rcu, __bpf_tramp_image_put_rcu_tasks);
}
-static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key)
+static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key, int size)
{
struct bpf_tramp_image *im;
struct bpf_ksym *ksym;
@@ -360,15 +360,15 @@ static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key)
if (!im)
goto out;
- err = bpf_jit_charge_modmem(PAGE_SIZE);
+ err = bpf_jit_charge_modmem(size);
if (err)
goto out_free_im;
+ im->size = size;
err = -ENOMEM;
- im->image = image = bpf_jit_alloc_exec(PAGE_SIZE);
+ im->image = image = arch_alloc_bpf_trampoline(size);
if (!image)
goto out_uncharge;
- set_vm_flush_reset_perms(image);
err = percpu_ref_init(&im->pcref, __bpf_tramp_image_release, 0, GFP_KERNEL);
if (err)
@@ -377,13 +377,13 @@ static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key)
ksym = &im->ksym;
INIT_LIST_HEAD_RCU(&ksym->lnode);
snprintf(ksym->name, KSYM_NAME_LEN, "bpf_trampoline_%llu", key);
- bpf_image_ksym_add(image, ksym);
+ bpf_image_ksym_add(image, size, ksym);
return im;
out_free_image:
- bpf_jit_free_exec(im->image);
+ arch_free_bpf_trampoline(im->image, im->size);
out_uncharge:
- bpf_jit_uncharge_modmem(PAGE_SIZE);
+ bpf_jit_uncharge_modmem(size);
out_free_im:
kfree(im);
out:
@@ -396,7 +396,7 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut
struct bpf_tramp_links *tlinks;
u32 orig_flags = tr->flags;
bool ip_arg = false;
- int err, total;
+ int err, total, size;
tlinks = bpf_trampoline_get_progs(tr, &total, &ip_arg);
if (IS_ERR(tlinks))
@@ -409,12 +409,6 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut
goto out;
}
- im = bpf_tramp_image_alloc(tr->key);
- if (IS_ERR(im)) {
- err = PTR_ERR(im);
- goto out;
- }
-
/* clear all bits except SHARE_IPMODIFY and TAIL_CALL_CTX */
tr->flags &= (BPF_TRAMP_F_SHARE_IPMODIFY | BPF_TRAMP_F_TAIL_CALL_CTX);
@@ -438,13 +432,31 @@ again:
tr->flags |= BPF_TRAMP_F_ORIG_STACK;
#endif
- err = arch_prepare_bpf_trampoline(im, im->image, im->image + PAGE_SIZE,
+ size = arch_bpf_trampoline_size(&tr->func.model, tr->flags,
+ tlinks, tr->func.addr);
+ if (size < 0) {
+ err = size;
+ goto out;
+ }
+
+ if (size > PAGE_SIZE) {
+ err = -E2BIG;
+ goto out;
+ }
+
+ im = bpf_tramp_image_alloc(tr->key, size);
+ if (IS_ERR(im)) {
+ err = PTR_ERR(im);
+ goto out;
+ }
+
+ err = arch_prepare_bpf_trampoline(im, im->image, im->image + size,
&tr->func.model, tr->flags, tlinks,
tr->func.addr);
if (err < 0)
goto out_free;
- set_memory_rox((long)im->image, 1);
+ arch_protect_bpf_trampoline(im->image, im->size);
WARN_ON(tr->cur_image && total == 0);
if (tr->cur_image)
@@ -464,9 +476,8 @@ again:
tr->fops->func = NULL;
tr->fops->trampoline = 0;
- /* reset im->image memory attr for arch_prepare_bpf_trampoline */
- set_memory_nx((long)im->image, 1);
- set_memory_rw((long)im->image, 1);
+ /* free im memory and reallocate later */
+ bpf_tramp_image_free(im);
goto again;
}
#endif
@@ -1032,10 +1043,50 @@ bpf_trampoline_exit_t bpf_trampoline_exit(const struct bpf_prog *prog)
}
int __weak
-arch_prepare_bpf_trampoline(struct bpf_tramp_image *tr, void *image, void *image_end,
+arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *image_end,
const struct btf_func_model *m, u32 flags,
struct bpf_tramp_links *tlinks,
- void *orig_call)
+ void *func_addr)
+{
+ return -ENOTSUPP;
+}
+
+void * __weak arch_alloc_bpf_trampoline(unsigned int size)
+{
+ void *image;
+
+ if (WARN_ON_ONCE(size > PAGE_SIZE))
+ return NULL;
+ image = bpf_jit_alloc_exec(PAGE_SIZE);
+ if (image)
+ set_vm_flush_reset_perms(image);
+ return image;
+}
+
+void __weak arch_free_bpf_trampoline(void *image, unsigned int size)
+{
+ WARN_ON_ONCE(size > PAGE_SIZE);
+ /* bpf_jit_free_exec doesn't need "size", but
+ * bpf_prog_pack_free() needs it.
+ */
+ bpf_jit_free_exec(image);
+}
+
+void __weak arch_protect_bpf_trampoline(void *image, unsigned int size)
+{
+ WARN_ON_ONCE(size > PAGE_SIZE);
+ set_memory_rox((long)image, 1);
+}
+
+void __weak arch_unprotect_bpf_trampoline(void *image, unsigned int size)
+{
+ WARN_ON_ONCE(size > PAGE_SIZE);
+ set_memory_nx((long)image, 1);
+ set_memory_rw((long)image, 1);
+}
+
+int __weak arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
+ struct bpf_tramp_links *tlinks, void *func_addr)
{
return -ENOTSUPP;
}