diff options
Diffstat (limited to 'kernel/bpf/helpers.c')
| -rw-r--r-- | kernel/bpf/helpers.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 8bd3812fb8df..7ff2a42f1996 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -22,6 +22,7 @@ #include <linux/security.h> #include <linux/btf_ids.h> #include <linux/bpf_mem_alloc.h> +#include <linux/kasan.h> #include "../../lib/kstrtox.h" @@ -1902,6 +1903,14 @@ __bpf_kfunc void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign) return p; } +__bpf_kfunc void *bpf_percpu_obj_new_impl(u64 local_type_id__k, void *meta__ign) +{ + u64 size = local_type_id__k; + + /* The verifier has ensured that meta__ign must be NULL */ + return bpf_mem_alloc(&bpf_global_percpu_ma, size); +} + /* Must be called under migrate_disable(), as required by bpf_mem_free */ void __bpf_obj_drop_impl(void *p, const struct btf_record *rec) { @@ -1930,6 +1939,12 @@ __bpf_kfunc void bpf_obj_drop_impl(void *p__alloc, void *meta__ign) __bpf_obj_drop_impl(p, meta ? meta->record : NULL); } +__bpf_kfunc void bpf_percpu_obj_drop_impl(void *p__alloc, void *meta__ign) +{ + /* The verifier has ensured that meta__ign must be NULL */ + bpf_mem_free_rcu(&bpf_global_percpu_ma, p__alloc); +} + __bpf_kfunc void *bpf_refcount_acquire_impl(void *p__refcounted_kptr, void *meta__ign) { struct btf_struct_meta *meta = meta__ign; @@ -2435,6 +2450,49 @@ __bpf_kfunc void bpf_rcu_read_unlock(void) rcu_read_unlock(); } +struct bpf_throw_ctx { + struct bpf_prog_aux *aux; + u64 sp; + u64 bp; + int cnt; +}; + +static bool bpf_stack_walker(void *cookie, u64 ip, u64 sp, u64 bp) +{ + struct bpf_throw_ctx *ctx = cookie; + struct bpf_prog *prog; + + if (!is_bpf_text_address(ip)) + return !ctx->cnt; + prog = bpf_prog_ksym_find(ip); + ctx->cnt++; + if (bpf_is_subprog(prog)) + return true; + ctx->aux = prog->aux; + ctx->sp = sp; + ctx->bp = bp; + return false; +} + +__bpf_kfunc void bpf_throw(u64 cookie) +{ + struct bpf_throw_ctx ctx = {}; + + arch_bpf_stack_walk(bpf_stack_walker, &ctx); + WARN_ON_ONCE(!ctx.aux); + if (ctx.aux) + WARN_ON_ONCE(!ctx.aux->exception_boundary); + WARN_ON_ONCE(!ctx.bp); + WARN_ON_ONCE(!ctx.cnt); + /* Prevent KASAN false positives for CONFIG_KASAN_STACK by unpoisoning + * deeper stack depths than ctx.sp as we do not return from bpf_throw, + * which skips compiler generated instrumentation to do the same. + */ + kasan_unpoison_task_stack_below((void *)ctx.sp); + ctx.aux->bpf_exception_cb(cookie, ctx.sp, ctx.bp); + WARN(1, "A call to BPF exception callback should never return\n"); +} + __diag_pop(); BTF_SET8_START(generic_btf_ids) @@ -2442,7 +2500,9 @@ BTF_SET8_START(generic_btf_ids) BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE) #endif BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_percpu_obj_new_impl, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_obj_drop_impl, KF_RELEASE) +BTF_ID_FLAGS(func, bpf_percpu_obj_drop_impl, KF_RELEASE) BTF_ID_FLAGS(func, bpf_refcount_acquire_impl, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_list_push_front_impl) BTF_ID_FLAGS(func, bpf_list_push_back_impl) @@ -2462,6 +2522,7 @@ BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU) #endif BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_throw) BTF_SET8_END(generic_btf_ids) static const struct btf_kfunc_id_set generic_kfunc_set = { |